最新刊期

2005 年第 6 期

Biotechnology

Differentiation of xanthomonads causing the bacterial leaf spot of poinsettia in China from the pathotype strain of Xanthomonas axonopodis pv. poinsettiicola
Bin Li,Guan-lin Xie,J. Swings
2005, 6B(6): 451-453. DOI: 10.1631/jzus.2005.B0451

摘要：In October 2003, a new bacterial disease with symptoms similar to those caused by Xanthomonas axonopodis pv. poinsettiicola was observed on poinsettia leaves at a flower nursery in Zhejiang Province of China. Three Xanthomonas strains were isolated from infected plants and classified as X. axonopodis. They were differentiated from the pathotype strain LMG849 of X. axonopodis pv. poinsettiicola causing bacterial leaf spot of poinsettia by comparison of pathogenicity, substrate utilization and BOX-PCR genomic fingerprints.
关键词：Bacterial leaf spot of poinsettia;BOX-PCR;Hypersensitive reaction;Pathogenicity;X. axonopodis pv. poinsettiicola

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发布时间：2022-01-05
Preparation, crystallization and preliminary X-ray diffraction analysis of PH1948, predicted RNA methyltransferase from Pyrococcus horikoshii
Yong-gui Gao,Min Yao,Isao Tanaka
2005, 6B(6): 454-456. DOI: 10.1631/jzus.2005.B0454

摘要：RNA methyltransferase is responsible for transferring methyl and resulting in methylation on the bases or ribose ring of RNA, which existed widely but mostly remains an open question. A recombinant protein PH1948 predicting RNA methyltransferase from Pyrococcus horikoshii OT3 has been crystallized. The crystals of selenomethionyl PH1948 belong to space group C2, with unit-cell parameters a=207.0 Å, b=43.1 Å, c=118.2 Å, β=92.1°, and diffract X-rays to 2.2 Å resolution. The V_M value was determined to be 2.8 Å³/Da, indicating the presence of four protein molecules in the asymmetric unit.
关键词：Pyrococcus horikoshii;Methyltransferase;X-ray diffraction;Protein crystallography

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发布时间：2022-01-05
Pathogenicity of bacterium, Xenorhabdus nematophila isolated from entomopathogenic nematode (Steinernema carpocapsae) and its secretion against Galleria mellonella larvae
Ali Nawaz Mahar,Muhammad Munir,Sami Elawad,Simon Richard Gowen,Nigel Graham Meckenzi Hague
2005, 6B(6): 457-463. DOI: 10.1631/jzus.2005.B0457

摘要：The entomopathogenic bacterium, Xenorhabdus nematophila was isolated from the hemolymph of Galleria mellonella infected with Steinernema carpocapsae. The bacterial cells and its metabolic secretions have been found lethal to the Galleria larvae. Toxic secretion in broth caused 95% mortality within 4 d of application whereas the bacterial cells caused 93% mortality after 6 d. When filter and sand substrates were compared, the later one was observed as appropriate. Similarly, bacterial cells and secretion in broth were more effective at 14% moisture and 25 °C temperature treatments. Maximum insect mortality (100%) was observed when bacterial concentration of 4×10⁶ cells/ml was used. Similarly, maximum bacterial cells in broth (95%) were penetrated into the insect body within 2 h of their application. However, when stored bacterial toxic secretion was applied to the insects its efficacy declined. On the other hand, when the same toxic secretion was dried and then dissolved either in broth or water was proved to be effective. The present study showed that the bacterium, X. nematophila or its toxic secretion can be used as an important component of integrated pest management against Galleria.
关键词：Biological control;Bacterial symbionts;Entomopathogenic nematodes;Xenorhabdus nematophila;Galleria mellonella

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发布时间：2021-12-30
Spatio-temporal expression of the pathway–specific regulatory gene redD in S. coelicolor
Li-hua Zhou,Yu-qin Li,Yong-quan Li,Dan Wu
2005, 6B(6): 464-469. DOI: 10.1631/jzus.2005.B0464

摘要：Confocal laser scanning microscopy was used to observe the spatio-temporal expression of the pathway-specific gene redD during S. coelicolor cell cultivation. The corresponding mutant S. coelicolor lyqRY1522 carrying redD::eyfp in the chromosome was constructed. The temporal expression results of the fusion protein during submerged cultivation demonstrated that expression of redD began in the transition phase, continuing through the exponential growth phase to the stationary phase, and reached maximum in the stationary phase. On the other hand, redD was expressed only in substrate mycelia during solid-state culture, while aerial mycelia remained essentially non-fluorescent throughout culture. Results demonstrated that the expression pattern of redD coincides with that of the biosynthesis of the antibiotics during culture, revealing a direct correlation between the spatio-temporal distribution of regulatory gene expression and second metabolism.
关键词：Streptomyces coelicolor;EYFP;Temporal and spatial expression;Pathway-specific gene redD

