内蒙古中部草原区光伏电站对土壤水分及其脉冲响应的作用机制

针对内蒙古草原地区光伏电站对降雨的再分配作用下土壤水分空间变异规律及其对降水事件的脉冲响应特征,对草原地区光伏组件下的土壤水分时空特征进行持续观测,并确定光伏组件干扰下的气象因子与土壤水分的关系,最终通过参数估计厘清光伏组件对土壤水分脉冲响应的作用机制。结果表明：光伏组件前檐下方的土壤总储水量整体高于组件下方和未架设组件区域的土壤储水量;光伏组件前檐的各土层储水量对降水的响应均较强,光伏组件下各层土壤储水量对降水无明显响应过程;光伏组件下大气湿度与0~10、10~20和20~30 cm土层储水量的相关系数分别为0.889、0.579和0.414;光伏组件前檐10、20和30 cm土层的含水量对降水量的脉冲响应方程R²分别为0.875、0.938和0.957,降水量的补给对0~30 cm土层的脉冲事件均产生促进作用。未架设组件区域的20 cm土层含水量对自然降水有较好的响应过程。     

Visualization investigation on flowing condensation in horizontal small channels with liquid separator

A simultaneous visualization and measurement experiment was carried out to investigate condensation flow patterns and condensing heat transfer characteristics of refrigerant R141b in parallel horizontal multi-channels with liquid-vapor separator. The hydraulic diameter of each channel was 1.5 mm and the channel length was 100 mm. The refrigerant vapor flowing in the small channels was cooled by cooling water. The parallel horizontal multi-channels were covered with a transparent silica glass for visualization of flow patterns. Experiments were performed at different inlet superheat temperatures(ranging from 3℃ to 7℃). Mass velocity was in the range of 82.37 kg m~(-2)s~(-1) to 35.56 kg m~(-2)s~(-1). It was found that there were three different flow patterns through the multi-channels with the increase of mass velocity. The flow patterns in each channel pass almost tended to be same and all of them were annular flows. The efficiency of the liquid-vapor separator with U-type was related to vapor mass velocity and the pressure in the small channels. It was also found that the heat transfer coefficient increased with the increase of the mass velocity while the cooling water mass flow rate increased. It increased to a top point and then decreased. It increased with the increase of superheat in the low superheat temperature region.     

盐业企业的营销策略初议

随着市场经济的发展,产品竞争的加剧,情感营销就显得越来越重要,盐业企业实施人性化管理的情感营销有利于培养顾客和员工的信赖和忠诚。     

Preparation of Polyimide Fiber/Thermoplastic Resin Composites with Improved Mechanical Properties

As a high-performance material for preparing composite materials, polyimide fibers suffer from many potential drawbacks, including poor bonding with other substrates, which results in composite materials with poor mechanical properties. Therefore, this study proposed a simple and rapid technique for obtaining loose, porous polyimide fiber papers by implementing a wet method using equal amounts of polyimide fiber and polyimide fiber paper as reinforcements, respectively. The polyimide resin-based composite materials were prepared by hand lay-up and hot pressing. The results showed that the paper-based reinforcement exhibited high porosity and the fibers were arranged with a uniform pore size distribution. The tensile properties, bending performance, and interlaminar shear performance of the paper-based composite improved by 130%, 108%, and 34.5%, respectively, compared to those of the fiber-based counterpart. The factors affecting the mechanical properties of the composites were analyzed based on the fiber length, fiber beating or lack thereof, and the basis weight of the paper. The increased uniformity of the polyimide fiber paper changed the ordering of the fibers and resolved drawbacks such as difficult dispersion, uneven pore size distribution, and poor mechanical properties related to single fibers in the resin-based composite material.     

General modeling and numerical simulation of the burning characteristics of porous chars

The modeling and numerical simulation of char burning rate within the temperature range of 1273–1700 K, which is the normal range in most boilers and furnaces, were carried out in this paper. Considering the differences in pore structure between char and non-porous carbon, several key issues were studied and discussed, including fresh char reactivity and its change during the burning process, and the effects of internal oxygen diffusion on the char burning rate. In the section of modeling, dozens of model equations were given and then implanted into the computational code. In the section of numerical simulation, the predicted values were compared with the experimental data gained from the entrained flow reactor including carbon conversion and apparent diameter change of coal char along the tube length, and good agreement was obtained. Additionally, the numerical simulation for biomass char burning was also done and the applicability of the developed model was discussed. The developed char burning model needs few empirical parameters, which can be used conveniently in the numerical simulation of actual combustion process.     

文字图形化设计在纺织品中的创意表达

置身于媒介环境时代中,图形已经成为受众增添认知和情感沟通的重要手段.文字图形化设计呈现独特的视觉形态,不仅可以拓展受众的想象思维,传递更多信息,还能刺激受众的感官体验,获得其情感认同.文章简要分析文字图形化的设计方法及应遵循的设计原则,充分运用现代设计语言以实践案例解读文字元素在纺织品中的设计呈现,旨在探究纺织品图案设...     

副干酪乳杆菌TD062对Ⅱ型糖尿病小鼠的降糖作用

对Ⅱ型糖尿病小鼠分别灌胃109,108 CFU/mL和107 CFU/mL副干酪乳杆菌TD062,研究其对糖尿病小鼠的降糖作用。同时检测糖原合成酶激酶-3β(GSK-3β)基因的表达情况,探讨其降糖机制。试验结果表明,副干酪乳杆菌TD062可有效改善糖尿病小鼠血糖水平、脏器指数和体重,显著提高葡萄糖耐受性及抗氧化能力,并通过降低GSK-3β的相对基因表达量,调节糖尿病模型中糖代谢紊乱,改善胰岛素抵抗,从而有效预防糖尿病的发生,为功能性食品的开发提供理论依据。     

玉米胚芽蛋白的提取及应用研究新进展

玉米胚芽蛋白是种全价优质蛋白,氨基酸全面均衡,极易被人体吸收,在营养学上有重要意义。综述了国内外玉米胚芽蛋白提取及应用研究新进展,包括玉米胚芽蛋白的营养价值、功能特性、提取及在食品工业中的应用,为玉米胚芽的综合利用提供参考。     

Liquid water transport in PEMFC cathode with symmetrical biomimetic flow field design based on Murray's law

Water management in the flow field as well as the flooding process in the gas diffusion and catalyst layers enormously influence proton exchange membrane fuel cells (PEMFCs) performance and reliability. Researchers have developed many different designs for flow channels that can be used to distribute fuel or oxidant in PEMFCs (proton exchange membrane fuel cells). Among these designs, novel biomimetic designs have captured special attentions from researchers due to their capability of distributing fluids effectively. This study presents an investigation of the liquid water transport within a porous layer and a symmetrical biomimetic flow field based on Murray's law. The volume of fluid (VOF) method is employed, and the dynamic contact angle (DCA) effects are also considered for better prediction of water distribution. The water transport process and water distribution inside the porous layer and flow field are obtained from the simulation results. Recommendations are given for this type of flow field design based on the behaviors of liquid water in the porous layer and flow field.