检索结果-南通市图书馆

Variable Selection via Generalized SELO-Penalized Cox Regression Models

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Science & Complexity 2019年第2期32卷 709-736页

作者： SHI Yueyong XU Deyi CAO Yongxiu JIAO Yuling School of economics and Management China University of Geosciences center for resources and environmental Economic Research China University of Geosciences School of Statistics and Mathematics Zhongnan University of Economics and Law

The seamless-L_0(SELO) penalty is a smooth function that very closely resembles the L_0 penalty, which has been demonstrated theoretically and practically to be effective in nonconvex penalization for variable selection. In this paper, the authors first generalize the SELO penalty to a class of penalties retaining good features of SELO, and then develop variable selection and parameter estimation in Cox models using the proposed generalized SELO(GSELO) penalized log partial likelihood(PPL) approach. The authors show that the GSELO-PPL procedure possesses the oracle property with a diverging number of predictors under certain mild, interpretable regularity conditions. The entire path of GSELO-PPL estimates can be efficiently computed through a smoothing quasi-Newton(SQN) with continuation algorithm. The authors propose a consistent modified BIC(MBIC) tuning parameter selector for GSELO-PPL, and show that under some regularity conditions, the GSELOPPL-MBIC procedure consistently identifies the true model. Simulation studies and real data analysis are conducted to evaluate the finite sample performance of the proposed method.

关键词： Continuation Cox models generalized SELO modified BIC penalized likelihood smoothing quasi-Newton

Pollution levels and characteristics of phthalate esters in indoor air in hospitals

在线全文

学校读者我要写书评

暂无评论

Journal of environmental Sciences 2015年第11期27卷 67-74页

作者： Xueqing Wang Min Song Min Guo Chenchen Chi Feifei Mo Xueyou Shen College of environmental & resource Sciences Zhejiang University Research center for Eco-environmental Sciences Chinese Academy of Sciences Chinese Research Academy of environmental Sciences Zhejiang Provincial Key Laboratory of Organic Pollution and Control

The concentrations of phthalate esters（PAEs） in Chinese hospitals were investigated by simultaneously determining concentrations of gas- and particle-phase PAEs. PAEs were detected in two third-class first-grade hospitals, two second-class first-grade hospitals, and a community health service center. Hospital drugstores had the highest concentration（24.19 μg/m3）, which was 1.54 times that of newly decorated houses. The second highest concentration was found in the transfusion rooms, averaging 21.89 μg/m3; this was followed by the concentrations of PAEs in the nurse＇s workstations, the wards, and the doctor＇s offices, with mean concentrations of 20.66, 20.0, and 16.92 μg/m3, respectively. The lowest concentrations were found in the hallways（16.30 μg/m3）. Of the six different kinds of PAEs found, major pollutants included diethyl phthalates, dibutyl phthalates, butylbenzyl phthalates and di（2-ethylhexyl） phthalates, comprising more than 80% of all PAEs ***, a comparison between different wards showed that PAE concentrations in the maternity wards were 1.63 times higher than in the main wards. Based on known health hazards, our results suggest that the PAEs seriously influence the health of the pregnant women and babies; therefore, it is of great importance to take the phthalate concentrations in hospitals into consideration. In addition, hospital indoor air was more seriously contaminated than the air of newly decorated houses.

关键词： Air pollution Hospital Indoor air Phthalate concentrations

Effect of temperature switchover on the degradation of antibiotic chloramphenicol by biocathode bioelectrochemical system

在线全文

学校读者我要写书评

暂无评论

Journal of environmental Sciences 2014年第8期26卷 1689-1697页

作者： Deyong Kong Bin Liang Duu-Jong Lee Aijie Wang Nanqi Ren State Key Laboratory of Urban Water resource and Environment School of Municipal and Environmental EngineeringHarbin Institute of Technology Key laboratory of environmental Biotechnology Research Center for Eco-Environmental SciencesChinese Academy of Sciences

Exposure to chloramphenicol（CAP）,a chlorinated nitroaromatic antibiotic,can induce CAP-resistant bacteria/genes in diverse environments. A biocathode bioelectrochemical system（BES） was applied to reduce CAP under switched operational *** switching from 25 to 10°C,the CAP reduction rate（kCAP） and the maximum amount of the dechlorinated reduced amine product（AMCl,with no antibacterial activity） by the biocathode communities were both markedly decreased. The acetate and ethanol yield from cathodophilic microbial glucose fermentation（with release of electrons） was also reduced. Formation of the product AMCl was enhanced by the biocathode dechloridation reaction compared with that produced from pure electrochemical or microbial dechloridation processes. The electrochemical and morphological analyses of cathode biofilms demonstrated that some cathodophilic microbes could adapt to low temperature and play a key role in CAP degradation. The resilient biocathode BES has a potential for the treatment of CAP-containing wastewater in temperature fluctuating environments.

