检索结果-南通市图书馆

A review on analytical methods for pharmaceutical and personal care products and their transformation products

Journal of Environmental Sciences 2021年第3期33卷 260-281页

作者： Yuan Meng weiyi liu Xiaohui liu Jinlan Zhang Meng Peng Tingting Zhang Department of Environmental Science and Engineering Beijing Environmental Pollution Control and Resource Engineering Research CenterBeijing University of Chemical TechnologyBeijing 100029China National Engineering Laboratory for Lake Pollution Control and Ecological Restoration State Key Laboratory of Environmental Criteria and Risk AssessmentChinese Research Academy of Environmental SciencesBeijing 100012China School of Environment Tsinghua UniversityBeijing 100084China

Pharmaceutical and personal care products(PPCPs)and corresponding transformation products have caused widespread concern due to their persistent emissions and potential toxicity.They have wide octanol-water partition coefficients(K_(ow))and different ionization constants(pK_(a))resulting in a poor analysis accuracy and efficiency.A suitable analytical method is the first prerequisite for further research on their environmental behavior to prioritize the substances.This study reviewed a full-scale analytical protocol for environmental samples in the recent ten years:from sampling to instrumental methods.Passive sampling techniques were compared and recommended for long-term continuous and scientific observation.A quick and effective sample extraction and clean-up method are highly required.Chromatographic methods coupled to mass spectrometry for determining PPCPs with a wide range of logK_(ow)(-7.53 to 10.80)were summed up.High-resolution mass spectrometry was confirmed to be a promising strategy for screening unknown transformation products,which would provide a nanogram level of detection limits and more accurate mass resolution.Screening strategies and mass change principles were summarized in detail.The recovery rate was important in multiple contaminants analysis identification and factors affecting the recovery rate of PPCPs were also discussed in this review,including sample matrix,target compounds characteristics,extraction method and solid-phase adsorbent.This review provides useful information for the selection of appropriate analytical methods and future development directions.

关键词： Pharmaceutical and personal care products Transformation products Passive sampling Extraction High-resolution mass spectrometry

来源：

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

Adsorption behavior of imidacloprid pesticide on polar microplastics under environmental conditions:critical role of photo-aging

引用

Frontiers of Environmental Science & Engineering 2023年第4期17卷 13-26页

作者： weiyi liu Ting Pan Hang liu Mengyun Jiang Tingting Zhang Department of Environmental Science and Engineering Research Centre for Resource and EnvironmentBeijing University of Chemical TechnologyBeijing 100029China

The photo-aging behavior of microplastics(MPs)in natural environment has become a global concern.The ultraviolet radiation has enough energy to change the polymer structure and physicalchemical properties of MPs.Less attention has focused on the interactions of the photo-aged polar and biodegradable MPs with organic pollutants.This work investigated the structural properties of aged polar polyamide(PA)MPs and biodegradable polylactic acid(PLA)MPs exposed to ultraviolet irradiation and their adsorption behavior and mechanism for neonicotinoid insecticide imidacloprid(IMI).The results showed that the MPs had extensive changes in surface morphology and chemical properties after photo-aging.The C–N bond of PA MPs was disrupted to form more carbonyl groups.The oxygen-containing functional groups on the surface of aged PLA MPs were broken and generated relatively smaller molecules.The adsorption capacity of IMI on PA MPs decreased by 19.2%,while the adsorption capacity of IMI on PLA MPs increased by 41.2%after photo-aging.This depended on the natural structure of the MPs and their ability to absorb ultraviolet light.The electrostatic interactions,hydrogen bonds,van der Waals interactions,and polar-polar interactions were the main adsorption mechanisms of IMI on MPs.High initial solution pH and low ionic strength favored the adsorption of IMI by altering charge distribution on the MPs surface.The formation of the humic acid-IMI complexes decreased the concentration of IMI in the water phase and further decreased the adsorption on MPs.These results are enlightening for a scientific comprehension of the environmental behavior of the polar MPs.

