Influences of the surface wave-induced mixing and tidal mixing on the vertical temperature structure of the Yellow and East China Seas in summer

After a classification of the physical processes which affect the vertical mixing, diffusivity induced by the surface wave momentum and tidal currents and its influence on the vertical temperature structure are discussed. Based on three mixing schemes, the vertical temperature structure of the Yellow and East China Seas (YECS) is simulated. Results show that in summer, the surface wave-induced mixing plays a key role in forming the upper mixed layer in the YECS. The tidal mixing controls the lower layers within 30 m above the bottom, which is the main factor in forming the platform-shaped temperature structure in the southern Yellow Sea (YS). Together with the strong surface wave-induced mixing, the tidal mixing makes the thermocline ventilate near the east coast of the southern YS. The double cold cores in the deeper layers of the East China Sea have different causes. The western one is the maintenance of the winter cold water, while the eastern one is configured by circulation. The simulated vertical temperature structure of the YECS with the surface wave-induced mixing and tidal mixing has similar features to the observations, which indicates that these mixing processes are key factors in simulating the thermocline and pycnocline of the coastal oceans.     

Three-Dimensional Reconstruction of E. coli SecA at Low Resolution

SecA is the essential component of the signal-peptide dependent translocation pathway in Escherichia coil （E.coh）. The structure and function of SecA must be known to understand the molecular mechanism of preprotein translocation. The high flexibility of SecA causes a dynamic conformational heterogeneity which presents a barrier to the growth of crystals of high diffraction quality. Electron microscopy was used to resolve the macromolecular structure of SecA in solution by negative staining and single particle analysis at a resolution of 2.9 nm. The structure of E. coil SecA is similar to the dimeric form of Bacillus subtilis SecA and is 10 nm × 10 nm × 5 nm in size.     

Preparation and Characterization of Ester from Rosin Acrylic Acid Adduct and Hydroxyethyl Methacrylate

1 Results Rosin is a sort of important renewable resources,which is a foremost product of our country forestry. It has very important meaning to modify the rosin based on its molecule structure and active group, to develop some deep processing products, and to endure with rosin new characteristic[1]. This work uses the rosin and acrylic acid to form rosin adduct, and then reacted with 2-hydroxyethyl methacrylate (HEMA) to form ester under the different condition. The effect of different ratios with the adduct and HEMA, catalyst types and levels on the esterification was investigated. The molecular structure of the adduct and the ester was characterized with IR spectrum. Their thermal stabilities were conducted with thermal analyzer. Experiment results show that the rosin ester was prepared successful, the best esterification condition was found out. The thermal stability of the rosin ester from acrylic acid rosin and HEMA was improved. The rosin ester may be used as negative photoresist[2].     

Design and construction of Sutong Bridge tower

Sutong Bridge tower which is 300.4 m is the highest one in the world. The tower anchor area uses the steelconcrete composite structure, its structure and the stress mechanism are complex, so it must be paid more attention to the structure durable issue. The 300 m height makes the tower quite sensitive to the environmental factors such as wind and temperature. The wind resistance safety of tower in construction stage is especially important. In this paper, the design of composite structure is introduced. The key technologies of tower geometry control and wind resistance in construction stage are analyzed.     

Experimental investigation on friction and squeezing of roof structure key blocks corner upon long-wall face

The coefficients of friction and squeezing of the key blocks comer in the roof structure of underground coalface are key factors to roof structure stability quantitative analysis. In this paper, through the special test of three-type corner friction and squeezing of real rock specimens, and physical simulation test on the roof key blocks of roof structure as well as the finite element calculation of the corner stress distribution and failure mechanism, the characteristics of friction and squeezing of the roof key blocks comer are revealed. It is found that the friction angle of the roof key blocks corner is the residual friction angle, and the frictional angle of the roof key blocks is 22-32° (average 27°), so the friction coefficient is determined as 0.5. It also found the squeezing strength is less than the uniaxial strength, and the squeezing coefficient of the roof blocks corner is determined as 0.4. Based on the results, the ground control theory can be updated from qualitative analysis to quantitative analysis.     

Low Temperature Induced Conformation Changes of Aminoacylase

Introduction Aminoacylase (N-acylamino acid amido hydrolase. EC 3.5.1.14), which exists in mammalian kidneys and microorganisms, catalyzes the reversible hydrolysis of L-acylamino acids[1]. The enzyme is dimeric with a relative molecular mass of 8.6?04, containing one Zn2 ion per subunit, which is essential for enzyme activity[2,3]. The two subunits of the enzyme are identical in sequence. Although the primary structure of aminoacylase has been determined by cDNA sequencing[4,5], no X-ray…     

Analysis of Factors Affecting Execution Performance of OpenMP Programs

OpenMP is able to develop multithreaded programs with lower cost as a promising way to quickly parallelize a great number of serial programs. However, there are many difficulties when developing OpenMP multithreaded programs. Most importantly, the performance of OpenMP programs cannot be guaranteed, which has greatly affected the application of OpenMP. This paper examines several factors that affect the execution performance of OpenMP programs, including loop transformation, scheduling strategy, the number of threads, and nested parallelism. The results show that one of the key reasons for performance degradation is load imbalance, which can be corrected by reasonable use of these key factors to improve the execution performance of OpenMP programs.     

