检索结果-南通市图书馆

在线全文

学校读者我要写书评

暂无评论

矿井井下粉尘的危害与治理探析

世界有色金属 2024年第2期 205-207页

作者：郝飞张永红罗鸿贵州开磷有限责任公司贵州贵阳550302

随着工业化的不断发展,矿山行业的规模和产量也在不断地增加。然而,在矿山开采过程中,由于各种因素的影响,如采掘机具磨损、通风系统不完善等原因,导致了大量的粉尘飞扬到地面上,形成了大量粉尘。这些粉尘不仅对工人的身体健康造成了威... 详细信息

随着工业化的不断发展,矿山行业的规模和产量也在不断地增加。然而,在矿山开采过程中,由于各种因素的影响,如采掘机具磨损、通风系统不完善等原因,导致了大量的粉尘飞扬到地面上,形成了大量粉尘。这些粉尘不仅对工人的身体健康造成了威胁,还会对周边环境造成污染。因此,如何有效地控制矿井井下粉尘的产生和扩散已经成为当前研究的重要课题之一。首先,需要了解矿井井下粉尘产生的原理以及其对人体造成的危害。其次,针对不同的矿井类型和工作条件,应该采取相应的措施来减少粉尘的生成量并降低其浓度。最后,对于已经存在的粉尘问题,可以通过加强通风系统的建设、增强员工的工作防护意识等方面进行治理。综上所述,通过科学合理的管理手段可以有效控制矿井井下粉尘的产生和扩散,保障矿工身体健康的同时也保护了周围环境的安全。本文将从以上三个方面展开论述,以期能够为矿井井下粉尘问题的解决提供一定的参考价值。

关键词：矿井井下粉尘危害治理

维普期刊数据库博看期刊

在线全文

学校读者我要写书评

暂无评论

生态城市背景下市政给排水规划设计研究

工程建设与设计 2024年第11期 80-82页

作者：何永平董洁张永红中国城市发展规划设计咨询有限公司北京100120

研究了生态城市背景下市政给排水规划设计要点,在明确生态城市理念的基础上,从给水系统、雨水系统、污水系统角度出发,分析了市政给排水规划设计中存在的主要问题,并提出了针对性优化措施:根据城市发展现状和未来需求,明确城市供水、排... 详细信息

研究了生态城市背景下市政给排水规划设计要点,在明确生态城市理念的基础上,从给水系统、雨水系统、污水系统角度出发,分析了市政给排水规划设计中存在的主要问题,并提出了针对性优化措施:根据城市发展现状和未来需求,明确城市供水、排水压力,提高管网规划设计水平,减少生态环境破坏,在正确处理开发与保护矛盾的同时,促进人与自然和谐相处。

关键词：生态城市理念市政工程给排水规划设计

维普期刊数据库博看期刊

Molecular Dynamics Simulation Study of MgO Crystal

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 1999年第4期16卷 235-237页

作者： zhang yong-hong HUANG Shi-ping Institute of Materials Shanghai UniversityShanghai 200072 Shanghai Enhanced Laboratory of Ferrometallurgy Shanghai UniversityShanghai 200072

Molecular dynamics simulation of MgO crystal at different temperature and pressure was carried out by using the shell model of ionic *** prediction of thermal expansion is in good agreement with the *** heat capacity has been calculated with a semi-classical approximate *** calculated values are less than the experimental data because the anharmonic effect and quantum correlation were not taken into *** changes of transverse-optic and longitudinal-optic modes with the compression ration are also calculated.

关键词： Molecular Crystal transverse

Development of PLC-based Tension Control System

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 Journal of Aeronautics 2007年第3期20卷 266-271页

作者： REN Sheng-le LU Hua WANG yong-zhang FU hong-ya Department of Mechanical Engineering Harbin Institute of Technology Harbin 150001 China

Fiber winding tension is an important factor in the molding techniques of composite material which influences the quality of winding product directly, and the tension control is a key technique in fiber winding techniques. This paper introduces a closed-loop tension control system with the programmable logic controller （PLC） with function modules as its control kernel, the alternating current （AC） servo motor as execute element and the radius-following device to accomplish the real-time radius compensation. The mechanism of the tension control system is analyzed and the numerical model is set up. The compensation technique of the radius of the scroll is analyzed. Experimental results show that the system is well qualified with high control precision and high reaction speed.

