中国学术期刊论文机构存储政策调查问卷分析报告

中国科学技术信息研究所总工程师乔晓东介绍了对中国学术期刊论文机构存缴政策的调

中国学术期刊对机构知识库存缴政策调查分析

[目的]了解中国学术期刊对机构知识库存缴政策的态度。[方法]从《中国科技期刊引证报告》中选择326个样本， 以电话通知的方式， 确保他们进行线上问卷调查。[结果]回收有效问卷195份， 回收有效率为65%强。其中， 74.9%的期刊赞同论文存储到机构知识库中。说明他们对机构知识库存储和传播科技论文的态度和建议是正面的。[局限]总体调查规模有限， 集中在质量较高、名声显著、已有期刊数字化基础的期刊， 调查结论未必适用于全部中国期刊。[结论]多数调查对象赞成机构知识库存缴与传播论文， 但建议今后提供期刊论文开放获取的权益咨询服务。</p

Sediment records of DDTs in intertidal sediment core of Daliao River Estuary and their responses to anthropogenic activities in the past century

Dichlorodiphenyltrichloroethanes (DDTs) are still detected in various environmental matrices,although their usage in agriculture has been banned for about 30 years in China.Intertidal zone,as the intersection area of land and sea,is the final sink for contaminants.To comprehensively understand the deposition features of DDTs in intertidal sediment of Daliao River Estuary,a sediment core was sampled in this study.Combined with the dating data,the distribution,potential risk,source and fate of DDTs were investigated.The results showed that DDTs concentrations ranged from 0.313 ng&middot;g~(-1) to 4.116 ng&middot;g~(-1) (median:2.061 ng&middot;g~(-1)),with p,p&#39;-DDTs being the major components.Interestingly,the peak of DDTs concentrations (3.4364.116 ng&middot;g~(-1)) during 1988 1996 corresponded well with the peak of pesticide production during 19711981,and a 15-year-round time lag was observed between these two peaks.Possible usage of technical DDT was implied after year 2000 for the control and prevention of disease in Liaoning Province.The risk assessment of DDTs revealed that concentrations of DDT and DDE in sediment core rarely (&lt;25%) showed negative effect,while concentrations of DDD and total DDTs in the depth of 044 cm occasionally (25%50%) showed negative effect.The specific ratios of DDTs demonstrated that DDTs in the intertidal sediments were mainly from historical use of technical DDT rather than the use of dicofol.DDE and DDD were the main degradation products of DDT in the deeper layer (62110 cm) and shallower layer (061 cm),respectively.Further analysis revealed that the increased TOC content caused by human activities after year 1971 was the main reason that led the sediment environment changing from aerobic environment to anaerobic environment.What&#39;s more,DDTs concentrations in sediment core had strong positive correlations with sediment properties (TN,TP and TOC) (P &lt;0.01),and also had a significant positive correlation with anthropogenic activities (such as GDP,urbanization and total agricultural output value) (P &lt;0.01).Therefore,the results of the concentrations and compositions of DDTs in intertidal sediment core could reflect the direct and indirect influence of human activities on the occurrence and fate of contaminants in intertidal sediment.</p

Origin of the high activity of AuFeOx for low-temperature CO oxidation: Direct evidence for a redox mechanism

Origin of the high activity of AuFeOx for low-temperature CO oxidation: Direct evidence for a redox mechanis

Remarkable Performance of Ir1FeOx Single-Atom Catalyst in Water Gas Shift Reaction

Remarkable Performance of Ir1FeOx Single-Atom Catalyst in Water Gas Shift Reactio

The reactivity of methanol steam reforming over PdZn intermetallic catalyst: a microcalorimetric study

The reactivity of methanol steam reforming over PdZn intermetallic catalyst: a microcalorimetric stud

HIRFL-CSR主环电子冷却装置控制系统

介绍了HIRFL-CSR中主环电子冷却装置控制系统的整体设计、硬件结构和软件设计。实现了对主环电子冷却装置的计算机控制和网络界面操作,使主环电子冷却装置的运行更加方便、稳定和可靠