摘要：In order to detect and process underground vibration signal, this paper presents a system with the combination of software and hardware. The hardware part consists of sensor, memory chips, USB, etc. , which is responsible for capturing original signals from sensors. The software part is a virtual oscilloscope based on LabWindows/CVI （C vitual instrument）, which not only has the functions of traditional oscilloscope but also can analyze and process vibration signals in special ways. The experimental results show that the designed system is stable, reliable and easy to be operated, which can meet practical requirements.

摘要：以两轴角振动台为研究对象,设计角振动台加速度伺服控制器。依据各液压缸间的几何位置关系求取自由度合成及分解矩阵。采用三状态顺馈控制器提高系统的加速度响应频宽,采用三状态反馈控制器改善系统的稳定性,提高系统的阻尼比,采用输入滤波器实现角振动台的加速度控制。利用Matlab/XPC工具箱开发了两轴角振动台实时控制系统。最后,通过实验验证了所设计加速度伺服控制器的有效性。

摘要：Au/H相似性的研究是现代化学中的一个热门话题.我们从理论上报道Au/H相似的新成员:共价化合物B2Au4,离子化合物Al2Au4和BAl Au4.采用密度泛函和波函数理论方法对比研究了缺电子体系B2Au4、Al2Au4和BAl Au4的几何和电子结构.详细讨论了它们基态结构的轨道、适应性自然密度划分(Ad NDP)和电子局域函数(ELF)分析.计算结果表明稍微扭曲变形的C2B2Au4是基态结构,在这个共价化合物中含有两个B―Au―B三中心二电子(3c-2e)键.然而C3vAl+(Al Au4)-和C3vAl+(BAu4)-被研究证明是含有三个X―Au―Al三中心二电子键的类盐化合物(在Al2Au4中X=Al,BAl Au4中X=B).Al2Au4和BAl Au4是至今为止首例报道的在离子缺电子体系中含有金桥键的化合物.同时计算了B2Au4-、Al2Au4-和BAl Au4-阴离子基态结构的绝热剥离能和垂直剥离能,为实验表征提供依据.文中报道的金桥键为共价键和离子键相结合的缺电子体系提供了一个有趣的键合模式,有助于设计含有高度分散金原子的新材料和催化剂.

摘要：Existing research on grassroots rural governance in china adopts a network perspective to explore the role of traditional social vehicles including clans,clan clusters and popular beliefs in improving village ***,most of this research has concentrated on analyzing the way in which horizontal network relationships lead to effective village *** has thus to some extent neglected the basic reality of the overlapping interconnections between the ＂top-down＂ administrative system and the informal structure of village *** fact,an analysis that proceeds from the features of the government＇s own organizational network,the social structure of the village itself and the position of its elites in order to focus on modes of interaction within the village under the intermixture of（formal） system design and（informal） social relations,shows that differences in the composition of the government＇s promotional networks resulting from the traits of keyofficials affect the speed of policy dissemination as well as the government＇s mode of interaction with the village ***,differences in these modes of interaction further influence the subsequent operation of self-organization based on social traditions（＂filial piety＂ or ＂morality＂）.At the same time,structural elements,including the economic and social relations of the village itself,determine whether self-organization will improve the quality of governance in the long *** finding can serve as a reflection on and critique of the theories of ＂strong government＂ and ＂tradition＂ current in academia.

摘要：The recent discovery and realizations of higher-order topological insulators enrich the fundamental studies on topological ***,we report three-dimensional(3D)wave-steering capabilities enabled by topological boundary states at three different orders in a 3D phononic crystal with nontrivial bulk topology originated from the synergy of mirror symmetry of the unit cell and a non-symmorphic glide symmetry of the *** multitude of topological states brings diverse possibilities of wave *** judicious engineering of the boundary modes,we experimentally demonstrate two functionalities at different dimensions:2D negative refraction of sound wave enabled by a firstorder topological surface state with negative dispersion,and a 3D acoustic interferometer leveraging on second-order topological hinge *** work showcases that topological modes at different orders promise diverse wave steering applications across different dimensions.

