深基坑支护失效模式初探

工程中为了克服安全系数评定基坑稳定性中的缺陷,研究者已开始将可靠性理论应用到基坑分析中,而此理论要求必须正确建立基坑失效模式和功能函数。在前人研究的基础上,通过对深基坑稳定性影响因素分析研究,从失效机理上对深基坑支护失效模式进行探究性总结,提出7种失效模式,并认为此7种模式是相互耦合的,具有一定的相关度,从而为基坑支护体系可靠度的计算奠定基础。     

兴利调节计算的计算机自动化实现

以XMicrosoft Visual Basic6．0为平台,结合Excel的强大报表功能,通过VB与Excel相互间数据的交互,将VB与Office结合,用户按照规定格式输入数据,利用开发的VB程序载入数据,计算得到待求参数,实现了兴利调节计算过程中的自动化。     

特大值处理对频率计算结果影响分析

为研究特大值处理对频率计算结果的影响,通过对官寨水文站实测资料进行频率计算,对其中一次较大洪水的考虑,采用了不同方法进行处理,再运用皮尔逊Ⅲ型曲线进行配线,得到设计频率下的设计洪水值,并对所得结果进行对比分析,以说明较大洪水视为特大洪水与否对工程设计的影响,从而给水文工程设计者提供较为合理的建议。     

氧化镁复合膨胀剂膨胀性能的温度敏感性研究

为了瀑布沟导流洞工程的封堵,研究了氧化镁复合膨胀剂膨胀效能的温度敏感性和机理.试验表明,活性值相对较高的氧化镁膨胀剂对温度更加敏感,温度增加可明显加剧其膨胀效能;养护温度的升高对活性值较高的氧化镁膨胀剂的水化反应促进作用更大.瀑布沟导流洞封堵混凝土最终采用了一种掺氧化镁膨胀剂的复合膨胀剂,配制的微膨胀泵送混凝土完全满足工作性能、力学件能及耐久性要求.     

TiOx/Pd interfacial catalysts with controllable geometrical/electronic effects for industrial H2O2 production

Aiming at controllable modulating metal−support interactions to achieve an optimal trade-off of geometric/electronic effect in supported catalysts, we developed a reliable approach based on the typical 2D material layered double hydroxide (LDHs). A series of TiO_x/Pd/MgTiAl-MMO-X catalysts with adjustable interfacial effect were acquired by loading PdCl₄²⁻ precursor and further preciously adjusting the topological reduction temperature, based on the regulatory effect of Mg–O–Ti–O–Al–O structure in the support on the reducibility and mobility of Ti⁴⁺. The catalysts with semi-continuous and accessible TiO_x/Pd interface, confirmed by AC-HAADF-STEM, CO chemisorption, XPS, exhibit much higher H₂O₂ yield than the catalyst with over-encapsulation structure. The TiO_x/Pd/MgTiAl-MMO-450 catalysts possessed optimal geometric and electronic structure exhibited the highest activity with TOF of 9.75 s⁻¹, excellent H₂O₂ yield of 11.4 g/L, as well as good stability.     

Tunable focus poly(vinyl chloride) gel microlens Array fabricated by shaping in patterned electric field

In this work, we demonstrate a poly(vinyl chloride) (PVC)-gel-based microlens array (MLA) with tunable focus. The MLA is fabricated using a PVC solution and a glass substrate with a ring-array-patterned electrode. By coating the solution on the substrate and applying a direct current (DC) voltage to the electrode, a PVC gel membrane with a convex surface profile on the inner region of the electrode (anode) is formed with the solvent evaporation. After the complete evaporation of the solvent and removing the voltage, the solidified PVC gel membrane exhibits an MLA character. When an inverse DC voltage is applied to the electrode, the PVC gel accumulated on the inner region will shift toward the outer electrode connected to the anode, leading the curvature of the convex surface to decrease and the focal length to increase accordingly. The variable surface profile with voltage is precisely measured by a laser confocal microscope and the result shows that the focal length of the MLA can be tuned within a large range.     

乳发酵过程产生的天然防腐成分

综述了乳酸菌、霉菌和酵母发酵乳过程中产生的天然防腐成分,并分类论述了生物合成途径和抑菌机理,对乳发酵过程中产生的天然防腐成分的进一步应用提供了理论基础。     

The 7-decade degradation of a large freshwater lake in central Yangtze River, China

Freshwater lakes store water for human use and agricultural irrigation and provide habitats for aquatic fauna and flora. However, a number of these lakes have been degraded by human activities at a rapid rate. Here, we used historical land cover information and remotely sensed data to explore a 7-decade (between 1930s and 1998) shrinkage and fragmentation of Dongting Lake, the second largest freshwater lake in China, located in the drainage basin of Central Yangtze River. The water surface area of Dongting Lake decreased by 49.2%, from 4955 km2 in the 1930s to 2518 km2 in 1998, with an average decrease rate of 38.1 km2/yr in the past 7 decades. The lake was also fragmented, as indicated by a decreasing mean patch size from 4.2 km2 in the 1930s to 1.7 km2 in 1998. The degradation of the lake is largely attributed to a rapidly growing human population in the lake region that led to extensive impoldering. The degradation of the lake has resulted in negative ecological consequences, such as frequent flooding, a decline of biodiversity, and extinction of some endemic species. Our results also suggest that lake restoration projects implemented in this region since the end of the 1990s will help to decrease the lake degradation.     

鸡腿菇营养香肠的研制开发

研究了在肠馅中添加一定量的鸡腿菇对营养香肠感官评价和质构特性的影响，通过单因素和正交试验表明，蔬菜营养肠的最佳配方为：猪肉100％，鸡腿菇15％，玉米淀粉10％，复合磷酸盐0．4％，食盐6％，香辛料1％、味素0．3％、水适量。该产品具有独特的风味和良好的营养保健作用，市场前景广阔。