检索结果-南通市图书馆

不同放牧管理方式对新疆山地草原植物群落特征的影响

在线全文

学校读者我要写书评

暂无评论

干旱区研究 2024年第1期41卷 124-134页

作者：李小锋惠婷婷李耀明毛洁菲王光宇范连连新疆巴里坤县草原工作站新疆巴里坤839200 中国科学院新疆生态与地理研究所新疆乌鲁木齐830011 中国科学院中亚生态与环境研究中心新疆乌鲁木齐830011 中国科学院大学北京100049

本研究基于巴里坤县国家级山地草原监测站10 a植物群落观测数据,探究了长期不同放牧管理方式(长期禁牧M0、冬季放牧M1和全年放牧M2)对新疆山地草原植物群落特征值、植物多样性及多样性与地上生物量之间关系的影响。结果表明:M0、M1和M2... 详细信息

本研究基于巴里坤县国家级山地草原监测站10 a植物群落观测数据,探究了长期不同放牧管理方式(长期禁牧M0、冬季放牧M1和全年放牧M2)对新疆山地草原植物群落特征值、植物多样性及多样性与地上生物量之间关系的影响。结果表明:M0、M1和M2对优势种沙生针茅重要值无显著影响,M1和M2提高了非优势及草地退化的指示物种芨芨草、醉马草的重要值;随着放牧强度的增加,群落高度、盖度、密度、地上生物量及其响应比显著下降;Shannon-Wiener多样性指数、Simpson优势度指数和Pielou均匀度指数在各放牧处理下均无显著差异,但Margalef丰富度指数随放牧强度显著增加;M0处理地上生物量与Simpson优势度指数、Shannon-Wiener多样性指数和Pielou均匀度指数负相关,M1处理地上生物量与Margalef丰富度指数负相关。随着处理时间的增加,长期禁牧有利于退化草地的恢复,提高了群落特征值,在一定程度上有利于草地生产力的提高和群落稳定性的维持;放牧会影响生态系统中资源的再分配,导致物种多样性的增加,但是全年放牧管理方式下草地则退化加剧。

关键词：放牧管理山地草原群落特征可持续发展物种多样性新疆

输尿管软镜碎石术并发尿脓毒血症风险评估系统的构建及临床应用价值

在线全文

学校读者我要写书评

暂无评论

国际泌尿系统杂志 2024年第1期44卷 82-88页

作者：王光宇刘玉明湖南中医药大学研究生院长沙410000 南华大学附属长沙中心医院泌尿外科长沙410000

目的建立输尿管软镜碎石术(RIRS)的风险评估系统, 以评估术后并发尿脓毒血症的风险。方法选取2021年10月至2022年2月于长沙市中心医院行RIRS治疗的244例患者的临床资料。检索国内外有关RIRS术后并发尿脓毒血症危险因素的文献, 检索时间... 详细信息

目的建立输尿管软镜碎石术(RIRS)的风险评估系统, 以评估术后并发尿脓毒血症的风险。方法选取2021年10月至2022年2月于长沙市中心医院行RIRS治疗的244例患者的临床资料。检索国内外有关RIRS术后并发尿脓毒血症危险因素的文献, 检索时间为建库至2021年12月, 收集检索文献中接受RIRS患者的病例数据, 运用Meta分析筛选RIRS并发尿脓毒血症的危险因素, 构建RIRS术后并发尿脓毒血症风险评估系统(FURSS), 运用受试者工作特征(ROC)曲线验证评估系统的临床应用价值。结果筛选出7个危险因素[性别(女性)、手术时间≥60 min、糖尿病、术前尿培养阳性、结石长径≥1 cm、感染性结石、脓尿]与RIRS术后并发尿脓毒血症的风险相关。根据尿脓毒血症诊断标准, 术后发生尿脓毒血症的比率约为5.3%(13/244)。根据风险评分系统对所收集病例进行评分, 术前评分>6.5分的患者45例, 其中11例患者术后发生尿脓毒血症。ROC曲线下面积为0.890(95%CI:0.818~0.963, P6.5分时, 术后并发尿脓毒血症的风险较高。

关键词：肾结石输尿管结石输尿管软镜碎石术尿源性脓毒症

在线全文

学校读者我要写书评

暂无评论

基于作业分析法的M车间组装线优化研究

现代工业经济和信息化 2024年第2期14卷 200-203页

作者：王光玉刘俊艳青岛科技大学经济与管理学院山东青岛266000

针对某电子加工企业M车间PSS装配线作业台面布局不合理、作业不标准、产线效率低下等问题,通过作业分析方法对PSS装配过程进行分析优化。生产线平衡率由之前的48.89%提升为85.5%,生产效率得到提高,生产过程更加流畅。损失率由之前51.51... 详细信息

