检索结果-南通市图书馆

Chinese Journal of Chemical Engineering 2023年第6期58卷 40-52页

作者： xiaohong zhou Wenfeng zhou Wei Zhuang Chenjie Zhu Hanjie Ying Hongman Zhang School of Chemistry and Molecular Engineering Nanjing Tech UniversityNanjing 211816China State Key Laboratory of Materials-Oriented Chemical Engineering College of Biotechnology and Pharmaceutical EngineeringNational Engineering Technique Research Center for BiotechnologyNanjing Tech UniversityNanjing 211816China

Cytidine 5'-monophosphate(5'-CMP)is an essential nucleotide for additives.In this study,enhanced production of 5'-CMP was realized by the transformation of cytidine using co-immobilized di-enzymes,uridine-cytidine kinase(UCK)and acetate kinase(AcK).The immobilization yield of the enzyme had a clear correlation with the surface charges as zeta potential(ξ).Among them,ε-polylysinefunctionalized sepharose(SA-EPL,ξ=9.31 m V)showed high immobilization yield(78.8%),which was4.9-fold than that of nitrilotriacetic acid functionalized sepharose(SA-NTA,ξ=-12.6 m V).The residual activity of affinity co-immobilized enzyme(EPL-Ni/EPL@Ac K-UCK)was higher than 70.6%after recycled 10 times.Thus,this study provides an effective approach for the production of 5'-CMP with the advantages of low adenosine 5'-triphosphate(ATP)consumption,reduced side reactions,and improved reusability by co-immobilized UCK and Ac K on the functionalized Sepharose.

关键词： Sepharose ε-Polylysine Dual-enzyme cascade Cytidine 5'-monophosphate Enzyme immobilization

Effect of allelochemicals sustained-release microspheres on the ingestion, incorporation, and digestion abilities of Daphnia magna Straus

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2023年第2期124卷 205-214页

作者： Benhang Li Yijun Yin xiaohong zhou Li Feng Yongze Liu Ziwen Du Yajun Tian Liqiu Zhang Beijing Key Laboratory for Source Control Technology of Water Pollution Engineering Research Center for Water Pollution Source Control and EcoremediationBeijing Forestry UniversityBeijing 100083China College of Environment Zhejiang University of TechnologyHangzhou 310014China

Allelochemicals sustained-release microspheres(ACs-SMs)exhibited great inhibition effect on algae,however,few studies have focused on ACs-SMs toxicity on invertebrate.In this study,the effects of single high-concentration ACs(15 mg/L,SH-ACs),repeated lowconcentration ACs(3×5 mg/L,RL-ACs)and ACs-SMs containing 15 mg/L ACs exposure on the ingestion,incorporation,and digestion of Daphniamagna Straus(DS)were investigated by stable isotope 15N labeling method.Meanwhile,the diversity and abundance of microflora in DS guts were determined by 16S rRNA genes and cloning methods.The results showed that SH-ACs exposure caused 50%and 33.3%death rates for newborn and adult DS,while RL-ACs exposure caused 10%death rate for newborn DS and no obvious effect on the activity of adult DS.And ACs-SMs exposure did not diminish the motility of both newborn and adult DS,indicating the lower acute toxicity of ACs-SMs.Furthermore,SH-ACs inhibited the ingestion(-6.45%),incorporation(-47.1%)and digestion(-53.8%)abilities of DS and reduced the microbial abundance(-27.7%)in DS guts.Compared with SH-ACs,RL-ACs showed relatively low impact on the ingestion(-3.23%),incorporation(-5.89%)and digestion(-23.9%)abilities of DS.Interestingly,ACs-SMs enhanced the ingestion(+9.68%),incorporation(+52.9%)and digestion(+51.3%)abilities of DS and increased the microbial abundance(+10.7%)in DS guts.Overall ACs and ACs-SMs reduced the diversity of microflora in DS guts.In conclusion,ACs-SMs can release ACs sustainably and prolong the sustained release time,which not only effectively reduce the toxicity of ACs,but also had positive effects on DS.