关键词： Chloramphenicol degradation Biocathode Dechloridation Temperature switchover

DESIGN AND ANALYSIS OF THE GREEN CLIMATE FUND

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Science and Systems Engineering 2014年第3期23卷 266-299页

作者： Lian-biao CUI Lei ZHU Marco SPRINGMANN Ying FAN center for Energy and environmental Policy Research Institute of Policy and ManagementChinese Academy of Sciences Department of economics University of Oldenburg

The Green Climate Fund （GCF） has been one of the core issues of the world climate summits under the United Nations Framework Convention on Climate Change （UNFCCC） in recent years. However, the GCF has not progressed smoothly, and currently there are no satisfactory schemes for raising and distributing the fund. This paper first discusses how to finance the GCF among Annex II countries. It introduces the ＇preference score compromises＇（PSC） approach which is based on environmental responsibility and economic capacity, with historical emissions as an indicator for environmental responsibility and GDP as indicator for economic capacity. The results show that the United States and the European Union are the two largest contributors to the GCF, sponsoring more than 80% of the funds. Second, we discuss how to allocate the funds among non-Annex II parties. The ＇adaptation needs＇（AN） approach, which takes account of economic strength and climate damages, is proposed to achieve the adaptation purpose of the GCF, and the results reveal that African countries with high levels of climate vulnerability could get most funds, with a share of almost 30%. Regarding the mitigation purpose of the GCF, this research introduces two approaches： the ＇carbon reduction contribution＇（CC） approach and the ＇incremental cost＇（IC） approach. Both approaches could achieve significant reductions in carbon emissions in non-Annex II parties, whereas the latter may provide limited adaptation finance but result in more mitigation effects. This paper also develops a method to combine abatement efficiency and adaptation fairness of the GCF, and we find that with an equal split between the AN and CC （or AN and IC） approaches, the amount of USD 100 billion could finance an emissions reduction of 1613 MtCO2 （2477 MtCO2）, while allocating USD 16 （or USD 9） per capita for adaptation in non-Annex II parties. The schemes proposed may be useful for promoting the development of the GCF in the future.

关键词： Climate change green climate fund preference score compromises carbon reductioncontribution mitigation and adaptation

Investigation of colloidal biogenic sulfur flocculation:Optimization using response surface analysis

在线全文

学校读者我要写书评

暂无评论

Journal of environmental Sciences 2016年第4期28卷 227-235页

作者： Fan Chen Ye Yuan Chuan Chen Youkang Zhao Wenbo Tan Cong Huang Xijun Xu Aijie Wang State Key Laboratory of Urban Water resource and Environment Harbin Institute of Technology Key Laboratory of environmental Biotechnology Research Center for Eco-Environmental SciencesChinese Academy of Sciences

The colloidal properties of biogenic elemental sulfur（S^0）cause solid–liquid separation problems,such as poor settling and membrane *** this study,the separation of S^0 from bulk liquids was performed using *** chloride（PAC）,polyacrylamide（PAM）and microbial flocculant（MBF）were compared to investigate their abilities to flocculate S^0 produced during the treatment of sulfate-containing wastewater.A novel approach with response surface methodology（RSM）was employed to evaluate the effects and interactions of flocculant dose,pH and stirring intensity,on the treatment efficiency in terms of the S^0 flocculation and the supernatant turbidity *** dose optimization results indicated that the S^0 flocculation efficiency decreased in the following order PAC〉MBF〉*** S^0 flocculation conditions were observed at pH 4.73,a stirring speed of 129 r/min and a flocculant dose of 2.42 mg PAC/mg *** optimum flocculation conditions,the S^0f locculation rate reached 97.53%.Confirmation experiments demonstrated that employing PAC for S^0 flocculation is feasible and RSM is an efficient approach for optimizing the process of S^0 *** results provide basic parameters and conditions for recovering sulfur during the treatment of sulfate-laden wastewaters.

