space

摘要： In order to deal with coarse-grained and multi-grained calculation problems,as well as granularity transformation problems in information system,quotient space theory is introduced in rough set theory.The main idea of this research is to try to maintain the important properties of the original space into the quotient space.Aimed to preserve the micro properties and the macro properties,two pairs of approximation operators on the quotient space are defined.When it comes to the composite of quotient spaces,the idea of these operators shows greater advantages.Examples are cited to illustrate possible applications of these operators,and their matrix representations are also given to make the calculations easy.Finally,all approximation operators on the quotient space involved so far are compared and their relationships are shown through a diagram.

摘要： Bildung is the process of the individual growing into the subject in time and space.As a bildungsroman,Abraham Chan’s The Rise of David Levinsky unfolds the spatial subject is produced through bodily spatial activities in the complicated social relations.Experiencing the spatial transformation and conflict between the“feminized”Jewish community in Russia and the“heroized”space in America,the protagonist David shows his subjective desire by gendered performing to reconstruct the gendered subject in spatial movement.

摘要： There is currently considerable interest in what degrowth compatible business practices may be and what they may look like.However,while the embeddedness of a degrowth business in the wider environment has been recognised,and this affects theorising of practices and principles,there remains a need to seriously consider the inter-connection between degrowth business and its surrounding environment as a physical and cultural space.To avoid merely hinting at geographical concepts such as space,place,and location,a better approach is establishing a dialogue between degrowth business and geography.To do this,I use the degrowth business framework and connect its elements with the concepts of space,place,and location.This analysis shows that each of the elements is intimately inter-related with geographical concepts and needs to be thought of,theorised,and implemented as such.I conclude that geographical concepts should not be merely implied when theorising degrowth business.Rather,looking at degrowth business through various lenses provided by geographies is indispensable for making degrowth reality in diverse locations.

摘要： 自然资源资产负债表的编制是保护自然资源、考核领导干部任期绩效和离任审计的关键举措,对于实现我国经济社会及生态的可持续性发展具有重要意义。在当前大数据时代下,为理清自然资源资产负债表研究领域的发展动态,本文以CNKI数据库中检索得到的相关文献作为基础数据信息,利用Cite Space可视化软件对自然资源资产负债表相关研究的发文量、支持基金、收录期刊、核心作者、研究机构展开具体分析,并进一步构建关键词时区分析图、关键词共线分析图、关键词聚类分析图、关键词突现分布图,以期能够全面地反映我国自然资源资产负债表研究的阶段性特征与发展趋势,并为后续开展相关研究提供理论基础与实践参考。

摘要： Electric propulsion technology is the most active professional technology in the field of space propulsion in recent years.China began the research of electric propulsion technology in the 1970s,and entered the stage of rapid development after 2000.It has successively completed the principle research,technical breakthrough and ground test verification.Driven by the increasing demand for space missions,various new types of electric propulsion are emerging.

摘要： 3D printing is nowadays used for many applications far beyond pure rapid prototyping.As tools to prepare custom-made objects which may be highly complex,different 3D printing techniques have emerged into areas of application where the mechanical,thermal,optical and other properties have to meet high requirements.Amongst them,applications for space,e.g.for microsatellites,make extreme demands regarding the stability under high temperatures.Nevertheless,polymeric 3D printed materials have several advantages for space application in comparison with metal objects.Here we thus investigate the impact of temperatures up to 85◦C and 185◦C,respectively,on typical 3D printing materials for fused deposition modeling or stereolithography(SLA)with inexpensive 3D printers.The materials are found to differ strongly in terms of mechanical properties and dimensional stability after the treatment at a higher temperature,with SLA resins and co-polyester showing the best dimensional stability,while acrylonitrile–butadiene–styrene and SLA resin after long UV post-treatment has the best mechanical properties.

