Advanced Materials Research Vol. 934

Abstract: The sequential microhydration of sodium glycinate is investigated at the MP2/6-311++G(d,p) level. Our results clearly indicate that the microhydration process is driven by the charge site of sodium cation and a bridge site is losing its dominant position. Eventually, a comparison of theoretical and experimental Raman spectra provides the evidence of the predicted structural information.

Abstract: In order to solve the problem of low degree of installation automation on handles of the domestic cartons, the problem that the plastic handle is not environmental friendly and the problem that the finished cartons are not convenient for piling, a threading device for the non-woven fabric handle based on a Cam mechanism is designed. Kinematics analysis is done to the simulation model of the handle threading device by utilizing a simulation software ADAMS to obtain the variation curves of the displacement, velocity, accelerated velocity and jerk. The result of analysis shows that the designed threading device of the handle is able to meet with the requirements for non-woven fabric threading technology and it further verifies the validity of the design methods; Moreover, the velocity and the accelerated velocity of the threading device have no sudden change and the jerk values are small so that high speed and high automatic threading can be achieved. Besides, the threading efficiency of the designed device is significantly improved.

Abstract: Suspension in tunnel construction usually cause tunnel callapse in weak ground if the suspension time is long. Dongkeling tunnel on Guizhou-Guangxi line being as the engineering background, the indoor rheological experiment and back analysis were performed to obtain the rheological model and parameters of the surrounding rock, and the 3D viscoelasto-plastic calculation model was established to find the evolving rules of deformation at critical locations under two different water contents. It was found that the primary support has little effect on rheology of tunnel work face but on the cross section, and decreasing the water content of the surrounding rock to medium or low saturation level favors the tunnel stabillity greatly for water abundent tunnels.

Abstract: Based on the Donnell’s approximations of the thin shell theory, this paper presents solutions for the problem of free non-axisymmetric vibration of stepped circular cylindrical shells with cracks. The shell under consideration is sub-divided into multiple segments separated by the locations of thickness variations. It is assumed that at the jth step there exists a circumferential surface crack with uniform depth c_j . The influence of circular cracks with constant depth on the vibration of the shell is prescribed with the aid of a matrix of local flexibility. The latter is related to the coefficient of the stress intensity known in the linear fracture mechanics. Numerical results are obtained for cylindrical shells of stepped thickness containing cracks at re-entrant corners of steps. Shells with various combinations of boundary conditions can be analyzed by the proposed method. Furthermore, the influences of the shell thicknesses, locations of step-wise variations of the thickness and other parameters on the natural frequencies are examined. The results can be used for the approximate evaluation of dynamic parameters of cylindrical shells with cracks and flaws.

Abstract: Based on the equivalent radius model and superposition potential, a productivity model for ultra-low permeability tight gas reservoirs was developed, which considered the influence of the threshold pressure gradient and the variable mass flow in fractures, and pressure loss inside the wellbore. With examples for capacity sensitive factors are analyzed. The results show that the threshold pressure gradient must be accounted to evaluate the productivity in ultra-low permeability tight gas reservoirs; after considering wellbore pressure loss; close toe fractures inflow velocity segment has been reduced; the larger matrix permeability, the greater the optimum fracture conductivity; When the number of fracture is more, the greater the impact on the capacity of the fracture angle. The research results provide a scientific basis for the design of multi-fractured horizontal wells in the ultra-low permeability tight gas reservoirs.

Abstract: The large capacity storage technologies at present are reviewed, particular attention is paid to the principle and current situation of compressed air energy storage power generation. Considering the operating characteristic of non-fuel compressed air energy storage, this paper proposes a hybrid expansion system with piston expander and turbine expander in series and preliminarily analyses the expansion process. The results display that the application of hybrid expansion system can significantly enhance the efficiency of compressed air energy storage power generation and it shows a broad application prospect.

Abstract: Protein-protein interaction (PPI) networks provide a simplified overview of the web of interactions that take place inside a cell. According to the centrality-lethality rule, hub proteins (proteins with high degree) tend to be essential in the PPI network. Moreover, there are also many low degree proteins in the PPI network, but they have different lethality. Some of them are essential proteins (essential-nonhub proteins), and the others are not (nonessential-nonhub proteins). In order to explain why nonessential-nonhub proteins don’t have essentiality, we propose a new measure n-iep (the number of essential neighbors) and compare nonessential-nonhub proteins with essential-nonhub proteins from topological, evolutionary and functional view. The comparison results show that there are statistical differences between nonessential-nonhub proteins and essential-nonhub proteins in centrality measures, clustering coefficient, evolutionary rate and the number of essential neighbors. These are reasons why nonessential-nonhub proteins don’t have lethality.

Abstract: Saponins from Rhizoma Panacis Majoris (SRPM), the bioactive component in Rhizoma Panacis Majoris, were reported to possess protective effects on myocardial injury, but the underlying mechanisms remain poorly understood. This study was performed to investigate the protective effects and possible mechanism of SRPM on myocardial ischemia/reperfusion (I/R) injury in vivo. Cardioprotective effects of SPRM in I/R rats was evaluated by hemodynamic, infarct size, biochemical values, histopathological observations, antioxidative relative gene expressions; And the antioxidant activity of SPRM was studied using DPPH scavenging and β-carotene/linoleic acid tests. In the study, we found that SRPM possessed significant free radical-scavenging activity and considerable antioxidant activity, and significantly improved cardiac function, serum biochemical index and antioxidation level, decreased infarct size, reversed the down-regulated mRNA expressions of the SOD1, SOD2, SOD3 in I/R rats. The studies demonstrated that oxidative stress caused the overgeneration and accumulation of ROS, which was central of myocardial I/R injury. SPRM exerted beneficially cardioprotective effects on myocardial I/R injury, mainly scavenging oxidative stress-triggered overgeneration and accumulation of ROS, alleviating myocardial I/R injury and apoptotic cell death.

Abstract: DNA molecules can be considered as a smart material. In particular, synthetic DNA can reliably self-organize. In this paper, we consider an approach to design of active DNA membranes with two stable states. Our approach is based on the usage of SAT-solvers to find proper set of DNA tiles.

Abstract: Objective: To test and contrastive analysis the crystal structure and mechanical characteristics of enamel and dentin of primary and permanent teeth by XRD and contact angle meter, provide information and experimental data for bionics and designs of dental materials. Methods: Teeth were randomly divided into four groups, including permanent teeth enamel group, permanent teeth dentin group, primary teeth enamel group, and primary teeth primary teeth. The crystal structure and mechanical characteristics of teeth were tested by XRD and contact angle meter. The results were analyzed with one-way ANOVA. Results: The crystalline and grain size of enamel were significantly larger than dentin’s. The crystalline and grain size of enamel and dentin of permanent teeth were also larger than primary teeth. Conclusions: The XRD and contact angle of primary and permanent teeth are closely related to their structures, Dental filling material to give full consideration to their different property.