检索结果-南通市图书馆

煤矸石和粉煤灰在我国墙体材料中的应用(二)

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

砖瓦 2024年第3期 38-41页

作者：闫开放林永淳师晓明全国墙材科技信息网专家委员会陕西西安710061 陕西宝深机械(集团)有限公司陕西眉县722300

为了推进煤矸石和粉煤灰固废减量化、资源化、无害化处理,国家发展和改革委员会等十部委提出了《关于“十四五”大宗固体废弃物综合利用的指导意见》(发改环资[2021]381号)。为此,就六大固废之首煤矸石和粉煤灰,在我国墙体材料中的应用... 详细信息

为了推进煤矸石和粉煤灰固废减量化、资源化、无害化处理,国家发展和改革委员会等十部委提出了《关于“十四五”大宗固体废弃物综合利用的指导意见》(发改环资[2021]381号)。为此,就六大固废之首煤矸石和粉煤灰,在我国墙体材料中的应用现状及研究创新成果方面进行了简要汇总,并进行了简要分析。

关键词：大宗固废煤矸石粉煤灰墙体材料

煤矸石和粉煤灰在我国墙体材料中的应用(一)

在线全文

学校读者我要写书评

暂无评论

砖瓦 2024年第2期 40-43,47页

作者：闫开放林永淳师晓明全国墙材科技信息网专家委员会陕西西安710061 陕西宝深机械(集团)有限公司陕西眉县722300

关键词：大宗固废煤矸石粉煤灰墙体材料

大宗固废污泥在我国墙体材料中的应用及研究创新成果分析

在线全文

学校读者我要写书评

暂无评论

砖瓦 2024年第4期 29-35页

作者：闫开放林永淳施晓明全国墙材科技信息网专家委员会陕西西安710061 陕西宝深机械(集团)有限公司陕西眉县722300

城市污泥无害化处理以及再利用已成为墙材行业关注的焦点,据统计,2020年我国含水率80%的污泥年产量已超过6500万t,预计2025年我国污泥年产量将突破9000万t,面对如此大量的污泥,如果不能进行资源的二次开发和利用,将会对土地河流产生不... 详细信息

城市污泥无害化处理以及再利用已成为墙材行业关注的焦点,据统计,2020年我国含水率80%的污泥年产量已超过6500万t,预计2025年我国污泥年产量将突破9000万t,面对如此大量的污泥,如果不能进行资源的二次开发和利用,将会对土地河流产生不良影响,对大气环境造成污染。墙体材料是污泥产业化利用的重要途径之一,为此,就污泥固废在我国墙体材料中的应用及未来研究创新成果方面进行了简要分析讨论。

关键词：污泥固废墙材应用发展建议

Clean air actions and health plans in China

在线全文

学校读者我要写书评

暂无评论

Chinese Medical Journal 2020年第13期133卷 1609-1611页

作者： Chen Chen Jian-Long Fang Wan-Ying shi Tian-Tian Li xiao-ming shi Department of Environmental Health Risk Assessment National Institute of Environmental HealthChinese Center for Disease Control and PreventionBeijing 10001China National Institute of Environmental Health Chinese Center for Disease Control and PreventionBeijing10001China

China has been experiencing some of the world's most serious air pollution,especially severe smog events swept China in January of 2013,leading to extensive interna-tional *** to understand and mitigate the impacts of ambient air pollution on public health have been taken to tackle this pollution in *** air actions developed nationwide have aggressively lowered fine particulate matter(PM2.5)pollution in recent years.1 National health plans and research projects on air pollution have been motivated and funded by the *** growing epidemiological evidence has emerged to preliminarily uncover the effects of elevated levels of ambient air pollution on human ***,China's pollution levels still exceed that of the World Health Organization(WHO)least-stringent *** air pollution still poses a serious threat to human health and welfare.

关键词： pollution Clean China.

