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Table of Content

    25 December 2012, Volume 40 Issue 12
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    Mechanical Engineering
    Fault Pattern Recognition of Energy Loss Based on Locally Linear Embedding
    Xie Xiao-peng Xiao Hai-bing Feng Wei Huang Bo Ge Shuang
    2012, 40(12):  1-6. 
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    This paper deals with the fault pattern recognition of gears based on energy loss. In the investigation,first,a modified LLE ( Locally Linear Embedding) algorithm,which combines the supervised learning with the local principal component analysis,is proposed to effectively extract the low-dimension manifold structure and the classification feature of data. Then,the energy loss of gear tribological system and its fault pattern recognition method are analyzed. Finally,by taking the test rig for energy loss monitoring of gear box as an example,the variations of input power loss under different kinds of gear faults are analyzed,the dimensionality reduction and pattern recognition are performed by using the modified LLE algorithm,and the classification performance of the algorithm is evaluated according to the recognition rate of the multi-class support vector machine. The results show that the modified LLE algorithm is of high recognition rate and is effective in fault pattern recognition of gear energy loss.

    Development of Photoelastic Experimental Device for Elastohydrodynamic Lubrication Analysis
    He Jun Yang Qian-qian Huang Ping
    2012, 40(12):  7-11. 
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    By taking into consideration the advantages and disadvantages of the existing measurement methods of elastohydrodynamic lubrication ( EHL) pressure,a novel measurement method based on the photoelastic theory is proposed,and the corresponding mechanism is discussed. Then,an experimental device consisting of a stereomicroscope,a polarizer,a LED light source and a loading mechanism is developed. The linear-contact fiction pairs of the device consist of an upper polycarbonate disk and a lower cylinder made of GCr15 bearing steel and driven by a DC motor through a synchronous belt. By using a camera mounted on the stereomicroscope,the photoelastic images of the EHL contact region and the polycarbonate disk,which are enlarged 40 times,can be captured,with their fringe grades well reflecting the variations of the lubricant film pressure in the contact region and the inner stress beneath the friction surface. Finally,some experiments are carried out under the load varying from 2 to 50N and at the friction-pair rolling speed of 24,44 and 63 mm/s. The results show that the proposed method is feasible and effective in measuring the lubricant film pressure and the inner stress.

    Adaptive Fuzzy Variable Structure Control Algorithm for Trajectory Tracking of Industrial Robots
    Zhai Jing-mei Kang Bo Tang Hui-hua
    2012, 40(12):  12-16,23. 
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    Proposed in this paper is an adaptive fuzzy variable structure control ( AFVSC) algorithm to improve the performance of trajectory tracking control of industrial robots. In this algorithm,the reaching law varying with the trajectory tracking error is redesigned for the reaching motion in the sliding mode region,which reduces the buffeting of the system,improves the reaching motion and enhances the control performance. Moreover,an adaptive fuzzy variable structure controller is designed and is compared with some existing schemes by experiments. The results indicate that the proposed AFVSC algorithm is of higher response rate and tracking accuracy.

    Development and Walking Experiment of Hexapod Robot HITCR-I
    Zhao Jie Zhang He Liu Yu-bin Chen Fu
    2012, 40(12):  17-23. 
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    Developed in this paper is a hexapod robot HITCR-I to implement the free walking of hexapod robots on unstructured terrain. In the investigation, first,the structure of robot leg based on four-bar linkage mechanism is designed to realize an omnidirectional motion. Next,in order to further improve the motion performance of the robot,an expression describing the global flexibility of the robot is constructed and is applied to the optimization of structure parameters. Then,based on the idea of function-behavior-integration,the control objective is planned,and a motion controller is constructed. Moreover,by combining the trajectory planning suitable for the leg motion on unstructured terrain and the generation of free gaits based on local rules,effective and steady walking of the robot is achieved. An experiment is finally carried out to verify the walking ability of robot HITCR-I on unstructured terrain.

    Effects of Assembly Errors on Transmission Precision of Space Curve Meshing Wheel
    He En-yi Chen Yang-zhi Chen Zhen
    2012, 40(12):  24-29. 
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    In order to improve the transmission precision of space curve meshing wheel ( SCMW) ,the effect of assembly error is investigated. In the investigation,first,the surface equations of SCMW are obtained based on the transmission theory of orthogonal SCMW. Then,based on the tooth contact analysis ( TCA) ,the parameters of the actual contact curve in the presence of assembly errors,as well as the transmission errors and the actual contact ratio,are obtained. Finally,the effects of assembly errors on the transmission error and the contact ratio are analyzed via numerical simulation. The results indicate that the angular assembly error around the Yo axis and the displacement assembly error in the Xo direction are two main factors affecting the transmission error. This investigation provides theoretical references and specific methods for the control and reduction of the adverse impact of assembly errors on the transmission error and the contact ratio.

