Performance of synthesized polycarboxylic grinding aid

Hydrolyzed polymaleic anhydride (HPMA) and polyethylene glycol monomethyl ether(MPEG) synthesized a kind of polycarboxylic grinding aid, the esterification was prompted by the mechanical force during the process of cement grinding. The effects on cement grinding and mortar property were tested from HPMA, MPEG, the mixture of HPMA and MPEG, and the resultant of HPMA and MPEG. The results showed that the mixture of HPMA and MPEG and the resultant of HPMA and MPEG had better grinding performance than HPMA and MPEG, and which can improve the fluidity and early strength of cement mortar. Laser Raman spectrum tests showed that the resultant of HPMA and MPEG had a similar Raman shift spectrum with the mixture of HPMA and MPEG, when they were adsorbed on the cement particle surface after co-grinding.     

Preparation and characterization of carbon cones by reaction plasma

Carbon cones are prepared on Si substrates film in plasma-enhanced hot filament chemical vapor deposition system using CH4, H2 and NH3 as the reaction gas, and the substrates are deposited with Ti and carbon film, respectively. Morphology and structure of the carbon cones are characterized by field emission scanning electron microscopy (FESEM), energy dispersive X-ray (EDX)and micro-Raman spectroscopy. The SEM results indicate that the carbon cones are formed on the Si substrate deposited with carbon film. Furthermore, the EDX and Raman spectra indicate that the formed carbon cones are carbon nitride structure, which are composed of sp 3 C-N, sp 2 C and sp 2 C=N bonds. According to the mechanisms of sputtering and diffusion, the formation of carbon cones is analyzed. Simultaneously, the photoluminescence background in the Raman spectrum of carbon cones is analyzed, and results indicate that the carbon cone evolves from nonpolar carbon material to polarity carbon material due to the doping of nitrogen.     

风廓线雷达晴空大气返回信号功率谱特征分析

风廓线雷达谱参数是生成基本数据产品的重要参数,谱参数的正确估算是风廓线雷达运用的基础。基于晴空大气服从高斯分布的假设,本文给出了判断晴空大气返回信号功率谱服从高斯分布的2个判据,一是均方差值,二是面积相对比,利用这2个判据统计分析了风廓线雷达晴空探测资料服从高斯分布的情况,并分析了可能出现的带有杂波的大气返回信号以及杂波剔除方法,得出晴空大气返回信号功率谱服从高斯分布的结论,为快速估算晴空大气谱参数提供了新的方法,即功率谱的波峰位置对应多普勒频移,相对波峰位置的半功率点对应谱宽。     

直剪法用于糙米内摩擦角的测定与研究

利用土工合成材料综合测定仪（直剪仪）,以水分含量14.57%的糙米为样品,测定了在不同的法向压应力、不同的剪切速率下糙米的剪切应力并计算出内摩擦角。实验结果表明：糙米的剪切应力随着法向压应力（25kPa～100kPa）的增大而增大;剪切速率（1.33mm/min～2.67mm/min）较低时糙米的内摩擦角随着法向压应力的增大而减小;随着剪切速率（1.33mm/min～5.20mm/min）的增大,糙米的内摩擦角减小。     

The influence of initial internal structure of coal sample on gas flow characteristic

Three kinds of coal samples with different components are chosen as study objects.Density calculation and SEM are adopted to study their internal structures,and a self made triaxial gas seepage instrument is used to study their internal gas flow characteristics.The results show that internal structures of coal samples made of different particle size coal powders under identical external conditions are various,and nonlinearity is presented on the influence caused by fabric.Gas flow characteristic is complex in complete stress strain process,generally it firstly increases and then decreases,initial gas flow velocity is lower than the one after the failure of coal sample,and obvious hysteretic nature of gas flow characteristic is showed.The influence of gas flow characteristic caused by initial internal structure of coal sample is nonlinear and the stress sensitivity is high on the influence of gas flow characteristic caused by initial internal structure.The more complex the initial internal structure of the coal sample is,the lower the axial tress sensitivity is,and the higher the confining pressure sensitivity is.     