Synthesis and Characterization of Heterobimetallic Zigzag Chains with a Close-packed Structure Based on Macrocyclic Metalloligands

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Structural Chemistry 2020年第8期39卷 1465-1474,1359页

作者： shi xiao-ming xiao Li-Na LI Shu-Jing LI xiao-Zeng College of Chemistry and Chemical Engineering Zhoukou Normal UniversityZhoukou 466001China Department of Chemistry School of ScienceTianjin Universityand Collaborative Innovation Center of Chemical Science and EngineeringTianjin 300072China

Two new heterobimetallic coordination polymers{[Co(NiL)(H2O)3]·4H2O}n(1)and{[Cu(NiL)(H2O)3]·4H2O}n(2)were synthesized based on metalloligand under the same self-assembly conditions.X-ray diffraction analyses reveal that the two compounds involve close-packed zigzag chains,which expand into various three-dimensional supramolecular frameworks through the second interactions such as hydrogen bonds andπ···πstacking *** these two compounds,NiL as a bridging ligand chelates the metal ion nodes via two oxamido carbonyls and carboxylate oxygen *** central Co(Ⅱ)and Cu(Ⅱ)ions in 1 and 2 both exhibit distorted octahedral coordination *** are bridged by macrocyclic oxamido metalloligands fusing the zigzag chains with a‘‘head-to-tail’’*** Ni(Ⅱ)ion in metalloligand is coordinated by four nitrogen atoms with the[NiN4]chromophore exhibiting distorted *** two investigated compounds were further characterized by thermogravimetric analysis and FT-IR *** fluorescent properties of 1 and 2 in the solid state were also investigated.

关键词： zigzag chain heterobimetallic metalloligand crystal structure fluorescence

Prevalence and Correlates of Elevated Blood Pressure in Chinese Children Aged 6-13 Years: a Nationwide School-Based Survey

在线全文

学校读者我要写书评

暂无评论

Biomedical and Environmental Sciences 2015年第6期28卷 401-409页

作者： ZHAI Yi LI Wei Rong SHEN Chong Frank QIAN shi xiao ming Division of Non-communicable Disease Control and Community Health Chinese Center for Disease Control and Prevention Office of Medical Statistics Beijing Friendship Hospital Department of Division of Epidemiology and Biostatistics School of Public HealthNanjing Medical University Center for Global Health University of Chicago Institute of Environmental Health and Related Product Safety Chinese Center for Disease Control and Prevention

Objective To estimate the prevalence of elevated blood pressure（EBP） in Chinese children and identify individual and family factors associated with EBP. Methods A nationwide cross-sectional study was conducted in 2010 using stratified cluster sampling. Participants＇ blood pressure was measured, and their parents completed a questionnaire on personal and family characteristics. Prevalence and correlates of EBP were assessed. Results Among a total of 24,333 participants, 20.2% of boys and 16.3% of girls had EBP. The prevalence of EBP increased with the ascending trend of waist circumference, Waist-to-height ratio, and body mass index. The adjusted prevalence ratios（aP Rs） for obese boys and girls were 2.50 and 2.97, respectively. Fewer urban boys（16.2%） had EBP than rural boys（21.7%）. Boys with a family history of hypertension were 12% more likely to have EBP. Children whose mothers received a college education tended to have lower likelihood of EBP; with an aP R was 0.85 among boys and 0.78 among girls. Conclusion EBP is common among obese students and those who have a family history of hypertension. A negative association between mothers＇ education levels and EBP risk in children was found.

关键词： Elevated blood pressure Waist circumference Waist-to-height ratio Body mass index Children Cross-sectional study China

稀土元素Ce对AISI 410钢膏剂渗硼层组织与性能的影响

在线全文

学校读者我要写书评

暂无评论

材料热处理学报 2024年第4期45卷 159-166页

作者：石铭霄徐清鹏李敬勇茅卫东李盛良杨志东江苏科技大学材料科学与工程学院江苏镇江212003 奇瑞新能源汽车有限公司安徽芜湖241003 安徽省新能源汽车轻量化技术重点实验室安徽芜湖241003

钢的表面强化技术在各个工业领域的应用都具有重要的实际意义。渗硼技术是最经济的选择之一,然而,该技术存在的主要问题是难以获得厚且致密的渗硼层。为解决这一问题,在AISI 410不锈钢表面进行了添加6 mass%的CeO_(2)的膏剂渗硼处理。... 详细信息

钢的表面强化技术在各个工业领域的应用都具有重要的实际意义。渗硼技术是最经济的选择之一,然而,该技术存在的主要问题是难以获得厚且致密的渗硼层。为解决这一问题,在AISI 410不锈钢表面进行了添加6 mass%的CeO_(2)的膏剂渗硼处理。采用光学显微镜、扫描电镜、X射线衍射、摩擦磨损实验和电化学工作站等研究了渗硼层的组织、物相和耐蚀耐磨性能。结果表明:渗硼层的显微组织由外到内分别是FeB和Fe_(2)B。在渗硼剂中添加CeO_(2)可以使AISI 410不锈钢基体表面产生更厚、更致密的渗硼层,从而提高其耐磨性和耐蚀性。稀土元素铈的催化机理可以归结为两个方面。首先,添加CeO_(2)可以参与渗硼过程中的化学反应,从而产生更活跃的硼原子。二是由于Ce原子尺寸大,扩散到钢表面会产生严重的晶格畸变,从而促进了硼原子的扩散。