针对某电子加工企业M车间PSS装配线作业台面布局不合理、作业不标准、产线效率低下等问题,通过作业分析方法对PSS装配过程进行分析优化。生产线平衡率由之前的48.89%提升为85.5%,生产效率得到提高,生产过程更加流畅。损失率由之前51.51%降低至14.5%,作业人数从23人减少到17人,直接降低人工成本,间接降低管理成本,有益于企业效益的增加。

关键词：工业工程作业分析 ECRS原则产线平衡

Impacts of COVID-19 on tourism and management response from Banff National Park,Canada

在线全文

学校读者我要写书评

暂无评论

林业研究:英文版 2023年第5期34卷 1229-1244页

作者： Christina Dehui Geng Howie WHarshaw Wanli Wu guangyu wang Department of Forest Resources Management Faculty of ForestryUniversity of British ColumbiaVancouverCanada Faculty of Kinesiology Sportand RecreationUniversity of AlbertaEdmontonCanada

The COVID-19 pandemic posed challenges to the tourism sector *** investigated changes in visitor demographics,satisfaction level,and its determinants pre-and *** were collected using questionnaire surveys in 2019 and 2021 within Banff National Park(BNP).The data analyses were based on a sample size of 1183 respondents by conducting factor analysis,correlation analysis and stepwise regression *** highlight that there were fewer international visitors and more local and domestic visitors during the *** attributes were evaluated at a higher satisfaction level *** quality of the Park facilities and services were the most important satisfaction determinants pre-and peri-COVID-19,and all the Park COVID-19 measures and actions received positive experience from *** research fills this knowledge gap by developing a better understanding in the change of visitor demographics and satisfaction level in BNP under the context of the *** also provides implication for both scholars and practitioners to understand the impacts of the pandemic on Park *** study can provide insights for utilizing the pandemic as a transformative strength and for mitigating its negative impact on tourism industry.

关键词： National park COVID-19 pandemic Visitor experience Tourism management Visitor perception

Analysis of clinical,pathological and genetic features of 3 patients with limb girdle muscular dystrophy type 2A caused by non-canonical splice site mutations in the CAPN3 gene

在线全文

学校读者我要写书评

暂无评论

China Medical Abstracts(Internal Medicine) 2024年第1期41卷 61-61页

作者：王光裕 Dept Neurol Qilu HospShandong UnivJinan 250012

Objective To investigate the clinical,pathological and genetic features of 3 cases of limb-girdle muscular dystrophy 2A (LGMD2A) caused by non-canonical splice site mutations in the CAPN3 *** For the 3 LGMD2A patients admitted to Qilu Hospital of Shandong University from July 2016 to July 2018 were selected as the *** data were collected.

关键词： admitted patients dystrophy

Moisture content thresholds for ignition and rate of fire spread for various dead fuels in northeast forest ecosystems of China

在线全文

学校读者我要写书评

暂无评论

Journal of Forestry Research 2021年第3期32卷 1147-1155页

作者： Maombi Mbusa Masinda Long Sun guangyu wang Tongxin Hu Key Laboratory of Sustainable Forest Ecosystem Management-Ministry of Education College of ForestryNortheast Forestry University26 Hexing RoadHarbin 150040People’s Republic of China Faculty of Sciences UniversitéOffi cielle de RuwenzoriPO Box 560ButemboNorth KivuDemocratic Republic of the Congo Heilongjiang Vocational Institute Ecological Engineering HarbinHeilongjiang ProvincePeople’s Republic of China

Fuel moisture content is one of the important factors that determine ignition probability and fire behaviour in forest *** this study,ignition and fire spread moisture content thresholds of 40 dead fuel were performed in laboratory experiments,with a focus on the source of ignition and wind *** in fuel moisture content at time of ignition and during fire spread was observed for different *** were more efficient to result in ignition and spread fire with high values of fuel moisture content compared to the use of cigarette *** fuels did not ignite at 15%moisture content,whereas others ignited at 40%moisture content and fire spread at 38%moisture content in the case of matches,or ignited at 27%moisture content and spread fire at 25%moisture content using cigarette butts.A two-way ANOVA showed that both the source of ignition and the wind speed affected ignition and fire spread threshold significantly,but there was no interaction between these *** relationship between ignition and fire spread was strong,with R2=98%for cigarette butts,and 92%for *** information is needed,especially on the density of fuels,fuel proportion(case of mixed fuels),fuel age,and fuel combustibility.

