Climate,diseases, and the origins of corruption

It has been commonly observed that tropical countries tend to suffer from intense corruption and underdevelopment. This study provides an explanation for this long-standing disparity across the world based on variation in the intensity of ultraviolet radiation (UV-R). The central hypothesis is that UV-R is positively associated with the (historical) prevalence of eye diseases, which significantly shortens work-life expectancy as a skilled worker. This helps shape the worldwide distribution of corruption by affecting the incumbents' window of opportunity. Using data for up to 139 countries, I consistently find empirical support for the positive relationship between UV-R and corruption. The main findings withstand accounting for numerous alternative explanations for international differences in corruption levels. Employing individual-level data from the World Values Survey, I document suggestive evidence that exposure to UV-R is linked to surveyed respondents' tolerance towards corrupt activities. Furthermore, a subnational analysis for China lends credence to the cross-country evidence.     

Automatic extraction of 1D barcodes from video scans for drone-assisted inventory management in warehousing applications

The widespread use of barcodes has significantly contributed to accurate, efficient and economic inventory management in warehouses and distribution centres. However, its efficiency has always been limited by the primary method of reading barcodes with a handheld laser scanner. Compared with this reading by line-of-sight at close proximity, vision-based barcode reading algorithms can further improve efficiency, particularly if accompanied by automated data collection platforms such as drones. This paper introduces algorithms that are able to automatically extract barcodes from video data, and verifies their feasibility and promise for inventory management in warehousing applications. Three key techniques corresponding to different recognition levels are proposed: For a known barcode region, a Harris corner detector and Hough transform-based algorithm is applied to quickly estimate the angle by which the frame area needs to rotate to orient the bars vertically for information extraction. Then, the idea of exploiting connectivity and geometry property of barcode areas is proposed to directly recognise multiple barcode regions in a single video frame to eliminate reading difficulties resulting from interactive influence of multiple juxtaposed barcodes, and to save computation time by only processing frame areas of interest for valid barcodes. In addition, a histogram difference-based fast extraction strategy is designed to further improve efficiency by reducing duplicate information processing. Finally, the performance of each technique is evaluated by analysing video data from a large logistics warehouse, demonstrating satisfactory performance in inventory management applications.     

各类火灾探测器原理分析及应用探讨

火灾探测器能在火灾发生初期,将燃烧物产生的烟雾、热量、火焰等物理量变成电信号传输到火灾报警控制器,是现代消防系统的核心部件。文章通过对各类火灾探测器的工作原理进行分析,并对其应用场合进行探讨,为火灾自动报警系统的设计、施工与运行维护提供参考依据。     

热释电BST薄膜红外探测器噪声分析及前置放大电路设计

针对热释电红外探测中微信号放大时的低信噪比问题,在分析热释电红外探测器及前置放大电路噪声来源的基础上,提出了一种热释电红外探测前置放大电路.电路仿真表明,文中所设计的前置放大电路具有低频特性好、高信噪比、高增益的特点,能有效放大微弱信号.     

料浆水分旋转式检测头数学模型的建立

利用旋转式检测头测量料浆的水分含量时,料浆水分含量的变化可引起检测头所受的阻力矩发生变化,其转速也会发生相应改变。对实验数据进行多元线性回归处理,建立了检测头的数学模型,即料浆水分含量δ、检测头转速脉冲P及数字电压U之间的关系,通过测量检测头的转速可间接地测量料浆的水分含量或浓度。     

混合粒子群优化算法在CDMA系统多用户检测中的应用

针对粒子群优化算法易早熟的问题,提出了一种混合粒子群优化算法(HPSO)。首先在算法中采用惯性权重的分段递减策略,以提高算法的全局搜索能力;然后在算法后期,引入拉伸技术剔除比局部极值大的点,缩小搜索空间,使算法能及时跳出局部最优从而加速收敛,最后提出了基于HPSO算法的多用户检测器。仿真结果表明在信噪比相同的条件下,该多用户检测器的误码率和抗远近效应性能更接近于最佳多用户检测器,有效解决了码分多址通信系统中的多址干扰问题。     

