Research of Energy Regeneration Technology in Electric Vehicle

The theory of energy regeneration in electric vehicle (EV) has been introduced in most papers, but the mathematic model of EV energy regeneration system was little studied. In this paper the mathematic model of EV energy regeneration system is studied, and then the system ability under four control strategies is analyzed. In the end the system reliability is researched, and the calculation model of system reliability is proposed.

有限元程序生成系统及其在工程中的应用(英文)

A completely new finite element software, Finite ElementProgram Generator (FEPG), is introduced and its designing thought and organizing structure is presented.FEPG uses the method of components and the technique of artificial intelligence to generate finite element program automatically by a computer according to the general principles of mathematic and internal rules of finite element method,as is similar to the deduction of mathematics.FEPG breaks through the limitation of present finite element software,which only applies to special discipline,while FEPG is suitable for all kinds of differential equations solved by finite element method.Now FEPG has been applied to superconductor research,electromagnetic field study,petroleum exploration,transportation,structure engineering,water conservancy,ship mechanics, solid-liquid coupling problems and liquid dynamics,etc.in China.

AFM Study on Reliability of Nanoscale DLC Films Deposited by ECR-MPCVD

Nanoindentation, scratch and wear tests based on an atomic force microscope (AFM) were carried out to study the reliability of diamond-like carbon (DLC) films, deposited by electron cyclotron resonance microwave plasma chemical vapor deposition (ECR-MPCVD). The predictors for film reliability were given to investigate the resistance of DLC films to indent, scratch, and wear. Experimental results showed that the films at 64.9nm and 12.07nm exhibited better reliability than thin one at 2.78nm, 4.48nm. In addition, the reliability strength of films above 12.07nm went stable, and the films showed good performance of anti-indentation, and-scratch and anti-wear. Finally, size effect of nanoscale monolayer film was introduced to explain the reliability of nanoscale DLC films.

Application of Grey System Theory in Design For Cost (DFC)

Design For Cost (DFC) is a branch of Design For X (DFX). In this paper, wedefined DFC as a design method that analyzed and evaluated the product's life cycle cost (LCC), thenmodified the design to reduce the LCC. Nowadays it is a very difficult thing to obtain LCC data inChina or in developing countries. Statistical methods can not be used because available LCC data arefew. In order to solve this problem, we used grey system theory. Then relations of cost factorswere analyzed in LCC using grey relevant methods, and a GM(1,1) model between design parameters andLCC was established. Using this model, we can estimate and control LCC by changing design parametersat the beginning of the design stage.

Faults Analysis and Diagnosis of DRJ-460 Dish Centrifugal Separator′s Helical Gear

The main faults of dish centrifugal separator's helical gear are described inthis paper. In order to diagnose the DRJ-460 dish centrifugal separator correctly, the vibration istested with a helical gear under both normal and abnormal conditions. After comparing severalgeneral methods of the gear's fault feature extraction, a new convenient and effective method ispresented on the basis of analyzing the vibration spectrum under different rotary velocities.

Robust Stabilization of a Class of Feedforward Systems

Two kinds of saturated controllers are designed for a class of feedforward systems andthe closed-loop resulted is locally input-to-state stable and input-to-state stable, respectively. By theword “locally”, it is meant that there are restrictions on the amplitude of inputs. At first, underthe guidance of suitable energy functions, two kinds of saturated controllers are designed as locallyinput-to-state stabilizers for a class of perturbed linear systems, from which explicit gain estimationscan be obtained for the subsequent design. Then under the conditions that two subsystems of thefeedforward system are respectively of locally input-to-state stability and input-to-state stability, thesmall gain theory is used to determine saturated degrees for corresponding robust stabilizers. Thestability proofs are given by using a new characterization of input-to-state stability that is based onthe concept of ultimate boundedness. As an application, saturated controllers are designed for thepartial dynamics of a certain inverted pendulum.

Robust stability analysis of uncertain discrete-time systems with state delay

The sufficient conditions of stability for uncertain discrete-time systems with state delay have been proposed by some researchers in the past few years, yet these results may be conservative in application. The stability analysis of these systems is discussed, and the necessary and sufficient condition of stability is derived by method other than constructing Lyapunov function and solving Riccati inequality. The root locations of system characteristic polynomial, which is obtained by augmentation approach and Laplace expansion, determine the stability of uncertain discrete-time systems with state delay, the system is stable if and only if all roots lie within the unit circle. In order to analyze robust stability of system characteristic polynomial effectively, Kharitonov theorem and edge theorem are applied. Example shows the practicability of these methods.

