检索结果-南通市图书馆

Neural Regeneration Research 2025年第7期20卷 2011-2012页

作者： Sharon J.Brown Rafael J.Yáñez-Muñoz Heidi R.Fuller School of Pharmacy and Bioengineering Keele UniversityKeeleUK Wolfson center for Inherited Neuromuscular Disease TORCH BuildingRJAH Orthopaedic HospitalOswestryUK *** Center of Gene and Cell TherapyDepartment of Biological SciencesSchool of Life Sciences and the EnvironmentRoyal Holloway University of LondonEghamUK

Spinal muscular atrophy(SMA)is a genetic condition that results in selective lower motor neuron loss with concomitant muscle weakness and *** genetic cause of SMA was understood in 1995 when loss or impairment of the survival motor neuron 1(SMN1)gene was identified as the main contributing factor(Lefebvre et al.,1995).This,in combination with the discovery that humans have a“back-up”gene,SMN2,which can produce low levels(approximately 10%)of the full-length functional SMN protein,has led to the generation of SMA-specific gene *** was traditionally classified according to age of symptom onset and developmental milestones achieved,with life expectancy and severity varying between ***,SMN2 copy number is used as a proxy for the prediction of disease severity,with higher SMN2 copy number typically being associated with reduced severity of SMA,although this relationship is not absolute:some individuals with low SMN2 copy number have less severe SMA phenotypes and vice ***,the etiology of SMA is further complicated by other factors,such as non-typical nucleotide variants and SMN2-independent modifiers of disease severity.

关键词： atrophy traditionally absolute

Aeration optimization through operation at low dissolved oxygen concentrations:Evaluation of oxygen mass transfer dynamics in different activated sludge systems

在线全文

学校读者我要写书评

暂无评论

Journal of environmental Sciences 2017年第5期29卷 224-235页

作者： Haitao Fan Lu Qi Guoqiang Liu Yuankai Zhang Qiang Fan Hongchen Wang Research center for Low Carbon Technology of water environment Renmin University of China School of environment Jinan University

In wastewater treatment plants（WWTPs）using the activated sludge process,two methods are widely used to improve aeration efficiency — use of high-efficiency aeration devices and optimizing the aeration control strategy. Aeration efficiency is closely linked to sludge characteristics（such as concentrations of mixed liquor suspended solids（MLSS）and microbial communities）and operating conditions（such as air flow rate and operational dissolved oxygen（DO）concentrations）. Moreover,operational DO is closely linked to effluent quality. This study,which is in reference to WWTP discharge class A Chinese standard effluent criteria,determined the growth kinetics parameters of nitrifiers at different DO levels in small-scale tests. Results showed that the activated sludge system could meet effluent criteria when DO was as low as 0.3 mg/L,and that nitrifier communities cultivated under low DO conditions had higher oxygen affinity than those cultivated under high DO conditions,as indicated by the oxygen half-saturation constant and nitrification ability. Based on nitrifier growth kinetics and on the oxygen mass transfer dynamic model（determined using different air flow rate（Q′air）and mixed liquor volatile suspended solids（MLVSS）values）,theoretical analysis indicated limited potential for energy saving by improving aeration diffuser performance when the activated sludge system had low oxygen consumption; however,operating at low DO and low MLVSS could significantly reduce energy consumption. Finally,a control strategy coupling sludge retention time and MLVSS to minimize the DO level was discussed,which is critical to appropriate setting of the oxygen point and to the operation of low DO treatment technology.

关键词： Aeration optimization Low dissolved oxygen nitrification Mixed liquor suspended solids Oxygen mass transfer Oxygen uptake rate

Infiltration Experiments in Layered Structures of Upper Porous and Lower Fractured Media

在线全文

学校读者我要写书评

暂无评论

Journal of Earth Science 2013年第5期24卷 843-853页

作者：王慧芳王明玉 center for water System Security & water College of Resources and environment University of Chinese Academy of Sciences

Investigation of infiltration through unsaturated zone which consists of both porous and fractured media is important for comprehensively understanding water circulation and effectively man- aging groundwater resources and contamination control. Infiltration experiments for three kinds of porous-fractured layered structures were conducted with application of a rainfall simulator in this in- vestigation. During experiments, the volumetric water contents of porous media and on the interface of porous-fractured media were monitored by moisture sensors （TDT）. The infiltration rate, water amount in the profile and on the interface between the soil and the fractured bedrock, and outflow from the layered structures were analyzed to identify the effects of porous-fractured interface on water movement in the upper porous media and the effects of various kinds of porous media on infiltration in fractured rocks. It has been observed from the experiment results that the porous media and the frac- tured rock bear considerable reciprocal impact each other on infiltration processes and water content distribution. The results showed fractured rock prevented vertical water movement in the layered structure, and it decreases infiltration rate of layered structure and slows the process for upper porous media saturation.