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发布时间：2022-01-05
Maximal sequence length of exact match between members from a gene family during early evolution
Xiao Wen,Xing-yi Guo,Long-jiang Fan
2005, 6B(6): 470-476. DOI: 10.1631/jzus.2005.B0470

摘要：Mutation (substitution, deletion, insertion, etc.) in nucleotide acid causes the maximal sequence lengths of exact match (MALE) between paralogous members from a duplicate event to become shorter during evolution. In this work, MALE changes between members of 26 gene families from four representative species (Arabidopsis thaliana, Oryza sativa, Mus musculus and Homo sapiens) were investigated. Comparative study of paralogous’ MALE and amino acid substitution rate (d_A<0.5) indicated that a close relationship existed between them. The results suggested that MALE could be a sound evolutionary scale for the divergent time for paralogous genes during their early evolution. A reference table between MALE and divergent time for the four species was set up, which would be useful widely, for large-scale genome alignment and comparison. As an example, detection of large-scale duplication events of rice genome based on the table was illustrated.
关键词：Maximal length of exact match (MALE);Divergent time;Gene family;Minimal length of exact match (MILE);Genome alignment

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发布时间：2022-01-05
Identification of Rhodiola species by using RP-HPLC
Qiang Wang,Xiao Ruan,Zhi-hua Jin,Qi-chuan Yan,Shan-jun Tu
2005, 6B(6): 477-482. DOI: 10.1631/jzus.2005.B0477

摘要：An approach was established using RP-HPLC (reversed-phase high-performance liquid chromatography) to identify ten species of Rhodiola, R. coccinea A. Bor, R. junggarica C.Y. Yang et N.R. Cui spn., R. heterodonta A. Bor, R. linearifolia A. Bor, R. pamiro alaiucm A. Bor, R. kaschgarica A. Bor, R. litwinowii A. Bor, R. gelida schrenk, R. rosea L. and R. quadrifide Fisch et Mey collected from the Tianshan Mountains areas of China. Chromatograms of alcohol-soluble proteins, generated from these ten Rhodiola spp. were compared. Each chromatogram of alcohol-soluble proteins came from a single seed of one wild species only. The results showed that when using a Waters Delta Pak. C18, 5 μm particle size reversed phase column (150 mm×3.9 mm), a linear gradient of 22%–55% solvent B with a flow rate of 1 ml/min and a run time of 67 min, the chromatography gave optimum separation of Rhodiola alcohol-soluble proteins. Chromatogram of each species was different and could be used to identify those species. Cluster analysis of genetic similarity coefficients of 37% to 60% showed a medium degree of genetic diversity among the species in these eco-areas. Cluster analysis showed that the ten species of Rhodiola can be divided into four clusters and yielded the general and unique biochemical markers of these species. RP-HPLC was shown to be a rapid, repeatable and reliable method for Rhodiola species identification and analysis of genetic diversity.
关键词：Rhodiola;Genetic diversity;Species identification;RP-HPLC

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发布时间：2022-01-05
Firmness evaluation of melon using its vibration characteristic and finite element analysis
Jamal Nourain,Yi-bin Ying,Jian-ping Wang,Xiu-qin Rao,Chao-gang Yu
2005, 6B(6): 483-490. DOI: 10.1631/jzus.2005.B0483

摘要：The “Huang gua” melons were measured for their physical properties including firmness and static elastic modulus. The vibrational characteristics of fruits and vegetables are governed by their elastic modulus (firmness), mass, and geometry. Therefore, it is possible to evaluate firmness of fruits and vegetables based on their vibrational characteristics. Analysis of the vibration responses of a fruit is suggested for measuring elastic properties (Firmness) non-destructively. The impulse response method is often used to measure firmness of fruits. The fruit was excited using three types of balls (wooden, steel and rubber) and the vibration is detected by an accelerometer. The Instron device was used to measure the static elastic modulus of the inner, middle and outer portions of melon flesh. Finite element (FE) technique was used to determine the optimum excitation location of the chosen measurement sensor and to analyze the mode shape fruits. Four types of mode shapes (torsional or flexural mode shape, first-type, second-type spherical mode and breathing mode shape) were found. Finite element simulation results agreed well with experimental results. Correlation between the firmness and resonant frequency (r²=0.91) and between the resonant frequency and stiffness factor (r²=0.74) existed. The optimum location and suitable direction for excitation and response measurement on the fruit were suggested.
关键词：Melon;Sensing;Finite element;Experimental modal analysis;Firmness

