Effect of neodymium substitution on crystalline orientation,microstructure and electric properties of sol-gel derived PZT thin films

Pb(Nd_xZr_0.52Ti_0.48)O₃ (PNZT) (x = 0%, 1%, 2%, 3%, 4%, 5%) thin films were prepared by sol-gel process to investigate the effects of neodymium substitution on crystalline orientation, microstructure and electric properties of lead zirconate titanate (PZT) films. X-ray diffraction (XRD) and scanning electron microscope (SEM) analysis showed that PNZT films with Nd doping concentration below 3% exhibited dense perovskite structure with (100) preferred orientation. The average grain size of PNZT films decreased as the Nd substitution increased. The maximum dielectric constant, remnant polarization and minimum coercive field were obtained in 2% Nd-doped PZT films. Fatigue resistance was also improved significantly with 2% Nd dopant.     

Preparation of (110)-oriented SrTiO3 film on quartz glass by laser chemical vapor deposition

SrTiO₃ (STO) film was prepared on quartz glass by laser chemical vapor deposition at a deposition temperature (T_dep) ranged from 760 to 1104 K. Effect of the T_dep on the orientation, crystallinity, texture, and microstructure of the STO film was investigated. As the T_dep was increased, the preferred orientation of the STO film tended to be (110)-orientated with corresponding texture coefficient (TC) on the (110) reflection enhanced from 2.3 to 6; meanwhile, the full width at half maximum of the ω-scan on the (110) reflection decreased from 0.85° to 0.59°. The (110)-oriented grains were in wedge shape about 60 × 150 nm in size, which tended to be flat at an elevated T_dep of 1104 K.     

全球铬矿石资源国对中国供应安全度分析

近年来,中国铬矿石年均进口量维持在1 000万t的高位,我国目前主要铬资源进口国为南非、哈萨克斯坦、印度、阿尔巴尼亚、土耳其、伊朗六国,2017年这六国对我国供应占比分别为72.3%、8%、3.4%、2.1%、1%、0.6%;政治因素、资源量和产量会成为影响我国铬矿资源稳定供应的主要因素。本文分析了六国的储量、产量、对华出口量、运输距离及地缘政治的情况,利用决定系数和多样性指数建立模型并进行定量分析,得出我国未来铬矿石进口国优先顺序依次为南非、哈萨克斯坦、印度、阿尔巴尼亚、土耳其、伊朗。该模型未将突发事件的影响列入考虑,结果只适用于当前政治经济局势环境中。根据上述结果,提出我国未来应保持与南非、哈萨克斯坦两国的贸易合作并探索与其他国家进行更进一步合作的资源配置方案,在全球铬矿生产国进行投资建厂、完善全球铬矿资源布局;并提出了未来10～15年我国铬矿布局建议,控制全球产能15%;主要规划产能分布在南非、伊朗、阿曼、哈萨克斯坦四国。     

黄河悬河稳定性评价专家系统的研制

从区域稳定性研究入手，以地壳、堤坝与地基三系统控制论为理论基础，系统总结了悬河研究领域中的最新成果和结论。提出了工程治理与环境治理，环境治理与经济发展，地质工程治理与水利工程治理相结合的治理策略，并用先进的人工智能技术，研制出黄河悬河稳定性评价专家系统，为黄河下游悬河分析、评价与处理以及进一步研究提供有效手段     

湖南某大学校园建筑环境热舒适调查研究

对湖南某大学校园内建筑的环境热舒适度进行了现场调查和分析,采取现场测试与问卷调查相结合的方法。共测试了20间教室和5间学生宿舍,收集问卷调查表1273份。发现温度、风速、着衣热阻等参数对热舒适有明显的影响,但相对湿度对热舒适的影响不大。学生可接受的作用温度范围比ASHRAE标准规定的舒适区温度范围要宽得多,PMV指标与实际情况存在较大差别。讨论了适应性问题,推导出了室内舒适温度与室外平均温度之间的关系式,并将所得结果与其他研究成果进行了比较。     

地下工程研究的基本地学观点和原理

地下工程是典型的地质工程，所以地学在地下工程稳定性研究中具有重要意义。因此对地下工程研究的基本地学观点和原理予以讨论，着重分析了影响地下工程稳定性的基本地学要素、地下工程稳定性的优势面分析原理、量化评价模型以及地下工程治理的地质工程原理。     

地下工程中岩移的断层效应探讨

应用优势理论对地下工程开挖引起岩移的断层效应进行了探讨。通过先确定好一些优势指标。用优势指标法能找出断层网中哪些断层易受开挖影响而产生特殊的岩移现象，并预测其强度程度，最后，基于优势面理论对岩移的优势断层效应的机制进行了分析。     

Crystallization of progesterone polymorphs using polymer-induced heteronucleation (PIHn) method

Progesterone is a natural hormone steroid used in humans for several treatments and in livestock for artificial insemination, which exhibits two polymorphic forms at ambient conditions: form 1 and form 2. Form 2 is metastable and more soluble than form 1; however, it is not suitable to use as powder raw material because it transforms into form 1 by the effects of grinding. A polymorphic screening of progesterone based on polymer-induced heteronucleation method was performed as an alternative to prepare the metastable form. Polyvinyl alcohol, hydroxypropyl methylcellulose (HPMC), dextran, gelatin, polyisoprene (PI) and acrylonitrile-butadiene (NBR) copolymer were used. Crystals were prepared from 0.5, 10 and 40?mg/mL solutions in acetone at room temperature by solvent evaporation. The samples were characterized by X-ray powder diffraction, differential scanning calorimetry (DSC), scanning electron microcopy and attenuated total reflectance infrared Fourier transform spectroscopy. Form 1 was nucleated from 40?mg/mL solutions on the six polymers and from 10?mg/mL solutions on PI and NBR. The mixture of form 1 and form 2 was obtained from 10?mg/mL solution on HPMC, dextran and gelatin and from 0.5?mg/mL solution crystallizations. Therefore, the polymeric devices, which crystallized the metastable and more soluble polymorph (2) of progesterone, would be a promissory alternative for the pharmaceutical applications.     

Optimal display color for nighttime smartphone users

The study investigated the optimal display color for comfortable use of smartphones at night under low illuminance, while not distorting the perceived quality of displays. Two phases of psychophysical experiments were conducted to judge perceptibility and acceptability of the displays in various shades of white. The experimental results showed that the scores in acceptability were always higher than those in perceptibility all across the hues, and yellow received the highest scores in acceptability among the six hue categories. This can be interpreted that the observers have the intention of using a display in a yellow shade of white even though it is not perceived as pure white. Through the analysis, a white in yellow shade with the RGB values of 255, 255, and 230 was determined as the optimal display color for nighttime smartphone users regardless of display luminance or contents. The proposed display color supports physiological comfort by reducing the blue light, which involves an adverse effect on the biological system, and provides psychological satisfaction by allowing users to decide the color within the range of the user's acceptable threshold. © 2016 Wiley Periodicals, Inc. Col Res Appl, 42, 60–67, 2017     

川东北高温高压高产含硫气井井口装置的优选

川东北地区气藏是海相碳酸岩气藏,普遍具有高温、高压、高含硫化氢和二氧化碳酸性腐蚀性气体等特点,酸性气藏(H2S、CO2)对测试设施腐蚀严重,不适应高压气井生产和测试需求。基于最高井口关井压力、腐蚀分压、井口流温预测,确定出普光地区、元坝地区以及河坝区块宜选用相应的压力级别、温度类别、规范级别、材料类别以及性能级别的井口装置,为高温、高压、高产、含硫气井的井口装置优选提供基础。