关键词： Microplastics Neonicotinoid insecticide Photo-aging adsorption Environmental conditions

来源：

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

Associative categorization of frequent patterns based on the probabilistic graphical model

引用

Frontiers of Computer Science 2014年第2期8卷 265-278页

作者： weiyi liu Kun YUE Hui liu Ping ZHANG Suiye liu Qianyi WANG Department of Computer Science and Engineering School of Information Science and Engineering Yunnan University Kunming 650091 China Department of Economics State University of New York at Binghamton Binghamton NY13902-6001 USA Faculty of Economics and Administration University of Malaya Kuala Lumper 50603 Malaysia

Discovering the hierarchical structures of differ- ent classes of object behaviors can satisfy the requirements of various degrees of abstraction in association analysis, be- havior modeling, data preprocessing, pattern recognition and decision making, etc. In this paper, we call this process as associative categorization, which is different from classical clustering, associative classification and associative cluster- ing. Focusing on representing the associations of behaviors and the corresponding uncertainties, we propose the method for constructing a Markov network （MN） from the results of frequent pattern mining, called item-associative Markov net- work （IAMN）, where nodes and edges represent the frequent patterns and their associations respectively. We further dis- cuss the properties of a probabilistic graphical model to guar- antee the IAMN＇s correctness theoretically. Then, we adopt the concept of chordal to reflect the closeness of nodes in the IAMN. Adopting the algorithm for constructing join trees from an MN, we give the algorithm for IAMN-based associa- tive categorization by hierarchical bottom-up aggregations of nodes. Experimental results show the effectiveness, efficiency and correctness of our methods.

关键词： frequent pattem behavior association associa-tive categorization Markov network hierarchical aggrega-tion

来源：

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

Fate and risk assessment of emerging contaminants in reclaimed water production processes

引用

Frontiers of Environmental Science & Engineering 2021年第5期15卷 295-310页

作者： Yuan Meng weiyi liu Heidelore Fiedler Jinlan Zhang Xinrui Wei Xiaohui liu Meng Peng Tingting Zhang Department of Environmental Science and Engineering Research Centre for Resource and EnvironmentBeijing University of Chemical TechnologyBeijing100029China MTM Research Centre School of Science and TechnologyOrebro UniversityOrebroSE-70182Sweden State Key Laboratory of Environmental Criteria and Risk Assessment National Engineering Laboratory for Lake Pollution Control and Ecological RestorationResearch Centre of Lake EnvironmentChinese Research Academy of Environmental SciencesBeijing100012China School of Environment Tsinghua UniversityBeijing100084China

Reclaimed water has been widely applied in irrigation and industrial production.Revealing the behavior of emerging contaminants in the production process of reclaimed water is the first prerequisite for developing relevant water quality standards.This study investigated 43 emerging contaminants,including 22 pharmaceuticals and personal care products(PPCPs),11 organophosphorus flame retardants(OPFRs),and 10 antibiotic resistance genes(ARGs)in 3 reclaimed wastewater treatment plants(RWTPs)in Beijing.The composition profiles and removal efficiencies of these contaminants in RWTPs were determined.The results indicated that the distribution characteristics of the different types of contaminants in the three RWTPs were similar.Caffeine,sul2 and tris(1-chloro-2-propyl)phosphate were the dominant substances in the wastewater,and their highest concentrations were 27104 ng/L,1.4×10^(7) copies/mL and 262 ng/L,respectively.Ofloxacin and sul2 were observed to be the dominant substances in the sludge,and their highest concentrations were 5419 ng/g and 3.7×10^(8) copies/g,respectively.Anaerobic/anoxic/oxic system combined with the membrane bioreactor process achieved a relatively high aqueous removal of PPCPs(87%).ARGs and OPFRs were challenging to remove,with average removal rates of 6.5%and 31%,respectively.Quantitative meta-analysis indicated that tertiary treatment processes performed better in emerging contaminant removal than secondary processes.Diethyltoluamide exhibited the highest mass load discharge,with 33.5 mg/d per 1000 inhabitants.Octocrylene and tris(2-ethylhexyl)phosphate posed high risks(risk quotient>1.0)to aquatic organisms.This study provides essential evidence to screen high priority pollutants and develop corresponding standard in RWTPs.