区域高质量发展的时空演变及驱动因素分析 ——以甘青宁地区为例

从经济发展、社会和谐、生态安全、城乡融合出发构建指标体系,运用熵值法、变异系数法和地理探测器对甘青宁地区高质量发展的时空演变特征和驱动因素进行研究。结果表明,2010-2018年甘青宁地区高质量发展总体向好,但地区差异逐渐拉大,高质量发展仍处于初级阶段;经济发展、社会和谐、生态安全、城乡融合水平总体均呈增长趋势,经济发展和生态安全水平地区差异逐渐缩小,社会和谐和城乡融合水平地区差异逐渐扩大;高质量发展的主要驱动因素是经济发展,第三产业增加值占GDP比重、每千人口卫生技术人员数、森林覆盖率、城乡人均消费支出比分别是经济发展、社会和谐、生态安全和城乡融合的主要驱动因素,各层级任意两因子交互后解释力更强。基于以上结论得出了政策启示。     

两性霉素B菌种选育及发酵工艺研究

为了提高两性霉素B(amphotericin B,AmB)的产量,降低生产成本,满足市场需求,采用紫外诱变和常压室温等离子体(atmospheric and room temperature plasma, ARTP)诱变的复合诱变方法进行菌株选育。首先,对结节链霉菌出发菌株A318-10进行复合诱变;然后,筛选高产菌株,并利用软件Design-Expert 12对显著效应因子进行Box-Behnken Design试验设计,得到最优发酵配方;最后,在1 L摇瓶及50 L发酵罐中进行发酵优化配方验证。结果表明,在紫外诱变60 s并ARTP诱变35 s后,筛选得到了高产菌株20-2-15,其最优发酵配方为葡萄糖94.6 g/L、中温豆粉27.7 g/L、淀粉24.1 g/L;在最优配方下,结节链霉菌1 L摇瓶和50 L发酵罐的发酵最高水平分别为18 968μg/mL和21 257μg/mL,比原始配方分别提高了32.6%和29.4%。研究结果应用于规模化生产后,有利于降低成本、提高企业竞争力。     

光固化涂料生产技术及进展

概述了光固化涂料的基础理论，光固化涂料的发展过程、特点、固化机理、组成光固化涂料的各种组分及其作用，在分析涂料工业现状的基础上对光固化涂料的发展与应用领域进行了详述，指出辐射固化涂料、紫外光固化水性涂料、紫外光固化粉末涂料等对环境友好，是未来涂料发展的方向。未来光固化涂料的研究和发展应朝水性化和粉末化方向发展。     

陕西省乡村发展水平时空变化及其主导因素分析

[目的]不同区域的乡村因自然禀赋和社会环境存在差异,呈现出异构的变化脉络和发展态势。掌握其影响因素及时空变化情况,有益于探寻因地制宜的乡村发展对策。[方法]文章以农村居民可支配收入表征乡村发展水平,利用多元线性回归、地理探测器等模型解析影响县域乡村发展要素的主导因素,分析其时序变化和影响区域分布。[结果]（1）陕西省乡村发展水平具有显著的空间集聚特征,该特征随时间变化呈现先上升后下降的趋势;（2）各要素影响力排序结果存在一定差异,但靠前5个因素保持一致;（3）目前乡村发展尚未克服地形因素的阻碍,地区经济发展与人力资本的差异可能继续影响乡村的发展,县区交通基础设施建设逐渐成为乡村发展差异的主要矛盾;（4）不同地区所受的主导要素不同。[结论]加强县区自身经济发展、加大基础建设的投资,以及发挥乡村的能动作用并努力提升乡村劳动力质量水平,对乡村可持续发展尤其重要。陕西省各区域乡村发展限制条件有所差异,陕北地区应当注重人力资本的发展,加大教育投资或许是其发展之路;关中地区地区经济总体较好,应当发挥城市的带动作用,以城带乡、以工促农。陕南地区利用其生物与旅游资源的优势,发展特色农业促进乡村发展。