Theoretical Study of the C-CI Bond Dissociation Enthalpy and Electronic Structure of Substituted Chlorobenzene Compounds

Quantum chemical calculations were used to estimate the bond dissociation energies （BDEs） for 13 substituted chlorobenzene compounds. These compounds were studied by the hybrid density functional theory （B3LYP, B3PW91, B3P86） methods together with 6-31G^＊＊ and 6-311G^＊＊ basis sets. The results show that B3P86/6-311G^＊＊ method is the best method to compute the reliable BDEs for substituted chlorobenzene compounds which contain the C-C1 bond. It is found that the C-C1 BDE depends strongly on the computational method and the basis sets used. Substituent effect on the C-C1 BDE of substituted chlorobenzene compounds is further discussed. It is noted that the effects of substitution on the C-C1 BDE of substituted chlorobenzene compounds are very insignificant. The energy gaps between the HOMO and LUMO of studied compounds estimate the relative thermal stability ordering are also investigated and from this data we of substituted chlorobenzene compounds.

玉米CBS基因家族的鉴定和特征分析

为研究玉米CBS(ZmCBS)基因家族的特征,探讨其功能,对ZmCBS基因家族进行鉴定,分析其染色体定位、基因结构、保守结构域及进化关系,并对ZmCBS家族基因在玉米组织中的表达情况及其在非生物胁迫下的表达变化进行分析。基于玉米基因组数据库,鉴定到37个CBS基因家族成员,它们不均匀地分布在玉米的8条染色体上。该家族蛋白除保守的CBS结构域外,多数成员还包含其他结构域,包括电压门控的氯化物通道蛋白(voltage gated ClC)、Phox/Bemp1(PB1)结构域、五肽重复序列(penatricopeptider repeat, PPR)和E_SET结构域等。按照基因结构和进化关系可分为6个亚类,且同一进化分支上的基因具有相似的外显子结构和CDS长度,但内含子长度差异很大。启动子分析结果表明,ZmCBS基因启动子上含有响应激素和非生物胁迫的顺式作用元件。转录组数据的基因表达谱分析显示,ZmCBS基因家族部分成员在叶、花粉或胚中优势表达。ZmCBS3和ZmCBS14受冷胁迫诱导表达,ZmCBS14和ZmCBS22受干旱胁迫诱导表达,暗示这些基因在玉米响应外界胁迫中起重要作用。分析结果将为进一步研究ZmCBS家族基因奠定基础。

彰显龙岩CB-1烟叶清甜蜜甜香型风格密集烘烤工艺研究

研究龙岩地区‘翠碧一号’的密集烘烤工艺,为彰显其清甜蜜甜香型风格提供参考。为彰显‘翠碧一号’烟叶清甜蜜甜香型风格,以福建龙岩烟区栽种‘翠碧一号’下、中、上部的适熟烟叶为实验材料,设置3种烘烤工艺,采用“背靠背”编烟方式编竿装烟,对烤后烟叶分别按下、中、上部进行分级,然后进行鉴定,统计外观、化学成分及感官质量等信息。结果显示,‘翠碧一号’(CB-1)品种烟叶下部烟宜采用T3(高温/高低高湿)烘烤工艺,关键烘烤阶段干/湿球温度为:变黄期38~40/37~38℃、凋萎期42/36℃、变筋期46/36℃、干片期50~54/38~39℃、干筋期60~65/40~42℃,中、上部烟叶宜采用T1(高温/高湿)烘烤工艺,关键烘烤阶段干/湿球温度为:变黄期38~40/37~38℃、凋萎期42/38℃、变筋期46/38℃、干片期50~54/39~40℃、干筋期60~65/40~42℃。该研究为彰显‘翠碧一号’香型的密集烘烤工艺提供技术参考。