关键词： Trace organic pollution Antibiotic resistance genes Reclaimed wastewater Sludge Risk assessment Mass load

来源：

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

基于Mori-Tanaka方法的功能梯度厚壁圆筒近似热弹性理论解

引用

太原理工大学学报 2024年第4期55卷 591-602页

作者：刘伟艺李志强辛立彪太原理工大学机械与运载工程学院太原030024 太原理工大学航空航天学院山西晋中030600

【目的】功能梯度厚壁圆筒的热弹性问题存在不考虑组分材料微观结构影响,已有文献只给出了基于Mori-Tanaka方法功能梯度厚壁圆筒受力学和热学荷载的数值解,并且只考虑了球形夹杂这一单一夹杂形状的情形。【方法】基于Mori-Tanaka方法对... 详细信息

【目的】功能梯度厚壁圆筒的热弹性问题存在不考虑组分材料微观结构影响,已有文献只给出了基于Mori-Tanaka方法功能梯度厚壁圆筒受力学和热学荷载的数值解,并且只考虑了球形夹杂这一单一夹杂形状的情形。【方法】基于Mori-Tanaka方法对功能梯度厚壁圆筒的热弹性问题进行分析,给出了一种近似热弹性理论解,该理论解不仅与数值解契合度高,而且可以考虑夹杂形状对物理量的影响,最后分析了不同边界条件下夹杂形状对径向位移和各向应力的影响。【结果】结果显示,在两种边界下,夹杂形状对径向位移都有较大的影响;但在温度边界下,夹杂形状对径向应力有较大影响,对轴向应力和周向应力影响较小;在应力边界下,夹杂形状对轴向应力影响较大,对周向应力和径向应力影响较小。

关键词：功能梯度材料厚壁圆筒 Mori-Tanaka方法热弹性理论解夹杂形状

来源：

维普期刊数据库

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

考虑大气稳定度的典型复杂地形风场CFD模式

引用

太阳能学报 2024年第4期45卷 197-205页

作者：孙壮李树民朱蓉郑丹刘伟毅高建勇成都流体动力创新中心成都610072 国家气候中心北京100081

为评估中国典型复杂山地风资源,实现风资源的高效利用,结合雷诺时均的k-ε两方程模型、大气粗糙度壁面函数和热浮力作用,提出能模拟不稳定、中性和稳定状态复杂地形风场特性的大气CFD模式,并针对湍流参数、大气粗糙度对风速廓线的影响... 详细信息

为评估中国典型复杂山地风资源,实现风资源的高效利用,结合雷诺时均的k-ε两方程模型、大气粗糙度壁面函数和热浮力作用,提出能模拟不稳定、中性和稳定状态复杂地形风场特性的大气CFD模式,并针对湍流参数、大气粗糙度对风速廓线的影响进行参数化研究。采用两种方式驱动CFD模式:一种是通过来流上游的实测风速廓线驱动CFD模式,一种是通过WRF模式输出风速廓线和温度廓线驱动CFD模式。利用山西神池南桦山丘陵山地测风数据进行大气CFD模式验证,通过WRF-CFD耦合仿真研究山地公里级范围热浮力作用对风场的影响,详细对比不同热浮力作用下的大气CFD模式仿真精度。结果表明大气CFD模式能准确地模拟不同稳定度状态下的山区大气风环境,但对于不稳定状态下山后风场的模拟能力稍差。

关键词：风能风电场大气边界层复杂地形大气CFD模式风廓线大气稳定度

来源：

维普期刊数据库

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

Asymmetries of Positive Feedback Trading in Individual Stocks:Evidences from China