    β-Distribution Uniform Expression for Intelligent Form Error Evaluation Based on Particle Swarm Optimization Algorithm
    Jiang Yan-ming Liu Gui-xiong
    2012, 40(12):  30-34,40. 
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    As the intelligent evaluation results of form error are of poor stability,it is necessary to investigate the probability distribution characteristics of the evaluation results and the corresponding fitting method to improve the reliability of the intelligent evaluation method. In this paper,by taking the flatness error evaluation based on the particle swarm optimization ( PSO) algorithm as an example,the probability distribution characteristics of the intelligent evaluation results was analyzed,and a β-distribution uniform expression was proposed to fit the intelligent evaluation results,followed by a fitting performance test via the K-S method. Then,the three-coordinate data of a plate were measured,the plate flatness was evaluated for 100 times by using the PSO algorithm,and the intelligent evaluation results were fitted by employing the β-distribution uniform expression method. It is demonstrated that,when the intercept percentile Qp is in the interval of [20%,70%],the β-distribution uniform expression method is of high fitting performance for the intelligent evaluation results,the fitted shape parameters are both more than 1,and the fitted probability distribution deviates to the right,which is consistent with the probability distribution characteristics of the intelligent evaluation results.

    New Empirical Formula of Size Coefficient of Notched Samples
    Huang Ning Huang Ming-hui Zhan Li-hua
    2012, 40(12):  35-40. 
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    In order to comprehensively analyze the size effect of notched samples,the fatigue performance of notched samples was experimentally investigated for two kinds of materials ( 45# steel and Q235 steel) under cyclic tension. The results show that,for geometrically similar specimens,the effect of notch shape on the fatigue life can be neglected because it is too slight,and that there exists a thickness effect apart from the stress gradient,namely a critical thickness exceeding which the fatigue life may reduce. Moreover,by introducing the characteristic parameter L /G that represents the effect of geometric size on the fatigue performance,the test results of fatigue strength of geometrically similar specimens are fitted and compared with the calculated values obtained by the Peterson method,finding that the proposed fitting expression is more effective. Finally,an empirical formula of size coefficient of notched samples under tension,which well accords with the actual situation,is presented according to the equation of fatigue strength and the definition of size coefficient.

    Optimal Sensor Placement for Health Monitoring of Boom Structure of Concrete Pump Truck
    Hua Guang-jun Wu Yun-xin
    2012, 40(12):  41-46. 
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    In order to implement the optimal placement of strain sensors for the health monitoring of flexible multibody structures such as the boom structure of concrete pump trucks,a fuzzy support degree matrix is constructed by using the correlation coefficients of strain signals of the measuring points to be selected,and the comprehensive support degree of each measuring point is calculated. Then,some factors,such as the stress level,the sensor installation difficulty,the measuring point security and the stress gradient,are classified and standardized,and the weight of each factor is determined through an analytical hierarchy process. Moreover,the sensor locations are optimized according to the comprehensive evaluation results. Finally,a typical four-segment boom concrete pump truck is selected as the object to perform the sensor placement optimization under four different working conditions. The results show that the proposed comprehensive evaluation method is both stable and feasible.

    Optimization of Basic Structure for Thermal Dissipation of Heat-Pipe Milling Cutter
    Liu Zhi-jun Quan Yan-ming
    2012, 40(12):  47-52. 
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    In order to improve the heat dissipation of the heat-pipe milling cutter,the previous achievements on the thermal structure design of the cutter are analyzed,and the basic thermal model of the cutter is constructed. Then,the heat dissipation performance of the cutter is optimized. Moreover,the advantages and disadvantages of various structures are evaluated via milling temperature measurements,and an optimal structure for thermal dissipation is obtained. Based on the optimal structure,a milling cutter with excellent thermal dissipation performance is designed and fabricated. Finally,the effectiveness of the optimal structure is verified by cutting temperature measurements. The inverse solution results of the temperature field in the cutting zone demonstrate that the milling cutter with optimized basic structure effectively improves the heat dissipation performance,and that,when the milling cutter with heat pipe cooling is used,the temperature decrement in the cutting zone reaches 35℃ under certain technical conditions.

