检索结果-南通市图书馆

铂/{还原氧化石墨烯/硅钨酸盐}_n复合物的制备及其电催化性能

中国化学会第九届全国无机化学学术会议

作者： Xiaofeng Zhang Xiaoying Wang lijuan le Shen Lin College of Chem. & Chem. Engin. Fujian Normal Univ.

Due to the high catalytic activity for oxygen reduction reaction(ORR), platinum has long been regarded as one of the best cathode catalysts for fuel cells. However, the high cost and poor tolerance to fuel crossover and CO poisoning have greatly limited its commercialization. Therefore, numerous efforts have been devoted to exploring new ORR catalysts with less or no usage of Pt [1]. It has been reported that Cu2O can be used as a potential electrocatalyst for ORR and it shows structure-dependent electrocatalytic activity toward ORR in alkaline electrolyte [2]. In this work, truncated octahedral Cu2O/RGO(reduced graphene oxide) composite(Fig. a) was successfully prepared by a one-step electrochemical galvanostatic codeposition approach. The TEM image(Fig. b) reveals that the size of truncated octahedral Cu2O disperses on the RGO sheets is about 500000 nm. The electrocatalytic ORR performance of as-synthesized Cu2O/RGO composite was also studied. Fig. c shows a series of ORR polarization curves recorded at Cu2O/RGO in 0.1 M KOH solution at different rotation rates(from 225 to 3000 rpm). There is only one stage with defined current density and the limiting current density increases with increasing rotation rate. Such ORR polarization curves feature reveals that the ORR on Cu2O/RGO can proceed via the most efficient four-electron process. The numbers of electrons transferred can be calculated to be 3.9(≈4) for ORR on Cu2O/RGO from- 0.40 V to-0.80 V, thereby indicating that the ORR is dominated by a near four-electron(4e) process and O2 is reduced to OH-. Therefore, this study could provide guidance in the further development of easily prepared, scalable, and low-cost catalysts based on other metal oxides.

关键词： cuprous oxide reduced graphene oxide codeposition oxygen reduction reaction.

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

应用化学 2017年第10期34卷 1209-1220页

作者：黄火娣张晓凤张艺乐丽娟林深福建师范大学化学与化工学院福州350007

利用层层自组装(LBL)结合原位光照还原法,制备了一系列{还原氧化石墨烯/多金属氧酸盐}n多层复合膜({rGO/POMs}_n),并以此作为载体,再通过恒电势法将Pt纳米粒子电沉积到复合膜载体上,得到一种P t/{rGO/SiW_(12)}_n燃料电池阳极纳米复合... 详细信息

利用层层自组装(LBL)结合原位光照还原法,制备了一系列{还原氧化石墨烯/多金属氧酸盐}n多层复合膜({rGO/POMs}_n),并以此作为载体,再通过恒电势法将Pt纳米粒子电沉积到复合膜载体上,得到一种P t/{rGO/SiW_(12)}_n燃料电池阳极纳米复合膜催化剂。用紫外可见分光光度计(UV-Vis)、原子力显微镜(AFM)以及扫描电子显微镜(SEM)等技术手段对载体复合多层膜的生长情况以及负载Pt纳米簇的表面形貌进行表征。结果表明,载体多层膜{rGO/SiW_(12)}_6被连续均匀地组装到了不同基底(氧化铟锡,ITO或玻碳,GC)表面且多层膜表面平整,在选定恒电势下,沉积于其表面的Pt纳米粒子具有花簇状形貌且分布均匀。比较研究了分别引入3种不同的多金属氧酸盐(硅钨酸盐SiW_(12),磷钼酸盐PMo_(12),磷钨酸盐PW_(12))制得的多层复合膜催化剂,即Pt/{rGO/SiW_(12)}_6、Pt/{rGO/PMo_(12)}_6和Pt/{rGO/PW_(12)}_6。电化学实验研究表明,在甲醇酸性溶液中,Pt/{rGO/SiW_(12)}_6复合膜相较于Pt/{rGO/PMo_(12)}_6、Pt/{rGO/PW_(12)}_6和Pt作为催化剂对甲醇氧化具有更好的电催化活性、电化学稳定性以及更优异的抗CO毒化性能,是一种颇有应用前景的燃料电池阳极催化剂。