引用

Journal of Management Science and Engineering 2016年第1期1卷 3-27页

作者： Die Wan weiyi liu Junbo Wang Xiaoguang Yang School of Finance Zhejiang Gongshang UniversityHangzhouZhejiang 310018China School of Finance Capital University of Economics and BusinessBeijing 100070China Department of Economics and Finance City University of Hong KongHong KongChina Academy of Mathematics and Systems Science Chinese Academy of SciencesNo.55 Zhongguancun East RoadHaidian DistrictBeijing 100190China

The paper investigates the positive feedback trading phenomenon of individual stocks in China’s stock market.Heterogeneous regression models and a non-parametric Sentana-Wadhwani model are developed and applied to prove the existence of rise-favor asymmetric feedback trading.This result is consistent with the reality of China’s stock market,that is,the herding behavior of irrational retail investors has a significant influence on the market.However,the result is in contrast with the stylized findings using market indices.Further empirical research shows that this distinction could be explained by the average effect of indices.The asymmetries of positive feedback trading caused by heterogeneous feedback trading and the uneven distributed retail trading in individual stocks,are covered by the weighted average effect in indices.Therefore,the indices exhibit a different asymmetric pattern from that of individual stocks.

关键词： Positive feedback trading Asymmetry Individual stocks Index Retail investor

来源：

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

Car-following Model and Its Stability under Ice and Snowfall Conditions

引用

Journal of Harbin Institute of Technology(New Series) 2017年第1期24卷 91-96页

作者： Junqiang Leng Shi An Wenxiang Li weiyi liu Hantao Zhao School of Automotive Engineering Harbin Institute of Technologyat WeihaiWeihai 264209ShandongChina School of Transportation Science and Engineering Harbin Institute of TechnologyHarbin 150090China Key Laboratory of Road and Traffic Engineering Ministry of EducationShanghai 201804China

In order to describe the behavior of the car under ice and snowfall conditions more realistically,a vehicle following model based on the full velocity difference model is proposed under the premise of considering the speed difference and various kinds of ice and snowfall conditions. Under various road conditions,it obtains the critical stability curve of the model,and verifies that the worse the road condition is,the less stable the traffic flow is. In addition,the method of nonlinear analysis is used to obtain the solution of the kink density wave in the space headway under the unstable region. Finally,the conclusions are verified by numerical simulation,that worse road conditions,which means the road surface friction coefficient is small,will lead to greater instability region and worse anti-interference ability of traffic flow,and even cause more congestion and accidents. The conclusions make great contributions to handling the traffic jams and security issues under ice and snowfall conditions.

关键词： car-following model ice and snowfall conditions stability

来源：

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

雷州半岛东部近岸水体溴质量浓度空间分布及其影响因素

引用

激光与光电子学进展 2024年第5期61卷 79-87页

作者：刘维一熊正烨郭竞渊廖小婷余果广东海洋大学电子与信息工程学院广东湛江524088

利用X射线荧光光谱法检测海水中溴元素含量,研究雷州半岛东部近岸水体中溴元素空间分布特征,分析影响雷州半岛东部沿岸水体溴元素空间分布的原因。首先,利用小焦点X射线荧光光谱仪和直接进样法测量标准溶液并建立标准溶液校准曲线,根据... 详细信息

利用X射线荧光光谱法检测海水中溴元素含量,研究雷州半岛东部近岸水体中溴元素空间分布特征,分析影响雷州半岛东部沿岸水体溴元素空间分布的原因。首先,利用小焦点X射线荧光光谱仪和直接进样法测量标准溶液并建立标准溶液校准曲线,根据特征X射线的荧光强度与标准溶液中溴元素质量浓度的线性关系建立线性拟合方程,反演待测海水中溴元素的质量浓度;然后依据各采样点水体中溴元素质量浓度的空间变化、地表径流的空间分布、潮汐信息及雷州半岛东部沿岸的环流空间结构,分析地表径流、潮汐及环流等因素对雷州半岛东部近岸水体溴元素质量浓度空间变化的影响。对雷州半岛东部18个站位点取样海水的X射线荧光光谱反演计算,结果表明该区域溴元素质量浓度范围在50.79~62.11 mg/L,均低于大洋水体中的平均溴元素质量浓度。研究区内溴元素质量浓度空间变化较大,大致呈离两湾一岛(湛江湾、雷州湾及硇洲岛)近海水中溴元素质量浓度低,离两湾一岛远溴元素质量浓度高的空间分布特征。此外,在研究区南部及琼州海峡入口处,由于复杂的环流结构影响,溴元素质量浓度呈现出明显的沿琼州海峡流流向递增的趋势。雷州半岛东部近岸水体中各个采样点溴元素质量浓度随空间变化的现象表明雷州半岛东部近岸海水中的溴元素质量浓度分布是不均衡的。地表径流、潮汐、沿岸流、海峡流及气旋式环流是导致雷州半岛东部近岸水体溴元素质量浓度空间分布不均衡的主要因素。