关键词： tension control PLC numerical control winding machine AC digital servo motor

Development of a PC-based Open Architecture Software-CNC System

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2007年第3期20卷 272-281页

作者： MA Xiong-bo HAN Zhen-yu WANG yong-zhang FU hong-ya School of Electromechanical Engineering Harbin Institute of Technology Harbin 150001 China

As a key te..hnology in the field of advanced manufacturing, an open architecture controller is studied. In order to develop an open architecture software-CNC system on personal computer （PC） according to open modular architecture controllers （OMAC）. First, the software and hardware platform is chosen and software realization methodology for the CNC system is determined. Second, static modeling methods of an open architecture controller inclusive of object-oriented （OO） programming technology, dynamic link library （DLL） technology and system modules partition are investigated. Third, the dynamical behavioral modeling and the data flow representation of open architecture controller are discussed, which are both described in hierarchy fmite state machine （FSM） model. Fourth, a reusable software module model is established to develop software function module library. Finally, a 3-axis milling machine tool test-bed, named for HIT-CNC, is successfully designed by means of the constructed software function module library and the system configuring method. The experimental results show that, besides increasing the degree of reusability and openness, application of above-mentioned method- ology leads to significant decrease of development time as well as maintenance cost.

关键词： open architecture controller PC soflware-CNC behavioral model OMAC machine tool

Measures of Abdominal Adiposity and Risk of Stroke:A Dose-Response Meta-analysis of Prospective Studies

在线全文

学校读者我要写书评

暂无评论

Biomedical and Environmental Sciences 2016年第1期29卷 12-23页

作者： Zhong Chong Ke Zhong Xiao Yan Xu Tan zhang yong hong Department of Epidemiology School of Public Health and Jiangsu Key Laboratory of Preventive and Translational Medicine for Geriatric DiseasesMedical College of Soochow UniversitySuzhou 215123JiangsuChina School for Radiological&Interdisciplinary sciences(RAD-X) and School of Radiation Medicine and ProtectionSoochow UniversitySuzhou 215123JiangsuChina

Objective Waist circumference, waist-to-hip ratio and waist-to-height ratio, which are the indicators or measures of abdominal adiposity, have long been hypothesized to increase the risk of stroke; yet evidence accumulated till date is not conclusive. Here, we conducted a dose-response meta-analysis to summarize evidences of the association between these measures of abdominal adiposity and the risk of stroke. Methods PubMed and Web of Science databases were searched from inception to May 2015. Two investigators independently conducted the study selection and data extraction. Dose-response relationships were assessed by the generalized least squares trend estimation, while the summary effect estimates were evaluated by the use of fixed- or random-effect models. Subgroup and sensitivity analyses were performed to assess the potential sources of heterogeneity and the robustness of the pooled estimation. Publication bias of the literature was evaluated using Begg＇s and Egger＇s test. Results Altogether 15 prospective cohort studies were identified in this study. The summary of relative risks （95% confidence intervals） of stroke for the highest versus the lowest categories was 1.28 （1.18-1.40） for waist circumference, 1.32 （1.21-1.44） for waist-to-hip ratio, and 1.49 （1.24-1.78） for waist-to-height ratio. For a 10-cm increase in waist circumference, the relative risk of stroke increased by 10%; for a 0.1-unit increase in waist-to-hip ratio, the relative risk increased by 16%; and for a 0.05-unit increase in waist-to-height ratio, the relative risk increased by 13%. There was evidence of a nonlinear association between waist-to-hip ratio and stroke risk, Pnonlinearity=0.028, Conclusion Findings from our meta-analysis indicated that waist circumference, waist-to-hip ratio, and waist-to-height ratio were positively associated with the risk of stroke, particularly ischemic stroke.

关键词： Abdominal adiposity Waist circumference Waist-to-hip ratio Waist-to-height ratio Stroke Cohort studies Meta-analysis

On the application of DInSAR to deformation monitoring in desert areas

在线全文

学校读者我要写书评

暂无评论

Applied Geophysics 2011年第1期8卷 86-93,96页

作者： Chang Xiao-Tao Guo Jin-Yun zhang yong-hong Wang Xiao-Qing Satellite Surveying and Mapping Center State Bureau of Surveying and Mapping Beijing 100830 China Shandong University of Science and Technology Qingdao 266510 China Chinese Academy of Surveying and Mapping Beijing 100830 China National Geomatics Center of China Beijing 100830 China.

The DInSAR technique is used for monitoring the desert height changes to study sandstorms. Hunshandake Sandy Land, as the test area, is one of the main sources of sandstorms in Beijing. In order to study the sandstorm source and its impact, a pair of EnviSat ASAR images of Oct. 11, 2005, and Oct. 26, 2004, is processed on the basis of analysis of six ERS-2 and EnviSat radar images. After the image configuration, flat earth effect correction, data filtering, phase unwrapping, and geo-coding, a deformation model over Hunshandake desert is built. According to the results, the height decreased in most areas and increased in a few areas, which basically coincides with the strong sandstorm appearing in Beijing in the Spring of 2005. The results show DInSAR has an important role in monitoring of desert surface deformation.

