天然含水率状态下原状黄土动强度特性研究

通过对不同天然含水率状态下兰州原状黄土的室内动强度试验,得出了相应破坏振次为10和20次时原状黄土的动强度参数。根据试验所得动强度参数,分析了原状黄土的动强度参数随天然含水率和破坏振次的变化规律。探讨了天然含水率、破坏振次对该地区原状黄土动强度指标的影响,并对原状黄土的动强度参数与天然含水率之间的关系曲线进行了拟合,给出了其数学表达式。结果表明,动凝聚力与动内摩擦角随天然含水率变化规律,较好地符合乘幂函数关系和线性关系。

Flocculation Kinetics of Chitosan

Under the various conditions, the experiments of flocculation of bentonite solution with chitosari were carried out. And the flocculation kinetics was studied by the changes of floe size along with time. The results show that hydraulic gradient G (s-1) plays a key role in growing up of floe size and both of molecular weight and initial turbidity of bentonite solution influence the floe size in steady state and the time needed for steady floe size.

Kinetic Behaviour of the Aggregation—Annihilation Process of Two—Species—Group System

The kinetic behavior of an aggregation-annihilation system with two species groups is studied in this paper.We propose that an aggregation reaction occurs only between the same species and an irreversible joint annihilation reaction occurs only between the two species belonging to distinct groups. Based on the mean-field theory, we investigate the rate equations of the process with constant reaction rates and obtain the asymptotic descriptions of the cluster-mass distributions for the symmetrical cases. We find that the cluster-mass distribution of each species obeys a standard scaling description in certain cases. Meanwhile, breakdown of the standard scaling description is also found for the distribution in some special cases and the cluster-mass distribution comes in a peculiar scaling regime. The evolutionbehaviour of the system depends crucially on the reaction rates and the ratio of initial concentrations between the two groups. Moreover, the species numbers of the two groups also play important roles in the properties of the cluster distributions.

Growth Kinetics and Chitosan Flocculation of Spirufina platensis Algae

S. platensis （Spirulinaplatensis） algae were grown in batch reactors at 30 ± 1℃ with a continuous illumination of 50 ±2 μmol·m^-2·s^-1 using different growth media and air flow rates. A modified Gompertz kinetic model was applied to estimate the maximum concentration of algae and the growth rate at different conditions. A peak cell productivity of 21.91 mg·L^-1·day^-1 （dry biomass） was determined using commercial nutrient media （F/2, part A and part B） and modified Zarrouk medium at an air flow rate of 3 L·L^-1·min^-1. Using the commercial media at high concentrations yielded high biomass concentrations. The results of the modified Gompertz kinetic model indicated that the highest growth rate was 0.118 g·L^-1·day^-1. This growth rate was determined for S. platensis cultivated using 0.399 mL·L^-1 of the commercial media. Response surface methodology was applied to optimize the parameters （temperature, pH, and chitosan dose） that affect the efficiency of the flocculation of S. platensis. An optimum flocculation of 98.7% was determined at a pH, temperature, and chitosan dose of 5.5, 30℃, and 75 mL·L^-1, respectively.

Dynamics and Manipulation for Gap Solitons in Bose-Einstein Condensates under Optical Lattice and Harmonic Potentials

By means of an extended variational approach,we study dynamics for gap solitons in a repulsive interactionBose-Einstein condensate under both a harmonic and an optical lattice confinement.The simplified analytic theorygives the critical strength ratio of harmonic to optical lattice necessary to support multiple stable lattice sites for thecondensate.Moreover,we use numerical experiments to guide and manipulate the gap solitons to an arbitrary positionvia a time-dependent potential.All predictions of the extended variational approach are reasonably close to results ofthe simulations.In particular,the variational model helps capture the composition relationship between the variationsof chirp and amplitude.

How to Make Virtual Community More Active and Cohesive:From Brand and Perceived Protection Perspectives

With the increasing popularity of the Internet and mobile Internet, the Virtual Community （VC） is becoming an important medium for person-to-person communication. To realise the potential of the VC, it is neces- sary to cultivate within it good group cohesion and vitality. Using empirical and experimental research methods, this study explores the ef- fect of users＇ trust in the VC Platform （VCP） on group cohesion and vitality and how brand and perceived privacy security can affect us- ers＇ trust in the VC. The research results indi- cate that the brand of the VCP can directly af- fect users＇ trust in the VC, and can also influe- nce it indirectly through users＇ perceived pri- vacy protection and perceived security protec- tion. Further, this study also confu＇ms that the performance of the VC （group cohesion and vitality） is significantly affected by users＇ trust in the VC. The results of this study can provide theoretical guidance for internet companies to maintain and enhance the value of VCs.