关键词： Allelochemicals(ACs) Sustained-release microspheres (SMs) Daphnia magna Straus(DS)

Nutrient concentration variations during Oenanthe javanica growth and decay in the ecological floating bed system

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2010年第11期22卷 1710-1717页

作者： xiaohong zhou Guoxiang Wang School of the Environment Jiangsu University Zhenjiang 212013 China. Jiangsu Key Laboratory of Environmental Change and Ecological Construction College of Geographical Science Nanjing Normal University Nanjing 210046 China

The ecological floating bed system is a natural alternative to technical methods of wastewater treatment and involves complex processes induced by plants or microorganisms in the wastewater. This study aimed to identify nutrient concentration variations during Oenanthe javanica （Blume） DC growth and decay in the ecological floating bed system. Results showed that the third-order polynomial equation was suitable to describe pollutant concentration changes, showing that the effect of O. javanica ecological floating bed system on polluted water could be divided into the purification phase and decay phase. During the purification phase, nutrient concentrations rapidly decreased because O. javanica influenced water microbial communities and water physical parameters （i.e., dissolved oxygen, pH, and temperature）, and had a direct uptake of nutrients. However, during the decay phase, nitrogen and phosphorus concentrations in the plant tissues decreased, and these lost nutrients ultimately transferred to water and led to water quality deterioration. Results also showed that the uptake and storage of O. javanica in nutrients were temporary and the plant served only as media of the nutrients removed from the water. Under these circumstances, harvesting was an appropriate intervention to improve the treatment efficiency of O. javanica ecological floating bed system.

关键词： Oenanthe javanica ecological floating bed purification decay polluted water

An AuNPs/Mesoporous NiO/Nickel Foam Nanocomposite as a Miniaturized Electrode for Heavy Metal Detection in Groundwater

在线全文

学校读者我要写书评

暂无评论

Engineering 2023年第8期27卷 199-208页

作者： Boyuan Xue Qian Yang Kaidong Xia Zhihong Li George Y.Chen Dayi Zhang xiaohong zhou State Key Joint Laboratory of Environment Simulation and Pollution Control School of EnvironmentTsinghua UniversityBeijing 100084China National Key Laboratory of Science and Technology on Micro/Nano Fabrication Institute of MicroelectronicsPeking UniversityBeijing 100871China Shenzhen Key Laboratory of Photonic Devices and Sensing Systems for Internet of Things Guangdong and Hong Kong Joint Research Centre for Optical Fiber SensorsShenzhen UniversityShenzhen 518060China College of New Energy and Environment Jilin UniversityChangchun 130021China The Research Institute of Environmental Innovation(Suzhou) Tsinghua UniversitySuzhou 215000China

Heavy metals,notably Pb2+and Cu^(2+),are some of the most persistent contaminants found in groundwater.Frequent monitoring of these metals,which relies on efficient,sensitive,cost-effective,and reliable methods,is a necessity.We present a nanocomposite-based miniaturized electrode for the concurrent measurement of Pb2+and Cu^(2+)by exploiting the electroanalytical technique of square wave voltammetry.We also propose a facile in situ hydrothermal calcination method to directly grow binder-free mesoporous Ni O on a three-dimensional nickel foam,which is then electrochemically seeded with gold nanoparticles(Au NPs).The meticulous design of a low-barrier Ohmic contact between mesoporous Ni O and Au NPs facilitates target-mediated nanochannel-confined electron transfer within mesoporous Ni O.As a result,the heavy metals Pb2+(0.020 mg.L^(-1)detection limit;2.0–16.0 mg.L^(-1)detection range)and Cu^(2+)(0.013 mg.L^(-1)detection limit;0.4–12.8 mg.L^(-1)detection range)can be detected simultaneously with high precision.Furthermore,other heavy metal ions and common interfering ions found in groundwater showed negligible impacts on the electrode’s performance,and the recovery rate of groundwater samples varied between 96.3%±2.1%and 109.4%±0.6%.The compactness,flexible shape,low power consumption,and ability to remotely operate our electrode pave the way for onsite detection of heavy metals in groundwater,thereby demonstrating the potential to revolutionize the field of environmental monitoring.

关键词： AuNPs Mesoporous NiO Miniaturized electrode Heavy metal ions Groundwater Square wave voltammetry

A cellphone-based colorimetric multi-channel sensor for water environmental monitoring

在线全文

学校读者我要写书评

暂无评论

Frontiers of Environmental Science & Engineering 2022年第12期16卷 67-78页

作者： Yunpeng Xing Boyuan Xue Yongshu Lin Xueqi Wu Fang Fang Peishi Qi Jinsong Guo xiaohong zhou State Key Laboratory of Urban Water Resource and Environment School of EnvironmentHarbin Institute of TechnologyHarbin150090China State Key Joint Laboratory of ESPC Center for Sensor Technology of Environment and HealthSchool of EnvironmentTsinghua UniversityBeijing100084China Key Laboratory of the Three Gorges Reservoir Region’s Eco-Environments of MOE Chongqing UniversityChongqing400030China