Studying the interaction between gyrase and DNA using magnetic tweezers

The DNA gyrase of Escherichia coli plays an essential role in the life of this microorganism.It is unique among all topoisomerases because of its ability to introduce negative supercoils into DNA.This study investigated the single molecular interaction of E.coli gyrase with DNA using magnetic tweezers.The results showed that,in the absence of ATP,gyrase weakly binds the G and T segments.The stretched force of 0.7 pN can gradually destroy the binding,whereas that of 5.9 pN directly destroys it.Addition of high concentrations of norfloxacin enhances gyrase binding to both segments,making them adapt to 5.9 pN.DNA gyrase reduces the plectonemic dimension,which was determined by the bacterial enzyme and not by the pull force.Moreover,it has different affinities for positive supercoils,which it prefers,and negative supercoils.The time distribution of the dissociation of gyrase from DNA has a double-exponential form.We herein propose a model to explain this distribution and compare the results with those of other models.     

High-speed parallel matched filter designing and FPGA implementation

Matched filter is one of the key technologies to achieve high-speed data transmission. In this paper,a parallel finite-impulse response (FIR) filter structure based on polyphase filter-ing is used to achieve high-speed matched filter in quadrature phase-shift keying (QPSK) demodulation up to 800 Mb·s-1. First,a window function is employed of to obtain impulse response of matched filter. Second,the high-speed parallel FIR structure is presented based on polyphase filtering. Then,the filter with EP2S180F1020 on the Quartus II 7.2 platform is achieved. The final results show that the design is correct and can implement high-speed matched filtering,wherein the equivalent frequency of which is up to 2 037 MHz. In addition,this scheme is easy to real-ize,which brings great value to the application of this filter in high-speed matched filters design in demodulation systems.     

Relation Between Crystal Structure and Liquid Crystallinity of Ferrocene Derivatives

1 Results In order to obtain liquid crystals including an ion atom as a transition metal, the ferrocene derivatives containing mesogenic group were designed with a view to prevent great bulk of ferrocenyl moiety in the molecules, because rod-like molecular shape is preferable to show liquid crystallinity. Therefore, methylene chain was installed as a flexible spacer between ferocenyl moiety and mesogenic one. As a result, a lot of liquid crystalline ferrocene derivatives were synthesized successfully. Single crystal X-ray structure analyses were carried out using these derivatives, and the results were considered from a viewpoint of a relation of crystal structure and liquid crystallinity.     

Study and Development of a Simulation System for Dynamic Evaluation on Man-machine Interface Design of Advanced Main Control Rooms of Nuclear Power Plants

Since the man-machine interfaces (MMI) of a main control room provide the control platform of a nuclear power plant (NPP),the development of the design quality of MMIs plays a very important role in the operation of a NPP. With the development of digital technology, the development of the advanced main control rooms (AMCRs) has become an inexorable trend. Therefore, the positive and the negative effects of AMCRs on human factors engineering need to be evaluated. For this p~, a simulation system has been studied and developed to quantitatively evaluate a MMI design from the viewpoint of human factors. The simulation system takes advantage of computer simulation technology to simulate an operating process of an interaction between operators and a MMI design under an instruction of an operation procedure of the AMCR of a NPP. Meanwhile, the necessary data are recorded for evaluation. It integrates two editors and one simulator. In the paper, the simulation system is presented in detail. Furthermore, one sample is given to show the results of each of these three subsystems.     

Distribution of Random Session Key Based on Key-insulated Public-Key Cryptosystems

Based on the characteristic of key-insulated puhtic-key cryptosystem, we propose a distributed random session keys distribution protocol without a key distribution center. The session key is generated by different user and only used one time. So the key is one-time key. In addition, the user who generates the next one-time key, is random selected by the current session key. In the protocol of this paper, thecharacteristic of time in the key-insulated public-key, a dis-tributed protocol, translates into the characteristic of space which every point has different secret key in the different period. At the same time, the system is fit for key management in Ad Hoc, and is a new scheme of key management in Ad Hoc.     

P systems based multi-objective optimization algorithm

Based on P systems, this paper proposes a new multi-objective optimization algorithm (PMOA). Similar to P systems, PMOA has a cell-like structure. The structure is dynamic and its membranes merge and divide at different stages. The key rule of a membrane is the communication rule which is derived from P systems. Mutation rules are important for the algorithm, which has different ranges of mutation in different membranes. The cooperation of the two rules contributes to the diversity of the population, the conquest of the muhimodality of objective function and the convergence of algorithm. Moreover, the unique structure divides the whole population into several sub populations, which decreases the computational complexity. Almost a dozen popular algorithms are compared using several test problems. Simulation results illustrate that the PMOA has the best performance. Its solutions are closer to the true Pareto-optimal front     

Numerical Simulation of the Mechanical Properties and Failure of Heterogeneous Elasto-Plastic Materials

A general numerical approach was developed to simulate the mechanical properties and the failure of heterogeneous elasto-plastic materials using statistical distributions of the material properties. An appropriate elastic-plastic constitutive relation is used to describe the material behavior and failure in each element, with a two-parameter Weibull distribution used to produce the initial heterogeneous material property variations. An adaptive incremental load-step is applied so that only one or a few elements (or integra- tion points) change their status (i.e., from elastic to plastic, or from plastic to strain failure) within one load step. A failed element is then assigned a very small modulus to simulate the failure rather than removing it from the model, which keeps the continuity of the geometric mesh. The numerical results show that the model is suitable for simulating the effective mechanical properties and failure of heterogeneous materials with local elasto-plastic constitutive relations.     

