A STUDY ON HEAT AND MOISTURE STATE OF HULL LAYER FOR THERMAL INSTULATION OF A COLD STORAGE

This paper analyses the thermal moist characteristics of the hull layer beside an air layer at lower temperature in an envelope for a cold storage and presents a new method of waterproof by air layer. With test data from engineering practice, the theory on the barrier of self moisture proof at the surface sublayer of the hull layer in an attic on a cold storage is proven. The dried zone about three phase point is confirmed. It is a new knowledge for thermophysics on thermal design of a cold storage with an optimum thermal performance.     

不同生态环境马铃薯维生素C含量分析

对马铃薯参试品种在西北地区不同生态条件下的维生素C含量变化进行方差分析和稳定性分析。结果表明：试点间、品种间以及试点和品种的互作间都存在着极显著差异，6个品种平均维生素C含量为15．04mg／100g，陇薯3号最高，为18．68mg／100g，90-2-10最低。为12．23mg／100g；7个地点平均维生素C含量为15．04mg／100g，青海西宁最高，为16．75mg／100g，青海海南最低，为12．93mg／100g。中薯36这个品种的回归系数〈1，是稳定性较好的品种。     

可视化编程技术在发动机外特性曲线绘制中的应用

通过对汽车发动机外特性的理论分析,在处理汽车发动机外特性曲线时,建立了一种适合处理发动机外特性曲线的三次样条函数拟合的数学模型,在C Builder可视化开发平台上,编制了汽车发动机外特性曲线绘制程序.利用三次样条函数插值法对实验数据进行拟合,实现了发动机外特性曲线绘制的自动化.     

稻田水体碳氮稳定同位素组成与时空变化研究

利用稳定同位素技术研究了稻田沟渠、池塘、湿地等水体的碳、氮稳定同位素组成特征与时空变化。结果表明,水中颗粒性有机物(Particulate organic matter,POM)δ13C值(稳定性碳同位素比值)在-31.5‰~-24.3‰之间变化,平均值为-27.7‰,可能主要来自于浮游植物和浮游动物的贡献。POM稳定性碳同位素比值存在明显的季节变化,呈现出春、夏季高于秋、冬季的趋势。浮游动物与POM稳定性碳同位素比值之间的时空变化存在一定的相关性,说明研究区内浮游动物对内源有机碳的利用可能主要来自POM。颗粒性有机物δ15N存在秋、冬季高于春、夏季的趋势,但空间差异不显著,其中湿地的变化幅度相对较大(3.2‰~6.3‰),δ15NPOM平均值为4.1‰,说明研究区固氮作用较小,外源物的污染程度较低。     

论压弯构件

钢筋混凝土轴心受力构件、受弯构件和偏心受压构件在力学行为上有一个共同的特征,即构件的材料纤维均处于单向应力状态。为便于分析比较,特将这三类构件的力学性能一起讨论。     

厌氧氨氧化工艺在废水脱氮领域中的应用进展

厌氧氨氧化是一种全新的生物脱氮工艺。对于处理低碳氮比废水,与传统方法相比,它具有节省氧耗、无需外加有机碳源、污泥产量低等优点。近年来,随着基础研究的逐渐深入,各国学者开始将研究视角转向厌氧氨氧化工艺的实际应用。本文对该工艺在消化污泥上清液、垃圾渗滤液等实际废水脱氮研究中的进展进行了综述,并指出了目前存在的问题和今后的研究方向。     

基于CLIPS的农业灌溉专家系统研究

在干旱区高效用水灌溉决策支持系统研究过程中,农业灌溉过程中的很多问题无法用数学模型来求解,而必须使用农业专家的专家知识来对其进行解答。而早期由于专家系统不普及和开发困难等原因,致使农业灌溉专家系统应用不多。在对现行诸多专家系统进行详细了解后,决定采用CLIPS专家系统作为农业灌溉专家系统的支持平台。采用CLIPS组件和Visual C 语言开发出了农业灌溉专家系统,解决了农业灌溉过程中的诸多问题。同时介绍了将CLIPS组件嵌入到Visual C 中的方法。     