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发布时间：2022-01-05
Application of least squares vector machines in modelling water vapor and carbon dioxide fluxes over a cropland
Zhong Qin,Qiang Yu,Jun Li,Zhi-yi Wu,Bing-min Hu
2005, 6B(6): 491-495. DOI: 10.1631/jzus.2005.B0491

摘要：Least squares support vector machines (LS-SVMs), a nonlinear kemel based machine was introduced to investigate the prospects of application of this approach in modelling water vapor and carbon dioxide fluxes above a summer maize field using the dataset obtained in the North China Plain with eddy covariance technique. The performances of the LS-SVMs were compared to the corresponding models obtained with radial basis function (RBF) neural networks. The results indicated the trained LS-SVMs with a radial basis function kernel had satisfactory performance in modelling surface fluxes; its excellent approximation and generalization property shed new light on the study on complex processes in ecosystem.
关键词：Least squares support vector machines (LS-SVMs);Water vapor and carbon dioxide fluxes exchange;Radial basis function (RBF) neural networks

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发布时间：2022-01-05
Suppression of Meloidogyne javanica by antagonistic and plant growth-promoting rhizobacteria
Bin Li,Guan-lin Xie,A. Soad,J. Coosemans
2005, 6B(6): 496-501. DOI: 10.1631/jzus.2005.B0496

摘要：Four rhizobacteria selected out of over 500 isolates from rhizosphere of the vegetables in China were further studied for suppression of the root-knot nematode and soil-borne fungal pathogens in laboratory and greenhouse in Belgium. They were identified as Brevibacillus brevis or Bacillus subtilis by Biolog test and partial 16s rDNA sequence comparison. They not only inhibited the radial growth of the root-infecting fungi Rhizoctonia solani SX-6, Pythium aphanidermatum ZJP-1 and Fusarium oxysporum f.sp. cucumerinum ZJF-2 in vitro, but also exhibited strong nematicidal activity by killing the second stage larvae of Meloidogyne javanica to varying degrees in the greenhouse. The toxic principles of bacterium B7 that showed the highest juvenile mortality were partially characterized. The active factors were heat stability and resistance to extreme pH values. B7 used either as seed dressing or soil drench significantly reduced the nematode populations in the rhizosphere and enhanced the growth of mungbean plants over the controls in the presence or absence of R. solani.
关键词：Biocontrol;Meloidogyne javanica;Mungbean;Rhizobacteria;Rhizoctonia solani

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发布时间：2022-01-05
Characteristics of fruit ripening in tomato mutant epi
Zhong-feng Wang,Tie-jin Ying,Bi-li Bao,Xiao-dan Huang
2005, 6B(6): 502-507. DOI: 10.1631/jzus.2005.B0502

摘要：The characteristics of fruit ripening and expression of ripening-related genes were investigated in epi, an ethylene overproduction mutant of tomato (Lycopersicon esculentum Mill.). The epi produces apparently more ethylene than its wild type VFN8 at every stage of vegetative and fruit growth and ripening; compared to VFN8, the epi fruit showed higher CO₂ evolution, faster descending of chlorophyll, slightly quicker increase of carotenoid and lycopene, and faster reduction in pericarp firmness during maturation and ripening; and the mRNAs of three ripening-related genes including E8, pTOM5 and pTOM6 were at higher levels in epi. The ripening-related characteristics changing of the fruit are consistent with the increase of ethylene production and ripening-related genes expression. These results suggest that epi mutation possibly did not affect the ethylene perception and signaling during fruit ripening, and that the modified characteristics of fruit ripening possibly resulted from the ethylene overproduction and increased expression of ripening-related genes.
关键词：Epinastic (epi) mutant;Ethylene overproduction;Ethylene signaling;Fruit ripening

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发布时间：2022-01-05
Optimization of angiotensin I-converting enzyme (ACE) inhibition by rice dregs hydrolysates using response surface methodology
Guo-qing He,Guo-dong Xuan,Hui Ruan,Qi-he Chen,Ying Xu
2005, 6B(6): 508-513. DOI: 10.1631/jzus.2005.B0508