关键词： DInSAR Hunshandake Sandy Land height change monitoring sandstorm

家蚕体内细菌感染模型建立及不同菌株的协同致病特征分析

在线全文

学校读者我要写书评

暂无评论

南方农业学报 2024年第6期55卷 1854-1862页

作者：范仕弘邵榆岚张永红罗家福李玲利苏振国白兴荣云南省农业科学院蚕桑蜜蜂研究所云南红河州661101

【目的】建立家蚕体内细菌感染模型,揭示不同细菌协同感染家蚕的致病力,明确云南蚕区家蚕细菌病的发病原因及其规律,为指导家蚕生产过程中细菌病的防治提供科学依据。【方法】从家蚕龄期、感染浓度和感染方法3个因素出发构建家蚕体内细... 详细信息

【目的】建立家蚕体内细菌感染模型,揭示不同细菌协同感染家蚕的致病力,明确云南蚕区家蚕细菌病的发病原因及其规律,为指导家蚕生产过程中细菌病的防治提供科学依据。【方法】从家蚕龄期、感染浓度和感染方法3个因素出发构建家蚕体内细菌感染模型,然后选用从云南地区自然发病蚕体中分离获得的5株肠道致病菌[Mammaliicoccus sciuri(葡萄球菌属)、粘质沙雷氏菌(Serratia marcescens)、弗氏柠檬酸杆菌(Citrobacter freundii)、Klebsiella variicola(克雷伯菌属)和Pseudomonas soli(假单胞菌属)],开展5种单菌感染及17种组合协同感染试验。【结果】通过建立家蚕体内细菌感染模型发现,家蚕群体添食细菌比单头添食的存活率低;细菌感染浓度选择时建议二龄期家蚕感染选用5.0 OD/mL、四龄期和五龄期家蚕感染选用10.0 OD/mL。选取的5株细菌对家蚕均具有致病力,整体上表现为随着细菌感染时间的延长,家蚕存活率逐渐降低;小蚕期感染细菌对家蚕的影响更明显,至五龄期有大量家蚕发病死亡,与养蚕过程中的细菌病发生规律相同。无论是小龄期感染还是大龄期感染,细菌协同感染的家蚕存活率总体上低于单菌感染,尤其是粘质沙雷氏菌参与的协同感染,至上蔟期的家蚕存活率均较低。此外,无论是二龄期感染还是四龄期感染,夏季家蚕的存活率总体上均高于春季家蚕,说明云南蚕区夏季家蚕的抗病力优于春季家蚕。【结论】5株分离自云南地区自然发病蚕体的病原菌对家蚕产生明显致病性,其致病性与感染龄期、感染浓度、不同细菌组合及感染季节等均有关,总体上具体表现为小蚕期感染较大蚕期感染对家蚕的影响更明显,细菌协同感染比单菌感染的危害更严重,且夏季家蚕感染后的存活率高于春季家蚕。

关键词：家蚕肠道致病菌细菌感染模型存活率协同感染

维普期刊数据库博看期刊

Combined Effects of A Body Shape Index and Serum C-reactive Protein on Ischemic Stroke Incidence among Mongolians in China

在线全文

学校读者我要写书评

暂无评论

Biomedical and Environmental Sciences 2019年第3期32卷 169-176页

作者： WANG Guang Li zhang Rui ZHOU Yi Ting WANG Ai Li XU Tian zhang Ming Zhi LI hong Mei zhang yong hong Department of Epidemiology School of Public Health and Jiangsu Key Laboratory of Preventive and Translational Medicine for Geriatric Diseases Medical College of Soochow University Department of Neurology Affiliated Hospital of Nantong University

Objective We aimed to evaluate the combined effects of a high body shape index(ABSI) and a high serum C-reactive protein(CRP) level on the incidence of ischemic stroke in a Mongolian population in China. Methods A prospective cohort study was conducted among 2,589 participants from June 2002 to July 2012 in Inner Mongolia, China. The participants were categorized into 4 groups according to their level of ABSI and CRP. Cox proportional hazards models were used to assess the hazard ratios(HRs) and 95% confidence intervals(CIs) for ischemic stroke among all groups. Results The multivariate adjusted HRs(95% CI) of ischemic stroke for high ABSI and high CRP level were 1.46(0.89-2.39) and 1.63(0.95-2.79), respectively. Compared with the low ABSI/low CRP level group, the multivariate adjusted HRs(95% CI) of ischemic stroke in the low ABSI/high CRP, high ABSI/low CRP, and high ABSI/high CRP groups were 1.04(0.46-2.35), 1.06(0.58-1.95) and 2.52(1.27-5.00), respectively. The HR of ischemic stroke for the high ABSI/high CRP level group was the highest and most statistically significant. Conclusion We found that participants with simultaneously high ABSI and high CRP levels had the highest risk of ischemic stroke in the Mongolian population. Our findings suggest that the combination of high ABSI and high CRP levels may increase the risk of ischemic stroke.

关键词： A body shape index C-reactive protein Ischemic stroke