Effect and mechanism of on-chip electrostatic discharge protection circuit under fast rising time electromagnetic pulse

The electrostatic discharge(ESD)protection circuit widely exists in the input and output ports of CMOS digital circuits,and fast rising time electromagnetic pulse(FREMP)coupled into the device not only interacts with the CMOS circuit,but also acts on the protection circuit.This paper establishes a model of on-chip CMOS electrostatic discharge protection circuit and selects square pulse as the FREMP signals.Based on multiple physical parameter models,it depicts the distribution of the lattice temperature,current density,and electric field intensity inside the device.At the same time,this paper explores the changes of the internal devices in the circuit under the injection of fast rising time electromagnetic pulse and describes the relationship between the damage amplitude threshold and the pulse width.The results show that the ESD protection circuit has potential damage risk,and the injection of FREMP leads to irreversible heat loss inside the circuit.In addition,pulse signals with different attributes will change the damage threshold of the circuit.These results provide an important reference for further evaluation of the influence of electromagnetic environment on the chip,which is helpful to carry out the reliability enhancement research of ESD protection circuit.

Semi-analytical solution for mechanical analysis of tunnels crossing strike-slip fault zone considering nonuniform fault displacement and uncertain fault plane position

The tunnel subjected to strike-slip fault dislocation exhibits severe and catastrophic damage.The existing analysis models frequently assume uniform fault displacement and fixed fault plane position.In contrast,post-earthquake observations indicate that the displacement near the fault zone is typically nonuniform,and the fault plane position is uncertain.In this study,we first established a series of improved governing equations to analyze the mechanical response of tunnels under strike-slip fault dislocation.The proposed methodology incorporated key factors such as nonuniform fault displacement and uncertain fault plane position into the governing equations,thereby significantly enhancing the applicability range and accuracy of the model.In contrast to previous analytical models,the maximum computational error has decreased from 57.1%to 1.1%.Subsequently,we conducted a rigorous validation of the proposed methodology by undertaking a comparative analysis with a 3D finite element numerical model,and the results from both approaches exhibited a high degree of qualitative and quantitative agreement with a maximum error of 9.9%.Finally,the proposed methodology was utilized to perform a parametric analysis to explore the effects of various parameters,such as fault displacement,fault zone width,fault zone strength,the ratio of maximum fault displacement of the hanging wall to the footwall,and fault plane position,on the response of tunnels subjected to strike-slip fault dislocation.The findings indicate a progressive increase in the peak internal forces of the tunnel with the rise in fault displacement and fault zone strength.Conversely,an augmentation in fault zone width is found to contribute to a decrease in the peak internal forces.For example,for a fault zone width of 10 m,the peak values of bending moment,shear force,and axial force are approximately 46.9%,102.4%,and 28.7% higher,respectively,compared to those observed for a fault zone width of 50 m.Furthermore,the position of the peak internal forces is influenced by variations in the ratio of maximum fault displacement of the hanging wall to footwall and the fault plane location,while the peak values of shear force and axial force always align with the fault plane.The maximum peak internal forces are observed when the footwall exclusively bears the entirety of the fault displacement,corresponding to a ratio of 0:1.The peak values of bending moment,shear force,and axial force for the ratio of 0:1 amount to approximately 123.8%,148.6%,and 111.1% of those for the ratio of 0.5:0.5,respectively.

基于SAM的中国人群乘用车驾驶座椅位置设计研究

随着国内各车企乘用车设计水平的提升,设计手段已经由逆向开发转到正向设计阶段,同时中国经济的高速发展,中国市场已经成为乘用车主战场,针对中国人体的乘用车正向开发至关重要,乘用车座椅行程长度设计及行程分配决定了目标人群人体舒适性及内部空间布置,目前国内外车企设计规范依旧是基于美国人体SAE设计标准,因此,本文将基于中国人体尺寸提出适合中国乘用车驾驶员座椅行程长度正向设计方法,同时使用人机柔性台架进行了验证,为座椅行程正向设计提供了理论上的参考。

Wear mechanism and serious wear position of casing pipe in vertical backfill drill-hole

Vertical backfill drill-hole is usually a key project in an underground mine with backfill method and can be easily damaged by impact of backfill slurry.Observation of the damaged vertical backfill drill-holes in Jinchuan Nonferrous Metal Corporation（JNMC）,Gansu Province,China,given by a digital drill-hole video camera,indicated that there usually exist serious wear zones in casing pipe in vertical backfill drill-hole（CVBH）.It was suggested that serious wear position of CVBH should be located at an interface between air and solid-liquid mixture within CVBH.Backfill slurry falls freely and impacts the wall of CVBH near the interface with great momentum and energy coming from high speed free fall of backfill slurry.The depth of serious wear position of CVBH,i.e.,free fall height of backfill slurry in CVBH,can be estimated by the height of vertical backfill drill-hole,the length of horizontal pipeline,the density of slurry and the hydraulic gradient of pipeline system.A case study indicated that the estimation equation of serious damage depth of CVBH was of enough accuracy and was helpful for daily maintenance and management of vertical backfill drill-hole.

