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Search Results: 1 - 10 of 40376 matches for " 孟家琪 "
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岩质边坡滚石飞落模型与防治技术
Free-fly rolling model of stone on rock slope and control techniques

,??,石永飞,
- , 2018,
Abstract: 针对公路岩质边坡的滚石灾害问题,建立岩石跳跃滚落的理论分析模型,推导了岩石运动的轨迹方程、滚石第1次落点后的水平速度和竖向速度以及第2次落点的水平距离,计算了滚石掉入构筑物表面的水平距离和对砂垫层的撞击能,并计算了滚石撞入砂垫层的入土深度,分析了撞击能与入土深度的关系,同时推导出了滚石落入砂垫层的冲击压力、最大法向压应力、撞击能以及压入量,并通过2个算例对提出的模型进行验证,根据计算结果选取了合理的防护方式对滚石灾害进行防护。研究结果表明:算例1滚石对砂垫层的压入量为1.28 m,设计构筑物上的砂垫层厚度为2 m,同时考虑到构筑物的安全储备,滚石撞击坡面后的水平运动距离小于撞击点到公路路缘的水平距离,滚石飞落至地面的撞击能为167 kJ,采用型号为AXI-015(防护等级为200 kJ)的被动防护网可有效防护构筑物,避免安全事故的发生;算例2滚石落入砂垫层的压入量为0.87 m,撞击能为124 kJ,设计洞口顶回填1.5 m厚的砂垫层,采用防护等级为150 kJ的被动防护网可有效防护边坡滚石灾害。采用提出的模型计算并进行防护的效果非常明显,证明了所建模型的可实施性,为以后类似工程提供了有益指导。
Aiming the problem of rolling stone disasters of highway rock slopes, a theoretical analysis model of rock jumping and rolling was established. By deducing the trajectory equation of rock movement, the horizontal velocity and vertical velocity of the first drop point of rolling stone and the horizontal distance of the second drop point were derived. In addition, the horizontal distance of rolling stone falling into the structure surface and the impact energy on sand cushion were calculated, the depth of rock rolling into sand cushion was calculated, and the relationship between impact energy and depth was analyzed. At the same time, the impact pressure, the maximum normal compressive stress, the impact energy and the amount of indentation of rolling stone falling into sand cushion were derived. The proposed model was verified by two examples. According to the calculation results, a reasonable protection method was selected for the protection of rolling stone hazards. The results show that in the first example, the amount of indentation of rolling stone falling to sand cushion is 1.28 m, and the thickness of sand cushion on the designed structure is 2 m. Considering the safety reserve of structure, the distance of horizontal movement of rolling stone after hitting the slope is less than the horizontal distance from the impact point to road edge, and the impact energy of rolling stone flying down to the ground is 167 kJ. The passive protective net of AXI-015 (protection grade is 200 kJ) can effectively protect the structure and avoid accident. In the second example, the amount of indentation of rolling stone falling into sand cushion is 0.87 m, the impact energy is 124 kJ, and the thickness of sand cushion with 1.5 m is backfilled to the top of the designed hole. The passive protective net of AXI-015 (protection grade is 150 kJ) can effectively protect slope rolling rock hazards. The effect is obvious of which using proposed method for calculation and protection. At the same time, it is proved that the model can be implemented, which can provide
益气止血药对去势大鼠雌激素及出、凝血机制的影响
黄雪,林海,,庆刚,季绍良
中国中医药信息杂志 , 2004,
Abstract: 目的探讨益气止血药对去势大鼠雌激素及出、凝血机制的影响。方法通过摘除雌性大鼠卵巢塑造去势模型,从雌二醇(e2)、孕酮(p)、凝血酶原时间(pt)、活化部分凝血活酶时间(aptt)方面进行研究。结果模型组e2较正常组显著降低(p<0.05),pt较正常组延长(p>0.05),而aptt缩短(p<0.01)。结论益气止血药能够改变由于雌激素缺乏导致的异常状态。
美国数植分类学近况

植物学报 , 1983,
Abstract:
固体的激发态和发光

物理 , 1990,
Abstract: ?本文着重介绍了固体中主要的激发态和与之相关的发光现象,包括过渡金属离子和稀土离子形成的分立中心发光,半导体中的各种复合发光过程,特别是施主受主对复合发光和等电子陷阶复合发光,以及电子晶格耦合对发光的影响.
物理学与新型(功能)材料专题系列介绍(ⅵ)光谱烧孔──下一代光存储技术

