检索结果-南通市图书馆

Long-range transport of organic aerosol to Cape Hedo,Japan

在线全文

学校读者我要写书评

暂无评论

Particuology 2014年第2期12卷 35-41页

作者： Xiaoxiu Lun Akinori Takami weifang ma Akio Shimono Shiro Hatakeyama Beijing Forestry University National Institute for Environmental Studies Onogawa 16-2Tsukuba 305-8506Japan Sanyu Plant Service Co. Ltd.Hashimotodai 1-8-21Kanagawa 229-1132Japan Tokyo University of Agriculture and Technology 3-8-IHarumi-choFuchu-shiTokyo 183-8538Japan

An investigation at Cape Hedo, Japan, from 2005 to 2006, focused on the long-range transport of organic aerosol （OA） from the Asian continent. An Aerodyne aerosol mass spectrometer was used to investigate the OA data collected over the study. OA concentrations were low from July to September and peaked during march and April. Based on air mass origins, four OA source regions were identified： northern China, southern China, Japan, and Korea. OA concentrations measured at Cape Hedo from the four sources did not exhibit large differences. Conversely, the frequencies of the air masses reaching Cape Hedo from the different regions varied considerably. Northern China was identified as the primary source of organic aerosols at Cape Hedo. Examination of variations in the ratio of m/z 44 to OA concentrations with transport time showed that OAs were partially oxidized during transport

关键词： Long-range transportOrganic aerosolSource contributionOkinawa

Arsenic(V)removal from groundwater by GE-HL nanofiltration membrane:effects of arsenic concentration,pH,and co-existing ions

在线全文

学校读者我要写书评

暂无评论

Frontiers of Environmental Science & Engineering 2009年第4期3卷 428-433页

作者： Xiaowei WANG Wenjun LIU Desheng LI weifang ma School of Environmental and Municipal Engineering Lanzhou Jiaotong UniversityLanzhou 730070China Department of Environmental Science and Engineering Tsinghua UniversityBeijing 100084China School of Civil Engineering and Architecture Beijing Jiaotong UniversityBeijing 100044China

A laboratory-scale investigation was performed to study arsenic(As(V))removal by negatively charged GE-HL nanofiltration(NF)membrane in simulated drinking *** of As(V)concentration(0–200μg·L–1),pH,and co-ions and counter-ions were *** NF membrane presented good stability,and the rejection rates exceeded 90%.The rejection rates of As(V)decreased with the increase of As(V)concentration,while it increased with the increase of pH(reached 96%at pH 6.75).Moreover,a negative relationship was observed between the co-existing ions of Cl^(–),Na^(+),SO_(4)^(2–),and Ca^(2+)and the removal of As(V),in which bivalent ions presented more significant effects than monovalent ions.

关键词： nanofiltration(NF) rejection rate co-existing ion co-ion counter-ion

Adsorption and biodegradation of three selected endocrine disrupting chemicals in river-based artificial groundwater recharge with reclaimed municipal wastewater

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5期27卷 154-163页

作者： weifang ma Chao Nie Bin Chen Xiang Cheng Xiaoxiu Lun Fangang Zeng College of Environmental Science and Engineering Beijing Forestry University School of Environment and Natural Resource Renmin University of China

Endocrine disrupting chemical（EDC） pollution in river-based artificial groundwater recharge using reclaimed municipal wastewater poses a potential threat to groundwater-based drinking water supplies in Beijing, China. Lab-scale leaching column experiments simulating recharge were conducted to study the adsorption, biodegradation, and transport characteristics of three selected EDCs： 17β-estradiol（E2）, 17α-ethinylestradiol（EE2） and bisphenol A（BPA）. The three recharge columns were operated under the conditions of continual sterilization recharge（CSR）, continual recharge（CR）, and wetting and drying alternative recharge（WDAR）. The results showed that the attenuation effect of the EDCs was in the order of WDAR 〉 CR 〉 CSR system and E2 〉 EE2 〉 BPA, which followed first-order kinetics. The EDC attenuation rate constants were 0.0783, 0.0505, and 0.0479 m-1 for E2, EE2 and BPA in the CR system, respectively. The removal rates of E2, EE2, and BPA in the CR system were 98%, 96% and 92%, which mainly depended on biodegradation and were affected by water *** the CR system, the concentrations of BPA, EE2, and E2 in soil were 4, 6 and 10 times higher than in the WDAR system, respectively. According to the DGGE fingerprints, the bacterial community in the bottom layer was more diverse than in the upper layer, which was related to the EDC concentrations in the water-soil system. The dominant group was found to be proteobacteria, including Betaproteobacteria and Alphaproteobacteria, suggesting that these microbes might play an important role in EDC degradation.

