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Patterns and trends in grain self-sufficiency on the Tibetan Plateau during 1985–2016

Journal of Geographical Sciences 2020年第10期30卷 1590-1602页

作者： SHI Wenjiao LU changhe SHI Xiaoli CUI Jiaying Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources ResearchCASBeijing 100101China Key Laboratory of Environmental Evolvement and Ecological Construction of Hebei Province College of Resources and Environment SciencesHebei Normal UniversityShijiazhuang 050024China College of Resources and Environment University of Chinese Academy of SciencesBeijing 100049China

Capacity for grain self-sufficiency on the Tibetan Plateau(TP)is an important basis for ensuring social stability and regional ***,based on county-level statistical data for population,grain production and consumption,we analyzed patterns and trends in grain supply and demand at regional,provincial,and county levels on the TP between 1985 and *** applied two indices to evaluate capacity for grain self-sufficiency and found that the regional average self-sufficiency rate increased quickly by 1.97%/a since 1989,reaching 173.03%on the plateau over the period between 2010 and *** indicates that grain supply in this region is able to fully meet *** addition,all provinces apart from Xinjiang exhibited similar increasing trends,attaining grain self-sufficiency during 2010–***,59%of counties attained grain self-sufficiency over this period,mainly distributed in southern Tibet,in the Sichuan-Tibet junction area,and in eastern Qinghai Province.A number of gaps in grain supply and demand occurred within the headwater regions of the Yangtze and Yellow rivers as well as on the Qiangtang *** self-sufficiency significantly increased over the study period in 36%of counties,mainly distributed in the agricultural areas of southeastern Tibet and in eastern *** the whole plateau,capacity for grain self-sufficiency substantially increased between 1985 and 2016,although serious spatial imbalances remain.

关键词： Tibetan Plateau grain county scale self-sufficiency spatiotemporal distribution

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采棉机输棉系统的研究现状与分析

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新疆农机化 2024年第2期 38-41页

作者：石鑫刘延彬牛长河陈毅飞新疆农业科学院农业机械化研究所新疆乌鲁木齐830091 农业部林果棉与设施农业设备科学观测试验站新疆乌鲁木齐830091 江苏大学农业工程学院江苏镇江202123

输棉系统是采棉机的核心系统,对其研究可提高输棉系统输送能力、降低堵塞率和提高作业效率等方面起着重要作用。本文介绍了采棉机输棉系统的分类和工作原理,系统阐述了采棉机输棉系统的研究发展现状,分析了输棉系统存在问题并提出解决方... 详细信息

输棉系统是采棉机的核心系统,对其研究可提高输棉系统输送能力、降低堵塞率和提高作业效率等方面起着重要作用。本文介绍了采棉机输棉系统的分类和工作原理,系统阐述了采棉机输棉系统的研究发展现状,分析了输棉系统存在问题并提出解决方法,这为今后我国采棉机输棉系统的研制和发展提供技术支持。

关键词：采棉机输棉系统现状问题

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New Early Triassic paleo-magnetic data from Huangben section,Guangdong and its tectonic implications

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Chinese Science Bulletin 2006年第15期51卷 1894-1902页

作者： SHEN Zhongyue DING Jinghai YE changhe WEN Junwei WANG Zhaoliang CHEN Zhifei Department of Earth Sciences Zhejiang University Hangzhou 310027 China

A paleomagnetic study was carried out on a total of 122 oriented cores from Daye Formation of the Huangben section, Guangdong Province. Rock magnetic investigations show that low-titanium magnetite is a dominant carrier. Detailed progressive thermal demagnetization isolated 2―3 components. The low temperature component clusters around the present geomagnetic field direction. An intermediate temperature component is isolated at 100―400℃ and is interpreted as a Yanshanian remagnetization. A high-temperature characteristic remanent mag- netization (ChRM) is obtained at 400―530℃ with D = 51.1°,I = 15.3°,α95 = 5.0° and passes generalized fold test and reversal test, suggesting high tempera- ture component is a primary remanence. Its corre- spondent pole position is 38.5°N, 212.7°E (dp = 2.6, dm = 5.1), which overlaps contemporaneous pole of Yangtze Block at 95% confidence level. Therefore, we believe that Huanan and Yangtze blocks were not separated in the Early Triassic. Compared to other published Early Triassic paleomagnetic data from Huanan Block, the inclinations are very close but the declinations are greatly variable. In stereo-projection, all the Early Triassic poles from Huanan Block lie along a small circle around the Huanan Block, im- plying that local micro-blocks rotations lead to the inconsistence of Early Triassic paleomagnetic direc- tions.