THE THEOREM OF STATIONARY VALUE OF WEIGHTED ENERGY AND ITS WEIGHTING FUNCTIONS

This paper presents two energy functionals which are made as stationary values. Thus, the theorem of stationary value of weighted generalized potential energy and the theorem of stationary value of weighted generalized complementary energy are established. In the first theorem, the stress boundary weighting function must be equal to the internal weighting function while the displacement boundary weighting function is independen; and in the (?)econd theorem, the displacement boundary weighting function must be equal to the internal weighting function while the stress boundary weighting function is independent.     

茶树干旱胁迫研究进展

综述了在茶树干旱胁迫时内源激素ABA、IAA积累的速度与干旱胁迫程度（干旱时间、土壤水势）的关系以及保护性酶SOD活性呈现出的“先升后降”的规律,而POD活性则呈现出“先快后慢”的趋势;渗透调节物质脯氨酸,无机元素铁、锰、铜、锌含量随干旱胁迫而变化的研究结果。为抗旱性茶树品种的选育和提高茶树抗旱的栽培技术的研究提供理论依据。     

Analysis of accelerated fatigue test technology for wind turbines gearbox

In order to satisfy the high reliability requirements of wind turbines gearbox, a method of accelerated fatigue test is proposed to verify the fatigue reliability of the gearbox. According to the design load spectrum, the equivalent load and the number of stress cycles of parts in gearbox are deduced. Based on Miner linear cumulative damage theory, the fatigue degree of the gears and bearings are calculated. A linear accelerated load spectrum with the equivalent fatigue ratio of design load spectrum is provided to check the reliability of the gearbox. The results show that this method can verify the reliability of wind turbine gearbox within about 800 h.     

High night-time temperature during flowering and pod filling affects flower opening,yield and seed fatty acid composition in canola

Winter canola (Brassica napus L.) is highly sensitive to increasing temperatures during the reproductive and pod-filling stages. Although the impact of high day-time temperature stress on yield and quality has been documented in canola, similar information under high night-time temperature (HNT) stress is not available. Using six hybrids and four open-pollinated cultivars, we observed a marked shift in peak flowering towards earlier, cooler hours of the morning under HNT. Averaged across two independent experiments, the photochemical efficiency of photosystem II was significantly decreased (3%), with a significant increase in thylakoid membrane damage (13%) in the leaves of susceptible cultivars under HNT stress. Similarly, the susceptible cultivars also recorded significant reduction in biomass (34%), pod number (22%), pod weight (37%) and total seed weight (40%) per plant while the same set of agronomic traits were not affected among the tolerant cultivars. Quantitative impact of heat stress was confirmed with increased sensitivity to HNT exposure from gametogenesis until maturity resulting in a significantly higher yield loss compared to stress exposure from post-flowering till maturity. HNT significantly decreased oil concentration, but increased protein concentration and saturated fatty acid levels in seeds of the susceptible cultivars. However, HNT had no impact on the unsaturated fatty acids in both hybrids and the open-pollinated cultivars. Breeding targets based on fatty acid composition for enhancing canola seed quality may not be easily amenable due to the inconsistency documented with the compositional changes under heat stress. In summary, our findings conclude that canola hybrids are better suited to regions experiencing heat stress, compared to open-pollinated cultivars, indicating the possibility of a complete shift to hybrid canola cultivation under predicted hotter climates in the future.     