关键词： Endocrine disrupting chemicals Adsorption Biodegradation Artificial groundwater recharge Bacterial community

17α-Ethynylestradiol biodegradation in different river-based groundwater recharge modes with reclaimed water and degradation-associated community structure of bacteria and archaea

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2018年第2期30卷 51-61页

作者： weifang ma Jiaji Sun Yangyao Li Xiaoxiu Lun Dan Shan Chao Nie Miaomiao Liu College of Environmental Science and Engineering Beijing Forestry University Beijing 100083 China Friendship Center for Environmental Protection Beijing 100029 China Department of Civil and Environmental Engineering university of Illinois at Urbana-Champaign Urbana IL 61801-2352 USA

This study investigated 17α-ethynylestradiol（EE2） biodegradation process and primary metabolic pathways associated with community structures of microorganism during groundwater recharge using reclaimed water. The attenuation rate is 1.58 times higher in wetting and drying alternative recharge（WDAR） than in continual recharge（CR）. The primary biotransformation pathways of EE2 in WDAR system began with the oxidation of C-17 on ring D to form a ketone group, and D-ring was subsequently hydroxylated and cleaved. In the CR system, the metabolic pathway changed from the oxidation of C-17 on ring D to hydroxylation of C-4 on ring A, and ring A or B subsequently cleaved; this transition was related to DO, and the microbial community structure. Four hundred fifty four pyrosequencing of 16 s r RNA genes indicated that the bacterial communities in the upper layer of the WDAR system were more diverse than those found in the bottom layer of the CR system; this result was reversed for archaea. Unweighted Uni Frac and taxonomic analyses were conducted to relate the change in bacterial community structure to the metabolic pathway. Microorganism community diversity and structure were related to the concentrations of dissolved oxygen, EE2 and its intermediates in the system. Five known bacterial classes and one known archaeal class, five major bacterial genera and one major archaeal genus might be involved in EE2 degradation. The findings of this study provide an understanding of EE2 biodegradation in groundwater recharge areas under different recharging modes and can facilitate the prediction of the fate of EE2 in underground aquifers.

关键词： EE2 Biodegradation Groundwater recharge Microbial community and diversity Metabolic intermediates

Deposition of water-soluble inorganic ions in PM_(2.5) in a typical forestry system in Beijing,China

在线全文

学校读者我要写书评

暂无评论

Forest Ecosystems 2018年第4期5卷 486-497页

作者： Junqi Ding Xiaoxiu Lun weifang ma Lu Zhao Yingying Cao Fengbin Sun Renna Li College of Environmental Science and Engineering Beijing Forestry University State Key Laboratory of Environmental Criteria and Risk Assessment Chinese Academy of Environmental Sciences School of Soil and Water Conservation Beijing Forestry University

Background: Rapid economic development in China has resulted in an increase in severe air pollution in city groups such as the Beijing-Tianjin-Hebei Metropolitan Region. PM2.5(fine particles with an aerodynamic equivalent diameter of 2.5 μm or less) is one of the most important pollutants. The deposition process is an important way of removing particles from the air. To evaluate the effect of an urban forest on atmospheric particle removal, a concentration gradient method was used to measure the deposition velocities of water-soluble inorganics in PM2.5 in two national forest parks in Beijing, China. The following eight water-soluble inorganic ions in PM2.5 were investigated: sodium, ammonium, potassium, magnesium, calcium, chloride, nitrate, and ***: Samples were taken from two sites in Beijing from the 7 th to the 15 th may, 2013. The concentrations of water-soluble inorganic ions were analyzed with ion chromatography. We used the concentration gradient technique to estimate the deposition flux and velocity. To determine the relationships between leaf traits and particle accumulation, typical leaf samples from each selected species were studied using scanning electron ***: The total deposition flux and total deposition velocity during the daytime were higher than those at *** showed the biggest deposition flux and velocity at both study sites, whereas the other ions showed different trends at each site. Result from higher proportion of coniferous to broadleaved trees, the total deposition flux of the eight ions measured in Jiufeng National Forest Park was greater than that in Olympic Forest ***: The deposition velocity was affected by meteorological conditions such as wind speed, temperature,and humidity. The deposition velocity was also influenced by tree species. The surface of plants is an important factor influencing particle deposition. The results of this study may help in assessing the effects of forestry sy

