摘要：Ostrich eggshell beads and fragments collected from SDG site reflect primordial art and a kind of symbolic behavior of modern humans. Based on stratigraphic data and OSL dating, these ostrich eggshell beads are probably in Early Holocene (< 10 ka BP). Two different prehistoric manufacturing pathways are usually used in the manufacture of ostrich eggshell beads in Upper Paleolithic. According to statistic analysis of the characteristics of ostrich eggshell beads, Pathway 1 is identified from these collections. In pathway 1, blanks are drilled prior to being trimmed to rough discs. They exhibit great potential for the study of the origin of primordial art and the development of ancient cultures and provide important data for studying behavioral options adopted by hominids in SDG area. In addition, they bear important implications for the origin of modern humans in East Asia.

摘要：Experimental investigations are performed in a three-stage low-speed axial compressor with variable inlet guide vanes(IGV) and adjustable *** characteristics of the compressor,especially the efficiency and stall margin,are analyzed in design and off-design operation conditions by adjusting stagger angles of IGV and stators as well as changing the rotational *** experimental results show that the off-design performance of the multistage axial compressor is improved by restaggering of IGV and stators related to rotational *** the background of engineering applications,digital signal processing(DSP) technique is used to realize online adjustment of stagger angles according to the corresponding relations between incidence angles of rotor and rotational speed.

摘要：Based on the origin of message items and channel combination between transacting parties, and events and relations among events, this paper presents a concise, precise, and hierarchical model for general fair exchange protocols, formally specifies various security requirements which are able to reflect inherent requirements for fair exchange protocols more rigorously, and partition these security requirements with fine granularity. This work helps analyze, debug, and design multi-party fair exchange protocols more effectively and elaborately,

摘要：聚合物基固态电解质得益于其易加工性,最有希望应用于下一代固态锂金属电池.目前,聚合物基态电解质的离子电导率提升策略多为加入导锂陶瓷以构建离子传输通道,其提升程度有限.电场在锂离子输运过程中存在重要影响,目前研究中有关电场对锂离子传输的影响机制尚不明确.本文将兼具高离子电导率和高介电常数的铌酸锂嵌入聚偏氟乙烯基体中,设计了一种新型复合固态电解质.铌酸锂颗粒有效调节电解质内部电场结构,增强了离子输运方向电场强度,实现了离子电导率的大幅提升(7.39×10^(-4)S cm^(-1),25℃).该电解质匹配高镍正极和锂金属负极的固态电池可稳定循环1000次以上,容量保持率为72%.该研究为设计下一代固态锂电池用高离子电导复合固态电解质提供了新的策略.

摘要：在多线轴引擎，如果旋转货摊发生在在上游的压缩机，下游的压缩机经历旋转入口失真，它可以导致整个压缩机的不稳定性。在这份报纸，压缩机动态行为是主要焦点。实验在一台单个阶段的低速度的轴流动的压缩机上被执行。与不同失真部门装备的一个旋转失真发电机被设计顺时针方向或逆时针方向生产不同旋转入口失真与直到压缩机设计速度的 100% 。失真部门能被安装单个或在象四个部门那样的某联合一起。失真扇区 / 联合的三种类型在研究工作被使用，它是单身者 30 度部门，四 30 个度部门和单身者 120 度部门。失真速度什么时候升起，被发现总数迫使旋转部门增加引起的损失。为共同旋转失真，当失真速度对应于时，入口失真的所有三种类型在货摊边缘降级展出了一座山峰粗略地， 50% 转子加速。压缩机流动地的二维的数字模拟清楚地由失真部门显示出骚乱 trigged 的繁殖。关键词失真 - 压缩机 - 货摊边缘 CLC 数字 TK474.

摘要：An experimental investigation on the unsteady tip flow field of a transonic compressor rotor has been *** casing-mounted high frequency response pressure transducers were arranged along both the blade chord and the blade *** chord-wise ones were used to indicate both the ensemble averaged and time varying flow structure of the tip region of the rotor at different operating points under 95% design speed and 60% design *** pitch-wise circumferential transducers were mainly used to analyze the unsteadiness frequency of the tip leakage flow in the rotor frame at the near stall *** contours of casing wall pressure show that there were two clear low pressure regions in blade passages,one along the chord direction,caused by the leakage flow and the other along the tangential direction,maybe caused by the forward swept leading *** low pressure regions were originated from the leading edge and formed a scissor-like flow *** 95% design speed condition,the shock wave interacted with the low pressure region and made the flow field *** the mass flow reduced,the two low pressure regions gradually contracted to the leading edge and then a spike disturbance emerged.

摘要：We adopt the groove guide as the cavity of the undulator to reduce the diffraction effect. The groove guide has the advantages of lower surface energy loss, larger power capacity, less modes, and larger structure dimension over the traditional method waveguide. The attenuation calculation is given in this paper including the cavity optimization. And the dispersive character indicates that the oscillator can work in different modes with the change of the electron beam energy.

摘要：In recent years, people are dedicated to the research work of finding compact THz sources with high emission power. Smith-Purcell radiation is qualified for the possibility of coherent enhancement due to the effect of FEL mechanism. The compact experiment device is expected to produce hundreds mW level THz ray. The electron beam with good quality is provided under the optimized design of the electron gun. Besides, the grating is designed as an oscillator without any external feedbacks. While the beam passes through the grating surface, the beam bunching will be strong and the second harmonics enhancement will be evident, as is seen from the simulation results.

摘要：A previously published new rotation function has been improved by using a dynamic correlation coefficient as well as two new scoring functions of relative entropy and mean-square-residues to make the rotation function more robust and independent of a specific set of weights for scoring and ranking. The previously described new rotation function calculates the rotation function of molecular replacement by matching the search model directly with the Patterson vector map. The signal-to-noise ratio for the correct match was increased by averaging all the matching peaks. Several matching scores were employed to evaluate the goodness of matching. These matching scores were then combined into a single total score by optimizing a set of weights using the linear regression method. It was found that there exists an optimal set of weights that can be applied to the global rotation search and the correct solution can be ranked in the top 100 or less. However, this set of optimal weights in general is dependent on the search models and the crystal structures with different space groups and cell parameters. In this work, we try to solve this problem by designing a dynamic correlation coefficient. It is shown that the dynamic correlation coefficient works for a variety of space groups and cell parameters in the global search of rotation function. We also introduce two new matching scores： relative entropy and mean-square-residues. Last but not least, we discussed a valid method for the optimization of the adjustable parameters for matching vectors.

摘要：在在第一个压缩机转子前面的尖端区域的稳定的分离微空气注射被证明了是一个有效方法处于低速度推迟旋转货摊的开始轴的压缩机。就实际申请而言，微注射者的一种新类型被设计并且在这描述了纸，它在 casing 是嵌入的并且能沿着弦被移动。为了验证它的可行性到另外的盒子，一些另外的盒子例如高亚声的轴的压缩机或离心的压缩机，被学习了。新注射者能拥有许多其它，这除成功地稳定压缩机以外有利的轴的压缩机显示出的一样的低速度的试验性的结果。当在片尖端的相对速度是高亚声的时，在一台高亚声的轴的压缩机上执行的实验证实了微空气注射的有效性。同时以便在离心的压缩机探索它的可行性，一个类似的微注射者与 vaned 在低速度上被设计并且测试离心的压缩机更弥漫。注射集体流动比在轴的压缩机和结果使用了那证明微注射能也在离心的压缩机推迟旋转货摊的发作的大一些。