水稻基因OsASIE1抗逆功能分析

作为重要的植物转录因子家族, AP2/EREBP转录因子在植物发育、激素、病原反应及非生物胁迫如干旱、高盐、低温应答方面起重要作用。本研究发现水稻AP2/EREBP转录因子家族EREBP亚家族成员OsASIE1 (abiotic stress induced EREBP gene)在水稻受到高盐、干旱胁迫时表达量迅速提高, 并且在水稻中超表达OsASIE1能够改善水稻抵抗盐胁迫的能力。凝胶迁移率实验(electrophoresis mobility shift assay, EMSA)表明该转录因子的AP2结构域能够结合干旱应答顺式作用元件DRE (dehydration-responsive element)和乙烯应答元件GCC box (ethylene response element), 推测OsASIE1可能通过结合DRE和GCC box 作用元件调控下游相关基因的表达, 进而调控相关抗逆反应。     

The Elimination of Deformation Coupling in Thin Wall Composite Material Rod with Closed Section

Under the condition that normal stress and shear stress are coupled in constitutive equations,a set of displacements which depend on geometric and physical properties of a thin wall rod is specially designated to minimize the coupling of basic deformations in control equations,and general forms to describe self balance system of internal forces are proposed with the model given by the present paper.     

大豆内摩擦角的测定与实验研究

利用剪切仪,测定了在不同的剪切速度、不同的法向压应力、不同的水分条件下大豆的内摩擦角。结果表明:随着剪切速率的增大(1.33～4.33 mm/min)大豆内摩擦角减小,随着法向压应力的增大(0.25×105～1.00×105Pa)大豆内摩擦角减小,随着水分含量的增大(12.11%～18.02%)大豆内摩擦角先增大后减小。     

门架式抗滑桩结构模型试验研究

为了对门架式抗滑桩的结构特性有进一步的认识和提升,进行了门架式抗滑桩三维地质力学模型试验与门架式抗滑桩结构模型试验。通过在桩身内部贴置应变片以及桩身的关键位置处放置千分表,来测量在推力荷载施加过程中,门架式抗滑桩的桩身应力变化特点及关键位置点的位移变化特征。试验结果表明：门架式抗滑桩桩前、后排桩桩顶位移大于滑动面处位移,后排桩桩身位移大于前排桩桩身位移;前、后排桩桩身内力均呈现明显的“s”型分布,桩顶应力不为零,其数值随着推力荷载的增大的而增大。     

Joint Bearing Analysis for the Preloading Water-filled Spiral Case of Lager Hydropower Station

Spiral case is the core structure of powerhouse,therefore,it is critical to obtain its accurate stress and strain.Simplified algorithm is adopted to analyze the mechanical characteristics of preloading water-filled spiral case of a large hydropower project.The numerical results show that the adoption of preloading water-filled spiral case structure is feasible.The maximum stress of surrounding concrete mainly lies in the top of spiral case structure at various sections.The suitable internal pressure is 1.9MPa.The stress of surrounding concrete of spiral case is mainly caused by water pressure,and the effect of upper loading is limited,which is only about 5% to 24%.     

A Determination Method of Anchorage Length of Compression Anchor

The distribution of the axial stress and shear stress on the anchorage segment and the formulation for calculating the anchorage length were derived based on the stress analysis of the anchorage segment of compression anchor. And the effects of parameters, including the elastic modulus, poisson ratio, cohesion, and internal fiction angle of rock mass, on the anchorage length were studied. The results show that the anchorage length decreases with the increase of the elastic modulus, cohesion and internal friction angle of rock mass; and the anchorage length increases linearly but limited with increasing of poisson ratio of rock mass; and it also increases with increasing load.     

Evaluation of Common Bean for Drought Tolerance in Juana Diaz, Puerto Rico

Drought tolerance is an increasingly important trait in common bean ( Phaseolus vulgaris L.) due to the reduction in water resources, a shift in production areas and increasing input costs. The objective of this study was to evaluate 29 genotypes for drought tolerance under drought stress (DS) and reduced stress treatments in Juana Diaz, Puerto Rico. The use of DS and reduced stress treatments facilitated the identification of drought tolerant germplasm that also had good yield potential under more optimal conditions. Based on the results of seed yield under DS and reduced stress conditions, and DS indices, including the geometric mean (GM), stress tolerance index (STI) and percent yield reduction (YR), genotypes were identified with greater yield potential under the tested environment. Based on average GM over the 2 years, the superior common bean genotypes identified were SEA 5, G 21212, A 686, SEN 21 and SER 21. These genotypes performed well in both years and under both treatment conditions and thus may serve as parents for DS improvement and genetic analysis.     

