检索结果-南通市图书馆

Journal of China University of Mining and Technology 2008年第2期18卷 182-186页

作者： WANG Liang CHENG Yuan-ping LI Feng-rong WANG hai-feng LIU hai-bo National Engineering Research Center for Coal ＆ Gas control China University of Mining ＆ Technology Xuzhou Jiangsu 221008 China haizi Coal Mine Huaibei Mining Industry Group Huaibei Anhui 235000 China

When an extremely thick rock bed exists above a protected coal seam in the bending zone given the condition of a mining protective seam, this extremely thick rock bed controls the movement of the entire overlying stratum. This extremely thick rock bed, called a ＂main key stratum＂, will not subside nor break for a long time, causing lower fractures and bed separations not to close and gas can migrate to the bed separation areas along the fractures. These bed separations become gas enrichment areas. By analyzing the rule of fracture evolution and gas migration under the main key stratum after the deep protective coal seam has been mined, we propose a new gas drainage method which uses bore holes, drilled through rock and coal seams at great depths for draining pressure relief gas. In this method, the bores are located at a high level suction roadway （we can also drill them in the drilling field located high in an air gateway）. Given the practice in the haizi mine, the gas drainage rate can reach 73% in the middie coal group, with a gas drainage radius over 100 m.

关键词： extremely thick key stratum protective seam exploitation fracture evolution gas drainage distant borehole drilling

基于概率感知模型的线性无线传感网络可靠性分析

在线全文

学校读者我要写书评

暂无评论

计算机系统应用 2024年第9期33卷 183-191页

作者：李兆贾正锋杨海波沈阳工业大学信息科学与工程学院沈阳110870

线性无线传感网络(linear wireless sensor network,LWSN)广泛应用于监测铁路、天然气管道等线性拓扑的关键基础设施,其可靠性至关重要,其中覆盖率是衡量可靠性的重要指标.目前在评估LWSN覆盖率的方法大多采用0/1圆盘感知模型,但实际中... 详细信息

线性无线传感网络(linear wireless sensor network,LWSN)广泛应用于监测铁路、天然气管道等线性拓扑的关键基础设施,其可靠性至关重要,其中覆盖率是衡量可靠性的重要指标.目前在评估LWSN覆盖率的方法大多采用0/1圆盘感知模型,但实际中传感器的监测可靠性随着覆盖半径增加呈概率分布.因此,提出了一种基于概率感知模型的可靠性分析方法,该模型可根据传感器的物理参数计算其有效感知范围,进而提升了评估的准确性.为减小系统状态空间的大小,采用二元决策树构造LWSN的系统状态集合.本文假设节点的故障概率符合Weibull分布并针对不同通信半径和感知范围进行仿真实验,结果表明该方法可以有效地对LWSN的可靠性进行评估,评估准确率相比0/1圆盘感知模型更精准.

关键词：线性无线传感网络(LWSN) 可靠性概率感知模型二元决策树 Weibull分布

同方期刊数据库

在线全文

学校读者我要写书评

暂无评论

青海省三江源生态功能区文旅融合发展实证

湖北农业科学 2024年第3期63卷 1-7页

作者：张杰季海瑞张剑勇青海师范大学经济管理学院西宁810016 青海师范大学高原与可持续发展研究院西宁810016

为探究三江源生态功能区文旅融合发展的可行性,实现高质量文旅发展,基于文化、旅游耦合协调机理,采用2010—2020年的面板数据,通过耦合协调模型,从时间与区域分布对三江源生态功能区文旅产业耦合协调发展水平进行实证分析。结果表明,201... 详细信息

为探究三江源生态功能区文旅融合发展的可行性,实现高质量文旅发展,基于文化、旅游耦合协调机理,采用2010—2020年的面板数据,通过耦合协调模型,从时间与区域分布对三江源生态功能区文旅产业耦合协调发展水平进行实证分析。结果表明,2010—2020年,三江源生态功能区文化产业和旅游产业的发展整体呈上升趋势,但文化产业的发展滞后于旅游产业;从区域分布看,各州文化产业和旅游产业发展不同步,东、西部发展不协调。三江源生态功能区文旅融合总体上历经中度失调—轻度失调—濒临失调的阶段,随着各州耦合协调度的不断增长,耦合协调水平差距在缩小,但大部分州仍处于低水平阶段。三江源生态功能区东部地区文旅融合水平优于西部地区,黄南州依靠资源优势和地理条件,产业融合发展最优,达到中水平耦合协调。三江源生态功能区文化产业和旅游产业相互配合、相互支撑,文旅融合有利于促进产业间的转型升级,帮助两大产业提质增效。