关键词： layered structure of porous-fractured media infiltration experiment simulative rain-fall.

Characteristics of sewer biofilms in aerobic rural small diameter gravity sewers

在线全文

学校读者我要写书评

暂无评论

Journal of environmental Sciences 2020年第4期32卷 1-9页

作者： Wenkai Li Tianlong Zheng Yingqun Ma Junxin Liu State Key Joint Laboratory of environment Simulation and Pollution Control Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China University of Chinese Academy of Sciences Beijing 100049China Advanced environmental Biotechnology Centre Nanyang Environment&Water Research InstituteNanyang Technological UniversitySingapore637141Singapore

Small diameter gravity sewers(SDGS)are extensively used to collect rural sewage as they are low in cost and quick to ***,the characteristics of biofilms in rural SDGS are still not *** this study,biofilms characteristics of aerobic rural SDGS were investigated using simulations in a lab under different flow conditions and *** indic ated that the average thickness of aerobic rural SDGS biofilms was in the range of 350-650μm,decreasing at locations with variable flow and high *** was the most abundant substance in extracellular polymeric substance of SDGS *** most abundant bacteria,Proteobacteria,Actinobacteria,and Bacteroidetes,and functional bacteria showed different distributions when analyzed through Illumina HiSeq sequencing of 16 S *** relative abundances of denitrifying bacteria,nitrite-oxidizing bacteria,and sulfate-reducing bacteria(SRB)were lower during variable flow than during stable *** slopes(15‰)decreased SRB presence,which could be used to mitigate H2 S accumulation in aerobic ***,this study describes the characteristics of aerobic rural SDGS biofilms and provides valuable suggestions for the optimal design of SDGS based on these characteristics.

关键词： Bacterial community Biofilms Functional bacteria Rural area Small diameter gravity sewers

Scale-up effect analysis and modeling of liquid-solid circulating fluidized bed risers using multigene genetic programming

在线全文

学校读者我要写书评

暂无评论

Particuology 2020年第5期18卷 57-66页

作者： Shaikh A.Razzak Saddam A.AI-Hammadi Syed M.Rahman Mohammad R.Quddus Mohammad M.Hossain Jesse Zhu Department of Chemical Engineering King Fahd University of Petroleum&MineralsDhahran 31261Saudi Arabia center for environment&water RIKing Fahd University of Petroleum&MineralsDhahran 31261Saudi Arabia Department of Chemical and Biochemical Engineering University of Western OntarioCanada

Understanding scale-up effects on the hydrodynamics of a liquid-solid circulating fluidized bed(LSCFB)unit requires both experimental and theoretical *** implement multigene genetic programming(MGGP)to investigate the solid holdup and distribution in three LSCFB systems with different *** addition to data obtained here,we also use a portion of data sets of LSCFB systems developed by Zheng(1999)and Liang et al.(1996).Model predictions are in good agreement with the experimental data in both radial and axial directions and at different normalized superficial liquid and solid *** radial profiles of the solid holdup are approximately identical at a fixed average cross-sectional solid holdup for the three LSCFB systems *** performance indicators including the mean absolute percentage error(6.19%)and correlation coefficient(0.985)are within an acceptable *** results suggest that a MGGP modeling approach is suitable for predicting the solid holdup and distribution of a scaled-up LSCFB system.

关键词： Fluidization Liquid-solid circulating fluidized bed Multigene genetic programming Scale-up effect Normalized superficial liquid velocity Solid holdup

Recent improvements in oily wastewater treatment:Progress, challenges, and future opportunities

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11期27卷 15-30页

作者： Sanaa Jamaly Adewale Giwa Shadi Wajih Hasan Institute center for water and environment Department of Chemical and Environmental Engineering Masdar Institute of Science and Technology

Oily wastewater poses significant threats to the soil, water, air and human beings because of the hazardous nature of its oil contents. The objective of this review paper is to highlight the current and recently developed methods for oily wastewater treatment through which contaminants such as oil, fats, grease, and inorganics can be removed for safe *** include electrochemical treatment, membrane filtration, biological treatment,hybrid technologies, use of biosurfactants, treatment via vacuum ultraviolet radiation,and destabilization of emulsions through the use of zeolites and other natural *** review encompasses innovative and novel approaches to oily wastewater treatment and provides scientific background for future work that will be aimed at reducing the adverse impact of the discharge of oily wastewater into the environment. The current challenges affecting the optimal performance of oily wastewater treatment methods and opportunities for future research development in this field are also discussed.