Genetic Diversity of Achnatherum Splendens

[Objective] Study on the genetic diversities of A.splendens from different areas of xinjiang. [Method] The genetic diversities among seven populations and within two populations were analyzed by RAPD. [Result] Genetic clustering results presented that the relationships among populations of A. splendens are directly related with geographic positions, and within population are related with habitats. [Conclusion] RAPD technique can be used to study genetic diversity of A. splendens.

Prediction of Subcellular Localization of Eukaryotic Proteins Using Position-Specific Profiles and Neural Network with Weighted Inputs

Subcellular location is one of the key biological characteristics of proteins. Position-specific profiles （PSP） have been introduced as important characteristics of proteins in this article. In this study, to obtain position-specific profiles, the Position Specific lterative-Basic Local Alignment Search Tool （PSI-BLAST） has been used to search for protein sequences in a database. Position-specific scoring matrices are extracted from the profiles as one class of characteristics. Four-part amino acid compositions and lst-7th order dipeptide compositions have also been calculated as the other two classes of characteristics. Therefore, twelve characteristic vectors are extracted from each of the protein sequences. Next, the characteristic vectors are weighed by a simple weighing function and inputted into a BP neural network predictor named PSP-Weighted Neural Network （PSP-WNN）. The Levenberg-Marquardt algorithm is employed to adjust the weight matrices and thresholds during the network training instead of the error back propagation algorithm. With a jackknife test on the RH2427 dataset, PSP-WNN has achieved a higher overall prediction accuracy of 88.4% rather than the prediction results by the general BP neural network, Markov model, and fuzzy k-nearest neighbors algorithm on this dataset. In addition, the prediction performance of PSP-WNN has been evaluated with a five-fold cross validation test on the PK7579 dataset and the prediction results have been consistently better than those of the previous method on the basis of several support vector machines, using compositions of both amino acids and amino acid pairs. These results indicate that PSP-WNN is a powerful tool for subcellular localization prediction. At the end of the article, influences on prediction accuracy using different weighting proportions among three characteristic vector categories have been discussed. An appropriate proportion is considered by increasing the prediction accuracy.

Environmental cues associated with morphine modulate release of glutamate and γ-aminobutyric acid in ventral subiculum

Objective To investigate whether environmental cues associated with different properties of morphine could regulate the extracellular levels of glutamate and y-aminobutyric acid （GABA） in the hippocampal ventral subiculum, which play a critical role in the reinstatement of drug-seeking behavior induced by environmental cues. Methods Conditioning place preference （CPP） and conditioning place aversion （CPA） models were used to establish environment associated with rewarding and aversive properties of morphine respectively. Microdialysis and high performance liquid chromatography were used to measure the extracelluar level of glutamate and GABA in the ventral subiculum under these environmental cues. Results Exposure to the environmental cues associated with rewarding properties of morphine resulted in a decrease （approximately 11%） of extracellular level of GABA in ventral subiculum, and exposure to the environmental cues associated with aversive properties of morphine resulted in an increase （approximately 230%） of extracellular level of glutamate in ventral subiculum. Conclusion Environmental cues associated with different properties of morphine modulate the release of distinct neurotransmitters in the hippocampal ventral subiculum possibly through different neural circuit.

Variation of Nitrogen Uptake and Utilization Efficiency of Mid-Season Hybrid Rice at Different Ecological Sites under Different Nitrogen Application Levels

[Objective] The study aimed at investigating the effects of different geographic sites,soil chemical characteristics and nitrogen application levels on nitrogen accumulation and distribution in different organs and utilization efficiency for mid-season hybrid rice.[Method] By using mid-season rice varieties II-you 7 and Yuxiangyou203 as the experimental materials,field experiment was conducted at seven ecological sites in four provinces or cities in Southwestern China in 2009.A total of four nitrogen application levels were set as follows：by using 75 kg/hm2 of P2O5 and 75 kg/hm2 of K2O as the base fertilizer,extra 0,90,150 and 210 kg/hm2 of nitrogen fertilizer（in which,base fertilizer,base-tillering fertilizer and base-earing fertilizer respectively accounted for 60%,20% and 20%.） was applied,respectively.In the split-plot design,fertilizer was considered as the main factor while rice variety was taken as the secondary factor.A total of eight treatments were set with three replications.[Result] Highly significant differences of grain yield were found among seven locations,two varieties,four nitrogen application levels,interactions of site × variety and site × nitrogen application level,but the interaction of variety ×nitrogen application level had no significant influence on rice yield.There were highly significant effects of site,varieties and nitrogen application level on dry matter production,nitrogen content,nitrogen utilization efficiency.Highly significant negative correlations between uptake efficiency and utilization efficiency for nitrogen were found;and multiple stepwise regression analysis showed that nitrogen uptake-utilization efficiency were significantly influenced by different ecological sites,chemical quality of soil and the levels of nitrogen application.[Conclusion] The research will provide theoretical and practical basis for the highly efficient application of nitrogen in mid-season hybrid rice cultivation.