多倍体水稻DHF-CBS基因的抗旱性鉴定

为探究干旱胁迫下DHF-CBS基因调控多倍体水稻(Oryza sativa L.)的抗旱机制,选取2种水稻品种,分别为多倍体植株中花-11(DHF-CBS基因)、突变体植株UC-32(不表达DHF-CBS基因),对2种水稻的GUS化学染色结果、组织含水量、脱落酸(ABA)含量、硫代巴比妥酸活性物质(TBARS)含量、谷胱甘肽(GSH)含量等进行分析。结果表明,干旱胁迫第7天,中花-11仍有部分叶片保持绿色且坚挺,干旱胁迫第11天时整株叶片变黄,甚至有的叶片变枯,经过干旱胁迫后的表型观察发现,中花-11比UC-32的抗旱能力强;对水稻的含水量、ABA含量、TBARS含量、GSH含量进行分析,表明中花-11的抗旱性优于UC-32,说明DHF-CBS基因增强了水稻的抗旱能力。

Chlorobenzene degradation by electro-heterogeneous catalysis in aqueous solution:intermediates and reaction mechanism

This study was performed to investigate the variables that influence chlorobenzene (CB) degradation in aqueous solution by electro-heterogeneous catalysis.The effects of current density,pH,and electrolyte concentration on CB degradation were determined.The degradation effciency of CB was almost 100% with an initial CB concentration of 50 mg/L,current density 15 mA/cm2,initial pH 10,electrolyte concentration 0.1 mol/L,and temperature 25°C after 90 min of reaction.Under the same conditions,the degradation eff...

Biodegradation of Gaseous Chlorobenzene by White-rot Fungus Phanerochaete chrysosporium

Objective To evaluate the effect of white rot fungus Phanerochaete chrysosporium on removal of gaseous chlorobenzene. Methods Fungal mycelium mixed with a liquid medium was placed into airtight bottles. A certain amount of chlorobenzene was injected into the headspace of the bottles under different conditions. At a certain interval, the concentrations in the headspace were analyzed to evaluate the degradation of chlorobenzene by P. chrysosporium. Results The degradation effects of P. chrysosporium on chlorobenzene under different conditions were investigated. The difference in the optimum temperature for the growth of the fungi and chlorobenzene degradation was observed. The data indicated that a lower temperature （28℃） would promote the degradation of chlorobenzene than the optimum temperature for the growth of the fungi （37℃）. A low nitrogen source concentration （30 mg N/L） had a better effect on degrading chlorobenzene than a high nitrogen source concentration （higher than 100 mg N/L）. A high initial concentration （over 1100 mg/m3） of chlorobenzene showed an inhibiting effect on degradation by P chrysosporium. A maximum removal efficiency of 95% was achieved at the initial concentration of 550 mg/m3. Conclusion P. chrysosporium has a rather good ability to remove gaseous chlorobeuzene. A low nitrogen source concentration and a low temperature promote the removal of chlorobenzene by P. chrysosporium. However, a high initial chlorobenzene concentration can inhibit chlorobenzene degradation.

感染科临床带教中运用CBS联合翻转教学模式的效果分析

分析感染科带教中开展CBS+翻转教学模式的实施效果。方法 围绕60名在我院实习的学生进行分组,观察组(CBS+翻转教学)、对照组(LBL教学),对教学成果做出评估。结果 观察组学生在考核成绩上优于对照组,此外,观察组的教学质量更高、学习能力更强,同时,对教学的满意度更高与对照组相比(P<0.05),最后观察组综合能力更为出色(P<0.05)。结论 CBS结合翻转教学模式能够增强学生的团队合作意识和沟通能力,提高教学效果和学生的职业素养水平,在感染科临床带教中具有良好的效果。

Chlorobenzenes in waterweeds from the Xijiang River (Guangdong section) of the Pearl River