摘要：Angiotensin I-converting enzyme (ACE) inhibitory peptides have been shown to have antihypertensive effects and have been utilized for physiologically functional foods and pharmaceuticals. The ACE inhibitory ability of a hydrolysate is determined by its peptide composition. However, the peptide composition of a hydrolysate depends on proteolytic enzyme and the hydrolysis conditions. In this study, the effect of process conditions on the ACE inhibitory activity of rice dregs hydrolyzed with a trypsin was investigated systematically using response surface methodology. It was shown that the ACE inhibitory activity of rice dregs hydrolysates could be controlled by regulation of five process conditions. Hydrolysis conditions for optimal ACE inhibition were defined using the response surface model of fractional factorial design (FFD), steepest ascent design, and central composite design (CCD).
关键词：Angiotensin I-converting enzyme inhibitor;Rice dregs;Response surface methodology

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发布时间：2021-12-30
Application of derivative ratio spectrophotometry for determination of β-carotene and astaxanthin from Phaffia rhodozyma extract
Hui Ni,Guo-qing He,Hui Ruan,Qi-he Chen,Feng Chen
2005, 6B(6): 514-522. DOI: 10.1631/jzus.2005.B0514

摘要：A derivative ratio spectrophotometric method was used for the simultaneous determination of β-carotene and astaxanthin produced from Phaffia rhodozyma. Absorbencies of a series of the standard carotenoids in the range of 441 nm to 490 nm demonstrated that their absorptive spectra accorded with Beer’s law and that the additivity when the concentrations of β-carotene and astaxanthin and their mixture were within the range of 0 to 5 µg/ml, 0 to 6 µg/ml, and 0 to 6 µg/ml, respectively. When the wavelength interval (Δλ) at 2 nm was selected to calculate the first derivative ratio spectra values, the first derivative amplitudes at 461 nm and 466 nm were suitable for quantitatively determining β-carotene and astaxanthin, respectively. Effect of divisor on derivative ratio spectra could be neglected; any concentration used as divisor in range of 1.0 to 4.0 µg/ml is ideal for calculating the derivative ratio spectra values of the two carotenoids. Calibration graphs were established for β-carotene within 0–6.0 µg/ml and for astaxanthin within 0–5.0 µg/ml with their corresponding regressive equations in: y=−0.0082x−0.0002 and y=0.0146x−0.0006, respectively. R-square values in excess of 0.999 indicated the good linearity of the calibration graphs. Sample recovery rates were found satisfactory (>99%) with relative standard deviations (RSD) of less than 5%. This method was successfully applied to simultaneous determination of β-carotene and astaxanthin in the laboratory-prepared mixtures and the extract from the Phaffia rhodozyma culture.
关键词：Derivative ratio spectrum;β-carotene;Astaxanthin;Spectrophotometry

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发布时间：2022-01-05
Prediction and analysis model of temperature and its application to a natural ventilation multi-span plastic greenhouse equipped with insect-proof screen
Shu-zhen Liu,Yong He,Yu-bao Zhang,Xiang-wen Miao
2005, 6B(6): 523-529. DOI: 10.1631/jzus.2005.B0523

摘要：The natural ventilation widely used in greenhouses has advantages of saving energy and reducing expense. In order to provide information for climate control of greenhouse, a model was developed to predict the variation of air temperature in the naturally ventilated greenhouse equipped with insect-proof screen. Roof ventilation and combined roof and sidewall ventilation were considered in the model. This model was validated against the results of experiments conducted in the greenhouse when the wind was parallel to the gutters. The model parameters were determined by the least squares method. In the used model, effects of wind speed and window opening height on the air temperature variation were analyzed. Comparison between two types of ventilation showed that there existed a necessary ventilation rate which results in air temperature decrease in natural ventilation under special climatic conditions. In our experiments when wind speed was less than 3.2 ms⁻¹, wind had a more gradual effect on greenhouse temperature for roof ventilation, compared with combined roof and sidewall ventilation, which had greater air temperature decrease than roof ventilation only.
关键词：Greenhouse;Natural ventilation;Temperature;Model

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发布时间：2022-01-05
On-line estimation of concentration parameters in fermentation processes
Zhi-hua Xiong,Guo-hong Huang,Hui-he Shao
2005, 6B(6): 530-534. DOI: 10.1631/jzus.2005.B0530