    Development of Mechanical Energy Storage-Type Test Machine for High-Velocity Powder Compaction
    Guan Hang-jian Shao Ming Xiao Zhi-yu
    2012, 40(12):  53-57. 
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    Based on the comprehensive analysis of common types of HVC ( High-Velocity Compaction) equipment,a mechanical energy storage-type HVC method is put forward,and the corresponding test machine is designed.Then,the operating principle of the machine is briefly introduced and the mathematical models of velocity and kinetic energy of the hammer are deduced. Moreover,the virtual prototype of the test machine is modeled, followed with a dynamic simulation using the rigid-flexible coupling analysis method presented in ADAMS software. Finally,a test machine is developed and its performance is tested through a HVC experiment of 316 L stainless steel powders.The practice shows that the mechanical energy storage-type HVC method helps to perform high-velocity compaction and that the test machine is of preferable capability of powder forming.

    Secondary-Phase Shear Effect in Ultra-Thin Injection Molding Process
    Yin Su-feng Ruan Feng Wang Jian-yu
    2012, 40(12):  58-63,85. 
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    In order to overcome the difficulties existing in ultra-thin injection molding,the concepts of primaryphase and secondary-phase shears are defined,and the shear field of ultra-thin injection molding is analyzed. Then,based on the Poiseuille equation,the effects of the secondary-phase shear on the apparent viscosity and the apparent shear stress in the ultra-thin injection molding process are discussed in detail through slit rheological experiments,and the relationship between the secondary-phase shear and the viscous heating on the one hand and the gate pressure on the other is analyzed,finding that the secondary-phase shear effectively improves the melt filling during the ultra-thin injection molding. Moreover,a mixed network method is presented for the design of ultra-thin light guide plates,which helps to form secondary-phase shear in the melt-flowing plane and effectively improves the filling rate of products. The theoretical correctness of the secondary-phase shear effect is finally verified by experiments.

    Case Retrieval Method of MEMS Products Orientated to Conceptual Design
    2012, 40(12):  64-69. 
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    In order to solve the problems existing in the current case retrieval methods of products,a product path set-based case retrieval method of MEMS ( Micro Electromechanical System) products is proposed according to the characteristics of product structure in conceptual design. In this method,product structure trees are created based on key parts and their topological relations. The trees are then divided into product path sets,and the structural similarities of product cases are evaluated according to the edit distance of product path sets. The authors first define the concepts of product path set and the corresponding edit operations,and construct a model to computate the weighted edit distance based on the product path set. Then,they propose an algorithm for the edit distance between double product paths according to the rules of edit operations,as well as the computation method and process for the edit distance of product path sets. Thus,the evaluation of structural similarities of MEMS product cases is implemented. A case retrieval of micro mechanical filter is finally carried out to verify the effectiveness of the proposed method.

    Automotive Engineering
    Biomechanical Responses and Injury Evaluation of Human Thorax and Abdomen During Vehicle Collision
    Lan Feng-chong Cai Zhi-hua Chen Ji-qing Ma Zheng-wei
    2012, 40(12):  70-78. 
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    Statistical data has shown that the thoracic and abdominal injury takes a great proportion in the human injury in vehicle traffic accidents. In order to investigate the biomechanical responses to the injuries of human thorax and abdomen and the corresponding mechanisms during vehicle collision,a biomechanical finite element model of human thorax and abdomen is constructed,the data of cadaver tests of human thorax and abdomen performed by international peer scholars are introduced,and then,the biomechanical responses of human thorax and abdomen during vehicle collision are simulated in terms of force,acceleration,compression deformation and stress-strain distribution. It is found from a comparative analysis that the simulated results accord well with the tested ones,and that the finite element simulation of biomechanical responses of human thorax and abdomen accurately reflects the injury degree during the collision. It is thus concluded that the proposed model can be applied to the optimal design and evaluation of vehicle structure,safety restraint system and protection system.