关键词：文化产业旅游产业文旅融合三江源生态功能区青海省

基于大数据的地铁供电系统运行状态预测与维护

在线全文

学校读者我要写书评

暂无评论

价值工程 2024年第2期43卷 45-47页

作者：庞浩倪海超郝志升北京市轨道交通运营管理有限公司北京102600

为提升地铁供电系统运行状态的预测与维护效能,本文使用大数据分析地铁供电系统电流特征,精确识别不同站点和线路的峰谷情况。通过发现电流数据中的异常偏离点,实现对异常点数据的历史统计和实时提醒功能。同时增强了对设备管理的宏观... 详细信息

为提升地铁供电系统运行状态的预测与维护效能,本文使用大数据分析地铁供电系统电流特征,精确识别不同站点和线路的峰谷情况。通过发现电流数据中的异常偏离点,实现对异常点数据的历史统计和实时提醒功能。同时增强了对设备管理的宏观把控。利用大数据收集每类电能质量指标参数及相关关键因素数据构建训练样本,通过支持向量机模型得到新建城轨线路的电能质量预测数据。为了评估系统可用性,采用序贯Monte Carlo法进行计算。结果显示,大数据方法预测准确性,达到92%。随着故障数量的增加,大数据方法的耗时仍能维持相对较低的水平,分别为2.2、3.5、5.1分钟,为地铁供电系统的整体性能提升提供了强有力的支持。

关键词：地铁供电系统大数据分析支持向量机实时提醒预测准确性

Abrasive Wear Map of Polymer Tapes in Sand Dust Environment

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

Journal of China University of Mining and Technology 2006年第2期16卷 128-131页

作者： WU Tong-hai DIAO Dong-feng Key Laboratory of Education Ministry for Modern Design and Rotor-Bearing System Xi＇ an Jiaotong University Xi＇an shaanxi 710049 China

To make clear the wear conditions of ATM (Automatic Teller Machine) tribosystem when servicing in Chi- nese sand dust environment, abrasive wear of two kinds of polymer tapes specified for ATM, PI (Polyimide) and PEN (Polyethylene-2, 6-naphthalenedicarboxylate), was investigated in simulated sand dust environment with ATM tape-scraper tribosystem under various conditions of loads and sliding distances. The surface profiles of worn tape were measured with a surface profiler in order to calculating the wear cross-section areas and the wear volumes. The specific wear rates of polymer tapes were calculated under load conditions of 0.6, 1 and 1.5 N, and wear mechanisms were in- vestigated with optical topography photos. As main results, the specific wear rates show stage variations in the wear process and the wear resistance of polymer tape shows good relationship with the mechanical deformation factors. In consideration of the service life, four wear models are generalized according to the magnitude of specific wear rates, which include no wear, mild wear, normal wear and severe wear model and the corresponding wear mechanisms for the four wear models are discussed with typical worn topographies. Based on the wear models and corresponding wear mechanisms, the abrasive wear maps of two polymer tapes servicing in sand dust environments are concluded for its industrial applications.

关键词： abrasive wear polymer wear map sand dust environment

变形和能量注入协同作用制备可控非晶纳米晶结构超高饱和磁化强度FeCoB粉末

在线全文

学校读者我要写书评

暂无评论

Science China Materials 2024年第6期67卷 1985-1993页

作者：李枧邵里良白荣晟周靖童星林怀俊张猛柯海波汪卫华 Institute of Advanced Wear&Corrosion Resistance and Functional Materials Jinan UniversityGuangzhou 510632China Songshan Lake Materials Laboratory Dongguan 523808China Institute of Physics Chinese Academy of SciencesBeijing 100190China

非晶纳米晶磁粉芯(ANMPCs)是电子元器件在高频应用的关键软磁材料.但其相对较低的饱和磁化强度无法满足器件的小型化要求.强Fe-Co交换耦合非晶纳米晶粉是制备高磁化强度ANMPCs的潜在材料.本文采用机械球磨法制备了一系列(Fe_(0.8)Co_(0.... 详细信息