关键词： Oily wastewater Electrochemical Biological Membrane Treatment

Occurrence, polarity and bioavailability of dissolved organic matter in the Huangpu River,China

在线全文

学校读者我要写书评

暂无评论

Journal of environmental Sciences 2014年第9期26卷 1843-1850页

作者： Qianqian Dong Penghui Li Qinghui Huang Ahmed A.Abdelhafez Ling Chen Key laboratory of Yangtze River water environment of the Ministry of Education College of Environmental Science and EngineeringTongji University Soils Water and Environment Research InstituteAgricultural Research CenterGizaEgypt

Dissolved organic matter （DOM） plays an important role in biogeochemical cycles in aquatic ecosystem. To investigate the characteristics of DOM in Huangpu River {the last tributary of the Yangtze River）, surface water samples were collected along the river from December 2011 to June, 2013. The concentrations of dissolved organic carbon （DOC）, the absorbance and fluorescence spectrum of DOM in water samples were measured. Fluorescent DOM in the Huangpu River was decomposed into four components by the parallel factor analysis （PARAFAC）, including one humic-like substance and three protein-like substances. It showed that high spatial variability of DOC concentration was observed in the upstream water compared to the downstream water, and so did the absorbance coefficients of chromophoric dissolved organic matter and the total fluorescence intensities of different PARAFAC components of DOM. Furthermore, there was a large difference between the polarity and bioavailability of DOM in the Huangpu River. Polar compounds dominated tyrosine-like component of fluorescent DOM in all seasons. Tryptophan-like and humic-like substances had more polar fraction in summer and autumn than those in winter, while aromatic protein-like materials had the highest polar fraction in winter. Almost all of fluorescent DOM components were refractory in spring, while less than 20% of fluorescent DOM in average were biodegradable within 4 weeks in other seasons. We concluded that the spatial variation in the abundance of DOM in the Huangpu River is mainly affected by the water discharges from the Hangjiahu Plain and the seasonal difference in polarity and bioavailability of DOM is largely determined by its origins.

关键词： Chromophoric dissolved organicmatterDissolved organic carbonPolarityBioavailabilityAbsorbance coefficientsFluorescence

Effect of temperature on anoxic metabolism of nitrites to nitrous oxide by polyphosphate accumulating organisms

在线全文

学校读者我要写书评

暂无评论

Journal of environmental Sciences 2014年第2期26卷 264-273页

作者： Zhijia Miao Wei Zeng Shuying Wang Yongzhen Peng Guihua Cao Dongchen Weng Guisong Xue Qing Yang Key Laboratory of Beijing for water Quality Science and water environment Recovery Engineering Engineering Research Center of Beijing Beijing University of Technology

Temperature is an important physical factor, which strongly influences biomass and metabolic activity. In this study, the effects of temperature on the anoxic metabolism of nitrite （NO2） to nitrous oxide （N2O） by polyphosphate accumulating organisms, and the process of the accumulation of N2O （during nitrite reduction）, which acts as an electron acceptor, were investigated using 91% ：e 4% Candidatus Accumulibacterphosphatis sludge. The results showed that N2O is accumulated when Accumulibacter first utilize nitrite instead of oxygen as the sole electron acceptor during the denitrifying phosphorus removal process. Properties such as nitrite reduction rate, phosphorus uptake rate, N2O reduction rate, and polyhydroxyalkanoate degradation rate were all influenced by temperature variation （over the range from 10 to 30℃ reaching maximum values at 25℃）. The reduction rate of N2O by N2O reductase was more sensitive to temperature when N2O was utilized as the sole electron acceptor instead of NO2, and the N2O reduction rates, ranging from 0.48 to 3.53 N2O-N/（hr.g VSS）, increased to 1.45 to 8.60 mg N2O-N/（hr·g VSS）. The kinetics processes for temperature variation of 10 to 30℃ were （01 = 1.140-1.216 and θ2 = 1.139-1.167）. In the range of 10℃ to 30℃, almost all of the anoxic stoichiometry was sensitive to temperature changes. In addition, a rise in N2O reduction activity leading to a decrease in N2O accumulation in long term operations at the optimal temperature （27℃ calculated by the Arrhenius model）.

