检索结果-南通市图书馆

机车电传动 2013年第3期 30-33页

作者：哈大雷长春轨道客车股份有限公司技术中心吉林长春130062

介绍了新型动车组塞拉门电气控制系统的组成及控制要求,阐述了塞拉门电气控制系统的原理及设计方法,经过型式试验验证,新型动车组塞拉门电气控系统工作稳定,运行良好,能够较好地适应目前高速铁路的需要。

关键词：动车组塞拉门电气控制系统原理设计方法

在线全文

学校读者我要写书评

暂无评论

新型轻质雷达吸波材料的应用研究及进展

材料工程 2006年第3期34卷 55-59页

作者：哈恩华黄大庆丁鹤雁北京航空材料研究院北京100095

综述了目前国内外轻质雷达吸波材料的研究动态,详细介绍了具有发展前景的空心微珠吸波材料、碳纳米管吸波材料、导电高聚物吸波材料、纳米吸波材料和智能隐身材料等新型轻质雷达吸波材料的隐身机理及最新研究状况,并对雷达隐身材料应用... 详细信息

综述了目前国内外轻质雷达吸波材料的研究动态,详细介绍了具有发展前景的空心微珠吸波材料、碳纳米管吸波材料、导电高聚物吸波材料、纳米吸波材料和智能隐身材料等新型轻质雷达吸波材料的隐身机理及最新研究状况,并对雷达隐身材料应用技术的未来做了展望。

关键词：雷达吸波材料空心微珠碳纳米管导电高聚物纳米材料智能隐身材料

Improving Indigenous technologies for Sustainable Land Use in Northern Mountainous Areas of Vietnam

在线全文

学校读者我要写书评

暂无评论

Journal of Mountain Science 2004年第3期1卷 270-275页

作者： Le Quoc Doanh ha Dinh tuan Vietnam Agricultural Science Institute (VASI) D7 Phoung Mai Dong Da Hanoi VietnamVietnam Agricultural Science Institute (VASI) D7 Phoung Mai Dong Da Hanoi Vietnam

More than 30 ethnic groups are now living in northern mountainous regions, Vietnam, mainly relying on shifting cultivation with the fallow period being shortened from time to time. Naturally, soil fertility reduces from cycle to cycle, entailing the reduction of productivity. Large areas of moderately sloping lands suitable for upland agriculture have become bare after many cultivation-fallow cycles. the soils there have been severely degraded with more toxicity, low porosity, low water retention capacity and poor floral diversity. Normally, these lands cannot be used for food crop cultivation. So farmers in uplands have to rely on slash-and-burn practices for their livelihood. As there is no more forest with good soil in medium slopes, farmers go to cut forests in watershed, high slope lands and old forests up to the mountains’ top. there are ecologically and environmentally very sensitive areas, so their destruction will inevitably cause hazardous consequences in the whole basin. Meanwhile, cultivation in these areas has low economic efficiency and sustainability because the crop yield may decrease very fast due to severe erosion as the higher the slope, the more serious erosion. Consequently living standards of highland farmers remain low and unstable. Sustainable farming on these lands in the perspective of a seriously deteriorated ecology and environmental is not an easy task. there have been many projects trying to help mountainous farmers get out of their vicious circle. However, due to different reasons, the results gained are low, and in some cases, things ceased to move after the projects phased out. During past few years, based on the farmer experiences, the Vietnam Agricultural Science Institute has cooperated with local and international partners to implement different projects in order to solve the problems by developing simple, easy and cheap cultivation technologies, which can be accepted and applied by local poor farmers for sustainable agricultural

关键词： Indigenous technologies sustainable agriculture upland eco-regions northern vietnam

Litter removal impacts on soil biodiversity and eucalypt plantation development in the seasonal tropics