非晶纳米晶磁粉芯(ANMPCs)是电子元器件在高频应用的关键软磁材料.但其相对较低的饱和磁化强度无法满足器件的小型化要求.强Fe-Co交换耦合非晶纳米晶粉是制备高磁化强度ANMPCs的潜在材料.本文采用机械球磨法制备了一系列(Fe_(0.8)Co_(0.2))_(87)B_(13)软磁粉末,这些粉末的非晶相、纳米晶相含量和粒径可调.在球磨过程中,出现了合金化、玻璃化和纳米化三个阶段以及粉末形貌和尺寸的非线性变化,进而导致ANMPCs软磁性能的非单调变化.磁粉具有超高饱和磁化强度达239 emu g^(-1),有效磁导率为33.球磨150 h后,FeCoB粉末非晶-纳米晶双相结构达到动态平衡,同时粒径达亚微米尺度,从而提高了粉末高频稳定性且降低了磁芯损耗.在变形和能量注入的协同作用下,机械球磨实现了含极高铁磁元素的非晶-纳米晶双相粉末可控制备、提高了高磁化强度ANMPCs综合软磁性能.

关键词： amorphous-nanocrystalline magnetic powder core mechanical ball milling ultrahigh ferromagnetic element sa-turation magnetization high-frequency properties

Advancing the predictive accuracy of PNTML in rectal prolapse:An ongoing quest

在线全文

学校读者我要写书评

暂无评论

World Journal of Clinical Cases 2024年第29期12卷 6266-6270页

作者： Jin Meng Zhi-Gang Wang Li-Mei Zhang De-Yu Chen Ying Wang hai-Xia Bai Cheng-Chun Ji De-Long Liu Xiao-Fei Zhao Yuan Liu Bo-Yang Li Lei Wang Tian-Fu Wang Wei-Gang Yu Zhi-Tao Yin Department of Anorectal Disease Shenyang Coloproctology HospitalShenyang 110000Liaoning ProvinceChina Department of Neurology Central Hospital of Dalian University of TechnologyDalian 116001Liaoning ProvinceChina Department of Acupuncture and Tuina college Liaoning University of Traditional Chinese MedicineShenyang 110032Liaoning ProvinceChina

Fecal incontinence is a common symptom among patients with rectal *** nerve terminal motor latency(PNTML)testing can serve as a reference indicator for predicting the outcomes of rectal prolapse surgery,thereby assisting surgeons in formulating more appropriate surgical *** direct correlation between preoperative PNTML testing results and postoperative fecal incontinence in patients with rectal prolapse remains a contentious issue,necessitating further ***,we analyze the existing publications from both clinical and statistical perspectives to comprehensively evaluate the accuracy of preoperative PNTML testing in rectal prolapse and provide some feasible statistical solutions.

关键词： Rectal prolapse Fecal incontinence Anal manometry Pudendal nerve terminal motor latency Diagnosis Surgical procedures

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

杨志波教授运用培土生金法治疗银屑病经验

中国药物经济学 2024年第4期19卷 126-129页

作者：汪碧滢汪海珍湖南中医药大学第二中医临床学院长沙410208 湖南中医药大学第二附属医院皮肤科长沙410005

银屑病是一种免疫介导的慢性复发性炎症性疾病,随着现代生活压力和环境污染的加剧,银屑病的发病率不断上升、发病年龄呈年轻化趋势。杨志波教授认为银屑病发病与“风邪致肺气失宣”及“湿邪致脾失健运”相关,故在诊治中重视肺脾同治,运... 详细信息

银屑病是一种免疫介导的慢性复发性炎症性疾病,随着现代生活压力和环境污染的加剧,银屑病的发病率不断上升、发病年龄呈年轻化趋势。杨志波教授认为银屑病发病与“风邪致肺气失宣”及“湿邪致脾失健运”相关,故在诊治中重视肺脾同治,运用“培土生金”法,注重内外兼治,整体调理,临床疗效显著。

关键词：银屑病培土生金杨志波

Association between complement factor I gene polymorphisms and the risk of age-related macular degeneration:a Meta-analysis of literature