关键词： polyphosphate accumulating organisms temperature nitrite denitrifying phosphorus removal N2O kinetics stoichiometry

A novel ceria hollow nanosphere catalyst for low temperature NOx storage

在线全文

学校读者我要写书评

暂无评论

Journal of Rare Earths 2022年第4期40卷 626-635,I0004页

作者： Wenxu Liu Huiming Cao Zhongpeng Wang Chenchen Cui Liangran Gan Wei Liu Liguo Wang School of water Conservancy and environment University of JinanJinan 250022China Shandong Provincial Eco-environment Monitoring center Jinan 250101China

In this work,a highly active CeO_(2) catalyst with hollow nanosphere morphology for low temperature NO_(x) storage was prepared by a surfactant-assisted solvothermal *** physicochemical properties of ceria samples were characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM),transmission electron microscopy(TEM),N_(2) adsorption–desorption,H_(2)-temperature programmed reduction(H_(2)-TPR),X-ray photoelectron spectroscopy(XPS)and in situ diffused reflectance infrared Fourier transform spectroscopy(DRIFTS).The as-prepared CeO_(2) nanosphere possesses excellent NO oxidation capacity,smaller mesopores,better reducibility and more surface Ce^(3+)*** with CeO_(2) with nanorod and nanoparticle morphologies,CeO_(2) nanosphere shows better intrinsic low temperature NO_(x) trapping performance,with a wide operating temperature window(150–300℃),high NO_(x) adsorption capacity(NAC,640–745μmol/g)and high NO_(x) storage capacity(NSC,250–350μmol/g).Two reaction pathways are speculated for NO_(x) adsorption on CeO_(2) nanosphere,including“nitrate route”and“nitrite route”.The thermally unstable surface nitrites formed on the CeO_(2) nanosphere allow ceria to release more NO_(x) during the desorption *** present work provides a new ceria morphology for NO_(x) traps,which may become a potential excellent NO_(x) storage material.

关键词： Ceria Nanosphere NO_(x)storage Low temperature DRIFTS Rare earths

Diel and seasonal variation of methane and carbon dioxide fluxes at Site Guojiaba, the Three Gorges Reservoir

在线全文

学校读者我要写书评

暂无评论

Journal of environmental Sciences 2013年第10期25卷 2065-2071页

作者： Shangbin Xiao Yuchun Wang Defu Liu Zhengjian Yang Dan Lei Cheng Zhang Engineering Research center of Eco-environment in Three Gorges Reservoir Region Ministry of EducationChina Three Gorges University Institute of Earth environment Chinese Academy of Sciences Department of water environment China Institute of Water Resources and Hydropower Research College of Resources and environment Sciences Hubei University of Technology

In order to investigate the CH4 and CO2 fluxes across the water-gas interface and identify their controlling factors, four diel field campaigns and one monthly sampling campaign during June 2010-May 2011 were carried out at a site near the Three Gorges Dam, China. The averaged CH4 and CO2 fluxes across the air-water interface from the site were much less than those reported from reservoirs in tropic and temperate regions, and from the natural river channels of the Yangtze River. CH4 Fluxes at the site were very low compared to most other reservoirs or natural lakes. One of the most important reasons may be due to the oxidation of CH4 in the water column owing to the great water depth and high DO in water in the Three Gorges Reservoir. The averaged monthly CH4 and CO2 fluxes at the site during the observation year were 0.05 mg/（m^2·hr） and 104.43 mg/（m^2·hr） respectively with the maximum occurred in July 2010. The monthly CO2 fluxes during the observation year were positively correlated to the surface water temperature, and negatively correlated to the air pressure and the surface water pH. The CO2 flux showed a positive correlation with DOC to some extent, although not significantly, which indicated that allochthonous organic C was a major source of CO2 and biogeochemical processes in this reservoir were C-limited. The significantly positive correlation between the reservoir outflow and the seasonal gas flux indicate the disturbance condition of the water body dominated the seasonal gas emission.

关键词： diel flux seasonal flux methane and carbon dioxide emission the Three Gorges Reservoir methane oxidation environmental factors reservoir outflow