Externalities, Floating Population and Spatial Agglomeration

With the further development of socialist market economy, the mobility of factor markets in China, especially the labor market, is strengthened. Externalities interacts with the agglomeration of productive factors. Under the framework of new economic geography, this article presents a theoretical model involving the endogenous population density affected by urban externalities. Results show that the population density is more concentrated around the center because the degree and extent of interaction between individuals intensifies when the distance from the center decreases. When there are several externalities resources, the aggregation of externalities changes the configuration of spatial factor allocation. These results fit well with the empirical facts about the decreasing density of floating population along the cities of Guangzhou, Dongguan and Shenzhen in Guangdong Province which is situated in the eastern coast of the Pearl River Delta. We fred that under the impacts of externalities released from Hong Kong into the coast, floating population was more concentrated around Shenzhen and Dongguan, which are more adjacent to Hong Kong compared with Guangzhou City.

Quark Condensate in the Strange Matter

In a nonlinear chiral SU(3) framework, we investigate the quark condensate in the strange matter including and Λ, making use of chiral symmetry spontaneous breaking Lagrangian and mean-field approximation. The results show that the chiral symmetry is restored partially when the strange matter density increases and that plays a very important role in the strange matter which may approach the constituents of the neutron stars. In addition, we can find that the strange matter density where the π-condensate emerges leads to the ratio of the nucleon number to baryon number.

Analyzing Dynamics of a Bright Soliton in Bose-Einstein Condensates with Time-Dependent Atomic Scattering Length

We analyze the dynamics of a bright soliton in atomic scattering length in an expulsive parabolic potential. Bose-Einstein condensates （BECs） with time-dependent Under a safe ravage of parameters in which the Gross-Pitaevskii （GP） equation is effective in one dimension, our results show that, the dynamics of the bright soliton can be classed into two phases, depending on the value of the scattering length. Meanwhile, there exists a critical value of the absolute value of the atomic scattering length, below which, the dynamics of the bright soliton is very regular. Those phenomena can be useful for developing concrete applications of the nonlinear matter waves. We also obtain the orbital equation of the bright soliton and get some interesting data which may be useful for the experimental observation of the bright soliton and the application of the atom laser with manipulated intensity.

Enterprise salary system research （study of Jetter company）

Facing with the future increasingly changed economy environment, a company who wants to survive forever has to control the key point of owning person with ability and core competence. However, the main question needs to he solved is to design a motivational compensation system which not only have competence when compared with other companies but also have cohesive force for the staffand can evaluate them fairly. Salary should not just be the cost of paying for worker＇s labor but should have more functions to introduct them to obey orders and stimulate their activities. This essay has some reference to enrich the motivational compensation system by discussing the motivational plans in different period of a company and analyzing the actual working operation. This essay aims at applying present compensation theory to small and medium-sized enterprises to get some beneficial discoveries, concluding a compensation dcsign system which suits for the traits of small and medium-sized enterprises from the strategic level and technical level. As a result, we can improve our company＇s core competence.

Energetics and kinetics of direct phase conversion from graphite to diamond

The atomistic mechanism for direct conversion of graphite to diamond is a long-standing problem in condensed matter physics. The newly identified cold-compressed graphite phases of M, W and 0 carbon provide a crucial link to understand the graphite-to- diamond phase transformation. We demonstrate by ab initio calculations that pressure has a dual role in lowering the conversion barrier and enhancing the production stability during the first-stage cold-compressed phase conversion of graphite toward the intermediate metastable M, W and 0 carbon phases. However, it has little effect on the relative enthalpy and high conversion barrier during the second-stage conversion process toward the diamond polytypes, showing a temperature dominated conversion process. These results may give explanation regarding the necessity of high pressure and high temperature during the graphite-to- diamond reaction.

Dynamic Structure Factor of an Optically Trapped Dipolar Bose–Einstein Condensate

Motivated by the recent experimental achievements in using the Bragg spectroscopy to measure the excitation spectrum of an ultra-cold atomic system with long-range interactions, we investigate the dynamic structure factor of a cigar-shaped dipolar Bose condensate trapped in a one-dimensional optical lattices. Our results show that the Bogoliubov bands of the system, particularly the lowest one, can be significantly influenced when one tunes the dipole orientation. Consequently, the calculated static structure factor of an optically trapped dipolar Bose gas shows marked difference from the non-dipolar one. Moreover, we show that the effects of dipole-dipole interaction on the dynamic structure factor is also strongly affected by the strength of the optical confinement.