关键词：甲醇燃料电池电催化氧化电沉积石墨烯多金属氧酸盐铂

A Preliminary Review of Metallogenic Regularity of Tungsten Deposits in China

在线全文

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 2015年第4期89卷 1359-1374页

作者： SHENG Jifu LIU Lijun WANG Denghong CHEN Zhenghui YING lijuan HUANG Fan WANG Jiahuan ZENG le Key Laboratory of Metallogeny and Mineral Resource Assessment Institute of Mineral ResourcesChinese Academy of Geological Sciences China University of Geosciences Changjiang University College of Earth Science Jilin University

Tungsten ore resources are abundant in China with relatively complete types of deposits. Skarn type and quartz vein type deposits are dominated in the tungsten resources, whereas quartz vein type wolframite deposits are most important in terms of exploitation and utilization. Skarn type tungsten deposits are concentratedly distributed in the central Nanling region, such as South Hunan, South Anhui and the eastern Qinling region, while quartz vein type tungsten deposits occur mainly in South China, such as West Fujian, South Jiangxi, North Guangdong and South Hunan. The most important metallogenic epoch of tungsten is the Mesozoic, while the metallogenic tectonic setting is featured by an intracontinental environment after orogeny with sever tectonic movements, deep-seated faults and frequent magmatic activities, especially Mesozoic granitoids closely related to tungsten-tin mineralization. 22 metallogenic series of ore deposits characterized by or significantly related to tungsten were defined based on precise statistic information of 1199 tungsten mining areas and thorough the summary of metallogenic regularities. Based on studies of the metallogenic regularity of tungsten deposits, skarn type （or greisen type）, quartz vein type and massif-type of tungsten deposits are thought to be the key prediction types. 65 tungsten-forming belts and 22 key ore concentration areas were ascertained and a distribution map of tungsten-forming belts of China was compiled, which provided a theoretical basis for evaluation and prediction of potential tungsten resources.

关键词： tungsten resources characteristics types of tungsten deposit tungsten-forming belt,metallogenic regularity

The Circadian System Is Essential for the Crosstalk of VEGF-Notch-mediated Endothelial Angiogenesis in Ischemic Stroke

在线全文

学校读者我要写书评

暂无评论

Neuroscience Bulletin 2023年第9期39卷 1375-1395页

作者： Yuxing Zhang Xin Zhao Chun Guo Ying Zhang Fukang Zeng Qian Yin Zhong Li le Shao Desheng Zhou lijuan Liu Department of Neurology The First Hospital of Hunan University of Chinese MedicineChangsha410007China Key Laboratory of Hunan Province for Integrated Traditional Chinese and Western Medicine on Prevention and Treatment of Cardio-Cerebral Diseases Changsha410208China Hunan University of Chinese Medicine Changsha410006China Laboratory of Prevention and Transformation of Major Diseases in Internal Medicine of Traditional Chinese Medicine Changsha410007China

Ischemic stroke is a major public health problem *** the circadian clock is involved in the process of ischemic stroke,the exact mechanism of the circadian clock in regulating angiogenesis after cerebral infarction remains *** the present study,we determined that environmental circadian disruption(ECD)increased the stroke severity and impaired angiogenesis in the rat middle cerebral artery occlusion model,by measuring the infarct volume,neurological tests,and angiogenesis-related *** further report that Bmal1 plays an irreplaceable role in *** of Bmal1 promoted tube-forming,migration,and wound healing,and upregulated the vascular endothelial growth factor(VEGF)and Notch pathway protein *** promoting effect was reversed by the Notch pathway inhibitor DAPT,according to the results of angiogenesis capacity and VEGF pathway protein *** conclusion,our study reveals the intervention of ECD in angiogenesis in ischemic stroke and further identifies the exact mechanism by which Bmal1 regulates angiogenesis through the VEGF-Notch1 pathway.