    Parameter Identification and SOC Estimation of Lithium-Ion Battery Pack Used in Electric Vehicles
    Luo Yu-tao Xie Bin He Xiao-chan
    2012, 40(12):  79-85. 
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    Proposed in this paper is a SOC ( State of Charge) estimation method to correct the initial error of SOC of the lithium-ion battery pack used in electric vehicles. The new method employs an algorithm combining the extended Kalman filtering with the Ampere-hour integral method. In the investigation,first,the advantages and disadvantages of several equivalent battery circuit models were analyzed,and the improved PNGV model with double RC parallel networks was selected to perform the parameter identification of a lithium-ion battery. Then,a nonlinear dynamic model of the battery in the state-space form was constructed with the help of the improved PNGV model,and the relationship between the open circuit voltage and the corresponding SOC of the battery was analyzed based on the polynomial fitting. Finally,some experiments in the conditions of constant-current pulse discharge and ECE15 were carried out. The results indicate that the proposed algorithm effectively corrects the initial error of SOC and guarantees the estimation accuracy of SOC.

    Modular Equalization Control Scheme of Power Battery Packs
    2012, 40(12):  86-91,127. 
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    In this paper,first,the impacts of imbalanced battery cell on the performance of power battery packs are discussed,and several equalization schemes and the corresponding control circuits are analyzed. Then,an equalization control scheme of the power battery packs in modular structure is proposed,which determines the equalization control strategy according to the voltage difference of adjacent battery cells by considering the relationship between the terminal voltage and the state of charge of the battery cell and by monitoring the terminal voltage in real time. Moreover,two equalizers respectively corresponding to the dissipation and the non-dissipation equilibriums are designed to conduct the charging and discharging equalization experiments on LiFePO4 battery pack. The results show that the proposed scheme achieves effective equalization control of power battery packs consisting of random battery units.

    Modeling and Simulation of Electric Vehicles Based on Gluing Algorithm
    Li Wei-dong Hu Yong-ming Hu Ping Han Xiao-qiang Zhang Jun
    2012, 40(12):  92-98. 
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    Investigated in this paper is a gluing algorithm for the multi-body dynamic simulation,which helps to implement effective and accurate dynamic analysis of vehicles. In the investigation,first,the topologies of the multibody triple-pendulum system and the quadruple-pendulum system with elastic parts are analyzed,decomposed and glued,through which the theory of the gluing algorithm and the corresponding solving process are systematically illustrated. Then,the multi-body dynamic simulation model of an electric vehicle,which takes the front suspension,the rear suspension,the vehicle body and the wheel as four individual subsystems,is established based on the gluing algorithm. Finally,the modeling and simulation of the whole vehicle is implemented with Matlab. The results show that the proposed gluing algorithm-based method is feasible.

    Acceleration Slip Regulation Control of 4WID Electric Vehicles Based on Fuzzy Road Identification
    Li Gang Zong Chang-fu Zhang Qiang Hong Wei
    2012, 40(12):  99-104. 
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    Proposed in this paper is an ASR ( Acceleration Slip Regulation) control method based on the fuzzy road identification for 4WID ( Four-Wheel Independent Drive) electric vehicles. In this method,low road adhesion coefficient and slip rate are both estimated higher with fuzzy rules to quickly and accurately identify the road with low adhesion coefficient,and,according to the independent controllability of the drive torque as well as the accessibility of the rotational speed and torque of each wheel,both the road adhesion coefficient and the optimal slip rate are estimated in real time. Thus,the drive torque of each wheel is effectively controlled and the ASR is successfully implemented. Simulation results indicate that the proposed ASR control method helps to quickly and accurately identify the road with low adhesion coefficient,avoid the slip of the driving wheel,and improve the driving stability and power performance of vehicles.

    Serial RLS-Based Dual-Parameter Combined Identification for Vehicles
    Lin Fen Huang Chao Wang Wei
    2012, 40(12):  105-110. 
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    Gross mass and centroid position are two important structural parameters of vehicles that are necessary to be measured in experiments and are essential to the proper operation of vehicle's active safety control system. As the gross mass frequently changes in practice,a dual-parameter combined identification method for vehicles is proposed. This method,which is based on two serial recursive least squares ( RLS) procedures,uses the original vehicle parameters as the initial parameters of the serial RLS-based identification algorithm and identifies the centroid position with the combination of the pylon course slalom test. Then,the identified centroid position is applied to the identification of vehicle mass with the combination of the double-lane change test. Moreover,by taking the variance of the identified vehicle mass sequence as the threshold and by performing limited recursive circulation,the relative errors of the vehicle mass and the distance from the centroid to the front axle both converge to less than 3%. The
    effectiveness of the proposed algorithm is finally verified by the virtual test in ADAMS.