摘要：It has long been thought that bioprocess, with their inherent measurement difficulties and complex dynamics, posed almost insurmountable problems to engineers. A novel software sensor is proposed to make more effective use of those measurements that are already available, which enable improvement in fermentation process control. The proposed method is based on mixtures of Gaussian processes (GP) with expectation maximization (EM) algorithm employed for parameter estimation of mixture of models. The mixture model can alleviate computational complexity of GP and also accord with changes of operating condition in fermentation processes, i.e., it would certainly be able to examine what types of process-knowledge would be most relevant for local models’ specific operating points of the process and then combine them into a global one. Demonstrated by on-line estimate of yeast concentration in fermentation industry as an example, it is shown that soft sensor based state estimation is a powerful technique for both enhancing automatic control performance of biological systems and implementing on-line monitoring and optimization.
关键词：Gaussian processes (GP);Expectation maximization (EM);Multiple models;Soft sensor;Yeast concentration;Fermentation processes

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发布时间：2022-01-05
Automatic separation system for marine meiobenthos based on laser-induced fluorescence technology
Shu-ming Ye,Shao-jia Gao,Yi Pan,Jun-yi Yang,Shi-lun Li
2005, 6B(6): 535-539. DOI: 10.1631/jzus.2005.B0535

摘要：An automatic system for marine meiobenthos separation was developed by using laser-induced fluorescence technology. Rose Bengal was used as organism dye and the spectrums of Rose Bengal were measured. Laser-induced fluorescence system was established to detect marine meiobenthos in sediments. Data obtained from experiments were analyzed by using a mathematical model. The results showed that laser-induced fluorescence technology worked well in the system. The system could select the meiobenthos efficiently and precisely.
关键词：Meiobenthos;Automatic separating system;Optical sensor;Laser-induced fluorescence (LIF);Rose Bengal

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发布时间：2022-01-05

Environmental Sciences

Remediation of Cr(VI) in solution using vitamin C
Yong Liu,Xin-hua Xu,Ping He
2005, 6B(6): 540-542. DOI: 10.1631/jzus.2005.B0540

摘要：The effectiveness of vitamin C in treating Cr(VI)-contaminated water is being evaluated. Cr(VI) is an identified pollutant of some soils and groundwater. Vitamin C, an important biological reductant in humans and animals, can be used to transform Cr(VI) to essentially nontoxic Cr(III). The removal efficiency was 89% when the mass concentration of vitamin C was 80 mg/L in 60 min, and nearly 100% Cr(VI) was removed when the mass concentration was 100 mg/L. Our data demonstrated that the removal efficiency was affected by vitamin C concentration, the reaction temperature and the dissolved oxygen concentration. The reaction mechanism of Cr(VI) by vitamin C was presented. Our study opens the way to use vitamin C to remediate Cr(VI)-contaminated soils and groundwater.
关键词：Hexalent chromium;Vitamin C;Reduction

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发布时间：2022-01-05
A new configuration of membrane stack for retrieval of nickel absorbed in resins
Xue-fen Chen,Zu-cheng Wu
2005, 6B(6): 543-545. DOI: 10.1631/jzus.2005.B0543

摘要：A new configuration integrated ion exchange effect with both electro-migration and electrochemical reaction in a single cell was developed to effectively retrieve metal ions from simulated wastewater using ion exchange resins without additive chemicals. By simply assembling cation exchange resins and anion exchange resins separated by homogeneous membranes, we found that the system will always be acidic in the concentrate compartment so that ion exchange resins could be in-situ regenerated without hydroxide precipitation. Such a realizable design will be really suitable for wastewater purification.
关键词：Nickel;Ion exchange resin;Electro-migration;Electrochemical

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发布时间：2022-01-05
Changes of root morphology and Pb uptake by two species of Elsholtzia under Pb toxicity
Hong-yun Peng,Sheng-ke Tian,Xiao-e Yang
2005, 6B(6): 546-552. DOI: 10.1631/jzus.2005.B0546