Elastic-Perfectly Plastic Solution of Tunnel Surrounding Rocks Using Mogi-Coulomb Strength Criterion

Reasonable choice of rock strength criteria is crucial for stress and displacement prediction and support design in tunnel engineering. Based on Mogi-Coulomb strength criterion and elastic-perfectly plastic model, analytical solutions of stress and displacement for surrounding rocks around a circular tunnel were derived The intermediate principal stress coefficient was used to present the intermediate principal stress effect. The results in this study were compared with the current solutions in the literatures and the influence of intermediate principal stress and shear strength parameters of surrounding rocks was discussed. The results showed extensive applicability and the Mohr-Coulomb strength criterion and Matsuoka-Nakai criterion are two special cases; when the intermediate principal stress coefficient b was equals to 0.5, the results indicated that the intermediate principal stress effect and its range for rock strength; the influence of cohesion and internal friction angle on the plastic radius and tunnel wall displacement was significant; Care should be taken to the effects of intermediate principal stress and shear strength parameter variations of surrounding rocks on tunnel design and construction.     

玉米堆摩擦角的测定与研究

利用直剪仪对玉米(水分率为11.05%、12.34%、16.72%、17.57%w.b)的内摩擦角进行了实验测定与分析。结果表明:玉米的内摩擦角变化范围是22.81°~35.20°,玉米的内摩擦角随剪切速度的增加而减小,随法向压应力的增加而减小,随水分的增加而增加。     

羧甲基壳聚糖-铜(Ⅱ)-多吡啶型SOD模拟物的制备及其对玉米幼苗抗盐害作用的影响

【研究目的】试验旨在合成2个新型羧甲基壳聚糖-铜(Ⅱ)-多吡啶型超氧化物歧化酶模拟化合物,并研究这些模拟物对农作物抗逆作用的影响。【方法】用红外光谱,紫外-可见光谱,原子吸收光谱对这些抹模拟物: cmcts-Cu(Ⅱ)-bpy（1）和cmcts-Cu(Ⅱ)-phen（2）(cmcts=羧甲基壳聚糖, bpy=2,2’-联二吡啶,phen=1,10-邻菲咯啉)进行了表征;并研究了模拟物在中度土壤盐害的情况下对玉米幼苗抗盐害作用的影响。【结果】结果表明：在中度盐害情况下,经这些SOD模拟物浸种、叶面喷洒处理,发现生玉米物量提高2.38~53.02 %（茎叶长）和25.00~64.29 %（鲜重）,体内SOD活性提高最高达95.99 %。【结论】初步表明这些SOD模拟物具有较高的SOD活性,能有效抑制玉米幼苗所受的盐害胁迫作用。     

氮代谢参与植物低氮胁迫研究进展

环境的日益恶化迫使人们放弃高肥生产的观念,转向低肥绿色环保生产的理念。本文主要从低氮胁迫下氮代谢相关的酶、氮素同化途径、初级代谢、次级代谢以及氮代谢相关基因五方面综述了植物体内不同的代谢水平、形态、生理和分子响应,探讨了不同生长阶段植物的耐低氮策略,阐述了氮利用效率(NUE)相关的酶及其调控过程抵御氮胁迫过程中的作用机理。本文提出今后可针对不同植物或同一植物的不同生长期的低氮耐受差异,以及关键基因表达产物之间的关系,从多学科、多角度系统全面的研究植物在低氮胁迫下的分子响应机制,为氮代谢参与植物低氮胁迫研究提供理论参考。