    Ritz Transform Method for Interface Degree of Freedom of Modal Synthesis
    Li Xing-quan Deng Zhao-xiang Pang Jian Li Ying-qiang
    2012, 40(12):  111-116. 
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    In order to improve the computational efficiency of the fixed-interface modal synthesis method,first,the characteristic constraint modes are applied to the order reduction of the interface degree of freedom. Next,the static modes are filtrated to reduce the transformation time of interface matrixes of substructures. Then,the mass matrix of system interface is filtrated and the Ritz transform method is employed to obtain the characteristic constraint modes,thus improving the computational efficiency. Finally,the proposed method is used to analyze the vibration of a car body in white in the frequency range from 0 to 200Hz. The results show that the modified modal synthesis method is of high computational efficiency for the vibration analysis of complex structures in low or middle frequency range,with a computation time increasing by 32.4% and a computation error being less than 2%.

    Transmission Characteristics of Continuously Variable Transmission with Traction Drive
    Shen Chu-jing Yuan Shi-hua Hu Ji-bin Wu Wei Wei Chao
    2012, 40(12):  117-121. 
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    In this paper,the transmission principle of the continuously variable transmission with traction drive is analyzed,and the factors affecting the traction coefficient of the contact path and the corresponding solving methods are explored. Then,based on the relationship of the traction coefficient between the inner and the outer friction pairs,the normal force loading on the inner and the outer friction pairs,as well as the slip-roll ratio of the outer friction pairs,is investigated,and the main causes and solving method of the power loss are analyzed. Finally,the variations of the normal force,the power loss of spinning,the power loss of slipping and the transmission efficiency with the transmission ratio are discussed. The results show that ( 1) under given input rotational speed,torque and slip-roll ratio of the inner friction pairs,the normal force slightly increases with the transmission ratio; ( 2) with the increase of transmission ratio,the power loss of slipping increases while the power loss of spinning decreases,the effect of the power loss of slipping on the system transmission power becomes more important while the power loss of spinning has an opposite effect; ( 3) the total power loss decreases with the increase of transmission ratio and tends to be constant in the end; and ( 4) the total transmission efficiency of the system increases with the transmission ratio and tends to be constant,with its value remaining constant at about 83% in the end.

    Biological Engineering
    Expression of Green Fluorescent Protein-Tagged S2P Homologs in Synechocystis sp. PCC 6803
    Chen Gu Wen Pan-pan Qin Chun-yan Wang Yu-ling
    2012, 40(12):  122-127. 
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    In order to explore the functions of site-2 protease ( S2P) homologs Slr0643 and Sll0862 in Synechocystis sp. PCC 6803,enhanced green fluorescent protein ( EGFP) was added to the carboxyl terminal as a protein tag,and two transgenic Synechocystis sp. PCC 6803,namely,psbA2: : 0643GFP-Cmr /△0643-Kmr and psbA2: : 0862GFP-Cmr /△0862-Kmr,were obtained. The transcriptional expression of egfp in two transgenic lines was then detected via RT-PCR,and the GFP fluorescence was observed by using a laser scanning confocal microscope. Both of these confirm the successful expression of S2P fusion proteins tagged with EGFP under the psbA2 promoter.

    Cloning and Sequence Analysis of Protease ( SP1) Gene from Actinomucor elegans
    Ke Ye Huang Wei-qian Li Jia-zhou Xie Ming-quan Luo Xiao-chun
    2012, 40(12):  128-133,144. 
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    Proteases produced from Actinomucor elegans ( A. elegans) are of preferable debittering effect and high hydrolysis ability to soybean proteins. In order to reveal the relationship between the structure and the function and accelerate the development and application of the proteases,serine protease ( SP1) gene from A. elegans was obtained by means of PCR and RACE techniques,and was then predicted and analyzed in detail based on the bioinformatics theory and technology. The results show that SP1 gene,which contains 4 exons and 3 introns,encodes 454 amino acid residues, and that SP1 belongs to Proteinase K family and exhibits the closest genetic relationship to Rhizopus microsporus var. chinensis with the highest homology. Moreover,according to the SP1 structure modeled via homology modeling with Proteinase K ( PDB code: 1IC6) as the crystal coordinate,it is found that SP1 has no disulfide bonds and possesses a Ca2 + binding site,and that the differences in substrate-binding region, hydrogen bond, salt bridge and disulfide bond between SP1 and Proteinase K are probably responsible for the special hydrolysis ability and debittering effect of SPI.