关键词： Fine particle Water-soluble inorganics Forest Dry deposition Deposition velocity

Cutaneous sensory nerve as a substitute for auditory nerve in solving deaf-mutes' hearing problem: an innovation in multi-channel-array skin-hearing technology

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2014年第16期9卷 1532-1540页

作者： Jianwen Li Yan Li Ming Zhang weifang ma Xuezong ma College of Electric & Information Engineering Shaanxi University of Science & Technology Skin-Hearing Research Institute Shaanxi University of Science & Technology Library of Shaanxi University of Science & Technology College of Computer Science Xi’an Polytechnic University

The current use of hearing aids and artificial cochleas for deaf-mute individuals depends on their auditory nerve. Skin-hearing technology, a patented system developed by our group, uses a cutaneous sensory nerve to substitute for the auditory nerve to help deaf-mutes to hear sound. This paper introduces a new solution, multi-channel-array skin-hearing technology, to solve the problem of speech discrimination. Based on the filtering principle of hair cells, external voice sig- nals at different frequencies are converted to current signals at corresponding frequencies using electronic multi-channel bandpass filtering technology. Different positions on the skin can be stimulated by the electrode array, allowing the perception and discrimination of external speech signals to be determined by the skin response to the current signals. Through voice frequen- cy analysis, the frequency range of the band-pass filter can also be determined. These findings demonstrate that the sensory nerves in the skin can help to transfer the voice signal and to dis- tinguish the speech signal, suggesting that the skin sensory nerves are good candidates for the replacement of the auditory nerve in addressing deaf-mutes＇ hearing problems. Scientific hearing experiments can be more safely performed on the skin. Compared with the artificial cochlea, multi-channel-array skin-hearing aids have lower operation risk in use, are cheaper and are more easily popularized.

关键词： nerve regeneration peripheral nerve skin-hearing multi-channel electrode array aid deaf band-pass filter voice NSFC grant neural regeneration

吸收-微藻法固定燃气电厂低浓度CO_(2)同步产油技术研究进展

在线全文

学校读者我要写书评

暂无评论

化工进展 2023年第1期42卷 94-106页

作者：秦振芳廖日红马伟芳北京林业大学环境科学与工程学院北京100083 北京市南水北调环线管理处北京100176

燃气电厂利用稳定、清洁的化石能源发电,在“双碳”背景下发电过程产生的低浓度CO_(2)的捕集和资源化利用,对于实现碳中和至关重要。针对低浓度CO_(2)捕集难度大、脱附费用高的问题,利用CO_(2)吸收液同步培养微藻产油提供了一种实现低浓... 详细信息

燃气电厂利用稳定、清洁的化石能源发电,在“双碳”背景下发电过程产生的低浓度CO_(2)的捕集和资源化利用,对于实现碳中和至关重要。针对低浓度CO_(2)捕集难度大、脱附费用高的问题,利用CO_(2)吸收液同步培养微藻产油提供了一种实现低浓度CO_(2)捕集与资源化利用于一体的新途径。具有高CO_(2)捕集能力和同时快速培养微藻能力的吸收液是溶液设计和配制的决定性因素。本文总结了现有吸收液的应用现状,梳理出复合吸收液耦合微藻营养调控的碳捕集发展前景,其中吸收液的碱度和盐度对微藻同化CO_(2)具有显著影响。讨论了在不同温度和光照的工艺条件对微藻生物转化CO_(2)的影响,阐述了CO_(2)气体以微孔鼓泡和气升导流的方式通入反应器对CO_(2)捕集和微藻生长的不同效果。从促进微藻吸收CO_(2)同步产油的角度,介绍了藻种诱变驯化和基因改造以提升环境适应性同时增强脂质生产的研究进展,最后通过经济分析展望了规模化应用吸收-微藻法的经济可行性。与传统的CO_(2)吸收和微藻固定方法相比,吸收-微藻法一体化复合工艺可以成为从燃气电厂中捕获CO_(2)具有竞争力的替代方案。

