混凝土结构冬季施工和温度控制技术

以某高层建筑为例,介绍了采用综合蓄热法进行冬季混凝土施工,对其冬施准备作了探讨,从原材料、混凝土的搅拌和养护、模板工程等方面,对冬施质量保证措施作了阐述,以确保工程质量,并依据JGJ104—97建筑工程冬期施工规程对该结构的混凝土墙体进行了温度验算,对混凝土的冬季施工有一定参考价值。

Solubility of Emodin in Alcohols

Emodin is a kind of anthraquiones with pharmaceutical activities.The solubilities of emodin in ethanol,1-octanol,and ethanol+1-octanol at different temperatures were measured using an analytical method.The solubility of emodin in these solvents increased with an increase in temperature.With the temperature deviating from room temperature,the dependence of the solubility of emodin on temperature became a lot more remarkable.The solubility of emodin in ethanol was more sensitive to temperature than that in 1-octanol.The solubility data of emodin in the same species of solvent at different temperatures was correlated with an empirical equation.The calculated results agreed with the experimental data well.

Passivity Degradation of Nuclear Materials in Reduced Sulfur Environments:A Review

This paper reviews sulfur-induced passivity degradation of nuclear materials with emphasis on steam generator(SG)alloys. The state of arts on this topic concerning thermodynamic calculation and experimental data has been reviewed. Thermodynamic calculation results indicate that the distribution of sulfur species strongly depends on p H and temperature. Experimental data show that solution p H, temperature and solution chemistries can significantly affect the electrochemical behaviors of SG materials and the underlying degradation mechanisms. Some issues when conducting corrosion tests at high temperature should be paid attention to, such as the dissolution of the autoclave, which may affect the facticity of the experimental results.

Experimental and Finite Element Analysis of a T-Joint Welding

This paper presents the Finite Element （FE） modeling of a two-seam welding process for a T-joint with a V chamfer preparation： The aim of the model is to predict the deformations, distortions and residual stresses resulting from the welding of the plates and experiments have been carried out in order to compare to the FE model. The ＂birth and death＂ method is used in ANSYS to simulate the filler metal deposition and the heat generation and weld pool simulation are conducted accordingly with the double ellipsoid configuration as proposed by Goldak et al. The model takes into consideration the temperature dependent non-linear material properties and uses a new formulation to compute the temperature dependent combined coefficient of heat loss. Improvements in the calculation are achieved by combining two types of meshing. The FE simulation is divided into two consecutive parts： the thermal simulation followed by the structural simulation. The results of the numerical model are compared to experiments.

Statistical analyses of protein folding rates from the view of quantum transition

Understanding protein folding rate is the primary key to unlock the fundamental physics underlying protein structure and its folding mechanism.Especially,the temperature dependence of the folding rate remains unsolved in the literature.Starting from the assumption that protein folding is an event of quantum transition between molecular conformations,we calculated the folding rate for all two-state proteins in a database and studied their temperature dependencies.The non-Arrhenius temperature relation for 16 proteins,whose experimental data had previously been available,was successfully interpreted by comparing the Arrhenius plot with the first-principle calculation.A statistical formula for the prediction of two-state protein folding rate was proposed based on quantum folding theory.The statistical comparisons of the folding rates for 65 two-state proteins were carried out,and the theoretical vs.experimental correlation coefficient was 0.73.Moreover,the maximum and the minimum folding rates given by the theory were consistent with the experimental results.