创业自我效能感与创新机会识别：一个有调节的中介模型

创业自我效能感是创新机会识别的促进因素这一观点可能夸大了创业自我效能感的好处而忽视了其潜在的成本。为此,关注创业自我效能感在机会识别过程中的“黑暗”面,并将信息扫描频率引入创新机会识别过程,基于145名中国创业者的调查数据,构建一个有调节的中介模型来考察创业自我效能感、信息扫描频率、创业经验与创新机会识别之间的关系。结果显示：创业自我效能感对信息扫描频率有负向影响,而信息扫描频率的降低不利于创新机会的识别;信息扫描频率在创业自我效能感与创新机会识别的关系中发挥负向中介作用,而创业经验可以缓解信息扫描频率的负向中介效应。基于此,提出新创企业管理者应正确看待创业自我效能感对创新机会识别的作用机制,创业者应积极进行信息扫描并更好地利用创业经验等对策建议,以此启发创业者在实践中更好地识别创新机会。     

测压管路动态特性实测技术研究

利用声音振动发生原理研制了多功能声音振动发生装置,开发了测压管路动态特性的实测技术,并对风洞试验中典型测压管路的频响特性进行了实测.采用正弦压力波对不同的测压管路进行激励,采用多点联合扫描技术提高采样频率,得到完整的正弦波动曲线.实验研究结果表明,该实验技术可以得到高频的动态压力信号和准确的频响特性曲线,为误差修正提供了依据.     

三维彩色扫描系统及算法

提出了一种大尺寸 3D物体几何形状的扫描测量系统 ,该系统由一个线结构光源和一个彩色CCD摄像机组成 .CCD摄像机两次摄取被扫描物体的图像 ,首先从激光平面中获取被扫描物体的三维信息 ,然后将 3D物体的彩色信息和三维信息自动进行叠合 ,以获得 3D物体的真实模型 .     

光子隧道效应与电子隧道效应的比较研究

采用多层膜理论的菲涅尔矩阵系数法导出光子隧道信息的计算公式,并对电子隧道信息进行了光学方法的推导,得到了与量子力学中电子隧道效应一致的公式.此外,比较了光子隧道效应与电子隧道效应的异同.     

英语阅读的方法与技巧

阅读在英语学习中具有举足轻重的地位。培养阅读能力,首先要分析阅读的概念、心理过程和障碍;其次,归纳概括阅读方法与技巧:控制发音动作、猜词悟义、利用结构信息和关键词、注意理解句子或段落、养成集中注意力阅读的习惯。     

银包覆表面修饰提高LiFePO4的电化学性能

LiFePO4是一种用于锂离子二次电池的潜在正极材料．LiFePO4微粒通过简单的共沉淀方法合成,为了增加其电子导电率,在水中用硝酸银溶液对LiFePO4进行包覆．粒子表面高分散的银提高了电子导电率和容量．不同电流密度下银包覆LiFePO4的电化学性能和其他高导电率的LiFePO4是相似的．银包覆是一种保持容量的有效方法,甚至在高的电流密度下也是如此．     

论编辑的初审原则及其加工策略

初审是关涉稿件“生死”的关键环节,编辑应切实把握好内容要真实、观点要新颖和论证要充分的初审原则,认真审慎地处置初审稿件。加工是对拟刊发稿件必做不可的一项工作,编辑须按编辑出版规范的要求,针对稿件存在的问题,采取合适的方式,作出精当的修改。     

环境扫描电镜在牙本质湿黏结界面观察中的应用

用环境扫描电镜低真空模式观察新鲜制备的牙本质湿黏结样本。通过对条件的比较,发现在样品室气压1.19×102~1.30×102Pa,加速电压15 kV,束斑4.0,工作距离8.5~11 mm这一条件下,牙本质湿黏结样本变化小,充放电现象少,能获得满意的结果。     

基于垂直扫描白光干涉法的6JA干涉显微镜的改造

介绍了一种基于垂直扫描白光干涉法的6JA干涉显微镜改造的总体方案、系统测量原理、仪器结构,以及对标准样板及圆柱零件的测试结果。该测量系统已对本科生和研究生开出实验并投入实用,其垂直分辨率为2 nm,横向分辨率为0．3μm,垂直扫描范围为80μm。     

Efficiently capturing large,complex cultural heritage sites with a handheld mobile 3D laser mapping system

Accurate three-dimensional representations of cultural heritage sites are highly valuable for scientific study, conservation, and educational purposes. In addition to their use for archival purposes, 3D models enable efficient and precise measurement of relevant natural and architectural features. Many cultural heritage sites are large and complex, consisting of multiple structures spatially distributed over tens of thousands of square metres. The process of effectively digitising such geometrically complex locations requires measurements to be acquired from a variety of viewpoints. While several technologies exist for capturing the 3D structure of objects and environments, none are ideally suited to complex, large-scale sites, mainly due to their limited coverage or acquisition efficiency. We explore the use of a recently developed handheld mobile mapping system called Zebedee in cultural heritage applications. The Zebedee system is capable of efficiently mapping an environment in three dimensions by continually acquiring data as an operator holding the device traverses through the site. The system was deployed at the former Peel Island Lazaret, a culturally significant site in Queensland, Australia, consisting of dozens of buildings of various sizes spread across an area of approximately 400 × 250 m. With the Zebedee system, the site was scanned in half a day, and a detailed 3D point cloud model (with over 520 million points) was generated from the 3.6 hours of acquired data in 2.6 hours. We present results demonstrating that Zebedee was able to accurately capture both site context and building detail comparable in accuracy to manual measurement techniques, and at a greatly increased level of efficiency and scope. The scan allowed us to record derelict buildings that previously could not be measured because of the scale and complexity of the site. The resulting 3D model captures both interior and exterior features of buildings, including structure, materials, and the contents of rooms.