检索结果-南通市图书馆

Journal of Environmental Science and Engineering(A) 2015年第1期4卷 30-35页

作者： Tsadu Shaba Mohammed Thandime Apollos Garba Ibrahim Saratu Usman Yisa Tswayan Ananias department of water Resources Aquaculture and Fisheries Technology Federal University of Technology Minna Minna 920001Niger State Nigeria

African catfish Clarias gariepinus brood stocks were bred by normal induced breeding method, After fertilization, the eggs were treated with 0.40%, 0.50% and 0.60% concentration levels of MS （methylated spirit） and a control treatment without MS （0%）. The objective was to remove the stickiness of the egg outer vitelline membrane to improve hatchability and survival of the hatchlings. Two batches of the treatments were carried out according to treatment duration of 5 s and l0 s. The eggs hatched normally with the highest hatching percentage of 62.31% in eggs treated with 0.40% MS concentration in 5 s treatment and 61.92% in the same concentration for 10 s. The control treatment of 0.00% MS treatment gave the lowest hatchability of 49.69% at 5 s and 45.71% at 10 s exposure time. Growth performance of the hatchlings improved in eggs treated than those not treated. Those treated had higher weight gain and percentage specific growth rates than those not treated. Percentage survival ranged from 75% to 90 % in both treated and untreated groups. MS can therefore be safely used in fish hatchery to prevent egg stickiness to improve hatchability and larval development.

关键词： Clarias gariepinus egg MS antisticking.

Differentiable programming and density matrix based Hartree–Fock method

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics B 2021年第6期30卷 249-254页

作者： Hong-Bin Ren Lei Wang Xi Dai Beijing National Laboratory for Condensed Matter Physics and Institute of Physics Chinese Academy of SciencesBeijing 100190China School of Physical Sciences University of Chinese Academy of SciencesBeijing 100049China Songshan Lake Materials Laboratory Dongguan 523808China department of Physics Hong Kong University of Science and TechnologyClear Water BayKowloon 999077Hong KongChina

Differentiable programming is an emerging programming paradigm that allows people to take derivative of an output of arbitrary code snippet with respect to its input. It is the workhorse behind several well known deep learning frameworks,and has attracted significant attention in scientific machine learning community. In this paper, we introduce and implement a density matrix based Hartree–Fock method that naturally fits into the demands of this paradigm, and demonstrate it by performing fully variational ground state calculation on several representative chemical molecules.

关键词： differentiable programming quantum chemistry

The importance of picophytoplankton and its top-down control in marine environments

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

生态科学 2008年第5期27卷 303-309页

作者： Hongbin Liu Bingzhang Chen Atmospheric Marine and Coastal Environment (AMCE) Program Hong Kong University of Science and Technology Clear Water Bay Hong Kong department of Biology Hong Kong University of Science and Technology Clear Water Bay Hong Kong

Phytoplankton are classfied into three groups based on size: microphytoplankton (>20 μm), nanophytoplankton (2-20 μm), and picophytoplankton (<2 μm) (Sieburth et al. 1978) [1]. Picophytoplankton are composed of thr... 详细信息

关键词：海洋环境生态系统物种生态环境

Sorption of Organic Compounds in soil Organic Matter

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Journal of Northeast Agricultural University(English Edition) 2001年第1期8卷 72-80页

作者： XING Bao-shan,LIU Xiao-bing, SONG Chun-yu ( Heilongjiang Institute of Agricultural Modernization,Academia Sinica,Harbin, Heilongjiang 150040,P R C) ( department of Plant and soil Seinces, University of Massachussetts, Amherst, USA) Heilongjiang Institute of Agricultural Modernization Academia Sinica department of Plant and soil Seinces University of Massachussetts Heilongjiang Institute of Agricultural Modernization Academia Sinica

soil organic matter(SOM)is the predominant component for sorption of hydrophobic organic compouds in soil and sorption by SOM ultimately affects chemical fate and availability in soil,and the degree of remedia- tion success of contaminated soils. This paper summarizes the latest development on sorption of organic com- pounds in soil (natural) organic matter,addresses four sorption mechanisms: surface adsorption,solid - phase Partitioning,dual-mode sorption,and fixed-pore sorption model,and presents future research directions as well.