摘要： Traditional teaching and learning about industrial robots uses abstract instructions,which are difficult for students to understand.Meanwhile,there are safety issues associated with the use of practical training equipment.To address these problems,this paper developed an instructional system based on mixed-reality(MR)technology for teaching about industrial robots.The Siasun T6A-series robots were taken as a case study,and the Microsoft MR device HoloLens-2 was used as the instructional platform.First,the parameters of the robots were analyzed based on their structural drawings.Then,the robot modules were decomposed,and 1:1 three-dimensional(3D)digital reproductions were created in Maya.Next,a library of digital models of the robot components was established,and a 3D spatial operation interface for the virtual instructional system was created in Unity.Subsequently,a C#code framework was established to satisfy the requirements of interactive functions and data transmission,and the data were saved in JSON format.In this way,a key technique that facilitates the understanding of spatial structures and a variety of human-machine interactions were realized.Finally,an instructional system based on HoloLens-2 was established for understanding the structures and principles of robots.The results showed that the instructional system developed in this study provides realistic 3D visualizations and a natural,efficient approach for human-machine interactions.This system could effectively improve the efficiency of knowledge transfer and the student’s motivation to learn.

摘要： High power-to-weight ratio,good radiation resistance,and low manufacturing cost enable perovskite solar cells(PSCs)to be possibly used in space[1].Different from terrestri-al applications,PSCs used in space will face cosmic radiation,e.g.,electrons,protons,neutrons,gamma rays,X-rays,ultravi-olet(UV)rays,etc.(Fig.1(a)),harming their long-term opera-tional stability.Electrons are the most common high-energy particles in space.A series of terrestrial experiments mimick-ing electrons in the space environment were carried out,show-ing that PSCs can be deteriorated upon exposure.Al-Jassim et al.elucidated two failure pathways for perovskite films un-der electron-beam(e-beam)exposure through cathodolumin-escence(CL)signals variation,which are knock-on-induced de-fect formation and heat-induced phase transformation[2].Gao et al.revealed the decomposition process of MAPbI3 under e-beam exposure by in-situ TEM[3].

摘要： In 1937, Paul Dirac proposed Large Number Hypothesis and Hypothesis of Variable Gravitational Constant, and later added notion of Continuous Creation of Matter in the World. Hypersphere World-Universe Model (WUM) follows these ideas, albeit introducing different mechanism of Matter creation. In this paper, we show that WUM is a natural continuation of Classical Physics. WUM is proposed as an alternative to prevailing Big Bang Model (BBM) that relies on General Relativity. WUM and BBM are principally different Models: 1) Instead of Initial Singularity with infinite energy density and extremely rapid expansion of spacetime (Inflation) in BBM;in WUM, there was Fluctuation (4D Nucleus of World with extrapolated radius equal to basic size unit of a) in Eternal Universe with finite extrapolated energy density (~104 less than nuclear density) and finite expansion of Nucleus in Its fourth spatial dimension with speed c that is gravitodynamic constant;2) Instead of alleged practically Infinite Homogeneous and Isotropic Universe around Initial Singularity in BBM;in WUM, 3D Finite Boundless World (Hypersphere of 4D Nucleus) presents Patchwork Quilt of various Luminous Superclusters (≧103), which emerged in different places of World at different Cosmological times. Medium of World, consisting of protons, electrons, photons, neutrinos, and dark matter particles, is Homogeneous and Isotropic. Distribution of Macroobjects is spatially Inhomogeneous and Anisotropic and temporally Non-simultaneous. Most direct observational evidence of validity of WUM are: 1) Microwave Background Radiation and Intergalactic Plasma speak in favor of existence of Medium;2) Laniakea Supercluster with binding mass ~1017M⊙ is home to Milky Way (MW) and ~105 other nearby galaxies, which did not start their movement from Initial Singularity;3) MW is gravitationally bounded with Virgo Supercluster (VS) and has Orbital Angular Momentum that far exceeds its rotational angular momentum;4) Mass-to-light ratio of VS is ~300 times larger than that of Solar ratio. Similar ratios are obtained for other superclusters. These ratios are main arguments in favor of presence of significant amounts of Dark Matter in the World. 5) Astronomers discovered the most distant galaxy HD1 that is ~13.5 Bly away. WUM predicts discovery of galaxies with a distance of ~13.8 Bly. Medium of World, Dark Matter, and Angular Momentum are main Three Pillars of WUM.