Force assistant master-slave telerehabilitation robotic system

A prototype of the master slave telerehabilitation robotic system with force feedback is developed. This system contains a pair of robots with the master being operated by the therapist and the slave following the master to guide the patients to exercise. A slave device with a slave controller is designed to stretch and mobilize the impaired elbow joints accurately and safely. A master device with a master controller is designed to control/monitor the procedure of treatment and assess the outcome of treatment remotely and accurately. By using the twoport network theory and the circuit equivalent impedance models, the position-force control scheme is designed to generate force feedback for the therapist who is to be informed of the interaction force between the subject and the robot arm during exercise. Experiments were conducted with a healthy male. Results show that the therapist can guide the patient to exercise by the master arm and can feel the interaction forces between the impaired arm and the robot. Compared with the traditional therapy, this system is more cost-efficient, more convenient and safer for both the stroke patients and the clinicians.

Cooling performance analysis of radiant panel at different positions

The influence of the panel position on the cooling performance of a radiant panel is analyzed.The coupled simulation of convection and radiation is set up by a computational fluid dynamics（CFD）method.The simulations with different panel positions and different indoor heat sources are used to calculate the cooling capacity of the radiant panel and the indoor thermal environment.The simulation results are in good agreement with the experimental results.The results show that when the indoor heat source temperature is low,the convective heat flux is the main influence factor of the cooling capacity and the radiant panel should be placed on the wall or on the ceiling.Otherwise,when the indoor heat source temperature is high,the radiation heat flux is the main factor and the radiant panel should be placed as near to the heat sources as possible.

Spatial variation law of vertical derivative zero points for potential field data

In this paper we deduce the analytic solutions of the first- and second-order vertical derivative zero points for gravity anomalies in simple regular models with single, double, and multiple edges and analyze their spatial variation. For another simple regular models where it is difficult to obtain the analytic expression of the zero point, we try to use the profile zero points to analyze the spatial variation. The test results show that the spatial variation laws of both first- and second-order vertical derivative zero points are almost the same but the second-order derivative zero point position is closer to the top surface edge of the geological bodies than the first-order vertical derivative and has a relatively high resolution. Moreover, with an increase in buried depth, for a single boundary model, the vertical derivative zero point location tends to move from the top surface edge to the outside of the buried body but finally converges to a fixed value. For a double boundary model, the vertical derivative zero point location tends to migrate from the top surface edge to the outside of the buried body. For multiple boundary models, the vertical derivative zero point location converges from the top surface edge to the outside of the buried body where some zero points coincide and finally vanish. Finally, the effectiveness and reliability of the proposed method is verified using real field data.

Effect of atomic structure on migration characteristic and solute segregation of ordered domain interfaces formed in Ni_(75)Al_xV_(25-x)

Based on the microscopic phase-field model, ordered domain interfaces formed between D022 （Ni3V） phases along [001] direction in Ni75AlxV25-x alloys were simulated, and the effects of atomic structure on the migration characteristic and solute segregation of interfaces were studied. It is found that the migration ability is related to the atomic structure of interfaces, and three kinds of interfaces can migrate except the interface （001）//（002） which has the characteristic of L12 （Ni3Al） structure. V atoms jump to the nearest neighbor site and substitute for Ni, and vice versa. Because of the site selectivity behaviors of jumping atoms, the number of jumping atoms during the migration is the least and the jumping distance of atoms is the shortest among all possible modes, and the atomic structures of interfaces are unchanged before and after the migration. The preferences and degree of segregation or depletion of alloy elements are also related to the atomic structure of interface.

CONTROL OF ROBOT DRIVEN BY MULTIPLE ULTRASONIC MOTORS BASED ON ROBUST PARAMETER DESIGN

An ultrasonic motor （USM） is difficlt to be mathematically described because of its complex energy conversion and nonlinear parameters from increasing temperature and changing operating conditions. To achieve good performance of a three-joint robot directly driven by USM, according to the operating characteristics of USM, a new position-velocity feedback control strategy is proposed. In the control strategy, there are a total of 18 controller gains to he tuned. Through a series of ＂Design of Experiments＂ by the robust parameter design, an optimal and robust set of proportional integral derivative （PID） controller gains is obtained. Results show that the control strategy can achieve the best performance of the robot and the robust parameter design is effective and convenient to USMs.