The development of colorimetric analysis technologies for the commercial cellphone platform has attracted great attention in environmental monitoring due to the low cost,high versatility,easy miniaturization,and widespread ownership of cellphones.This work demonstrates a cellphone-based colorimetric multi-channel sensor for quantifying multiple environmental contaminants simultaneously with high sensitivity and stability.To improve the sensitivity of the sensor,a delicate optical path system was created by using a diffraction grating to split six white beams transmitting through the multiple colored samples,which allows the cellphone CMOS camera to capture the diffracted light for image analysis.The proposed sensor is a universal colorimetric detection platform for a variety of environmental contaminants with the colorimetry assay in the range of 400–700 nm.By introducing the diffraction grating for splitting light,the sensitivity was improved by over six folds compared with a system that directly photographed transmitted light.As a successful proof-of-concept,the sensor was used to detect turbidity,orthophosphate,ammonia nitrogen and three heavy metals simultaneously with high sensitivity(turbidity:detection limit of 1.3 NTU,linear range of 5–400 NTU;ammonia nitrogen:0.014 mg/L,0.05–5 mg/L;orthophosphate:0.028 mg/L,0.1–10 mg/L;Cr(VI):0.0069 mg/L,0.01–0.5 mg/L;Fe:0.025 mg/L,0.1–2 mg/L;Zn:0.032 mg/L,0.05–2 mg/L)and reliability(relative standard deviations of six parallel measurements of 0.37%–1.60%and recoveries of 95.5%–106.0%in surface water).The miniature sensor demonstrated in-field sensing ability in environmental monitoring,which can be extended to point-of-care diagnosis and food safety control.

关键词： Colorimetric analysis Multi-channel sensor Cellphone Water quality indexes Environmental monitoring

变迁时代的生命历程、人生转折与心理嬗变——“知青”一代社会学家的口述史与集体叙事

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

心理学报 2024年第7期56卷 964-976页

作者：胡洁周晓虹东南大学人文学院南京211189 南京大学社会学院南京210023

改革开放40年来,中国社会发生了朝向现代化的迅猛变迁。在经济与社会结构急剧变化并取得有目共睹的成就的同时,中国人的价值观和社会行为模式也发生了明显的嬗变。1979年中国社会学重建后,作为对社会变迁及其影响最为敏感的群体,知青一... 详细信息

改革开放40年来,中国社会发生了朝向现代化的迅猛变迁。在经济与社会结构急剧变化并取得有目共睹的成就的同时,中国人的价值观和社会行为模式也发生了明显的嬗变。1979年中国社会学重建后,作为对社会变迁及其影响最为敏感的群体,知青一代社会学人,因其个体生命史与改革开放同构及与社会学重建同步,成为表征转型时代心理蜕变的合适案例。就个体心理蜕变的向度说,转型或变迁影响到他们的认知方式、情感世界和个体行为的现代性;而就集体心态建构的向度说,他们在40年的职业生涯中,围绕中国式现代化与富民实践、遂生乐业的心态秩序、社会学本土化或中国化等议题所形成的话语叙事,都充分体现了这个独特群体在大变革时代的集体心态。进一步,在个体心理蜕变和集体心态建构之间,存在着多种重叠与共通的部分,它使得知青社会学人在变革时代的心理嬗变就是一部个体心理与集体心态互为镶嵌的精神蜕变史。

关键词：变迁时代心理史与心态史生命历程人生转折心理嬗变

Inhibitory effect of nitrobenzene on oxygen demand in lake sediments

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2012年第5期24卷 934-939页

作者： xiaohong zhou Xuying Wang Hanchang Shi School of Environment Tsinghua University Beijing 100084 China

Nitrobenzene is an important raw material and product, which presents a heavy threat to the ecosystem. The potential impacts of nitrobenzene on sediment oxygen demand （SOD） were studied in lake sediment simulating reactors receiving relatively low inputs of nitrobenzene. Oxygen microprofiles were measured in these sediment reactors using microelectrodes. After an initial microprofile measurement as a control, nitrobenzene was added to the overlying water resulting in concentrations of 0, 50, 100, and 150 μg/L. Microprofiles were measured on day 1, 2, 4 and 7 following the addition of nitrobenzene. SODs were determined from the microprofiles using a reaction-diffusion model. Results showed that the SODs increased relative to the initial values measured in the pre-treatment period in reactors exposed to all nitrobenzene concentrations on day 1. However, the values decreased gradually on the following days, which eventually resulted in a 50% loss in SODs after 7 days of exposure to nitrobenzene in all reactors. In addition, the inhibition effect of nitrobenzene on SOD exhibited a weak relationship with its concentration. The microscopic observation and count of algae in the sediment showed that the exposure to nitrobenzene did not change the composition of algae greatly, however, it decreased the number of dominant algae species sharply after 7 days of exposure. These results suggested that nitrobenzene could significantly alter SOD in lakes, which could ultimately affect the pollutant recovery in aquatic-sediment systems.