关键词： Elemental sulfur Flocculation Optimization Response surface methodology (RSM)

Efficient treatment of azo dye containing wastewater in a hybrid acidogenic bioreactor stimulated by biocatalyzed electrolysis

在线全文

学校读者我要写书评

暂无评论

Journal of environmental Sciences 2016年第1期28卷 198-207页

作者： Hong-Cheng Wang Hao-Yi Cheng Shu-Sen Wang Dan Cui Jing-Long Han Ya-Ping Hu Shi-Gang Su Ai-Jie Wang Key Laboratory of environmental Biotechnology Research Center for Eco-Environmental Sciences Chinese Academy of Sciences State Key Laboratory of Urban Water resource and Environment Harbin Institute of Technology

In this study, a novel scaled-up hybrid acidogenic bioreactor（HAB） was designed and adopted to evaluate the performance of azo dye（acid red G, ARG） containing wastewater treatment. Principally, HAB is an acidogenic bioreactor coupled with a biocatalyzed electrolysis module. The effects of hydraulic retention time（HRT） and ARG loading rate on the performance of HAB were investigated. In addition, the influent was switched from synthetic wastewater to domestic wastewater to examine the key parameters for the application of HAB. The results showed that the introduction of the biocatalyzed electrolysis module could enhance anoxic decolorization and COD（chemical oxygen demand） removal. The combined process of HAB-CASS presented superior performance compared to a control system without biocatalyzed electrolysis（AB-CASS）. When the influent was switched to domestic wastewater, with an environment having more balanced nutrients and diverse organic matters, the ARG, COD and nitrogen removal efficiencies of HAB-CASS were further improved, reaching 73.3% ± 2.5%, 86.2% ± 3.8% and 93.5% ± 1.6% at HRT of 6 hr, respectively, which were much higher than those of AB-CASS（61.1% ± 4.7%,75.4% ± 5.0% and 82.1% ± 2.1%, respectively）. Moreover, larger TCV/TV（total cathode volume/total volume） for HAB led to higher current and ARG removal. The ARG removal efficiency and current at TCV/TV of 0.15 were 39.2% ± 3.7% and 28.30 ± 1.48 mA,respectively. They were significantly increased to 62.1% ± 2.0% and 34.55 ± 0.83 mA at TCV/TV of 0.25. These results show that HAB system could be used to effectively treat real wastewater.

关键词： HAB(hybrid acidogenic bioreactor) Scale-up Azo dye Domestic wastewater Cyclic activated sludge system(CASS)

Estrogenic activities of two synthetic pyrethroids and their metabolites

在线全文

学校读者我要写书评

暂无评论

Journal of environmental Sciences 2010年第2期22卷 290-296页

作者： Meiqing Jin Ling Li Chao Xu Yuezhong Wen Meirong Zhao MOE Key Laboratory of environmental Remediation and Ecosystem Health College of Environmental and Resource Sciences Zhejiang University Hangzhou 310027 China Research center of environmental Science College of Biological and Environmental Engineering Zhejiang University of Technology Hangzhou 310032 China

Synthetic pyrethroids （SPs） are among the most common pesticides in current use, and so far, several SPs have been assessed for their potential estrogenicities by various methods. Previous studies have shown that the estrogenicities partly come from their metabolites. Although considerable information is available with respect to the metabolism and environmental degradation of SPs, little is known about the estrogenicities of the metabolites. In this study, permethrin （PM） and β-cypermethrin （CP）, as well as their metabolites （3-phenoxybenzoic alcohol （PBCOH）, 3-phenoxybenzaldehyde （PBCHO） and 3-phenoxybenzoic acid （PBCOOH） were evaluated for their estrogenic activities in the MCF-7 human breast carcinoma cell line. In the MCF-7 cell proliferation assay, PM and CP exhibited significant estrogenic activities at 10-7 mol/L, comparable to 17β-estradiol （E2） of 10-9 tool/L, with the relative proliferative effect ratios of 55.4% and 56.3%, respectively. The real-time quantitative polymerase chain reaction （qRT-PCR） results confirmed the estrogenicities of PM and CP with significant alteration of pS2 and ERα mRNA levels observed at 10-6 mol/L. For the three major metabolites, PBCOH and PBCOOH exhibited estrogenic activities in all assays, while no significant estrogenic responses was observed for PBCHO compared to the vehicle control. In particular, PBCOH had even slightly stronger estrogenic activity than its parent compounds, indicating that metabolism may be one of the reasons for the estrogenicities of the SPs. Given the widespread use of SPs, the toxicological effects of parent compounds and their metabolites should be taken into consideration in the risk assessment of SPs.