关键词： X射线光学 X射线荧光光谱法粤西沿岸流琼州海峡流气旋式环流

来源：

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

含砷中药复方治疗的高危骨髓增生异常综合征患者的生存特征分析

引用

北京中医药大学学报 2024年第5期47卷 709-720页

作者：靳楠毛悦吕妍陈卓王德秀刘为易刘驰唐旭东中国中医科学院研究生院北京100700 北京中医药大学研究生院中国中医科学院西苑医院血液科

目的探讨高危骨髓增生异常综合征(HR-MDS)患者的临床生存特征,为HR-MDS患者的临床预后评估提供参考。方法回顾性分析2016年1月—2022年9月在中国中医科学院西苑医院确诊为HR-MDS的200例患者的一般资料、血常规、骨髓涂片,以及组织病... 详细信息

目的探讨高危骨髓增生异常综合征(HR-MDS)患者的临床生存特征,为HR-MDS患者的临床预后评估提供参考。方法回顾性分析2016年1月—2022年9月在中国中医科学院西苑医院确诊为HR-MDS的200例患者的一般资料、血常规、骨髓涂片,以及组织病理学、细胞遗传学等临床资料。依据不同治疗方法把纳入患者分为含砷中药复方联合去甲基化药物(HMAs)治疗组与含砷中药复方联合雄激素治疗组,分析各组患者临床指标对生存特征的影响。结果 200例接受含砷中药复方联合HMAs或联合雄激素治疗的HR-MDS患者临床指标对生存特征影响比较结果显示,高危与极高危(P=0.018)、血红蛋白(Hb)<80 g/L与Hb≥80 g/L(P=0.035)、血小板(PLT)计数<50×10^(9) L^(-1)与PLT计数≥50×10^(9) L^(-1)(P<0.001)、骨髓增生异常综合征转白血病(MDS-AML)与非MDS-AML(P=0.003)中位无进展生存期(PFS)比较,差异有统计学意义。68例接受含砷中药复方联合HMAs治疗的HR-MDS患者临床指标对生存特征影响比较结果显示:PLT计数<50×10^(9) L^(-1)与PLT计数≥50×10^(9) L^(-1)(P<0.001)、化疗疗程<5个与疗程≥5个(P=0.018)的中位PFS比较,差异有统计学意义。132例接受含砷中药复方联合雄激素治疗的HR-MDS临床指标对生存特征影响比较结果显示,Hb<80 g/L与Hb≥80 g/L(P=0.028)、PLT计数<50×10^(9) L^(-1)与PLT计数≥50×10^(9) L^(-1)(P=0.002)、MDS-AML与非MDS-AML(P=0.024)的中位PFS比较,差异有统计学意义。结论接受含砷中药复方联合HMAs治疗的PFS延长患者临床特征有PLT计数≥50×10^(9) L^(-1)、化疗疗程≥5个。接受含砷中药复方联合雄激素治疗的PFS延长患者临床特征有Hb≥80 g/L、PLT计数≥50×10^(9) L^(-1)和非MDS-AML。

关键词：高危骨髓增生异常综合征血液疾病生存分析含砷中药复方雄激素总生存期无进展生存期

来源：

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

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：