关键词： nitrobenzene sediment inhibitory effect microelectrode sediment oxygen demand

Evaluation of oxygen transfer parameters of fine-bubble aeration system in plug flow aeration tank of wastewater treatment plant

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2013年第2期25卷 295-301页

作者： xiaohong zhou Yuanyuan Wu Hanchang Shi Yanqing Song State Key Joint Laboratory of Environment Simulation and Pollution Control School of EnvironmentTsinghua University

Knowledge of the oxygen mass transfer of aerators under operational conditions in a full-scale wastewater treatment plant （WWTP） is meaningful for the optimization of WWTP, however, scarce to best of our knowledge. Through analyzing a plug flow aeration tank in the Lucun WWTP, in Wuxi, China, the oxygenation capacity of fine-bubble aerators under process conditions have been measured in- situ using the off-gas method and the non-steady-state method. The off-gas method demonstrated that the aerators in different corridors in the aeration tank of WWTP had significantly different oxygen transfer performance; furthermore, the aerators in the same corridor shared almost equal oxygen transfer performance over the course of a day. Results measured by the two methods showed that the oxygen transfer performance of fine-bubble aerators in the aeration tank decreased dramatically compared with that in the clean water. The loss of oxygen transfer coefficient was over 50% under low-aeration conditions （aeration amount 〈 0.67 Nm 3 /hr）. However, as the aeration amount reached 0.96 Nm 3 /hr, the discrepancy of oxygen transfer between the process condition and clean water was negligible. The analysis also indicated that the non-steady-state and off-gas methods resulted in comparable estimates of oxygen transfer parameters for the aerators under process conditions.

关键词： fine-bubble aerator off-gas method non-steady-state method oxygen transfer parameters

A potentiometric cobalt-based phosphate sensor based on screen-printing technology

在线全文

学校读者我要写书评

暂无评论

Frontiers of Environmental Science & Engineering 2014年第6期8卷 945-951页

作者： Lei ZHU xiaohong zhou Hanchang SHI School of Environment Tsinghua University Beijing 100084 China Division of Ecology and Environment Yangtze Delta Region Institute of Tsinghua University Jiaxing 314006 China

A potentiometric cobalt-based screen-pritning sensor was fabricated by electroplating cobalt on the surface of a screen-printing electrode as the sensitive layer for the determination of dihydrogenphosphate （H2PO4） in wastewater samples. The electrochemical performance of this sensor was fully examined to determine its detection calibration, detection limit, response time, selectivity, and interference with pH, various ions, and dissolved oxygen （DO）. The cobalt-based phosphate sensor showed a phosphate-selective potential response in the range of 10 5mol·L^-1 to 10^-1 mol^-1, yielding a detection limit of 3.16 × 10μmol·L^l and a slope of -37.51 mV·decade＇ in an acidic solution （pH 4.0） of H2PO4-. DO and pH were found to interfere with sensor responses to phosphate. Ultimately, the performance of the sensor was validated for detecting wastewater samples from the Xiaojiahe Waste- water Treatment Plant against the standard speetrophotometric methods for HzPO4 analysis. The discrepancy between the two methods was generally ＋5% （relative standard deviation）. Aside from its high selectivity, sensitivity, and stability, which are comparable with conventional bulk Co-wire sensors, the proposed phosphate sensor presents many other advantages, such as low price, compactness, ease of use, and the possibility of integration with other analytical devices, such as flow injectors.

关键词： phosphate cobalt screen-printing technology electroplate wastewater

Sulfide elimination by intermittent nitrate dosing in sewer sediments

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2015年第1期27卷 259-265页

作者： Yanchen Liu Chen Wu xiaohong zhou David Z.Zhu Hanchang Shi School of Environment Tsinghua University Department of Civil and Environmental Engineering University of Alberta

The formation of hydrogen sulfide in biofilms and sediments in sewer systems can cause severe pipe corrosions and health hazards, and requires expensive programs for its prevention. The aim of this study is to propose a new control strategy and the optimal condition for sulfide elimination by intermittent nitrate dosing in sewer sediments. The study was carried out based on lab-scale experiments and batch tests using real sewer sediments. The intermittent nitrate dosing mode and the optimal control condition were investigated. The results indicated that the sulfide-intermittent-elimination strategy by nitrate dosing is advantageous for controlling sulfide accumulation in sewer sediment. The oxidation–reduction potential is a sensitive indicator parameter that can reflect the control effect and the minimum N/S（nitrate/sulfide）ratio with slight excess nitrate is necessary for optimal conditions of efficient sulfide control with lower carbon source loss. The optimal control condition is feasible for the sulfide elimination in sewer systems.

关键词： Sewer system Sulfide elimination Sediment Optimal condition Intermittent nitrate dosing