关键词： Dead fuel Ignition source Wind speed Ignition moisture threshold Propagation moisture threshold

Bimetallic Pd-Cu/Al_(2)O_(3) Catalyst for the Green Catalytic Synthesis of 2,2'-bipyridine from Pyridine

在线全文

学校读者我要写书评

暂无评论

Journal of Wuhan University of Technology(Materials Science) 2022年第6期37卷 1123-1128页

作者： wang Lin ZHANG Yimeng wang guangyu FENG Yisi LI Qianwen College of Light-Textile Engineering and Art Anhui Agriculture UniversityHefei 230036China School of Chemistry and Chemical Engineering Hefei University of TechnologyHefei 230009China Wuhu Youpai Nursing Products Technology Co. LtdWuhu 241000China

Bimetallic Pd-Cu/Al_(2)O_(3) was prepared by wetness impregnation method and its catalytic activity on coupling reaction of pyridine to 2,2'-bipyridine was assessed in view of the effects of different molar ratios of Pd:*** is found that Pd-Cu/Al_(2)O_(3) has the small particle size and good dispersion through the *** with Pd/Al_(2)O_(3),Pd-Cu(1:2)/Al_(2)O_(3) is the preferable catalyst under the optimum conditions of 1 MPa N2 pressure,310℃and 16 *** conversion of pyridine is 35.4%,and the selectivity for 2,2'-Bipyridine is up to 99%,which is much higher activity than Pd/Al_(2)O_(3).The directly coupled synthesis meets the requirements of the atomic economy *** addition of Cu also reduces the dosage of Pd and lowers the *** is worth noting that the recycled Pd-Cu/Al_(2)O_(3) catalyst still shows high activity and stability after three times.

关键词： Pd-Cu/Al_(2)O_(3) X-ray diffraction atomic economy 2,2'-bipyridine catalytic activity

Dynamics of major air pollutants from crop residue burning in China's Mainland,2000–2014

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2018年第8期30卷 190-205页

作者： Quanfeng Jin Xiangqing Ma guangyu wang Xiajie Yang Futao Guo College of Forestry Fujian Agriculture and Forestry UniversityFuzhou 350002China Co-innovation Center for Soil and Water Conservation in the Red Soil Region of the Cross-straits Fuzhou 350002China Li Shui Vocational Technical College Lishui 323000China Asia-Pacific Forest Research Centre Faculty of ForestryUniversity of British ColumbiaVancouverBC V6T 1Z4Canada

Based on satellite image data and China＇s Statistical Yearbooks（2000 to 2014）, we estimated the total mass of crop residue burned, and the proportion of residue burned in the field *** as domestic fuel. The total emissions of various pollutants from the burning of crop residue were estimated for 2000-2014 using the emission factor method. The results indicate that the total amount of crop residue and average burned mass were 8690.9 Tg and4914.6 Tg, respectively. The total amount of emitted pollutants including CO2, CO, NOx,VOCs, PM（2.5）, OC（organic carbon）, EC（element carbon） and TC（total carbon） were 4212.4–8440.9 Tg, 192.8–579.4 Tg, 4.8–19.4 Tg, 18.6–61.3 Tg, 18.8–49.7 Tg, 6.7–31.3 Tg, 2.3–4.7 Tg, and8.5–34.1 Tg, respectively. The emissions of pollutants released from crop residue burning were found to be spatially variable, with the burning of crop residue mainly occurring in Northeast, North and South China. In addition, pollutant emissions per unit area（10 km ×10 km） were mostly concentrated in the central and eastern regions of China. Emissions of CO2, NOx, VOCs, OC and TC were mainly from rice straw burning, while burning of corn and wheat residues contributed most to emissions of CO, PM（2.5） and EC. The increased ratio of PM（2.5） emissions from crop residue burning to the total emitted from industry during the study period is attributed to the implementation of strict emissions management policies in Chinese industry. This study also provides baseline data for assessment of the regional atmospheric environment.

关键词： Agricultural pollutants Crop residue Straw burning Air pollution Temporal and spatial variations

Impacts of COVID-19 pandemic on urban park visitation:a global analysis

在线全文

学校读者我要写书评

暂无评论

Journal of Forestry Research 2021年第2期32卷 553-567页

作者： Dehui(Christina)Geng John Innes Wanli Wu guangyu wang Faculty of Forestry University of British Columbia2424 Main MallVancouverBC V6T 1Z4Canada

The COVID-19 pandemic has resulted in over 33 million confirmed cases and over 1 million deaths globally,as of 1 October *** the lockdown and restrictions placed on public activities and gatherings,green spaces have become one of the only sources of resilience amidst the coronavirus pandemic,in part because of their positive effects on psychological,physical and social cohesion and spiritual *** study analyzes the impacts of COVID-19 and government response policies to the pandemic on park visitation at global,regional and national levels and assesses the importance of parks during this global *** data we collected primarily from Google’s Community Mobility Reports and the Oxford Coronavirus Government Response *** results for most countries included in the analysis show that park visitation has increased since February 16th,2020 compared to visitor numbers prior to the COVID-19 *** on social gathering,movement,and the closure of workplace and indoor recreational places,are correlated with more visits to ***-at-home restrictions and government stringency index are negatively associated with park visits at a global *** from residents for parks and outdoor green spaces has increased since the outbreak began,and highlights the important role and benefits provided by parks,especially urban and community parks,under the COVID-19 *** provide recommendations for park managers and other decision-makers in terms of park management and planning during health crises,as well as for park design and *** particular,parks could be utilized during pandemics to increase the physical and mental health and social well-being of individuals.

关键词： COVID-19 COVID-19 response policies Parks visitation Stepwise regression analysis Urban parks