摘要：The ability to detect conspecific＇s distress is crucial for animal survival. In rodent models, observational fear （OF） occurs when one animal perceives another fear related negative emotions, which may model certain behaviors caused by witnessing traumatic experiences in humans. Anterior cingulate cortex （ACC） has been showed to play a crucial role in OF. However, cellular and neural circuit basis relating to ACC governing OF is poorly understood. Here, we used Designer Receptor Exclusively Activated by a Designer Drug （DREADD） system to investigate the cell type specific circuit mechanism of ACC in OF. Firstly, inhibitory hM4D （Gi） designer receptor together with clozapine N-oxide （CNO） injection was applied to inactivate ACC neurons in the observer mice. We found that, chemogenetic inhibition of ACC resulted in a decreased freezing response in the observer mice. Next, combining PV-ires-Cre mice and Cre-dependent DREADD system, we selectively targeted the ACC parvalbumin （PV） interneurons with the excitatory hM3D （Gq） designer receptor. Activation of ACC PV interneurons following CNO injection reduced freezing response in the observer mice, while had no effect on freezing response in the demon- strator mice. Finally, monosynaptic rabies retrograde tracing revealed that ACC PV interneurons receive inputs from the mediodorsal thalamic nucleus （MD） and the ventromedial thalamic nucleus （VM）, both known for their roles in OF. Taken together, these findings reveal that ACC activation is important for OF, during which PV interneurons in ACC play an important regulatory role. Abnormal function of ACC PV interneurons might contribute to the pathology of empathy- deficits related diseases, such as autism and schizoohrenia.

摘要：Sodium ions(Na+) and ether electrolyte coinserted graphite possesses a considerable volume expansion effect. However, the mechanism fails to clearly explain its stability. In response to this deficiency, the co-inserted reaction is proposed, which is affected by the Lorentz force of the applied electric field under the high-current condition. The Na^(+) ions are separated out, while the ethylene glycol dimethyl ether molecules remain between the graphite layers. This insight provides a reasonable explanation for the extraordinary stability of this material. In situ X-ray diffraction and density functional theory calculations confirm the separation and release of Na+. On the basis of this result, unmodified commercial graphite was stably cycled 6400 times at a current density of up to 10 A g^(-1), and the capacity retention rate was as high as 97.2%. The full battery assembled in the laboratory has a maximum output power of 14,846 W kg^(-1)and an output energy density of 103 W h kg^(-1)(relative to the weight of anodic and cathodic active materials). The new mechanism provides innovative ideas for the design of large-scale energy storage devices.

摘要：滴灌的灌水器是滴灌系统的重要部件,其消能效果的好坏决定了滴灌系统是否节能。为提出更高效消能效果的灌水器,研究分析了先进的双向流流道灌水器的流场数值计算结果,总结存在的问题,提出了缩颈改流的设计方案,使用Fluent软件进行数值计算和模拟,对双向流流道型和缩颈改流型进行比较,结果表明：从压力云图可以发现压力经过3级降压,缩颈改流型压力下降更明显,从速度云图可以看出,在入口压力相同情况下,出口流速低6%,能够通过的颗粒物体积增加1倍,改进后的灌水器消能效果和抗堵性能更好。

摘要：为了获得对自然火灾现象的深入了解,从而促进消防安全设计/工程、消防管理以及灭火技术的发展,在中国NKBRSF(国家重点基础性研究基金)的赞助下,承担的“火灾动力学演化与防治基础”五年计划项目。该项目从2002年开始实施以来,与中国几个著名大学以及从事消防基础科学研究的研究所之间的合作,取得了一定的进展。对2002-2004之间的最新研究进展情况做了总结,对中国基础火灾科学研究的前景进行了展望。