关键词：吸收-微藻法低浓度CO_(2) 吸收液生物柴油诱变基因改造

再生水受纳河流自然入渗过程中B(a)P对浅层地下水的影响预测

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

环境工程技术学报 2023年第3期13卷 1061-1069页

作者：任杰马伟芳北京林业大学环境科学与工程学院

在调查和监测再生水受纳河流凉水河中苯并芘[B(a)P]浓度的基础上,利用Hydrus-1D耦合GMS模型研究B(a)P的时空分布和迁移演变,预测再生水受纳河流对地下水水质的影响。结果表明:B(a)P在包气带的垂直入渗率为0.102 m^(-1),仅为水运移的0.73... 详细信息

在调查和监测再生水受纳河流凉水河中苯并芘[B(a)P]浓度的基础上,利用Hydrus-1D耦合GMS模型研究B(a)P的时空分布和迁移演变,预测再生水受纳河流对地下水水质的影响。结果表明:B(a)P在包气带的垂直入渗率为0.102 m^(-1),仅为水运移的0.73%。由于吸附和生物降解作用,B(a)P穿透16 m深的包气带时间约为63年,其中吸附和生物降解的贡献率分别为78.4%和19.3%。当B(a)P与地下水相交,受地下水流的推动,B(a)P的迁移以地下水流方向迁移为主。B(a)P在地下水中沿地下水流方向的迁移速率为6.65 m/a,分别为垂直地下水流方向和垂向迁移速率的2.42倍和16.22倍。时空分布表明,地下水中B(a)P浓度随与河流距离的增加而降低,其在平行地下水流方向、垂直地下水流方向和垂向的衰减率常数分别为1.19×10^(-4)、3.05×10^(-4)和3.67×10^(-3)m^(-1),与迁移率呈负相关。然而,地下水中B(a)P浓度随入渗时间的延长而增加,积累率为7.3×10-2d^(-1)。B(a)P的迁移和积累对以地下水为饮用水的沿岸居民造成潜在的危害,导致地下水安全利用范围在20年内将从平行地下水流方向、垂直地下水流方向和垂向的438、276和19.8 m分别缩减至568、324和27.7 m。

关键词：苯并芘[B(a)P] 河流入渗数值模拟溶质运移

同方期刊数据库

可见光催化降解水中卤代有机污染物的研究进展

在线全文

学校读者我要写书评

暂无评论

化工进展 2022年第S01期41卷 571-579页

作者：刘怡璇林跃朝马伟芳北京林业大学环境科学与工程学院北京100083 北京市水科学技术研究院北京100048

卤代有机污染物(HOCs)在水环境中检出频率高达45%,由于其具有毒性大、持久性强和易累积等特点,该类污染物引发的环境问题已引起越来越多的关注。可见光催化技术具有高效太阳能利用率、强选择性及反应条件温和、处理费用低等优点,对于降... 详细信息

卤代有机污染物(HOCs)在水环境中检出频率高达45%,由于其具有毒性大、持久性强和易累积等特点,该类污染物引发的环境问题已引起越来越多的关注。可见光催化技术具有高效太阳能利用率、强选择性及反应条件温和、处理费用低等优点,对于降解水中HOCs具有独特的处理优势,因此近年来被广泛研究。本文梳理了可见光催化降解水中HOCs的核心脱卤机制,包括氧化脱卤、还原脱卤和水解脱卤,在脱卤机制的基础上汇总了三大类主流催化剂的脱卤贡献率,主要包括金属基光催化剂、碳基光催化剂及其他新型光催化剂三类光催化材料。基于可见光作用下降解水中HOCs的应用案例分析,探讨了光催化反应过程中的主要影响因素是溶液pH、催化剂用量及反应温度等。可见光催化降解去除效率高是本技术的核心优势,但由于催化剂的成本高和选择性差导致了其无法大规模应用,未来可见光催化材料设计应向成本低廉、精准匹配污染物从而实现高选择性的方向改进。

关键词：光化学催化剂降解卤代有机污染物光催化效率材料改性