摘要：The Weihe River Basin has a significant number of tributaries and a delicate ecological *** the spatial and temporal evolution and determinants of landscape ecological risk in the Weihe River Basin(WRB)can improve the scientific protection and development of its watershed *** study is based on land use statistics from the WRB for a 30-year period represented by 1990,2000,2010,and *** initial model for the assessment of landscaping ecological hazards was created using the software that was also used to generate the landscape ecological risk index,such as ArcGIS 10.4 and Fragstats ***,the spatial and temporal evolution of landscape ecological risk in the vicinity of the study area was characterized by the trajectory of the center of gravity migration and the spatial autocorrelation of ***,Geodetector was used to analyze ecological risk drivers in the *** to the findings,the high-risk and relatively high-risk regions are steadily expanding,while the low-risk and relatively low-risk areas dominate the ecological risk landscape in the *** the Weihe River Basin,Xianyang and Xi'an are the areas to which the high-risk centers of gravity are *** spatial correlations were found between the landscape ecological hazards in the study area,most prominently in the form of high-high and low-low *** primary drivers are the interplay between the GDP component,temperature,and elevation as a single factor.

摘要：通过相图计算和气体雾化的方法,设计并制备Al-10Bi-7Zn和Al-10Bi-7Zn-1.5X (X:Cu, Fe, Ni)(质量分数,%)复合粉体。研究Cu、Fe和Ni对Al-Bi-Zn基复合粉体水解制氢性能的影响。通过X射线衍射(XRD)和扫描电子显微镜(SEM)以及能量色散谱(EDS)分析对粉体的组成和形貌进行表征。水解制氢性能测试结果表明,添加Cu、Fe或Ni可以改变Al-10Bi-7Zn三元合金复合粉体的制氢速率,并且提高其抗氧化性能。在四元复合粉体体系中,Al-10Bi-7Zn-1.5Ni表现出最佳的制氢性能,在60℃下与蒸馏水反应时,500 min内的产氢率为75.3%(954.1 m L/g),在储存7 d后(30℃,相对湿度60%),1500 min内保持57.9%(733.7 m L/g)的产氢率。此外,机理研究表明,在Al-Bi-Zn基复合粉体中添加Cu、Fe或Ni可以稳定Al基体,抑制复合粉体在空气中的开裂,保持粉体的高活性。

摘要：跟踪注册是增强现实(Augmented reality,AR)中一项至关重要的技术。基于人工标识和基于图像的注册方法已广泛应用于增强装配系统中。然而,由于空间产品的弱纹理、结构对称、数据有限以及难以张贴标识等特点,空间站的跟踪注册仍面临挑战。本文提出了一种专门为中国空间站诱导维修应用设计的三维物体跟踪方法,旨在用AR技术取代传统的纸质手册,为宇航员提供更直观的操作指导。本文提出了一种无标记的中国空间站智能维护方法。采用点对特征方法来估计初始帧姿态,不需要手动调整来获得相应的姿态,这对宇航员来说至关重要,因为在微重力环境中精确运动是一项重大挑战,而且结合曲率信息可以提高采用点对特征方法估计初始帧姿态的效率。通过结合纹理和区域信息,消除了对宇航员位置的精确限制,进一步增强了空间对称产品的跟踪鲁棒性。该方法利用点云匹配来估计第一帧的初始姿态,并在失去跟踪后重新计算姿态。一旦获得了前一帧的姿态,则仅根据二维图像的区域和纹理信息来计算跟踪,以获得实时跟踪。实验结果表明:本文方法与基于标识的方法具有相同的姿态趋势;基于电子游标卡尺测量之间的误差在毫米级;使用专门为航天产品设计的专用工具成功更换过滤器,证明了在空间站上实施诱导维修程序的实用性和潜力。

摘要：目的为乳腺癌患者提供满意的医疗服务,可有效减轻患者的负担和医疗资源压力。本研究的目的是利用卡诺模型探讨社区乳腺癌患者的健康服务需求。方法2023年1月—3月对某三级肿瘤医院出院的乳腺癌患者进行横断面调查。患者填写了基于卡诺模型自行设计的健康服务需求调查问卷,同时也提供了社会人口学信息。调查问卷中包括30项健康服务内容,基于卡诺模型对这些项目的属性进行分类和优先级排序。结果共回收有效问卷296份。对30项医疗服务的需求属性进行评价的结果显示,30项服务中有1项被归类为“必备型属性”(身体形象管理),13项被归类为“期望型属性”(侧重于医疗保障支持、健康管理和健康咨询),3项被归类为“魅力型属性”(侧重于沟通需求和远程保健服务),11项被归类为“无差异型属性”(主要集中在社会心理服务领域)。结论社区乳腺癌患者对不同健康服务项目的需求程度不同。医务工作者应根据患者需求确定有效的健康服务策略,优先提供必备型和期望型属性的服务,努力提供魅力型属性服务,以提高社区乳腺癌患者的生活质量。