关键词： Circadian clock Ischemic stroke Angiogenesis VEGF Notch pathway

就业机会成本对城镇地区已婚妇女择业行为的影响分析

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

浙江社会科学 2007年第3期 17-25页

作者：乐君杰屈利娟浙江大学公共管理学院

本文基于补偿性工资差别假说,对影响城镇地区已婚妇女就业选择的决定因素进行了分析。计量结果表明,城镇地区已婚妇女的就业决策不仅取决于其保留工资率和市场工资率的相对大小,还受由就业类型本身所具的工作特性所引起的就业机会成本... 详细信息

本文基于补偿性工资差别假说,对影响城镇地区已婚妇女就业选择的决定因素进行了分析。计量结果表明,城镇地区已婚妇女的就业决策不仅取决于其保留工资率和市场工资率的相对大小,还受由就业类型本身所具的工作特性所引起的就业机会成本大小的影响;补偿性工资差别假说在非公有制部门中有较好的拟合性,对公有制部门则缺乏解释力。计量结果还发现,已婚妇女的择业行为与其配偶的收入和就业类型之间存在较强的相关关系。

关键词：就业选择就业机会成本配偶效应补偿性工资差别假说分割的劳动力市场

Effect of aerobic exercise on insulin resistance and centra1 adiposity disappeared after the discontinuation of intervention in overweight women

在线全文

学校读者我要写书评

暂无评论

Journal of Sport and Health Science 2016年第2期5卷 166-170页

作者： Shenglong le lijuan Mao Dajiang Lu Yifan Yang Xiao Tan Petri Wiklund Sulin Cheng Department of Physical Education Shanghai Jiao Tong University School of Physical Education and Training Shanghai University of Sport School of Kinesiology Shanghai University of Sport Department of Health Sciences University of Jyvaskyla

Purpose： This study aimed to assess whether the benefits of exercise on central adiposity and insulin resistance （HOMA-IR） are maintained after discontinuation of intervention in the overweight/obese （OWOB） women. Methods： The study subjects were from 2 independent studies with similar aerobic exercise （AE） intervention programs. In study I, I50WOB postmenopausal women with pre-diabetes （body mass index, BMI = 24-33 kg/m2, aged 52-65 years） completed an 8-month exercise intervention and were followed for 2 years after the intervention. In study lI, 12 OWOB （BM1 = 25-35 kg/m2, aged 30-50 years） premenopausal women participated in a 6-week AE and were followed for 4 years after the intervention. The exercise program consisted of progressive AE with intensity of 60%-75% of initial fitness level, 30-60 min/time and 3-5 times/week. Fat mass （FM） was assessed by Dual Energy X-ray Absorptiometry （DXA Prodigy; study I） or bioelectrical impedance device （Inbody 720; study II）. Plasma glucose and insulin were assessed by chemiluminescent immunoassay and HOMA-IR was calculated. Results： Both 8-month and 6-week moderate AE were effective in reducing HOMA-IR （-18.9%, p = 0.012 and -26.7%, p = 0.046, respectively）, and 8-month AE reduced FM at upper abdominal region （-6.2%, p = 0.021）. However, these improvements were not maintained in either study at the follow-up. Conclusion： The AE program used in these studies was effective to reduce insulin resistance and/or FM in central body region among overweight and obese women. However, when exercise intervention was discontinued, the beneficial effects following both short- and long-term intervention disappeared. Thus maintaining exercise seems to be required if one wants to reap the benefits of exercise in the long-term.

关键词： Exercise intervention Obesity Postmenopause Premenopause Relapse

Postoperative chemotherapy use and survival in non-high-risk young and high-risk old-aged patients with stageⅡcolon cancer

在线全文

学校读者我要写书评

暂无评论

Holistic Integrative Oncology 2023年第1期2卷 61-70页

作者： Tian Jin Yingshuang Zhu Wei Lu Chenqin le lijuan Wang Qian Xiao Kefeng Ding Department of Colorectal Surgery and Oncology(Key Laboratory of Cancer Prevention and Intervention China National Ministry of EducationKey Laboratory of Molecular Biology in Medical SciencesZhejiang ProvinceChina)The Second Affiliated HospitalZhejiang University School of MedicineHangzhouZhejiangChina Zhejiang Provincial Clinical Research Center for CANCER ZhejiangChina Cancer Center of Zhejiang University ZhejiangChina Centre for Global Health Usher InstituteUnversity of EdinburghEdinburghUK