On Spatial Variability and Distribution of Soil Nutrients in Different Nitraria tangutorum Bobr.Populations in Tsaidam Basin

In this paper,six important distribution areas of Nitraria tangutorum Bobr.in Tsaidam Basin were selected as research objects,to study spatial variability and distribution of soil nutrients in different N.tangutorum populations and analyze the relationship between soil nutrient contents and geographical location,by measuring soil pH and the contents of organic matter（OM）,total nitrogen（N）,total phosphorus（P）,total potassium（K）,hydrolysis N,available P and available K in soils.Results showed that：（1） soil nutrient contents among different populations showed significant spatial variability,and soil depth had a significant effect on soil nutrients contents,but the variation rules were not obvious.（2）Average pH and average contents of OM,total N,total P,total K,hydrolysis N,available P and available K in soils with different depths（0-15,15-30,30-45 cm） varied in the range of 8.37-9.21,3.34-20.68,0.18-1.21,0.35-0.75,16.12-22.04,5.13-553.28,1.10-52.54 and 103.83-562.28 mg/kg,respectively.（3） The analysis results of correlation between average values of pH and contents of nutrient indexes in soils with different depths（0-15,15-30,30-45 cm） showed that the correlation of these indexes were different.（4）OM and total N contents in soils with different depths（0-15,15-30,30-45 cm） all had a significant positive correlation with latitude and negative correlation with longitude and altitude,and the correlation of available P and available K contents in surface soils（0-15 cm） with latitude,longitude and altitude were significant positive,significant negative and significant negative,respectively;moreover,longitude and latitude also showed a significant impact on soil available K contents with the depth of 30-45 cm.In addition,comprehensive analysis result of nutrient contents showed that N.tangutorum populations in Huaitou Tala Town had the highest fertility,and the fertility levels of N.tangutorum populations in Chaka Town and Wulan Keke Town were relatively lower.

ACYL RADICAL CYCLISATIONS

Several phenylselenyl esters were selected as precursors of acyl radicals and synthesised by our established method. Treatment of these phenylselenyl esters with tributyltinhydride and AIBN generated the corresponding acyl radicals, which were found to proceed in 5 exo trig or 6 endo trig cyclisations to afford high yields of cyclopentanones and cyclohexanones, The substitution groups on the substrates have played an important role on the regioselectivity of cyclisations.

Separation Properties of a New Polysiloxane-Anchored β-Cyclodextrin Derivative as Gas Chromatography Stationary Phase

A new capillary gas chromatography stationary phase, monokis (2,6 di O benzyl 3 O propyl (3’)) hexakis(2,6 di O benzyl 3 O methyl) β CD bonded polysiloxane, was synthesized. It exhibited separation abilities to disubstituted benzene isomers and some chiral solutes. It was also found that the polarity of CD derivatives can be lowered both by chemically bonding it to polysiloxane and by diluting it in polysiloxane. The separation abilities of the polysiloxane anchored CDs (SP CD) are higher than that of the unbonded CDs (S CD) and the diluted S CD at lower column temperature. Hydrosilylation reaction is one of the best methods to lower the operating temperature of CDs.

机器人连杆参数的视觉标定

机器人的连杆参数很难由几何方法测量。本文介绍了一种基于视觉测量装置的连杆参数确定方法,可对各种未知机械臂的连杆参数进行标定。

“副+名”讨论补议

文章对三种“副+名”用例中的相关词——“凡”、“只”、“位置词”进行了分析,指出:该三种词在词类划分或归类上存留一些问题,因此作为“副+名”例证,用以证明副词可以修饰名词,是缺乏说服力的。另外,“很+名”的组合视为副词修饰名词也不妥,应看作词类活用现象。

Effect of Silicon-on-Insulator Substrate on Residual Strain in 3C-SiC Films

One group of SiC films are grown on silicon-on-insulator （SOI） substrates with a series of silicon-overlayer thickness. Raman scattering spectroscopy measurement clearly indicates that a systematic trend of residual stress reduction as the silicon over-layer thickness decreases for the SOI substrates. Strain relaxation in the SiC epilayer is explained by force balance approach and near coincidence lattice model.

桔皮油中与发泡聚苯乙烯塑料相溶组分的分析

气相色谱法测定结果表明：桔皮提取物中有一绝对优势组分。通过红外光谱和核磁共振进一步协同确定，与聚苯乙烯具有良好相溶性的组分是(d)-柠烯，即d-limonene。