The Xijiang River is the major source of water for about 4.5 millions of urban population and 28.7 millions of rural population. The water quality is very important for the health of the rural population. The concentration and distribution of chlorobenzenes （CBs） in both water and waterweeds collected from 4 stations in the Xijiang River （Gangdong section） of the Pearl River in April and November were determined. The result showed that nearly every congener of CBs was detected. The total contents of CBs （ZCBs） in the river water ranged from 111.1 to 360.0 ng/L in April and from 151.9 to 481.7 ng/L in November, respectively. The pollution level of CBs in the water in April was higher than that in November. The contents of ZCBs in waterweeds ranged from 13.53×10^2μg/g to 38.27×10^2μg/g dry weight （dw）. There was no significant difference between April and November in waterweeds. The distribution of CBs in roots, caulis, and leaves of Vallisneria spiralis L. showed different patterns. The leaves mainly contained low-molecular-weight CBs （DCBs）, whereas the roots accumulated more PCBs and HCBs. The average lgBCFlip （bioconcentration factor） of CBs ranged from 0.64 to 3.57 in the waterweeds. The spatial distribution character of CBs in the Xijiang River was： Fengkai County 〈 Yunan County 〈 Yun＇an County 〈 Gaoyao County according to the ZCBs, and the pollution deteriorated from the upstream to the downstream of the Xijiang River. Further analysis demonstrated that the discharge of waste containing CBs may be the main source of CBs pollution in the Xijiang River .

Catalytic Dechlorination of Chlorobenzene in Water by Pd/Fe System

Chlorobenzene was dechlorinated by Pd/Fe bimetallic system in water through catalytic reduction. The dechlorination rate increases with increase of bulk loading of Pd due to the increase of both the surface loading of the Pd and the total surface area. For conditions with 0.005% Pd/Fe, 45% dechlorination efficiency was achieved within 5 h. The dechlorinated reaction is believed to take place on the bimetal surface in a pseudo-first-order reaction, with the rate constant being 0.0043 min-1.

Catalytic dechlorination of chlorobenzene in water by Pd/Fe bimetallic system

Catalytic reductive dechlorination of monochlorobenzene(MCB) was carried out in the palladium/iron system. With low Pd loading(0 005%), 45% dechlorination efficiency was achieved within 5 h. Pd as catalyst accelerated the reductive dechlorination reaction. Dechlorination mechanism and kinetics were discussed. The reaction took place on the bimetal surface in a pseudo first order reaction, with the rate constant being 0 0071 min -1 ( K SA =8 0×10 -3 L/(m 2·h). The reduction product for MCB was benzene.

Electrokinetic movement of multiple chlorobenzenes in contaminated soils in the presence of β-cyclodextrin

This study investigated the electrokinetic （EK） behavior of multiple chlorobenzenes, including 1,2,3,4-tetrachlorobenzene （TeCB）, 1,2,4,5-tetrachlorobenzene （i-TeCB）, and 1,2,3-trichlorobenzene （TCB） in contaminated clayed soils. The effect of β-cyclodextrin （β- CD） on the EK removal of the chlorobenzenes was studied. The largest removal was obtained when Na2CO3/NaHCO3 buffer was used as anodic purging solution without β-CD. The removal efficiencies were related to the aqueous solubilities of chlorobenzenes. With the same cumulative electroosmotic flow, greater solubility led to higher removal efficiency. The addition of β-CD inhibited the EK removal efficiency of all chlorobenzenes. The inhibition increased with the increase of β-CD concentration. With the same β-CD concentration, the inhibition increased with the rise of electric potential. It was found that the inclusion compounds between β-CD and chlorobenzenzes were less soluble than chlorobenzenes. The formation of the less soluble inclusion compounds reduced the aqueous solubility of chlorobenzenes and led to the partial immobilization of the chlorobenzenes that desorbed from soil. It was feasible to use the EK technology to remove chlorobenzenes in contaminated soils using water as the anodic flushing solution. The addition of β-CD was not recommended for the EK removal of chlorobenzenes.