Purpose Intensive postoperative chemotherapy treatment use in early-onset colon cancer and late-onset colon cancer remains to be defined and their effects on prognosis were *** study aims to investigate whether intensive adjuvant chemotherapy for stageⅡcolon cancer would result in matched survival improvement in young patients(le patients with pathologically confirmed TNM stageⅡcolon cancer from the Surveillance,Epidemiology,and End Results database between 2004 and *** agedle stageⅡcolon cancer patients,3341 non-HREOCC patients and 11,722 HRLOCC patients were included.37.68%and 16.8%of patients received adjuvant chemotherapy among non-HREOCC and HRLOCC patients,*** non-HREOCC patients,there was no significant association between adjuvant chemotherapy and CSS(HR=1.09,95%CI0.83–1.44).For HRLOCC patients,adjuvant chemotherapy was associated with a better CSS(HR=0.88,95%CI0.79–0.99).Conclusion Our findings suggested that potential overuse of adjuvant chemotherapy among non-high-risk young patients with stageⅡcolon cancer did not lead to survival improvement,and caution should be called when using chemotherapy in these ***,chemotherapy can be used appropriately for high-risk stageⅡcolon cancer patients aged 70 to 85 years.

关键词： StageⅡcolon cancer Early-onset Late-onset Adjuvant chemotherapy Prognosis

Investigation on the mechanism of adsorption and desorption behavior in cerium ions modified Y-type zeolite and improved hydrocarbons conversion

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 Rare Earths 2016年第12期34卷 1221-1227页

作者：张乐李强秦玉才张晓彤高雄厚宋丽娟 College of Chemical Engineering China University of Petroleum(East China)Qingdao 266580China Liaoning Key Laboratory of Petrochemical Catalytic Science and Technology Liaoning Shihua UniversityFushun 113001China Research Institute of Petroleum and Petrochemical Petro China Company Limited Beijing 100083China

Different types of Y zeolites（HY, USY and Na Y） containing various amounts of cerium（Ce） were prepared with the method of liquid ion exchange and characterized by X-ray diffraction（XRD）, intelligent gravimetric analyzer（IGA）, and a molecular simulation technology（grand canonical Monte Carlo simulation, GCMC）. A novel calculation method of desorption index（DI） was proposed and the influence of cerium cationic species on the processes of adsorption-desorption of hydrocarbon molecules（n-octane） on the cerium modified Y zeolites（Ce Y） was studied. The results indicated that Ce ion species played a key role in reducing desorption activation energy of n-octane on Y type zeolites, leading to an improvement of the desorption ability of the Ce Y and the regulation of the adsorption state of n-octane from aggregation to decentralization. These findings are essential factors for enhancing the product selectivity of light hydrocarbon component and the catalytic activity of rare earth modified Y zeolites（REY） catalysts in fluid catalytic cracking（FCC） process.

关键词： catalysis Y zeolite adsorption model GCMC rare earth ion species

Optimization of Texture Determination of ‘Yali' by Texture Analyzer

在线全文

学校读者我要写书评

暂无评论

Agricultural Biotechnology 2018年第4期7卷 125-128,135页

作者： Jintao XU lijuan GAO Longfei LI Hai'e ZHANG Wenquan le Baofeng HAO Changli Institute of Pomology Fruit Tree Hebei Academy of Agriculture and Forestry Sciences

[Objectives] This study was carried out to determine texture parameters for texture profile analysis （TPA）, and optimize the texture determination of ‘Yali’ by texture analyzer.[Methods] The traditional varieties of ‘Yali’ were taken as the materials, and texture parameters were determined at different compression rates and deformations at target.[Results] In the process of the TPA, the deformation at target had an extremely significant influence on 8 TPA texture parameters, namely, the hardness, cohesiveness, springiness, adhesiveness, gumminess, resilience, fracturability, and chewiness （ P ≤0.01）, while the compression rate had significant influence on the hardness and gumminess （ P ≤0.05）, had an extremely significant influence on fracturability （ P ≤0.01）, and had no significant influence on other 5 TPA parameters.[Conclusions] Taking the compression rate of 1 mm/s and 20% deformation at target as the experimental conditions for TPA could avoid the impact load of high speed on the tissue and objectively reflect the textural characteristics of ‘Yali’ pulp tissue.

关键词： Texture profile analysis (TPA) 'Yali' Texture parameters Optimization of texture determination