关键词： Sorption soil organic matter Sorption mechanism Organic compounds

Remediation of Endosulfan by Biotic and Abiotic Methods

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Protection 2013年第5期4卷 418-425页

作者： Puthenveedu S. P. Harikumar Kottekottil Jesitha Mannodi Sreechithra Centre for water Resources Development and Management Kozhikode India department of Chemical Engineering Government Engineering College Kozhikode India

Endosulfan is a persistent, toxic broad-spectrum organochlorine insecticide and acaricide used on food and non-food crops. To overcome the problem of hydrophobicity of endosulfan, surfactants play a major role in soil remediation. A concentration of 1 g/L tween 80 released 83.89% ± 1.22% of endosulfan from the soil in 24 hours and a total of only 13.96% ± 0.14% was found remaining in the soil. Phytoremediation is an emerging technology that promises effective and inexpensive cleanup of contaminated hazardous waste sites. The potential of aquatic plant species Salvinia molesta and the terrestrial plant species, Spinach (Spinacia oleracea) and Tomato (Solanum lycopersicum), to remove persistent organochlorine pesticide endosulfan from contaminated water and soil respectively were investigated. Remediation of endosulfan in water using different aquatic plants showed that Salvinia molesta is more efficient in endosulfan removal as the percentage removal of endosulfan obtained was 97.94% ± 0.33% in 21 days (with an initial concentration of 123 μg/L endosulfan). Among the selected terrestrial plant species, Spinach and Tomato, percentage removal of endosulfan was found to be higher with tomato. On Day 21, complete removal of pesticide (with an initial concentration of 140 μg/Kg endosulfan) occurred in the soil in which phytoremediation was done with tomato while spinach took about 28 days for complete removal of endosulfan. Microbial degradation offers an effective approach to remove toxicants from the environment. Microbial degradation of endosulfan was studied and Pseudomonas species was able to completely degrade endosulfan in 16 days. The technologies developed can be utilized for the complete removal of endosulfan from a contaminated area. The surfactant enhanced recovery and phytoremediation will help to decontaminate the polluted water and soil. The recovered endosulfan in the surfactants and plants can be subjected to biodegradation by bacterial species using a bi

关键词： Endosulfan Surfactant Tween 80 Phytoremediation Pseudomonas

A comprehensive simulation approach for pollutant bio-transformation in the gravity sewer

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Environmental Science & Engineering 2019年第4期13卷 179-190页

作者： Nan Zhao Huu Hao Ngo Yuyou Li Xiaochang Wang Lei Yang Pengkang Jin Guangxi Sun School of Environmental and Municipal Engineering Xi'an University of Architecture and TechnologyXi'an 710055China Centre for Technology in water and Wastewater School of Civil and Environmental EngineeringUniversity of TechnologySydneyNSW 2007Australia department of Civil and Environmental Engineering Tohoku UniversitySendaiMiyagi 980-8579Japan Research Center for Eco-Environmental Sciences Chinese Academy of SciencesBeijing 100085China

Presently, several activated sludge models (ASMs) have been developed to describe a few biochemical processes. However, the commonly used ASM neither clearly describe the migratory transformation characteristics of fermentation nor depict the relationship between the carbon source and biochemical reactions. In addition, these models also do not describe both ammonification and the integrated metabolic processes in sewage transportation. In view of these limitations, we developed a new and comprehensive model that introduces anaerobic fermentation into the ASM and simulates the process of sulfate reduction, ammonification, hydrolysis, acidogenesis and methanogenesis in a gravity sewer. The model correctly predicts the transformation of organics including proteins, lipids, polysaccharides, etc. The simulation results show that the degradation of organics easily generates acetic acid in the sewer system and the high yield of acetic acid is closely linked to methanogenic metabolism. Moreover, propionic acid is the crucial substrate for sulfate reduction and ammonification tends to be affected by the concentration of amino acids. Our model provides a promising tool for simulating and predicting outcomes in response to variations in wastewater quality in sewers.