Heterogeneous Photocatalytic Mineralization of Chlorobenzene by Paratungstate-loaded Titania Catalysts in an Aqueous Medium

Paratungstate-loaded titania catalysts were prepared %via% the addition of a series of aqueous solutions of paratungstate(denoted as W_ 7) into an isopropanol solution of Ti[OCH(CH_ 3)_ 2]_ 4 by means of the sol-gel method. The catalysts were characterized by EDX, BET, FTIR, UV-Vis DRS, XRD and the results indicate that such paratungstate-loaded catalysts maintained their heptatungstate structure in the anatase titania matrix up to 400 ℃. The catalysts were tested for the heterogeneous photodegradation of chlorobenzene in aqueous media and showed a better catalytic activity than P-25 TiO_ 2 because paratungstate can prevent the recombination of the holes and electrons produced during irradiation. Moreover, the paratungstate-loaded titania catalysts can resist the disaggregation during the photoirradiation and can be easily recycled from the aqueous suspensions after reactions.

Improvement of trickling biofilter purification performance on treating chlorobenzene in waste gases using surfactant

A laboratory-scale trickling biofilter column, filled with Raschig rings and inoculated with Pseudomonas putida （ATCC 1785） was used to ＇purify chlorobenzene contained waste gases. Sodium dodecyl sulfonate （SDS） was used to enhance the performance of trickling biofilter. Purification performance of the trickling biofilter was examined for chiorobenzene inlet concentration of 1.20,-5.04 g/m^3 at different EBRTs between 76N153 s. Without SDS addition, with simultaneous increase in chlorobenzene inlet loading rate and gas flow rate, 100% removal efficiency was achieved at EBRT of 109 s and inlet loadings below 5120 mg/m^3. Addition of SDS to nutrient solution led to improvement of trickling biofilter purification performance. By introducing 25 mg/L SDS, the removal efficiency was increased by 21% and elimination capacity up to 234 g/（m^3.h） was achieved at chlorobenzene inlet loading of 241 g/（m^3.h）. Although SDS concentration experienced a low rate reduction after continuous nutrient solution recirculation, this result has period little influence on trickling biofilter＇s removal efficiency in monitoring period.

Preparation of MnCo/MCM-41 catalysts with high performance for chlorobenzene combustion

MCM-41 was synthesized by a soft template technique.The specific surface area and pore volume of the MCM-41 were 805.9 m2/g and 0.795 cm3/g,respectively.MCM-41-supported manganese and cobalt oxide catalysts were prepared by an impregnation method.The energy dispersive X-ray spectroscopy clearly confirmed the existence of Mn,Co,and O,which indicated the successful loading of the active components on the surface of MCM-41.The structure and function of the catalysts were changed by modulating the molar ratio of manganese to cobalt.The 10%MnCo(6:1)/MCM-41(Mn/Co molar ratio is 6:1)catalyst displayed the best catalytic activity according to the activity evaluation experiments,and chlorobenzene(1000 ppm)was totally decomposed at 270°C.The high activity correlated with a high dispersion of the oxides and was attributed to the exposure of more active sites,which was demonstrated by X-ray diffraction and high-resolution transmission electron microscopy.The strong interactions between MnO2,Co3O4,MnCoOx,and MCM-41 indicated that cobalt promoted the redox cycles of the manganese system.The bimetal-oxide-based catalyst showed better catalytic activity than that of the single metal oxide catalysts,which was further confirmed by H2 temperature-programmed reduction.Chlorobenzene temperature-programmed desorption results showed that 10%MnCo(6:1)/MCM-41 had higher adsorption strength for chlorobenzene than that of single metal catalysts.And stronger adsorption was beneficial for combustion of chlorobenzene.Furthermore,10%MnCo(6:1)/MCM-41 was not deactivated during a continuous reaction for 1000 h at 260°C and displayed good resistance to water and benzene,which indicated that the catalyst could be used in a wide range of applications.

Measurement and Correlation of Isobaric Vapor-Liquid Equilibrium of Three Binary Systems Containing Chlorobenzene at 50.00 and 101.33 kPa

Isobaric vapor-liquid equilibrium(VLE) data for three binary systems, chlorobenzene + N,N-dimethylformamide, chlorobenzene + furfural, and chlorobenzene + benzaldehyde, were measured at 50.00 and 101.33 kPa using a modified Rose-Williams still. Gas chromatography was used to analyze the compositions of the samples and no azeotropic behavior was found. All of the measured VLE values were checked by the semi-empirical method proposed by Herington and the point-to-point Van Ness test method modified by Fredenslund. The experimental data were correlated by using the Wilson, the non-random two-liquid and universal quasi-chemical activity coefficient models. The corresponding parameters for the three models were obtained.