关键词： pyrethroids metabolites cell proliferation gene expression estrogenic activity

Morphology of single inhalable particle in the air polluted city of Shijiazhuang,China

在线全文

学校读者我要写书评

暂无评论

Journal of environmental Sciences 2008年第4期20卷 429-435页

作者： WANG Zanhong ZHANG Lingzhi ZHANG Yuliang ZHAO Zhou ZHANG Sumin College of resource and Environment Sciences Hebei Normal University Shijiazhuang 050016 China environmental Monitoring center of Shifiazhuang Shijiazhuang 050016 China

In the typical air polluted city of Shijiazhuang, single inhalable particle samples in non-heating period, heating period, dust storm days, and snowy days were collected and detected by SEM/EDS （scanning electron microscopy and energy dispersive X-ray spectrometry）. The particle morphology was characterized by the 6 shape clusters, which are： irregular square, agglomerate, sphere, floccule, column or stick, and unknown, by quantitative order. The irregular square particles are common in all kinds of samples; sphere particles are more, and column or stick are less in winter samples; in the wet deposit samples, agglomerate and floccule particles are not found. The surface of most particles is coarse with fractal edge, which can provide suitable chemical reaction bed in the polluted atmospheric environment. New formed calcium crystal is found to demonstrate the existence of neutralized reaction, explaining the reason for the high SO2 emission and low acid rain frequency in Shijiazhuang. The three sorts of surface patterns of spheres are smooth, semi-smooth, and coarse, corresponding to the element of Si-dominant, Si-Al-dominant, and Fe-dominant, The soot particle is present as floccule with average size around 10 μm, considerably larger than the former reported results, but wrapped or captured with other fine particles to make its appearance unique and enhance its toxicity potentially. The new formed calcium crystal, the 3 sorts of sphere surface patterns, and the unique soot appearance represent the single inhalable particle＇s morphology characteristics in Shijiazhuang City.

关键词： single particle morphology new formed calcium crystal spheres soot

Enhancing the Efficiency of Enterprise Shutdowns for environmental Protection:An Agent-Based Modeling Approach with High Spatial–Temporal Resolution Data

在线全文

学校读者我要写书评

暂无评论

Engineering 2024年第11期42卷 295-307页

作者： Qi Zhou Shen Qu Miaomiao Liu Jianxun Yang Jia Zhou Yunlei She Zhouyi Liu Jun Bi School of Management and economics Beijing Institute of TechnologyBeijing 100081China center for Energy and environmental Policy Research Beijing Institute of TechnologyBeijing 100081China State Key Laboratory of Pollution Control and resource Reuse School of the EnvironmentNanjing UniversityNanjing 210023China The center of Enterprise Green Governance Chinese Academy of Environmental PlanningBeijing 100012China State environmental Protection Key Laboratory of environmental Planning and Policy Simulation Chinese Academy of Environmental PlanningBeijing 100012China

Top-down environmental policies aim to mitigate environmental risks but inevitably lead to economic losses due to the market entry or exit of *** study developed a universal dynamic agent-based supply chain model to achieve tradeoffs between environmental risk reduction and economic *** model was used to conduct high-resolution daily simulations of the dynamic shifts in enterprise operations and their cascading effects on supply chain *** includes production,con-sumption,and transportation agents,attributing economic features to supply chain components and cap-turing their *** also accounts for adaptive responses to daily external shocks and replicates realistic firm *** coupling high spatial-temporal resolution firm-level data from 18916 chemical enterprises,this study investigates the economic and environmental impacts of an environmen-tal policy resulting in the closure of 1800 chemical enterprises over three *** results revealed a significant economic loss of 25.8 billion USD,ranging from 23.8 billion to 31.8 billion ***,over 80%of this loss was attributed to supply chain *** analyses indicated that imple-menting a staggered shutdown strategy prevented 18.8%of supply chain losses,highlighting the impor-tance of a gradual policy implementation to prevent abrupt supply chain ***,the study highlights the effectiveness of a multi-objective policy design in reducing economic losses(about 29%)and environmental risks(about 40%),substantially enhancing the efficiency of the environmental *** high-resolution simulations provide valuable insights for policy designers to formulate strategies with staggered implementation and multiple objectives to mitigate supply chain losses and environmental risks and ensure a sustainable future.

关键词： Agent-based model Supply chain network Economic sustainability environmental policy