关键词：早三叠纪古磁学华南板快扬子江板快

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Cu-Mn-Al三元尖晶石催化甲醇重整反应特性

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石油化工高等学校学报 2024年第2期37卷 50-57页

作者：吕昌赫吴殿卿张楷文于东北张财顺韩蛟高志贤辽宁石油化工大学石油化工学院辽宁抚顺113001

以硝酸铜为铜源、拟薄水铝石为铝源、柠檬酸为添加剂,以乙酸锰为第三组分部分取代铜,采用球磨法制备了Cu_(0.7)Mn_(0.3)Al_(2.5)三元固溶体尖晶石催化剂;借助XRD、BET、H_(2)-TPR和XPS等表征技术,对Cu_(0.7)Mn_(0.3)Al_(2.5)的晶相结构... 详细信息

以硝酸铜为铜源、拟薄水铝石为铝源、柠檬酸为添加剂,以乙酸锰为第三组分部分取代铜,采用球磨法制备了Cu_(0.7)Mn_(0.3)Al_(2.5)三元固溶体尖晶石催化剂;借助XRD、BET、H_(2)-TPR和XPS等表征技术,对Cu_(0.7)Mn_(0.3)Al_(2.5)的晶相结构、织构性质、还原性质及表面阳离子状态及分布进行研究,并在甲醇水蒸气重整制氢(MSR)反应中考察其缓释催化性能。结果表明,与Cu Al_(2.5)、Cu_(0.7)Zn_(0.3)Al_(2.5)相比,Cu_(0.7)Mn_(0.3)Al_(2.5)的晶粒最小,比表面积最大,且晶胞收缩最大,晶胞常数最小;该催化剂呈富铝状态,但表面尖晶石相Cu^(2+)占比更高,H_(2)气氛下还原难度增大,在MSR反应中表现出较好的缓释催化性能;在温度为265℃、n(H_(2)O)/n(CH_(3)OH)=2、质量空速为2.25 h^(-1)的条件下反应40 h,甲醇转化率高达84%。该研究为研发高效铜基缓释催化剂提供了数据参考。

关键词：缓释催化甲醇重整尖晶石球磨法

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跨走滑断层油气管道地震响应分析

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长江大学学报（自然科学版） 2024年第5期21卷 102-109页

作者：孙碧君战欣霖孙长河李刚方晓蕾中国石油天然气管道工程有限公司国际分公司河北廊坊065000 长江大学城市建设学院湖北荆州434023 长江大学电子信息与电气工程学院湖北荆州434023

为研究埋地油气管道在走滑断层作用下的地震响应规律,基于土箱-管道缩尺试验,构建管土耦合非线性数值模型并验证其准确性,分析了管道壁厚、管道直径、管道埋深和断层破碎带宽度对埋地管道地震响应的影响。研究结果表明:埋地油气管道整... 详细信息

为研究埋地油气管道在走滑断层作用下的地震响应规律,基于土箱-管道缩尺试验,构建管土耦合非线性数值模型并验证其准确性,分析了管道壁厚、管道直径、管道埋深和断层破碎带宽度对埋地管道地震响应的影响。研究结果表明:埋地油气管道整体应变沿断层面呈反对称分布,峰值应变位于断层面0.2~0.5 m范围内,且压应变峰值略大于拉应变峰值;管道埋深对峰值应变影响最大,断层破碎带宽度对峰值应变出现的位置产生重要影响;浅埋较大管径和较大壁厚的管道,可有效减弱地震荷载对管道的作用。研究结果可为埋地管道抗震设计提供参考,对跨走滑断层埋地管道地震响应进行预测。

关键词：埋地管道地震响应数值模拟峰值应变

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Assessing changes in wind erosion climatic erosivity in China＇s dryland region during 1961-2012

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Journal of Geographical Sciences 2016年第9期26卷 1263-1276页

作者： YANG Fengbo LU changhe Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources Research CAS Beijing 100101 China University of Chinese Academy of Sciences Beijing 100049 China