P systems based multi-objective optimization algorithm

Based on P systems, this paper proposes a new multi-objective optimization algorithm (PMOA). Similar to P systems, PMOA has a cell-like structure. The structure is dynamic and its membranes merge and divide at different stages. The key rule of a membrane is the communication rule which is derived from P systems. Mutation rules are important for the algorithm, which has different ranges of mutation in different membranes. The cooperation of the two rules contributes to the diversity of the population, the conquest of the muhimodality of objective function and the convergence of algorithm. Moreover, the unique structure divides the whole population into several sub populations, which decreases the computational complexity. Almost a dozen popular algorithms are compared using several test problems. Simulation results illustrate that the PMOA has the best performance. Its solutions are closer to the true Pareto-optimal front     

Correlation between echolocation calls and morphological features among three kinds of bats

The correlation between echolocation sound and morphological features of 18 species of bats, which are subordinated to 3 families including rhinolophidae, hipposideridae and vespertilionidae is studied. Pearson's correlation and regression analysis are adopted to analyze the correlations between noseleaf width (NW) and forearm length (FAL), NW and dominant frequency (DF), FAL and DF. The results show a positive correlation between NW and FAL and a negative correlation between NW and DF in Rhinolophidae. In each family, there is a negative correlation between FAL and DF. Some species have a higher or lower frequency than predicted one according to their body size. There are significant differences of the regression equation of FAL and DF among the three families. For the bats with the same body size, the order in frequency is: hipposiderid bats＞ rhinolophid bats＞ vespertilionid bats. The mechanism of interrelationship between FAL and DF of bats, the reason why these deviations occur in correlativity of the three families and the mechanism of the interaction between morphological, physiological and ecological characteristics are discussed.     

Bearing capacity analysis of reinforced concrete L-shaped cross-section under biaxial eccentric compression

The ultimate capacity of short L-shaped reinforced concrete (RC) members subjected to biaxial eccentric compression is investigated to provide a new tool for structure engineers. On the basis of nonlinear analysis of RC arbitrary cross-section, a new simplified cross-section numerical integration method is suggested. The cross-section is divided into several triangles, and each one is integrated with Gauss integration method. And L-shaped cross-sections subjected to biaxial eccentric compression are analyzed. The interaction curves of (N-M) and (My-Mz) for L-shaped sections are derived. The analytical results are well consistent with the experimental data and other analytical results.     

Effects of applied potential on the stress corrosion cracking behavior of 7003 aluminum alloy in acid and alkaline chloride solutions

Potentiodynamic polarization tests and slow strain rate test (SSRT) in combination with fracture morphology observations were conducted to investigate the stress corrosion cracking (SCC) behavior of 7003 aluminum alloy (AA7003) in acid and alkaline chloride solutions under various applied potentials (E_a). The results show that AA7003 is to a certain extent susceptible to SCC via anodic dissolution (AD) at open-circuit potential (OCP) and is highly susceptible to hydrogen embrittlement (HE) at high negative E_a in the solutions with pH levels of 4 and 11. The susceptibility increases with negative shift in the potential when E_a is less than -1000 mV vs. SCE. However, the susceptibility distinctly decreases because of the inhibition of AD when E_a is equal to -1000 mV vs. SCE. In addition, the SCC susceptibility of AA7003 in the acid chloride solution is higher than that in the alkaline solution at each potential. Moreover, the effect of hydrogen on SCC increases with increasing hydrogen ion concentration.     

Workspace and rotational capability analysis of a spatial 3-DoF parallel manipulator

The analysis on the workspace and rotational capability of HANA, a spatial 3-DoF parallel manipulator, is concerned. The parallel manipulator consists of a base plate, a movable platform, and three connecting legs. The moving platform has three degrees of freedom (DoFs) which are two translations and one rotation, with respect to the base plate. The new parallel manipulator is very interesting for the reason of no singularity in the workspace, the single-DoF joint architecture and high rotational capability of the moving platform. The inverse kinematics problem is described in a closed-form, which is very useful to present the workspace geometrically. The constant-orientation and reachable workspaces for the manipulator are analyzed firstly. The index that is used to evaluate the rotational capability of the manipulator is defined and discussed in detail. Finally, the distribution of rotational capability index on the workspace is presented, which helps us know how much the index is at different point. The parallel manipulator has wide application in the fields of industrial robots, simulators, micro-motion manipulators, and parallel kinematics machines.