摘要： Except for the speed of photons in vacuum, all speeds are relative. Could we develop an absolute scale for speed in which relative values for speed may be arbitrarily positioned and compared in absolute terms? The currently accepted definition for the meter as the distance covered by photons in vacuum during 1/299,792,458 s, and the view that the greater a material particle is accelerated towards c, the greater time dilation and length contraction will be, suggest that anything disturbing one of the four spacetime dimensions may affect the other three as well. One hypothetical experiment, one real experiment performed in the 1970s, and one experiment from a different field of science are discussed to propose that both time and velocity are only partially relative. In the first experiment, person A is standing still on the Earth’s surface, and person B is onboard a train passing by person A at the constant speed of 60 km/h (as measured by person B on the train’s speedometer). Persons A and B define two distinct inertial frames of reference, which correspond to two different spacetime conditions and which are therefore characterized by comparatively different lengths of the meter and durations of the second, as predicted by the Lorentz factor. Therefore, if person B onboard the train measures the train’s speed relative to person A as 60 km/h, a simple calculation will show that person A will perceive the train passing by at 59.99999999999981455834 km/h. If we consider the speed of photons in vacuum (c = 299,792,458 m/s) as a universal reference, and if we consider that the greater a material particle is accelerated towards c, the greater time dilation and length contraction will be, then person C, occupying an independent, distinct inertial frame of reference, will be unable to determine persons A and B’s absolute speeds, but may infer which one is moving at a speed closer to c by comparing, with his own meter and second, the durations of the second and the lengths of the meter experienced by persons A and B. The relativity of time may not be complete due to the bias that derives from the limit imposed on spacetime by c and the Lorentz factor, causing relativity to be partial. The second and third experiments further help understand this partiality.

摘要： 本发明公开了一种便携式Space Wire路由器测试系统及测试方法；该系统使用FPGA搭配触发按钮及LED指示灯，在系统上电后，测试人员只需通过按动触发按钮即可开始测试，LED指示灯直观显示测试结果正确与否，使得实操性强。该系统适与传统板级测试验证平台相比，减少了测试PC机，界面软件，复杂的物理连线，只需提供稳压电源，即可进行测试。测试系统具有一定的防静电能力，携带方便，在多种应用场所下均可使用，适用性强；该系统为Space Wire总线的应用推广提供一个便携的演示平台，为Space Wire路由器的国产化道路提供先例和测试验证平台，为Space Wire总线作为适用于航天环境的空间总线技术应用提供前期测试验证。

摘要： 本发明公开了一种基于6U VPX架构的抗辐照加固载荷主控器，涉及航天电路领域。所述主控器包括：处理器模块和FPGA模块。板卡标准化设计，结构统一，尺寸统一，接口标准化，其可移植性性强，可极大节约载荷产品的研制成本和研制周期；本发明使用“COTS+宇航级+抗幅噪加固”思想进行设计，作为载荷的控制单元，本发明在硬件电路设计上，载荷主控使用高可靠性的FPGA专用刷新电路和核心处理器，在软件设计上，使用三模冗余设计和EDAC设计，增强了载荷系统的可靠性。

摘要： 一种SPACE肽修饰的抗菌脂质体，所述抗菌脂质体为表面修饰SPACE肽且负载有疏水抗菌剂的脂质体，所述脂质体的制备原料包括：卵磷脂、胆酸钠、SPACE肽、疏水抗菌剂。本发明提供的脂质体表面修饰有SPACE肽，使脂质体能高效穿透角质层的阻隔进入真皮组织，从而提高活性成分的透皮吸收，并且具有细胞相容性优异、制备效率高的优点。

摘要： 本发明提供了一种基于SPACE6和双栈技术的网络系统，部署在网络出口处，包括交换机、路由器以及SPACE6平台，其中所有的路由器和交换机上开启双栈技术，所述SPACE6平台融合网络层和应用层翻译技术，可将IPv6协议的内容和IPv4协议的内容互相转换，用户端经由交换机和路由器传送过来的不同地址对应的用户需求可在所述SPACE6平台进行转换。本发明设计合理，在网络出口处部署一套基于Space6技术的IPv6‑IPv4转换系统，完成互联网IPv6用户访问外网IPv4网站的需求，也能完成互联网IPv4用户访问外网IPv6网站的需求，在尽量降低投资的情况下，高效率的对网络数据进行转发。