China＇s dryland region has serious wind erosion problem and is sensitive to climate change due to its fragile ecological condition. Wind erosion climatic erosivity is a measure of climatic factors influencing wind erosion, therefore, evaluation of its intensity and response to recent climate changes can contribute to the understanding of climate change effect on wind erosion risk. Using the FAO equation, GIS and statistical analysis tools, this study quantified the climatic erosivity, analyzed its spatiotemporal variations, and detected the trend and sen- sitivity to climate factors during 1961-2012. The results indicate that mean annual climatic erosivity was 2-166 at 292 stations and 237-471 at 6 stations, with the spatial distribution highly in accordance with wind speed （R^2 = 0.94）. The climatic erosivity varied greatly over time with the annual variation （CV） of 14.7%-108.9% and monthly variation （concentration degree） of 0.10-0.71 in the region. Meanwhile, annual erosivity showed a significant down- ward trend at an annual decreasing rate mostly above 1.0%. This significantly decreasing trend was mainly attributed to the obvious decline of wind speed during the period. The results suggest that the recent climate changes were highly possible to induce a decrease of wind erosion risk in China＇s dryland region.

关键词： wind erosion climatic erosivity trend climate change dryland region China

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催化剂ZIF-67的制备及合成D-阿洛酮糖的工艺优化

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食品工业科技 2024年第21期45卷 157-163页

作者：韩亚宏郭元亨吴祺路丁长河杨凯钱承敬王小艳河南工业大学粮油食品学院河南郑州450001 中粮营养健康研究院有限公司北京102209 中粮生物科技股份有限公司北京100005 吉林中粮生化有限公司玉米深加工国家工程研究中心吉林长春130033

为降低D-阿洛酮糖的生产成本,本研究旨在开发一款易回收、可重复使用的D-阿洛酮糖无机催化剂,并优化该催化剂生产D-阿洛酮糖的工艺。本文利用Co^(2+)和2-甲基咪唑在水相中合成沸石咪唑酯骨架材料(Zeolitic imidazolate framework-67,ZIF... 详细信息

为降低D-阿洛酮糖的生产成本,本研究旨在开发一款易回收、可重复使用的D-阿洛酮糖无机催化剂,并优化该催化剂生产D-阿洛酮糖的工艺。本文利用Co^(2+)和2-甲基咪唑在水相中合成沸石咪唑酯骨架材料(Zeolitic imidazolate framework-67,ZIF-67),并对其进行表征;并以pH(A)、催化温度(B)、催化时间(C)展开单因素实验;进一步采用响应面法对其催化工艺进行优化。ZIF-67呈现菱形十二面体的结构,催化性能良好,Design Expert 13预测最优反应条件为pH11.1、温度80.0℃、催化时间11.2 min。此条件下,ZIF-67催化活性为1003.5μmol·min^(-1)·g^(-1)。本文首次开发一款D-阿洛酮糖无机催化剂ZIF-67,并通过响应曲面较好地预测出ZIF-67合成D-阿洛酮糖的最佳反应条件,也为D-阿洛酮糖工业化生产开辟了新途径。

关键词：沸石咪唑酯骨架材料(ZIF-67) 无机催化剂响应曲面法 D-阿洛酮糖

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Machinability of ultrasonic vibration-assisted micro-grinding in biological bone using nanolubricant

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Frontiers of Mechanical Engineering 2023年第1期18卷 115-130页

作者： Yuying YANG Min YANG changhe LI Runze LI Zafar SAID Hafiz Muhammad ALI Shubham SHARMA School of Mechanical and Automotive Engineering Qingdao University of TechnologyQingdao 266520China College of Physics Qingdao UniversityQingdao 266071China Department of Biomedical Engineering University of Southern CaliforniaLos AngelesCA 90089USA Department of Sustainable and Renewable Energy Engineering University of SharjahSharjah 27272United Arab Emirates Mechanical Engineering Department King Fahd University of Petroleum and MineralsDhahran 31261Saudi Arabia Department of Mechanical Engineering IK Gujral Punjab Technical UniversityJalandhar 144603India

