摘要：Exploring the water yield and soil conservation in the Three-River-Source region is of great significance for evaluating both the ecological stability of the Qinghai-Tibet Plateau,Yellow River basin,Yangtze River basin and Lancang River basin and the sustainable development of human *** data sources for this study were land use/cover data from four phases(2000,2005,2010 and 2015),daily precipitation and temperature datasets,and the 1:1000000 chinese soil *** data were combined with vector data,such as data on settlements,roads,and rivers,along with population,economic raster datasets and CCSM4 common climate model prediction *** Three-River-Source region was taken as the study area,and four land use/cover development scenarios and two climate change scenarios were designed based on the FLUS model and the downscaling correction *** InVEST model was used to quantitatively simulate the water yield and soil erosion under different scenarios in the study area in *** results showed the following:(1)Under different land use/cover development scenarios,grassland remained the dominant land use/cover type in the Three-River-Source region,and the area ratio was always greater than 67%.(2)Under the RCP4.5 climate scenario,the annual water yield and soil erosion increased by more than 7%and 3.9%,*** the RCP8.5 climate scenario,the annual water yield and soil erosion decreased by more than 3.3%and 1.3%,respectively.(3)Climate change played a leading role in the changes in water yield and soil *** change contributed as much as 89.97%–98.00%to the change in water yield and 60.49%–95.64%to the change in the soil erosion ***,the contribution of land use/cover changes to the change in regional water yield was only 2.00%–10.03%,and the contribution of the soil erosion modulus change was 4.36%–39.91%.Therefore,the land use development strategy in the Three-River-Source region should comprehensively consider

摘要：为降低叶顶泄漏损失,本文首次将NACA翼型引入向心涡轮,并采用正交试验设计和计算流体动力学(CFD)方法获得了具有最优NACA叶顶型线的向心涡轮叶片,并揭示了该叶片对叶顶泄漏损失的控制机理。结果表明,最优NACA叶顶型线具有较大的前缘内接圆半径、较小的尾缘厚度,以及更靠近前缘的最大厚度位置。其内接圆半径和最大厚度位置对向心涡轮等熵效率的影响度也随叶顶间隙增加而增大。当叶顶间隙为8%出口叶高时,最优NACA叶顶型线可使向心涡轮等熵效率提高1.47%,并使向心涡轮能够在非设计工况下具有较高效率。该型线能够降低尾缘附近的叶顶泄漏速度,减弱泄漏流与主流掺混强度,使流动损失降低。

摘要：针对将客户端请求向Web系统中各SSL反向代理网关分发的问题,提出了两种系统架构设计方案,为SSL会话粒度的SSL反向代理网关请求分发算法设计提供了理论支持,并总结了两种设计方案的优缺点。其中一种方案的请求分发设备串联在客户端与安全网关系统之间,用TCP hand-off的方法转发客户端请求,其额外开销较小,响应速度较快,但无法分析客户端请求内容,且实现较为复杂;另一种方案的请求分发设备利用HTTP的重定向机制转发客户端请求,其额外开销较大,但可以分析客户端请求内容,且实现较为容易。

摘要：It is well known that the motion of a charged particle with a nonzero emittance in a storage ring is characterized by betatron oscillations in the transverse plane of the ion motion^([1]).The effects of the betatron oscillation on the revolution time has been observed in the isochronous mass measurement experiments in CSRe^([2]).

摘要：开发非贵金属催化剂,特别是用于碳上铁氮(FeNC)材料的催化剂,对于质子交换膜燃料电池(PEMFC)的广泛应用是一个迫切需求。然而,传统铁氮位点在酸性条件下的氧还原反应(ORR)活性较差,严重阻碍了其电池性能的进一步提高。本文通过限域的小分子合成策略,大规模合成了具有一氧化氮(NO)基团轴向修饰的FeN_(4)(表示为NO-FeN_(4))。得益于NO基团的强吸电子效应,与传统的FeN_(4)样品相比,富含电子中心FeN_(4)位点表现出超高的ORR活性,具有三倍高的质量活性(0.85 V时为1.1 A·g^(−1)),以及全四电子反应选择性。此外,用所制备的电催化剂组装的质子交换膜燃料电池也表现出显著增强的峰值功率密度(>725 mW·cm^(−2))。这项工作为合理设计用于氧还原的先进M-Nx非贵金属电催化剂提供了一种新的方法。

摘要：The chart of the nuclides is one of the basic tools in nuclear science and *** have designed a new two-dimensional chart of the nuclides,which displays up-to-date ground state nuclear properties such as isotopic abundances of stable nuclei,decay modes,half-lives of radioactive nuclei,atomic mass errors,and other experimental information extracted from the latest AME2020(Atomic Mass Evaluation)and NUBASE2020(evaluation of nuclear physics properties)^([1]).

摘要：云计算、物联网、社交网络等新兴服务促使人类社会的数据种类和规模正以前所未有的速度增长,大数据时代正式到来。数据从简单的处理对象开始转变为一种基础性资源,如何更好的存储和利用大数据已经成为普遍关注的话题。本文对大数据的基本概念进行剖析,分析了大数据带来的挑战,在此基础上,设计了一种安全的混合云存储平台架构。该混合云存储平台架构已经应用于智能云电视产业链项目,目前已正常运行10个月。