关键词：膏剂渗硼二氧化铈微观组织耐磨性耐蚀性

Vortex identification based on the Liutex method and its effect on fish passage upstream

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2024年第1期36卷 130-141页

作者： Chun-ying Shen Rui-guo Yang xiao-tao shi ming-ming Wang shi-hua He Faculty of Electrical Power Engineering Kunming University of Science and TechnologyKunming650500China Hubei International Science and Technology Cooperation Base of Fish Passage China Three Gorges UniversityYichang443002China Shanghai Investigation Design and Research Institute Co.LtShanghai200434China

Fishway research is important for mitigating the fragmentation of river habitats caused by hydraulic *** vertical slit fishway is a broadly used fishway type because of its high efficiency and adaptability to water ***,the resulting vortex current disrupts the fish passage hence directly affecting fish *** study aims to accurately capture the vortex structure in the fishway and analyze the effect of vortex elements(vortex structure,vortex intensity,etc.)on *** conducted an analysis of the 3-D current flow field in the fishway through the utilization of an experimental model and the large eddy simulation(LES)***,we captured the vortex information in the fishway at different flow rates using the Liutex vortex identification method and investigated the effect of the vortex on fish *** results revealed that the structures inside the fishway pool occupy most of the room,however,the areas with higher vortex strength were primarily located in the vortex near the vertical seam and the mainstream,the vortex strength inside the fishway gradually increases with increasing flow,suppressing fish *** experienced significantly increased resistance when encountering strong *** suggests that the vortex may act as a physical barrier to fish *** findings highlight the potential negative effects of vortex on fish movement and reiterate the importance of understanding vortex dynamics for aquatic environmental *** an effective tool for identifying vortices in fluid flow,the Liutex method demonstrates features of vortex within the fishway,thereby providing important insights into the interaction between fluid dynamics and aquatic organisms.

关键词： Vertical slit fishway vortex identification method Liutex large eddy simulation(LES) fish experiment computational fluid dynamics

Effect of Primary Elective Cesarean Delivery on Placenta Accreta： A Case-Control Study

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

Chinese Medical Journal 2018年第6期131卷 672-676页

作者： xiao-ming shi Yan Wang Yan Zhang Yuan Wei Lian Chen Yang-Yu Zhao Department of Obstetrics and Gynaecology Peking University Third Hospital Beijing 100191 China

Background： Cesarean section （CS） is an independent risk factor for placenta accreta. Some researchers think that the timing of primary cesarean delivery is associated with placenta accreta in subsequent pregnancies. The aim of this study was to investigate the risk of placenta accreta following primary CS without labor, also called primary elective CS, in a pregnancy complicated with placenta previa. Methods： A retrospective, single-center, case-control study was conducted at Peking University Third Hospital. Relevant clinical data of singleton pregnancies between January 2010 and September 2017 were recorded. The case group included women with placenta accreta who had placenta previa and one previous CS. Control group included women with one previous CS that was complicated with placenta previa. Maternal age, body mass index, gestational age, fetal birth weight, gravity, parity, induced abortion, the rate of women received assisted reproductive technology, other uterine surgery, and primary elective CS were analyzed between the two groups. Results： The rate of primary elective CS （90.1% vs. 69.9%, P 〈 0.001 ） was higher, and maternal age was younger （32.7 ± 4.7 years vs. 34.6 ± 4.0 years, P 〈 0.001） in case group, compared with control group. Case group also had higher gravity and induced abortions compared with the control group （both P 〈 0.05）. Primary CS without labor was associated with significantly increased risk of placenta accreta in a subsequent pregnancy complicated with placenta previa （odds ratio： 3.32; 95% confidential interval： 1.68-6.58）. Conclusion： Women with a primary elective CS without labor have a higher chance of developing an accreta in a subsequent pregnancy that is complicated with placenta previa.

关键词： Cesarean Section Placenta Accreta Placenta Previa