在线全文

学校读者我要写书评

暂无评论

International Journal of Ophthalmology(English edition) 2016年第2期9卷 298-305页

作者： Qin Wang hai-Sheng Zhao Li Li Department of Ophthalmology the Second Affiliated Hospital of Chongqing Medical University Center of Ophthalmology the Second Affiliated Hospital of Chongqing Medical University

AIM： To systematically review the association between complement factors I （CFI） polymorphisms and age- related macular degeneration （AMD） and to explore whether CFI polymorphisms are associated with AMD, METHODS： Meta-analysis of articles published from 1995 to January 2015 of articles involved with AMD and polymorphisms of the CFI gene. Eligible data were pooled in a Meta-analysis, analyzing using STATA software （version 12.0）, Review Manager （version 5.2） and different models based on the heterogeneity of effect sizes. Egger＇s test, Begg＇s rank correlation methods were used to evaluate for publication bias.~ RESULTS： Thirteen articles were eligible, describing two loci polymorphisms of the CFI gene （of which 12 articles focus on rs10033900T〉C and 3 articles focus on rs2285714C〉T）. For rs10033900T〉C, the results of our study revealed that having a mutant allele C, TC, CC and TC＋CC was associated with a decreased risk of AMD in all population groups studied （C versus T models, OR=0.84, 95%Ch 0.72-0.99, P=0.04; TC versus TT models OR= 0.89, 95%Ch 0.88-0.99, P=0.04;CC versus ＂1-1＂ models, OR=0.76, 95%Ch 0.60-0.98, P=-0.03; TC＋CC versus TT models, OR=0.81, 95%Ch0.65-0.99, P=0.04）. We found that C allele were related to lower AMD risk in the Caucasian population by subgroup analysis, but there was no association with AMD under the allele and genotypes comparison in Asian studies. For rs2285714 C〉T, the TC, TT genotypes contributed to a higher risk of AMD, compared with the CC carriers and CT＋CC （OR=1.34, 95%Ch 1.09-1.63, P=0.004; OR=1.50, 95%Ch 1.25-1.80, P〈0.0001）. CONCLUSION： This Meta-analysis suggests that CFI rs10033900T〉C and rs2285714C〉T polymorphisms may contribute to AMD.

关键词： complement factors I age-related maculardegeneration age-related maculopathy single-nucleotidepolymorphisms Meta-analysis

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

秦岭北麓地下水水文地球化学演化规律及模式

长江科学院院报 2024年第4期41卷 62-69页

作者：袁磊马涛韩双宝李甫成吴玺李海学中国地质调查局水文地质环境地质调查中心河北保定071051 中国地质调查局地下水勘查与开发工程研究中心河北保定071051

秦岭北麓是黄河重要的水源涵养区,分析其水文地球化学特征及演化模式对于加强秦岭地下水资源的开发与保护、推进关中平原乃至黄河流域生态保护与高质量发展具有重要意义。利用2019—2021年在渭河流域开展水文地质调查所获取的资料,运用... 详细信息

秦岭北麓是黄河重要的水源涵养区,分析其水文地球化学特征及演化模式对于加强秦岭地下水资源的开发与保护、推进关中平原乃至黄河流域生态保护与高质量发展具有重要意义。利用2019—2021年在渭河流域开展水文地质调查所获取的资料,运用数理统计、水文地球化学反向模拟等方法,分析了秦岭至渭河河谷地下水的水文地球化学演化规律及模式。结果表明:由基岩区至细土平原区,地下水水化学类型由HCO3-Ca型向HCO3·SO4-Ca·Na型转变,溶解性固体总量(TDS)浓度由254 mg/L增至889 mg/L,分带性不强;随着地下水流动,水-岩作用主要由碳酸盐岩风化溶滤控制向硅酸盐岩与岩盐风化溶滤控制转变,同时阳离子交换作用增强;14C测年显示研究区地下水年龄多在2 450 a以内,地下水循环更新快,蒸发浓缩作用不显著;山前洪积扇作为地下水重要的涵养区与径流通道,对于关中平原潜水和承压水水质保障有关键作用,由于洪积扇含水层防污性能差,在地下水开发利用和工农业活动中要加强地下水资源的保护。

关键词：地下水保护秦岭北麓水文地球化学溶解性固体总量(TDS) 离子比演化规律