物理 , 1992,
Abstract: ?光存储技术由于能实现比其他信息存储技术更高的密度,受到各国重视.然而现行光存储技术的最高存储密度受到激光聚焦光斑最小尺寸限制.各国科学家竞相研究能突破这一限制.实现超高密度的下一代新技术.光子选通光谱烧孔就是其中的佼佼者.中国科学家在提高光子选通光谱烧孔工作温度方面做出了国际同行公认的贡献.光子选通光谱烧孔实际应用还有许多问题有待解决.
用于冲压发动机的富燃料固体推进剂的选择和评价

推进技术 , 1984,
Abstract: 本文着重从能量特性和燃烧特性对富燃料推进剂进行了讨论,以便得出选择和评价富燃料推进剂的基本原则。对硼在冲压发动机中的使用和存在的主要问题作了简要讨论。
缓凝剂对碱碳酸盐矿-矿渣灌浆材料性能的影响

武汉理工大学学报 , 2006,
Abstract: ?研究了数种缓凝剂对碱碳酸盐矿-矿渣灌浆材料工作性能的影响。结果表明,适用于碱矿渣水泥的部分缓凝剂均不适用于碱碳酸盐矿-矿渣灌浆材料,而缓凝剂bacl2无论是以粉末形式还是以溶液形式掺入,均可很好地改善该灌浆材料的流动性能,有效延长其凝胶时间并促进材料后期强度的发展,但早期强度降低。以粉末形式掺入时,3d强度降低约36%左右。同时分别探讨了bacl2溶液和粉末bacl2的作用机理。
黄芪组分及主要成分保肝作用研究进展
Progress in Hepatoprotective Effect of Main Compositions in Astragali Radix
 [PDF]

,, 马越鸣
Traditional Chinese Medicine (TCM) , 2016, DOI: 10.12677/TCM.2016.52011
Abstract:
黄芪为中医临床常用保肝中药之一,研究表明其有效组分及主要成分对肝损伤具有保护作用。本文从抗肝纤维化、肝缺血再灌注、免疫性肝损伤、肝癌、乙肝病毒感染等方面,对黄芪有效组分(包括黄芪总皂苷、黄芪总黄酮及黄芪多糖)和主要成分(包括黄芪甲苷、芒柄花素和毛蕊异黄酮)的保肝作用及可能机制进行综述,为黄芪的进一步研发和临床应用提供参考。
Astragali Radix is one of the commonly used Traditional Chinese Medicines for treatment of liver diseases in clinic. It has been reported that its main components and constituents had a protective effect on multiple liver injury. This article reviews the protective effect and mechanism of main components including astragalosides, total flavonoids of Astragali Radix, astraglus polysaccharide and constituents including astragaloside IV, formononetin, calycosin on liver injury such as liver fibrosis, liver ischemia and reperfusion injury, immunological liver injury, hepatoma and hepatitis B, so that to provide reference for further research and clinical application.
中药双重疗法治疗女性外阴溃疡临床体会

中国中医药信息杂志 , 2002,
Abstract:
燃气冷热电三联供的设备间通风系统模拟研究
Simulation Study on Ventilation System of the Equipment Room for CCHP System
 [PDF]

许伟明, 王瑞祥,
Sustainable Energy (SE) , 2015, DOI: 10.12677/SE.2015.55007
Abstract:
燃气冷热电三联供(Combined cooling heating and Power system, CCHP)的设备间散热量大,需要合理其通风气流组织,保证设备间的温度满足设备运行最佳温度。通过实验方法确定通风方案成本过高,有必要利用模拟方式辅助设计通风系统。本文通过构建设备间三维数学模型,利用Fluent软件,对CCHP系统设备间的温度场进行数值分析,提出了气流组织形式的改进方案及相应的通风设计依据。按照改进后的通风系统,夏季在进风温度为室外设计温度307 k时,通过模拟分析利用增设冷风设备能够有效地降低发电机组运行的环境温度。冬季在进风温度设计室外温度为269.4 K时,通过模拟分析可利用自然进风和强制排风方式保证设备间的运行环境温度,可节省系统运行成本。
Heat dissipation between equipments of CCHP system, which need well organized ventilation to assure the optimum temperature for equipments running. It costs much to obtain the ventilation plan by experimental method; it is necessary to use simulation as an auxiliary for the design of ventilation system. By the building of mathematical model of equipments and using the software Fluent for numerical analysis of the temperature field between equipments, this paper gives the improvement scheme for air distribution mode and design criteria for ventilation. According to the improved ventilation system, the extra use of cold wind equipment can decrease the running temperature of power generator effectively by simulation under the condition that the inlet air temperature is equal to the design temperature 307 K of outside in summer. In winter, when the inlet air temperature is equal to the design temperature 269.4 K of outside, the use of natural air inlet and forced air exhaust can keep the running ambient temperature between equipments, which can save operation costs of the system.
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