摘要：直径超过2 m的超大型涡轮盘的锻造载荷接近甚至超过了国内最大压力机的极限(800 MN),是真正的极限制造。因此,保持良好的力学性能和控制锻造载荷是超大型涡轮盘热锻生产过程中必须同时兼顾的2个因素。基于田口法设计了25组不同的热锻参数,采用SNR和ANOVA方法对有限元模拟结果进行多目标优化分析,获得了最优锻造载荷和最均匀细化的再结晶组织,确定了极端制造条件下的最佳工艺参数组合(温度1120℃,应变速率0.06 s^(-1),预锻尺寸985/610/475 mm,模具温度280℃)。各参数对模拟结果的重要性顺序如下:变形温度>应变速率>坯料形状>>模具温度。使用最佳参数组合获得的实验结果与数值模拟结果吻合较好,表明该方法可以避免大量实验和数值模拟工作量,有效地控制超大型锻件的载荷和微观组织。

摘要：“学者”写作群体因所处人文环境的典型性、自足性,及思维方式的独特养成,而成为知识分子群体的重要“切片”。观察这一写作群体的写作取材、叙事手法及审美形式等方面,可见出其对于不同话语空间的思辨及反拨,而这一点也成为穿刺当下学者小说体系的窥口。从戴维·洛奇、索尔·贝娄、约翰·威廉斯等学者作家的经典小说文本及笔者自身的创作经验中得出,学者小说的“空间观”主要体现在学院空间与他性空间的话语关涉、小说叙事的互文性转化与空间流动等方面。这一“空间观”及其所伴生的历史沉淀、价值观厘定和文化主体重认,对于探讨学院派创意写作的发展具有一定启示。

摘要：This study reviews the state of the art in structural design and the corresponding mechanical behaviours of composite vascular grafts. We critically analyse surface and matrix designs composed of layered, embedded, and hybrid structures along the radial and longitudinal directions;materials and manufacturing techniques, such as tissue engineering and the use of textiles or their combinations;and the corresponding mechanical behaviours of composite vascular grafts in terms of their physical–mechanical properties, especially their stress–strain relationships and elastic recovery. The role of computational studies is discussed with respect to optimizing the geometrics designs and the corresponding mechanical behaviours to satisfy specialized applications, such as those for the aorta and its subparts. Natural and synthetic endothelial materials yield improvements in the mechanical and biological compliance of composite graft surfaces with host arteries. Moreover,the diameter, wall thickness, stiffness, compliance, tensile strength, elasticity, and burst strength of the graft matrix are determined depending on the application and the patient. For composite vascular grafts, hybrid architectures are recommended featuring multiple layers, dimensions, and materials to achieve the desired optimal flexibility and function for complying with user-specific requirements. Rapidly emerging artificial intelligence and big data techniques for diagnostics and the threedimensional(3D) manufacturing of vascular grafts will likely yield highly compliant, subject-specific, long-lasting, and economical vascular grafts in the near-future.

摘要：研究的目的是在胃的癌房间学习人的 yrdC 基因的功能的目的。方法人的 yrdC 基因被 RT-PCR 从人的脾组织孤立。反人的 yrdC 单音的同种细胞的抗体被 hybridoma 准备房间技术。带 yrdC 基因的 Recombinant 侵入人体气管粘膜的病菌 *** 被使用 AdEasy adenoviral 向量系统构造。Recombinant 侵入人体气管粘膜的病菌 *** 调停了 yrdCshRNA 被 RNA 干扰技术准备。中等区别的胃的腺癌 BGC-823 房间是 transfected， transfected 房间的吸收度在由甲基 thiazolyl tetrazolium (MTT ) 的 490 nm 是计算的方法。transfected *** 组的结果 A 价值比 non-transfected 和 transfected 广告的显著地大。*** 的空组，和价值组织比 non-transfected 和 transfected 广告的显著地低。空组。yrdC 基因的结论表示有支持胃的癌房间的增长的功能。

摘要：Spawned by fast-paced progress in new materials and integrate circuit technology,the past two decades have witnessed tremendous development of humanoid robots for both scientific and commercial purposes,*** response and daily life *** the root of this trend are the increasing research interests and cooperation opportunities across different laboratories and *** application-driven requirements of high effectiveness and reliability of humanoid robots led intensive research and development in humanoid locomotion and control *** spite of the progress in the area,challenges such as unnatural locomotion control,inefficient multi-motion planning,and relatively slow disturbances recovery set further requirements for the next generation of humanoid ***,the purpose of this work is to review the current development of highly representative bipedal humanoid robots and discuss the potential to move the ideas and models forward from laboratory settings into the real *** this end,we also review the current clinical understanding of the walking and running dynamics to make the robot more human-like.

摘要：The probability of the rendezvous between a single spacecraft and three non-coplanar constellation satellites is studied,and the necessary and sufficient conditions of the rendezvous without orbital maneuver are *** rendezvous orbit design can be transformed into the patching of two spacecraft orbits,either of which can achieve the rendezvous with two ***,due to the precious quality of spherical geometry,the unique existence of the rendezvous orbit for two constellation satellites is ***,according to the difference between equispaced and non-equispaced orbital planes of three satellites,the necessary and sufficient conditions are given respectively,and the calculating method of the spacecraft orbit is *** last,the constraint conditions between two different rendezvous orbits is derived,while the relative position of two groups of objects are under specific *** results can be applied to the rendezvous between a single spacecraft and multiple constellation satellites without orbital maneuver.