关键词： Gravity sewer Modeling Pollutant transformation Biochemical reaction process

Assessing Risk of Injection of Reclaimed water into the Biscayne Aquifer for Aquifer Recharge Purposes

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 Geoscience and Environment Protection 2019年第7期7卷 184-201页

作者： Frederick Bloetscher Daniel E. Meeroff Pollop Phonpornwithoon Florida Atlantic University Boca Raton USA Palm Beach County water department Boynton Beach FL USA

The recharge of non-potable water into a drinking water aquifer is one means to overcome decreasing groundwater supplies and maintain availability of these resources for current and future generations. However, health concerns exist regarding the use of waters of “impaired quality” such as reclaimed wastewater for aquifer recharge. The objective of this study is to evaluate the potential risk to drinking water from the use of reclaimed water for recharge purposes using computational modeling with MODFLOW and MT3D groundwater transport simulation based on an actual situation using rotavirus as a surrogate. The results from the simulation showed that after seven months, the risk of contamination based on concentration contours from the injection well to the production wells was stabilized below 10-6.

关键词： Potable Reuse Risk Rotavirus Groundwater Contamination

Cross-stacked super-aligned carbon nanotube/activated carbon composite electrodes for efficient water purification via capacitive deionization enhanced ultrafiltration

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Environmental Science & Engineering 2020年第6期14卷 181-190页

作者： Min Li Shuai Liang Yang Wu Meiyue Yang Xia Huang Beijing Key Laboratory for Source Control Technology of water Pollution College of Environmental Science and EngineeringBeijing Forestry UniversityBeijing 100083China department of Mechanical Engineering and Tsinghua Foxconn Nanotechnology Research Center Tsinghua UniversityBeijing 100084China State Key Joint Laboratory of Environment Simulation and Pollution Control School of EnvironmentTsinghua UniversityBeijing 100084China

The practical application of the capacitive deionization(CDI)enhanced ultrafiltration(CUF)technology is hampered due to low performance of *** current study demonstrated a novel super-aligned carbon nanotube(SACNT)/activated carbon(AC)composite electrode,which was prepared through coating AC on a cross-stacked SACNT *** desalination capability and water purification performance of the prepared electrode were systematically investigated at different applied voltages(0.8-1.2 V)with a CDI system and a CUF system,*** the CDI tests,as compared with 5ie control AC electrode,the SACNT/AC electrode achieved an approximately 100%increase in both maximum salt adsorption capacity and average salt adsorption rate under all the applied voltage conditions,demonstrating a superior desalination ***,a conspicuous increase by an average of-26%in charge efficiency was also achieved at all the *** the CUF tests,as compared with the control run at 0 V,the treatment runs at 0.8,1.0,and 1.2 V achieved a 2.40-fold,2.08-fold,and 2.43-fold reduction in membrane fouling(calculated according to the final transmembrane pressure(TMP)data at the end of every purification stage),*** average TMP increasing rates at 0.8,1.0,and 1.2 V were also roughly two times smaller than that at 0 V,indicating a dramatical reduction of membrane *** SACNT/AC electrode also maintained its superior desalination capability in the CUF process,resulting in an overall improved water purification efficiency.

关键词： Carbon nanotube Super aligned Conductive membrane Capacitive deionization Ultrafiltration Desalination

Comparison between Neuman(1975) and Jacob(1946) application for analysing pumping test data of unconfined aquifer

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 Groundwater Science and Engineering 2016年第3期4卷 165-173页

作者： Dana Mawlood Jwan Mustafa Civil Engineering department College of Engineering University of Salahaddin General Directorate of Dams and Reservoirs Ministry of Agricultural and Water Resources

Pumping test of a water table aquifer is carried out to estimate the aquifer parameters, the obtained data were analysed through the solution of both Neuman(1975) and Jacob(1946) methods through AQTESOLV and Spreadsheet programs, the results of each methods are compared to evaluate the applicability and accuracy of the solution theoretically and practically. In the paper an example is presented, which is conducted for a constant rate pumping test from Ohio, in Fairborn(near Dayton), and it supplied by S.E. Norris(U.S. Geological Survey, Columbus, Ohio). The main objective of this study is to introduce both program and the way of the applications, and compare the results and the hand on of both programs in the field.

关键词： Neuman(1975) Unconfined aquifer Pumping test AQTESOLV program Microsoft Excel(Spreadsheet) program