摘要：Elsholtzia argyi and Elsholtzia splendens, which are Chinese endemic Pb/Zn mined and Cu mined ecotype respectively, were investigated on the aspect of their response to Pb toxicity in the presence or absence of EDTA addition. After 8 d’s Pb treatment, root length, root surface area and root volume of E. splendens decreased much more than those of E. argyi, and reduced considerably with increase of Pb, while no marked change was noted for root average diameter. Compared to E. argyi, length of root with diameter (D)<0.2 mm was significantly reduced for E. splendens as Pb increased. D<0.1 mm E. splendens root had cross-sectional surface area at Pb≥10 mg/L, while for E. argyi, it was at Pb≥25 mg/L. With increase of Pb, DW of E. splendens decreased much more than that of E. argyi. E. argyi exhibited much more tolerance to Pb toxicity than E. splendens. Treatment with 100 mg/L Pb plus 50 mmol/L EDTA significantly decreased the length and surface area of D≤0.2 mm root, increased the length and surface area of 0.2≤D≤0.8 mm root for the case of E. argyi, while for E. splendens, length and surface area of D<0.6 mm root reduced, as compared to 100 mg/L Pb treatment, alone. At 100 mg/L Pb, shoot Pb accumulation in E. splendens and E. argyi were 27.9 and 89.0 μg/plant DW respectively, and much more Pb was uptaken by the root and translocated to the stem of E. argyi as compared to E. splendens. Treatment of the plant with 100 mg/L Pb plus 50 mmol/L EDTA increased leaf Pb accumulation from 16.8 to 84.9 g/plant for E. splendens and from 18.8 to 52.5 g/plant for E. argyi, while both root and stem Pb pronouncedly reduced for both Elsholtzia species. The increased translocation of Pb to the leaf of E. splendens being than that of E. argyi after treatment with 100 mg/L Pb plus 50 mmol/L EDTA should be further investigated.
关键词：EDTA;Elsholtzia;Pb;Phytoremedation;Root morphology

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发布时间：2022-01-05
Study on US/O₃ mechanism in p-chlorophenol decomposition
Xian-wen Xu,Xin-hua Xu,Hui-xiang Shi,Da-hui Wang
2005, 6B(6): 553-558. DOI: 10.1631/jzus.2005.B0553

摘要：Study on the effects of sonolysis, ozonolysis and US/O₃ system on the decomposition of p-chlorophenol in aqueous solutions indicated that in the cases of US/O₃ system, individual ozonolysis and sonolysis, the decomposition rate of p-chlorophenol reached 78.78%, 56.20%, 2.79% after a 16-min reaction while its CODcr (chemical oxygen demand) removal rate was 97.02%, 62.17%, 3.67% after a 120-min reaction. The decomposition reaction of p-chlorophenol follows pseudo-first-order kinetics. The enhancement factors of p-chlorophenol and its COD_cr under US/O₃ system reached 63% and 237% respectively. The main intermediates during the decomposition include catechol, hydroquinone, p-benzoquinone, phenol, fumaric acid, maleic acid, oxalic acid and formic acid. The decomposition mechanism of p-chlorophenol was also discussed.
关键词：US/O₃;p-chlorophenol;Synergetic effect;Decomposition mechanism

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发布时间：2021-12-30
Isobaric vapor-liquid equilibrium for methyldichlorosilane-methyltrichlorosilane-dimethyldichlorosilane system
Zu-min Qiu,Xin-liang Xie,Mei Luo,Feng-xia Xie
2005, 6B(6): 559-562. DOI: 10.1631/jzus.2005.B0559

摘要：This paper describes measurement of vapor-liquid equilibrium (VLE) data of methyldichlorosilane-methyltrichloro silane-dimethyldichlorosilane system and that of the three binary systems at 101.325 kPa with a new pump-ebulliometer. The equilibrium composition of the vapor phase was calculated from pTx by indirect method. The model parameters of the liquid activity coefficient of the Wilson, NRTL, Margules and van Laar equations was corrected by the least square method. The ternary system VLE data were predicted by the Wilson equation, with the calculated boiling points showing good agreement with the experimental data.
关键词：Ebulliometer;Vapor-liquid equilibrium;Methyldichlorosilane;Methyltrichlorosilane;Dimethyldichlorosilane

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发布时间：2022-01-05
Dechlorination by combined electrochemical reduction and oxidation
Yan-qing Cong,Zu-cheng Wu,Tian-en Tan
2005, 6B(6): 563-568. DOI: 10.1631/jzus.2005.B0563

摘要：Chlorophenols are typical priority pollutants listed by USEPA (U.S. Environmental Protection Agency). The removal of chlorophenol could be carried out by a combination of electrochemical reduction and oxidation method. Results showed that it was feasible to degrade contaminants containing chlorine atoms by electrochemical reduction to form phenol, which was further degraded on the anode by electrochemical oxidation. Chlorophenol removal rate was more than 90% by the combined electrochemical reduction and oxidation at current of 6 mA and pH 6. The hydrogen atom is a powerful reducing agent that reductively dechlorinates chlorophenols. The instantaneous current efficiency was calculated and the results indicated that cathodic reduction was the main contributor to the degradation of chlorophenol.
关键词：Electrochemical reduction;Electrochemical oxidation;Dechlorination;Combined process