在线全文

学校读者我要写书评

暂无评论

Journal of Forestry Research 2023年第3期34卷 735-748页

作者： Jonas Inkotte Barbara Bomfim Sarah Camelo da Silva Marco Bruno Xavier Valadão Márcio Gonçalves da Rosa Roberta Batista Viana Alcides Gatto Reginaldo SPereira Department of Forestry Engineering University of BrasiliaBrasíliaDistrito FederalBrazil Climate and Ecosystem Sciences Division Lawrence Berkeley National LaboratoryBerkeleyCA 94720USA SESI/SENAI Social Service Industry Santa Catarina StateChapecóBrazil

the little layer of tree plantations provides primary nutrients for uptake,buff ers changes in soil moisture,and provides habitat and substrate to soil epigeic ***,this layer in eucalypt plantations is often removed to reduce fuel load during the fi re season in the Brazilian savanna(Cerrado).therefore,it is necessary to quantify the eff ects of changes in litter dynamics on the function of these plantations,on key nutrient cycling processes and on epigeic fauna diversity and *** two adjacent stands(one juvenile and one mature),the consequences of two years of litter removal were quantifi ed as monthly litterfall,leaf and fi ne wood litter decomposition,epigeic fauna abundance and diversity,soil biogeochemical variables,and tree diameter and basal area *** litterfall rates in juvenile and mature stands did not change with litter removal over the study *** litterfall ranged from 4.1 to 4.9 Mg ha^(−1)a^(−1)in litter removal plots and from 3.9 to 4.8 Mg ha^(−1)a^(−1)in control *** wood litter decomposition was slower in litter removal plots compared to controls,while leaf decomposition rates were similar in *** years of litter removal in the juvenile stand did not aff ect topsoil biogeochemical parameters but decreased available phosphorus at 20–40 cm depth relative to *** the mature stand,total cation exchange capacity(0–20 cm)was higher in controls(6.4 cmol c dm^(−3))relative to litter removal plots(6.3 cmol c dm^(−3)),while soil moisture(0–40 cm depth)was lower in litter removal(25.45 m 3 m^(−3))compared to control plots(26 m^(3)m^(−3))in the dry season.A non-metric multidimensional scaling ordination revealed an increased homogeneity in epigeic fauna where litter was ***,decomposition,diameter increment,four soil physical parameters and fourteen chemical parameters at 0–20 and 20–40 cm depth explained the diff erences in soil epigeic fauna composition between litter removal and control p

关键词： Cerrado Nutrient cycling Soil ecology Soil epigeic fauna Plantation management

考虑承压含水层间越流的地下水回灌现场试验研究

在线全文

学校读者我要写书评

暂无评论

岩土工程学报 2019年第9期41卷 1609-1618页

作者：郑刚曹剑然程雪松哈达天津大学滨海土木工程结构与安全教育部重点实验室天津300072 天津大学建筑工程学院天津300072

当场地存在多层层间有一定水力联系的承压含水层时,基坑内降水可引发基坑止水帷幕墙底以下的承压含水层的水头下降,并相应引起坑外多个含水层水位降低,若对所有层进行回灌则将导致成本大幅提高,此时可对某一层回灌,通过越流对其他含水... 详细信息

当场地存在多层层间有一定水力联系的承压含水层时,基坑内降水可引发基坑止水帷幕墙底以下的承压含水层的水头下降,并相应引起坑外多个含水层水位降低,若对所有层进行回灌则将导致成本大幅提高,此时可对某一层回灌,通过越流对其他含水层进行水位补给。通过在天津地铁某车站基坑所在场地开展抽水试验、单井回灌试验、先抽后灌试验对基坑内外的水力联系、不同含水层间的水力联系和隔层回灌的效果进行了研究。结果表明,由于各含水层间之间有一定水力联系导致竖向越流补给较强,基坑内疏干降水可引起坑外承压含水层水头下降并引起坑外地层沉降。对基坑外第Ⅰ微承压含水层进行回灌可有效对其上部潜水层和下部第Ⅱ-1承压层的水头起到抬升作用,通过隔层回灌从而控制其水位下降导致的坑外沉降。对第Ⅰ承压含水层进行回灌对基坑外第Ⅱ-2承压层水位抬升也有一定的作用,但是尚不足以使其因基坑内降水引起的坑外水位下降值完全恢复,建议结合设置此层的备用回灌井以控制其水位下降。