The Design and Control of Distillation Column with Side Reactors for Chlorobenzene Production

The distillation column with side reactors (SRC) can overcome the temperature/pressure mismatch in the traditional reactive distillation, the column operates at temperature/pressure favorable for vapor-liquid separation, while the reactors operate at temperatures/pressures favorable for reaction kinetics. According to the smooth operation and automatic control problem of the distillation column with side reactors (SRC), the design, simulation calculation and dynamic control of the SCR process for chlorobenzene production are discussed in the paper. Firstly, the mechanism models, the integrated structure optimal design and process simulation systems are established, respectively. And then multivariable control schemes are designed, the controllability of SRC process based on the optimal steady-state integrated structure is explored. The dynamic response performances of closed-loop system against several disturbances are discussed to verify the effectiveness of control schemes for the SRC process. The simulating results show that the control structure using conventional control strategies can effectively overcome feeding disturbances in a specific range.

A Study on Side Reactions of Hydroxyethylation of 3-Nitro-4- chlorobenzenesulfinic Acid with Ethylene Oxide

The reaction of 3-nitro-4-chlorobenzenesulfinic acid and ethylene oxide to obtain 2-nitro-4-（β-hydroxyethylsulfonyl）chlorobenzene had been studied. Except hydroxyethylation on the sulfur atom of 3-nitro-4-chlorobenzenesulfinic acid to form the target product, 2-nitro-4-（β- hydroxyethylsulfonyl）chlorobenzene, there presented three kinds of side reactions： 1. Condensation and elimination of HCI to form biphenyl sulfone derivatives; 2. Addition to give bisulfonyl ethane derivative via vinyl sulfone; and 3. Hydroxylethylation on O-atom to produce hydroxylethylsulfinate due to the tautomerism of sulfinic acid.

Study on the Effect of Underground Temperature on the Adsorption Behavior of Chlorobenzene under Artificial Recharge Condition

[ Objective] The research aimed to study the effect of underground temperature on the adsorption behavior of chlorobenzene under artifi- cial recharge condition. [ Method] Based on the prior researches, combining actual condition of the artificial recharge test site, the adsorption be- havior of chlorobenzene under the background of artificial recharge was discussed. [ Reset ] The adsorption reaction of chlorobenzene correspon- ded with quasi-first-order and quasi-second-order kinetics equations at certain concentration. When temperature rose, reaction rate accelerated, and adsorption balance time shortened to 12 （0 ℃）, 10 （10 ℃） and 8 （20 ℃） h. The adsorption of chlorobenzene corresponded with isothermal adsorption model very well at different concentrations. When temperature ranged from 0 to 20 ℃, the adsorption amount of medium on chloroben- zene increased at equilibrium time. The maximal adsorption amounts calculated by Langmuir model were 20.747, 21. 505, 23.364 μg/g at 0, 10 and 20 ℃, respectively. [ Conclusion] The adsorption of chlorobenzene in aquifer medium was endothermic reaction, and the best season of artifi- cial recharne was in summer.

小样本下岭PLS-SEM与岭CB-SEM的比较

目前主要有两种结构方程模型(SEM):CB-SEM和PLS-SEM。当样本量较小时,CB-SEM常常会出现不收敛的情况,使用岭方法可以改善这个问题。文章主要研究将岭方法运用到PLS-SEM中,对比岭方法下PLS-SEM与CB-SEM的表现。研究表明,岭CB-SEM和岭PLS-SEM估计量总体上比常规的CB-SEM和PLS-SEM估计量更精确,但偏差没有明显改善;当样本量较小时,PLS-SEM、岭PLS-SEM估计的精确性都优于CB-SEM、岭CB-SEM;对于受到中介变量影响的内生潜变量来说,岭PLS-SEM在估计其他潜变量对它的影响(路径系数)时最精确。