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发布时间：2022-01-05
Fe salts as catalyst for the wet oxidation of o-chlorophenol
Xin-hua Xu,Ping He,Jian Jin,Zhi-wei Hao
2005, 6B(6): 569-573. DOI: 10.1631/jzus.2005.B0569

摘要：Catalytic wet air oxidation (CWAO) of o-chlorophenol in wastewater was studied in a stainless steel autoclave using four different Fe catalysts in the temperature range of 100–200 °C. Experimental results showed that high rate of o-chlorophenol and COD_Cr (Chemical Oxygen Demand, mg/L) removal by CWAO was obtained at relatively low temperature and pressure. The catalysts Fe₂(SO₄)₃, FeSO₄, Fe₂O₃ and FeCl₃ all exhibited high catalytic activity. More than 93.7% of the initial COD_Cr and nearly 100% of o-chlorophenol were removed at 150 °C after 150 min with FeSO₄ as catalyst. The CWAO of o-chlorophenol was found to be pseudo-first order reaction with respect to o-chlorophenol, with activation energy of 75.56 kJ/mol in the temperature range of 100–175 °C.
关键词：Fe;o-chlorophenol;Catalytic wet air oxidation;Kinetic

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发布时间：2022-01-05
Study on anaerobic treatment of wastewater containing hexavalent chromium
Yan-bin Xu,Hua-hua Xiao,Shui-yu Sun
2005, 6B(6): 574-579. DOI: 10.1631/jzus.2005.B0574

摘要：A self-made anaerobic bio-filter bed which was inoculated with special sludge showed high efficiency in removing hexavalent chromium. When pump flow was 47 ml/min and COD_Cr of wastewater was about 140 mg/L, it took 4 h to decrease the Cr⁶⁺ concentrations from about 60 mg/L to under 0.5 mg/L, compared with 14 h without carbon source addition. Cr⁶⁺ concentrations ranged from 64.66 mg/L to 75.53 mg/L, the system efficiency was excellent. When Cr⁶⁺ concentration reached 95.47 mg/L, the treatment time was prolonged to 7.5 h. Compared with the contrast system, the system with trace metals showed clear superiority in that the Cr⁶⁺ removal rate increased by 21.26%. Some analyses also showed that hexavalent chromium could probably be bio-reduced to trivalent chromium, and that as a result, the chrome hydroxide sediment was formed on the surface of microorganisms.
关键词：Hexavalent chromium;Wastewater;Anaerobic;Bio-filter bed;Hexavalent chromium bio-removal

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发布时间：2022-01-05

Materials and Chemical Engineering

Preparation of high-permeability NiCuZn ferrite
Jun Hu,Mi Yan
2005, 6B(6): 580-583. DOI: 10.1631/jzus.2005.B0580

摘要：Appropriate addition of CuO/V₂O₅ and the reduction of the granularity of the raw materials particle decrease the sintering temperature of NiZn ferrite from 1200 °C to 930 °C. Furthermore, the magnetic properties of the NiZn ferrite prepared at low temperature of 930 °C is superior to that of the NiZn ferrite prepared by sintering at high temperature of 1200 °C because the microstructure of the NiZn ferrite sintered at 930 °C is more uniform and compact than that of the NiZn ferrite sintered at 1200 °C. The high permeability of 1700 and relative loss coefficient tanδ/μ_i of 9.0×10⁻⁶ at 100 kHz was achieved in the (Ni_0.17Zn_0.63Cu_0.20)Fe_1.915O₄ ferrite.
关键词：NiZn ferrite;Low temperature;High permeability;Low loss

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发布时间：2022-01-05
Study on the prediction of visible absorption maxima of azobenzene compounds
Jun-na Liu,Zhi-rong Chen,Shen-feng Yuan
2005, 6B(6): 584-589. DOI: 10.1631/jzus.2005.B0584