关键词：疏干降水隔层回灌层间越流承压含水层

Differences of yield and nitrogen use efficiency under different applications of slow release fertilizer in spring maize

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Agriculture 2021年第2期20卷 554-564页

作者： LI Guang-hao CHENG Gui-gen LU Wei-ping LU da-lei Jiangsu Key Laboratory of Crop Genetics and Physiology/Jiangsu Key Laboratory of Crop Cultivation and Physiology/Agricultural College Yangzhou University/Jiangsu Co-Innovation Center for Modern Production Technology of Grain CropsYangzhou 225009P.R.China

Excessive or insufficient application of fertilizer has raised broader concerns regarding soil and environmental ***-time application of slow release fertilizer (SF) has been widely used to reduce yield gap with potential maize yield and improve nitrogen use efficiency (NUE).A 2-year field experiment (2018–2019) was conducted to evaluate the effects of SF rates from 0 to 405 kg N ha^(–1) (named F0,SF225,SF270,SF315,SF360,and SF405) and 405 kg N ha^(–1) of common fertilizer(CF405) on the grain yield,biomass and N accumulation,enzymatic activities related with carbon–nitrogen metabolism,NUE and economic *** indicated that the highest grain yields,NUEs and economic returns were achieved at SF360in both *** enzymatic activities related with carbon–nitrogen metabolism,pre-and post-silking accumulation of biomass and N increased with increasing SF rate,and they were the highest at SF360 and *** grain yield at SF360had no significant difference with that at ***,the N partial factor productivity,N agronomic efficiency and N recovery efficiency at SF360 were 9.8,6.6 and 8.9% higher than that at *** results also indicated that the average grain yields,NUE and economic benefit at SF405 were 5.2,12.3 and 18.1% higher than that at *** conclusion,decreasing N rate from 405 kg ha^(–1)(CF) to 360 kg ha^(–1)(SF) could effectively reduce the yield gap between realized and potential maize *** N decreased by 11.1%,but the yield,NUE and economic benefit increased by 3.2,22.2 and 17.5%,which created a simple,efficient and business-friendly system for spring maize production in Jiangsu Province,China.

关键词： spring maize grain yield slow release fertilizer nitrogen use efficiency economic benefit

基于网络药理学与分子对接探讨芍药苷治疗糖尿病的作用

在线全文

学校读者我要写书评

暂无评论

中国临床药理学杂志 2024年第15期40卷 2261-2264页

作者：宋思瑶陆彭伍鼎骁康达何雨惠吕莹林岩齐齐哈尔医学院基础医学院黑龙江齐齐哈尔161000

目的基于网络药理学与分子对接技术,探究芍药苷作用糖尿病的相关靶点及通路,初步探讨潜在作用机制。方法用小分子靶点预测数据库对芍药苷的潜在靶点进行分析。在Genecards、OMIM数据库中收集糖尿病相关疾病基因。两者取交集后,用StRING... 详细信息

目的基于网络药理学与分子对接技术,探究芍药苷作用糖尿病的相关靶点及通路,初步探讨潜在作用机制。方法用小分子靶点预测数据库对芍药苷的潜在靶点进行分析。在Genecards、OMIM数据库中收集糖尿病相关疾病基因。两者取交集后,用StRING、Cytoscape程序建立蛋白-蛋白相互作用(PPI)网络系统,检索相关性强的关键基因,并完成基因本体(GO)及京都基因与基因组百科全书(KEGG)富集分析研究。用AutoDocktools、Pymol程序完成蛋白质分子对接验证。结果通过网络药理学相关研究,得到芍药苷相关靶点63个,糖尿病相关基因4758个,交集靶点50个,筛选出血管内皮生长因子A(VEGFA)、表皮生长因子受体(EGFR)、肉瘤病毒癌基因同源物(HRAS)、原癌基因酪氨酸蛋白(SRC)和热休克蛋白基因(HSP90AA1)5个关键基因。KEGG通路分析得到Ras相关蛋白1、Ras、钙等信号通路。分子对接结果显示,芍药苷与关键基因具有良好的结合能力。结论芍药苷可通过多靶点、多通路治疗糖尿病,该机制可为芍药苷在抗糖尿病方面的应用及药物研发提供依据。