扭振减振器对曲轴弯曲和纵向振动的影响研究

以一台多缸柴油机为例,采用结合有限元法(FEM)的多体系统仿真(MSS)方法,研究了扭转振动减振器振动对曲轴弯曲、纵向振动的影响;实验测量了有无扭振减振器时的曲轴自由端的弯曲和纵向振动,其与计算结果吻合得较好。     

Expression of cathepsin C and tumor necrosis factor-α in human coronary artery and their relationships with coronary heart disease

AIM To explore the possible mechanism of cathepsin C （CTSC） and tumor necrosis factor-α （TNF-α） in coronary heart disease （CHD） by detecting the protein expression of CTSC and TNF-α in human coronary artery tissue. METHODS The coronary artery tissues from 52 cases of CHD and 25 cases of accidental death without any heart disease in the Forensic Judicial Expertise Center of Guizhou Medical University from October 2018 to December 2019 were collected as CHD group and control group, respectively. The coronary artery stenosis and intimal plaque formation were examined by histopathology, the protein expression of CTSC and TNF-α was determined by Western blot, and the intracellular expression of CTSC and TNF-α was analyzed by immunohistochemical staining. RESULTS The results of HE staining showed that the intima of coronary artery in control group was smooth, and no thickening or stenosis was observed. In CHD group, the intima thickened irregularly, atherosclerotic plaques formed, the intima became thinner and the lumen showed eccentric stenosis in varying degrees （P<0.05）. The results of Western blot showed that the expression of CTSC and TNF-α in CHD group was significantly higher than that in control group （P<0.05）. Immunohistochemical staining showed that both CTSC and TNF-α were expressed in the cytoplasm of foam cells, and their positive expression was significantly higher than that in control group （P<0.05）. The results of Pearson moment correlation analysis showed that there was positive correlation between the expression of CTSC and TNF-α in CHD （r²=0.743, P<0.05）. CONCLUSION The up-regulated expression of CTSC in coronary artery tissue may promote the expression of TNF-α and affect the occurrence and development of CHD.     

MicroRNA-9-5p mediates sympathetic overactivity by targeting KCNN3 in paraventricular nucleus of rats with T2D

AIM To investigate whether microRNA-9-5p （miR-9-5p） mediates sympathetic overactivity by targeting KCNN3 （potassium intermediate/small conductance calcium-activated channel, subfamily N, member 3） gene,which encoded small-conductance calcium-activated potassium channel 3 （SK3） protein, in paraventricular nucleus （PVN） of rats with type 2 diabetes mellitus （T2D）. METHODS A rat model of T2D was established by high-fat diet combined with intraperitoneal injection of 30 mg/kg streptozotocin. The levels of miR-9-5p and KCNN3 mRNA in PVN were detected by real-time PCR. The relationship between KCNN3 and miR-9-5p was predicted by TargetScan. Recombinant adeno-associated virus （rAAV）-miR-9-5p or KCNN3 were bilaterally microinjected into the PVN to observe the changes in plasma glucose levels and sympathetic drive indicators. The number of FosB and SK3 positive cells was measured by immunofluorescence staining. The protein expression of SK3 was determined by Western blot. The relationship between KCNN3 and miR-9-5p were confirmed by cell transfection and dual-luciferase reporter assay. RESULTS Compared with the rats in diabetes control （DC） group, the blood glucose, sympathetic drive indexes and the level of miR-9-5p in PVN were significantly increased, while the SK3 expression in PVN was obviously reduced in the diabetes mellitus （DM） rats. After microinjecion of rAAV-miR-9-5p in PVN, the sympathetic drive indexes, blood glucose, and the number of FosB-positive cells were increased significantly, but the SK3 protein expression was significantly reduced （P<0.05）. However, up-regulation of KCNN3 in PVN had the opposite effect. These responses were obviously enhanced in DM rats compared with DC rats. The results of cell transfection and dual-luciferase reporter assay demonstrated that miR-9-5p bound to the 3’-UTR of KCNN3 and inhibit its expression. CONCLUSION miR-9-5p was up-regulated in PVN of the rats with T2D, and it may mediate sympathoexcitation by targeting KCNN3.