摘要：The geometries of azobenzene compounds are optimized with B3LYP/6-311G* method, and analyzed with nature bond orbital, then their visible absorption maxima are calculated with TD-DFT method and ZINDO/S method respectively. The results agree well with the observed values. It was found that for the calculation of visible absorption using ZINDO/S method could rapidly yield better results by adjusting OWF_π-π (the relationship between π-π overlap weighting factor) value than by the TD-DFT method. The method of regression showing the linear relationship between OWF_π-π and BL_N-N (nitrogen-nitrogen bond lengths) as OWF_π-π=−8.1537+6.5638BL_N-N, can be explained in terms of quantum theory, and also be used for prediction of visible absorption maxima of other azobenzne dyes in the same series. This study on molecules’ orbital geometry indicates that their visible absorption maxima correspond to the electron transition from HOMO (the highest occupied molecular orbital) to LUMO (the lowest unoccupied molecular orbital).
关键词：Azobenzene compound;Nature bond orbital (NBO);Visible absorption maxima

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发布时间：2021-12-30
A study on naphtha catalytic reforming reactor simulation and analysis
Ke-min Liang,Hai-yan Guo,Shi-wei Pan
2005, 6B(6): 590-596. DOI: 10.1631/jzus.2005.B0590

摘要：A naphtha catalytic reforming unit with four reactors in series is analyzed. A physical model is proposed to describe the catalytic reforming radial flow reactor. Kinetics and thermodynamics equations are selected to describe the naphtha catalytic reforming reactions characteristics based on idealizing the complex naphtha mixture by representing the paraffin, naphthene, and aromatic groups by single compounds. The simulation results based above models agree very well with actual operation unit data.
关键词：Naphtha;Catalytic reforming;Kinetics;Simulation and analysis

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发布时间：2021-12-30
Interaction of nonionic surfactant AEO₉ with ionic surfactants
Zhi-guo Zhang,Hong Yin
2005, 6B(6): 597-601. DOI: 10.1631/jzus.2005.B0597

摘要：The interaction in two mixtures of a nonionic surfactant AEO₉ (C₁₂H₂₅O(CH₂CH₂O)₉H) and different ionic surfactants was investigated. The two mixtures were AEO₉/sodium dodecyl sulfate (SDS) and AEO₉/cetyltrimethylammonium bromide (CTAB) at molar fraction of AEO₉, α_{AEO₉=0.5. The surface properties of the surfactants, critical micelle concentration (CMC), effectiveness of surface tension reduction (γ_CMC), maximum surface excess concentration (Γ_max) and minimum area per molecule at the air/solution interface (A_min) were determined for both individual surfactants and their mixtures. The significant deviations from ideal behavior (attractive interactions) of the nonionic/ionic surfactant mixtures were determined. Mixtures of both AEO₉/SDS and AEO₉/CTAB exhibited synergism in surface tension reduction efficiency and mixed micelle formation, but neither exhibited synergism in surface tension reduction effectiveness.}
关键词：Nonionic surfactant;Nonionic-ionic mixed surfactants;Molecular interaction parameter;Synergism;Mixed micelle;Mixed adsorption film

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发布时间：2022-01-05
Stability and electronic spectra of C₇₆N₂ isomers
Qi-wen Teng,Shi Wu
2005, 6B(6): 602-605. DOI: 10.1631/jzus.2005.B0602

摘要：Study of geometries of 16 possible isomers for C₇₆N₂ based on C₇₈(C_2v) by intermediate neglect of differential overlap (INDO) series of methods indicated that the most stable geometry 25,78-C₇₆N₂ where two nitrogen atoms substitute two apexes C(25) and C(78) near the shortest X axis and Y axis formed by two hexagons and a pentagon. Electronic structures and spectra of C₇₆N₂ were investigated. The reason for the red-shift for absorptions of C₇₆N₂ compared with that of C₇₈(C_2v) is discussed.
关键词：C₇₆N₂;Electronic spectra;INDO

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发布时间：2021-12-30
Quantum chemical study on asymmetric allylation of benzaldehyde in the presence of chiral allylboronate
Wan-suo Chen,Zhi-rong Chen
2005, 6B(6): 606-610. DOI: 10.1631/jzus.2005.B0606

摘要：The quantum chemical method is employed to study the modified asymmetric allylation of benzaldehyde controlled by diisopropyl D-(-)-tartrate auxiliary. All the structures are optimized completely at the B3LYP/6-31G(d,p) level. The (R)-secondary alcohol can be achieved mainly through a six-membered ring chair-like transition state structure. From the relative reaction rates theory the main product configuration predicted is in agreement with the experiment result.
关键词：Benzaldehyde;Asymmetric allylation;DFT

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发布时间：2021-12-30

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