关键词：芍药苷网络药理学糖尿病分子对接

碳纳米管／导电聚合物纳米复合物的合成与表征

在线全文

学校读者我要写书评

暂无评论

材料工程 2008年第10期36卷 122-125页

作者：哈恩华黄大庆哈恩平王智勇丁鹤雁北京航空材料研究院北京100095 石家庄石焦化工有限责任公司石家庄050031

为实现制备出导电性能优良的有机透明导电涂层,需要把具有导电性的碳纳米管在树脂中组装成一体化导电结构网络。运用可以在树脂中自组装的导电聚乙撑二氧噻吩和聚苯胺来实现碳纳米管自组装的方法,分别合成出了导电聚乙撑二氧噻吩和聚苯... 详细信息

为实现制备出导电性能优良的有机透明导电涂层,需要把具有导电性的碳纳米管在树脂中组装成一体化导电结构网络。运用可以在树脂中自组装的导电聚乙撑二氧噻吩和聚苯胺来实现碳纳米管自组装的方法,分别合成出了导电聚乙撑二氧噻吩和聚苯胺薄膜均匀覆盖的碳纳米管/聚乙撑二氧噻吩复合物与碳纳米管/聚苯胺纳米复合物,并运用透射电镜(tEM)、傅立叶红外光谱(FtIR)和四探针法对其进行了分析与表征,结果发现这种复合物的导电性较碳纳米管和聚乙撑二氧噻吩以及聚苯胺自身导电性都有一定程度的提高。

关键词：碳纳米管纳米复合物导电聚合物

在线全文

学校读者我要写书评

暂无评论

关于内蒙古学研究的起步及若干观点综述

前沿 2020年第2期 116-125,136页

作者：哈达内蒙古北宸智库研究中心内蒙古呼和浩特010010

从承担第一批内蒙古社会科学研究课题内蒙古学专项重点课题的5位项目主持人的研究中,就内蒙古学研究的相关话题,进行外观式的探察。旨在通过关于内蒙古学的若干理论观点整合,抛砖引玉,为今后内蒙古学研究提供一个基础;及时总结内蒙古学... 详细信息

从承担第一批内蒙古社会科学研究课题内蒙古学专项重点课题的5位项目主持人的研究中,就内蒙古学研究的相关话题,进行外观式的探察。旨在通过关于内蒙古学的若干理论观点整合,抛砖引玉,为今后内蒙古学研究提供一个基础;及时总结内蒙古学研究的进展,更好地支撑内蒙古学的构建。通过关于内蒙古学的若干实践思考整合,以期集思广益,为今后内蒙古学研究探索一条路径;提供智力支持,不断明确内蒙古学研究的实践方向。

关键词：内蒙古学文化智库

在线全文

学校读者我要写书评

暂无评论

基于运动目标检测的哨位夜间自动报警系统

指挥与控制学报 2018年第2期4卷 154-159页

作者：哈达武警警官学院信息通信系四川成都610213

针对在夜间,视野条件差,光靠人力肉眼观察目标,容易遗漏重要信息或判断失误,造成不可预知的后果这种现实情况,通过固定单摄像机的夜晚监控场景,结合对运动目标检测技术的深入研究,主要实现夜间锁定、动态识别、距离判断、自动报警4个过... 详细信息

针对在夜间,视野条件差,光靠人力肉眼观察目标,容易遗漏重要信息或判断失误,造成不可预知的后果这种现实情况,通过固定单摄像机的夜晚监控场景,结合对运动目标检测技术的深入研究,主要实现夜间锁定、动态识别、距离判断、自动报警4个过程,以此探讨哨位夜间自动报警系统.

关键词：智能视频监控目标检测监控技术报警系统