Bone grinding is an essential and vital procedure in most surgical ***,the insufficient cooling capacity of dry grinding,poor visibility of drip irrigation surgery area,and large grinding force leading to high grinding temperature are the technical bottlenecks of micro-grinding.A new micro-grinding process called ultrasonic vibration-assisted nanoparticle jet mist cooling(U-NJMC)is innovatively proposed to solve the technical *** combines the advantages of ultrasonic vibration(UV)and nanoparticle jet mist cooling(NJMC).Notwithstanding,the combined effect of multi parameter collaborative of U-NJMC on cooling has not been *** grinding force,friction coefficient,specific grinding energy,and grinding temperature under dry,drip irrigation,UV,minimum quantity lubrication(MQL),NJMC,and U-NJMC micro-grinding were compared and *** showed that the minimum normal grinding force and tangential grinding force of U-NJMC micro-grinding were 1.39 and 0.32 N,which were 75.1%and 82.9%less than those in dry grinding,*** minimum friction coefficient and specific grinding energy were achieved using *** with dry,drip,UV,MQL,and NJMC grinding,the friction coefficient of U-NJMC was decreased by 31.3%,17.0%,19.0%,9.8%,and 12.5%,respectively,and the specific grinding energy was decreased by 83.0%,72.7%,77.8%,52.3%,and 64.7%,*** with UV or NJMC alone,the grinding temperature of U-NJMC was decreased by 33.5%and 10.0%,*** results showed that U-NJMC provides a novel approach for clinical surgical micro-grinding of biological bone.

关键词： micro-grinding biological bone ultrasonic vibration(UV) nanoparticle jet mist cooling(NJMC) grinding force grinding temperature

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Autologous Transplantation for Parkinson's Disease Patients:Feasibility and Challenge

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Neuroscience Bulletin 2021年第7期37卷 1085-1086页

作者： Qi Zhang Yanlin Wang Yukai Wang Han Liu Huifang Sun Zhuoya Wang changhe Shi Jing Yang Yuming Xu Department of Neurology The First Affiliated Hospital of Zhengzhou UniversityZhengzhou 450052China Academy of Medical Sciences Zhengzhou UniversityZhengzhou 450052China State Key Laboratory of Stem Cell and Reproductive Biology Institute of ZoologyChinese Academy of SciencesBeijing 100101China Institute for Stem Cell and Regeneration Chinese Academy of SciencesBeijing 100101China Department of National Stem Cell Resource Center Institute of ZoologyChinese Academy of SciencesBeijing 100101China Beijing Institute for Stem Cell and Regenerative Medicine Beijing 100101China

Parkinson’s Disease(PD),second only to Alzheimer’s disease,is a neurodegenerative disease,most commonly occurring in people over the age of 65 years and is mostly caused by loss of dopamine neurons[1].Clinically,motor symptoms such as resting tremor,motor retardation,muscular rigidity,and disturbance of postural balance are the main symptoms,followed by non-motor symptoms such as cognitive impairment,autonomic nervous system dysfunction,depression,and sleep disorder[2].In 2016,>6.1 million people were affected with PD globally,2.4 times the number in *** large number of affected people,coupled with the high mortality and disability rates,has placed a great burden on society[3].Traditional treatment methods mainly include drugs and surgery and are supplemented by physical therapy.

关键词： drugs mortality Clinical

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基于协同过滤的产教一体化平台设计与实现

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现代计算机 2024年第3期30卷 107-111页

作者：韩家成何琳曾莉宁王长赫李吉祥北京信息科技大学计算机学院北京102206

当今社会上存在教育资源不平衡的现象,特别是在职业教育、就业学习等方面,所以基于协同过滤开发了“e习堂”产教一体化平台,一个集促进就业、教育学习功能于一体的教育公益平台。使用HTML5、CSS3、JavaScrapt搭建平台前端,使用Tomcat、J... 详细信息

当今社会上存在教育资源不平衡的现象,特别是在职业教育、就业学习等方面,所以基于协同过滤开发了“e习堂”产教一体化平台,一个集促进就业、教育学习功能于一体的教育公益平台。使用HTML5、CSS3、JavaScrapt搭建平台前端,使用Tomcat、JDBC、Servlet、Druid、MySQL搭建平台后端。利用Java实现登录、查看、推荐等平台功能。平台通过协同过滤将企业招聘版块和网课、图书学习资源相互关联,形成产学的闭环,均衡配置教学资源,明确学习的导向性和目的性,激发学生的内生活力。

关键词： UserCF 产教一体化平台 JavaWeb

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