Hydrothermal Synthesis and Crystal Structure of Binuclear Copper(Ⅱ) Complex Bridged by 1,2,4,5- Benzenetetracarboxylato Trivalent Anion

The title complex [(phen) 2Cu(Htcb)Cu(phen) 2]H 3tcb(tcb=1,2,4,5-benzenetetracarboxylato tetravalent anion; phen=1,10-phenanthroline) was synthesized by the hydrothermal synthesis method. The crystal structure was determined by single-crystal X-ray diffraction analysis. It crystallizes in the triclinic system with space group P1, a=1.04174(8) nm, b=1.07119(8) nm, c=1.26360(10) nm, α=98.169(2)°, β=99.679(10)°, γ=93.658(10)°, V=1.37031(18) nm3, Z=1. The two copper(Ⅱ) cations are bridged by Htcb in the monodentate fashion, and have the same five-coordinated environment completed by the four N atoms from the two phen molecules and one O atom from the carboxylic group of Htcb respectively, which can be best described as distorted trigonal-bipyramid geometry. Moreover, the three dimensional network is formed by H-bonding interactions [O…O distance from 0.2506(10) nm to 0.3176(11) nm] and π-π stacking interactions between the phen rings of adjacent binuclear entities with a face-to-face separation of ca. 0.354 nm.

Controllability for single-input mechanical control systems with dissipation

Within the affine connection framework of Lagrangian control systems, basedon the results of Sussmann on small-time locally controllability of single-input affine nonlinearcontrol systems, the controllability results for mechanical control systems with single-input areextended to the case of the systems with isotropic damping, where the Lagrangian is the kineticenergy associated with a Riemannian metric. A sufficient condition of negative small-time locallycontrollability for the system is obtained. Then,it is demonstrated that such systems are small-timelocally configuration controllable if and only if the dimension of the configuration manifold isone. Finally, two examples are given to illustrate the results. Lie bracketting of vector fields andthe symmetric product show the advantages in the discussion.

Study on particulate pollution in cities of China and evaluation of protective measurements

By studying the air quality in the public traffic area of Shanghai, the harm to people''s health caused by particulate pollution in Chinese cities has been evaluated. In addition, two devices were developed to test the performance of protective mask against ambient aerosol, and the efficiency of recycle filtedng of the air-condition was contrastive tested with the new filtration material. The results show that these protective measures need to be improved because that filtering efficiency of protective mask and air-condition in miniature is too low to filter superfine particles in ambient air.

Fabrication of a Bi-layer Tubular Scaffold Consisted of a Dense Nanofibrous Inner Layer and a Porous Nanoyarn Outer Layer for Vascular Tissue Engineering

Recent years, it has attracted more attentions to increase the porosity and pore size of nanofibrous scaffolds to provide the for the cells to grow into the small-diameter vascular grafts. In this study, a novel bi-layer tubular scaffold with an inner layer and an outer layer was fabricated. The inner layer was random collagen/poly （ L-lactide-co-caprolactone ） I P （ LLA- CL） ] nanofibrous mat fabricated by conventional electrospinning and the outer layer was aligned collagen/P （LLA-CL） nanoyarns prepared by a dynamic liquid dectrospinning method. Fourier transform infrared spectroscopy （FTIR） was used to characterize the chemical structure. Scanning electron microscopy （ SEM ） was employed to observe the morphology of the layers and the cross- sectioned bi-layer tubular scaffold. A liquid displacement method was employed to measure the porosities of the inner and outer layers. Stress-strain curves were obtained to evaluate the mechanical properties of the two different layers and the bi-layer membrane. The diameters of the nanofibers and the nanoyarns were （480 ± 197 ） nm and （ 19.66 ± 4.05 ） μm, respectively. The outer layer had a significantly higher porosity and a larger pore size than those of the inner layer. Furthermore, the bi-layer membrane showed a good mechanical property which was suitable as small-diameter vascular graft. The results indicated that the bi-layer tubular scaffold had a great potential application in small vascular tissue engineering.

A Set of Space-Time Block Codes for the High-Rate Transmission Scheme with One Information Bit

In [1], the authors have proposed one high rate transmission scheme for Space-Time Block Codes (STBC) without additional system source such as power, bandwidth and time slot. To maintain the full rank property of the coding gain matrix, we propose a set of STBCs for 4 transmit antennas transmission to transmit one additional information bit achieving rate-9/8. Another orthogonal STBC code with rate-1 is proposed in this paper within the set. It shows by computer simulation results that by employing the set of STBCs, it achieves better bit error rate (BER) performance and?throughput than that of [1] with a valid BER improvement at the high SNR region above 20dB.

OBJECTIVE MEASUREMENT FOR CHINESE DOMESTIC WOOL

This paper introduces objective measurement into domestic wool operations. An assessment of the implications of the results for the farm to mill supply chain in China will also be made. Chinese wool is heterogeneous and requires sorting at the mill. Sorting teams appear to be able to reliably sort the wool into a number of count grades although they largely base their decision on crimp characteristics. There is scope for implementing more objective measurement in the mill but the long-term priority is to produce more uniform lines at the farm level to allow mills to match their purchases of input material to the products their customers demand.

OPTIMAL INVESTMENT CONSUMPTION MODEL WITH A HIGHER INTEREST RATE FOR BORROWING

This paper considers a consumption and investment decision problem with a higher interest rate for borrowing as well as the dividend rate.Wealth is divided into a riskless asset and risky asset with logrithmic Brownian motion price fluctuations.The stochastic control problem of maximizating expected utility from terminal wealth and consumption is studied.Equivalent conditions for optimality are obtained.By using duality methods,the existence of optimal portfolio consumption is proved,and the explicit solutions leading to feedback formulae are derived for deteministic coefficients.