摘要： 本申请涉及一种基于复杂网络的公交网络分析方法、系统、存储介质及SP‑Space模型，涉及网络科学的技术领域，其包括获取分析单元以及与分析单元对应的公交线网，所述公交线网包括多个公交站点及公交站点之间的公交线路；将分析单元和公交线网匹配至同一坐标系；将公交站点关联至对应的分析单元，并建立分析单元间的P‑Space拓扑模型，定义分析单元间的P‑Space拓扑模型为SP‑Space拓扑模型，所述SP‑Space拓扑模型包括多个连接分析单元形心的边；根据所述SP‑Space拓扑模型得出所述边的权重；根据所述边的权重得出分析单元的权重。本申请具有在分析公交网络过程中考虑交通出行特征和城市空间特征，实用性强的效果。

摘要： 本发明涉及机械臂运动控制技术领域，具体涉及一种机械臂Constrain Space的控制方法，S1、确定机械臂的工作平面；S2、在工作平面内，根据障碍物的位置分布信息确定机械臂转动的安全区域；S3、在安全区域内设置机械臂的运动路径；S4、建立手臂的空间模型与机械臂的空间模型，并获取手臂与机械臂的映射关系；S5、获取手臂关节的三维坐标，根据手臂与机械臂之间的映射关系计算对应的机械臂关节的三维坐标；S6、由机械臂关节的三维坐标计算机械臂的关节值；S7、根据关节值控制机械臂沿着运动路径行进。本发明解决了现有技术中受限于算法缺乏灵活性等固有缺陷在两个自由度的情况下控制精度、灵活性低的技术问题。

摘要： 本发明公开了一种便携式Space Wire路由器测试系统及测试方法；该系统使用FPGA搭配触发按钮及LED指示灯，在系统上电后，测试人员只需通过按动触发按钮即可开始测试，LED指示灯直观显示测试结果正确与否，使得实操性强。该系统适与传统板级测试验证平台相比，减少了测试PC机，界面软件，复杂的物理连线，只需提供稳压电源，即可进行测试。测试系统具有一定的防静电能力，携带方便，在多种应用场所下均可使用，适用性强；该系统为Space Wire总线的应用推广提供一个便携的演示平台，为Space Wire路由器的国产化道路提供先例和测试验证平台，为Space Wire总线作为适用于航天环境的空间总线技术应用提供前期测试验证。

摘要： 本发明涉及在包括至少两个接收线圈的MR系统中生成检查对象的MR图像的方法。其中，与受激回波信号并发地将梯度磁场施加到检查区域，使得k‑空间中生成不是恒定线的轨迹。根据本发明的第一方面，施加RF脉冲序列以在检查对象中生成受激回波信号，使用弯曲的k‑空间轨迹，在接收所述受激回波信号期间，在至少两个接收线圈中检测欠采样MR测量数据，并且使用至少两个接收线圈的灵敏度信息从欠采样MR测量数据生成完全采样的MR测量数据。根据本发明的第二方面，MR测量数据在k‑空间的中心区域中被完全采样，其中中心区域外的区域未被完全采样，并且使用从k‑空间中心区域的完全采样的MR测量数据，利用局部傅里叶技术，对MR测量数据执行相位校正。

摘要： 本发明公开了一种双spacer序列识别切割CRISPR‑Cas9载体构建及其在疣孢菌中的应用。本发明提供了一种双spacer序列识别切割CRISPR‑Cas9载体构建方法，利用该方法成功构建了用于敲除海洋疣孢菌abyssomicin基因簇的双spacer序列识别切割CRISPR‑Cas9载体。通过实验证明：本发明构建的用于敲除海洋疣孢菌abyssomicin基因簇的双spacer序列识别切割CRISPR‑Cas9载体可成功敲除海洋疣孢菌abyssomicin基因簇。

摘要： 本实用新型属于石英晶体谐振器制造技术领域，具体公开了下holder与mask&spacer的分离设备，包括承载板、治具固定机构和脱离机构，承载板上设有用于放置治具的凹槽，脱离机构包括支撑板、顶升组件和升降组件；顶升组件包括针板以及至少两组缓冲结构，针板固定在支撑板上；针板上设有若干第一针孔，凹槽的底部设有若干第二针孔，支撑板上固定有若干顶针，第一针孔、第二针孔和顶针三者一一对应；每组缓冲结构包括直线轴和缓冲件，直线轴垂直固定在针板上，承载板上设有与直线轴对应的通孔；缓冲件的两侧分别固定在针板和承载板之间；升降组件用于带动承载板竖向移动。解决目前通常对组合治具采用人工拆卸，造成拆卸困难且容易对治具发生损坏的问题。