    Inhibition Mechanism of 4-Methoxycinnamic Acid to Tyrosinase
    Mu Yan Li Lin Dong Fang-yuan Hu Song-qing
    2012, 40(12):  134-138. 
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    In this paper,L-tyrosine and L-dopa were used as the substrates to reveal the inhibition of 4-methoxycinnamic acid ( MCA) to tyrosinase,finding that MCA greatly inhibits the catalytic activity of tyrosinase for monohydric phenol L-tyrosine but has no effect on the catalytic activity for diphenol L-dopa. Then,the inhibition mechanism of MAC to tyrosinase was investigated by means of the fluorescence spectroscopy and the molecular docking. It
    is shown that ( 1) the quenching mechanism of MCA to tyrosinase belongs to a static type; ( 2) MCA forms a complex with tyrosinase through hydrogen bonds and hydrophobic forces in the catalytic center of tyrosinase; and ( 3) as MCA occupies the position of monohydric phenols in the catalytic center of tyrosinase,it may provide a competitive inhibition to tyrosinase.

    Performance of Xylanase S7 for DQP Bleaching of Non-Wood Kraft Pulps
    Lin Ying Zhang Na Zheng Sui-ping Han Shuang-yan
    2012, 40(12):  139-144. 
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    Three kinds of non-wood pulps,namely,wheat straw pulp,reed pulp and bamboo pulp,were pretreated at 70℃ and pH9.0 with xylanase S7 secreted by recombinant Pichia pastoris and were then treated with chlorinefree DQP bleaching. Then,the aid-bleaching effect of xylanase S7 was compared with those of two kinds of commercial xylanases AU-PE89 and Pulpzyme HC. The results indicate that,with the same bleaching reagent consumption,the non-wood pulps treated with xylanase S7 are of a brightness increment of more than 1%ISO,a lower Kappa number and better physical properties,which means that xylanase S7 possesses an aid-bleaching effect similar to those of the commercial enzymes. Moreover,it is found from SEM results that,after the enzymatic pre-treatment,the fiber surface changes obviously.

    Serum Metabonomics Investigation into Responses of Rats to Cantonese Herbal Tea
    You Rong Li Bing Xu Zhen-bo Li Lin
    2012, 40(12):  145-150. 
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    As pointed out by the traditional Chinese medicine theory,Cantonese Herbal Tea ( CHT) is of various functions such as heat clearing and dampness removing. However,the corresponding action mechanism is hard to evaluate through traditional assessments due to its extremely complex components. In order to solve this problem,the NMR technology with stability and repeatability is employed to obtain the panoramic view of the fingerprints of the metabolites in the serum of rats,and a multivariate data analysis as well as an identification of discriminative biomarkers is carried out. It is found that long-term CHT intake modulates the metabolisms of fats,carbohydrates and energy in rats in a stage form. This study provides an approach to the deep analysis of action mechanism of CHT and to the construction of a scientific evaluation system of CHT.

    Effects of Aqueous Extract from Salvia miltiorrhiza Bunge on Serum Lipid Level and Liver in Ovariectomized Rats
    Li Chun-mei Yang Ri-fu Gu Qu-liang Wang Bo Wu Jian-hong Fan Xiao-dan Chan Shun-wan Qiu Tai-qiu Wong Man-sau
    2012, 40(12):  151-156. 
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    In order to evaluate the estrogenic effect of Salvia miltiorrhiza Bunge ( SM) ,32 six-month-old female SD rats were randomly divided into 4 groups,namely,sham-operated rats + vehicle ( marked as Sham) ,ovariectomized rats + vehicle ( marked as OVX) ,ovariectomized rats + 17 β-estradiol ( 1mg·kg -1·d -1,p. o. ,marked as E2) ,ovariectomized rats + SM ( 600 mg·kg -1·d -1,p. o. ,marked as SM) . After the treatment for 12 weeks,the body weight gain,uterus weight index,serum lipid level,serum transaminase activity and oxidant / antioxidant level were detected,and a histological examination of the liver was carried out. The results show that the treatment with aqueous extract for 12 weeks helps to reduce the body weight gain,stimulate the growth of the atrophic uterus,improve the serum lipid level,decrease the ALT and AST levels in serum and suppress the lipid
    accumulation in the liver of ovariectomized rats. All these above-mentioned protective effects of SM extract probably relate to the inhibition of oxidant ( Methane Dicarboxylic Aldehyde) level and the activity improvement of antioxidant enzymes such as super oxygen dehydrogenises,catalase and glutathione peroxidase.

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