路元理念在高速公路路面养护管理信息系统中的应用研究

鉴于桩号定位系统的不完善难以实现对高速公路路面养护的精细化管理。路元理论被引入到路面养护管理系统的设计中。该文详细论述了路元的概念、划分原理、编号方法及其作用。在此基础上研究了路元理念与路面养护管理系统的结合方法,提出了基于路元理念的高速公路路面养护管理系统设计框架及其实现方法。路元理念在湖南省高速公路路面养护管理系统中得到了应用,效果显著,表明路元理念具有重要的推广应用价值。

激光三维路元高程数值扫描仪

当前国内外高速公路自动智能检测设备如平整度仪、车辙仪、纹理构造深度仪和裂缝病害检测仪等及其集成的多功能检测系统存在许多不足。虽然它们都是从不同侧面测量同一路面的高程变化特性,但各功能设备独立设计,依据的原理各异,方法不同,基准不统一,由此得到的测量数据互不相关,甚至错位。整套设备更是价格昂贵,操作复杂。为此,该文提出了统一的车道半刚性路面物理模型。采用统一的设计路面—水平面组合基准,建立了以车道设计路面为基面,以分道线为轴的车道网格坐标系,按特定间隔进行数据采样,得到的路面三维轮廓图可正确描述任何复杂路面及其三维破损。该文提出用路面高程空间频谱方法分析复杂路面变形与病害,用频谱滤波方法处理路元高程数据,只须分别设置不同滤波参数,就可从同一路元高程数值数据库中得到不同特征频谱的技术指标数据,例如:低通滤波得到路面连续变形特性,并由此得到纵断面特征及其平整度指标;得到横断面特征及车辙指标,特别是可自动计算路段的三维破损率;高通滤波得到脉冲性病害与裂缝;得到细观纹理断面构造与深度。该文设计了包括结构激光标线断面扫描,高分辨CCD探测与车道坐标零位监测的激光三维路元高程数值扫描仪。该扫描仪得到的路元高程数值网格数据库,实现了路面技术状况的统一简明完全表达,不仅实现现有多套设备的全部功能,而且克服了它们由于原理基准与方法不统一产生的各种问题,并可成功解决它们难以解决技术条件适应性问题,特别是对裂缝病害与三维病害的全自动智能检测与处理难题。该扫描仪价格低得多,使用也方便得多,值得全面推广,可极大提高公路高效运行安全管理要求的自动智能检测水平。

基于路元模型的高速公路养护生产管理

公路病害的发生具有随机性、离散性,而公路养护要求做到预防性、及时性及全寿命周期控制。文中针对这些特征和属性,基于路元模型,建立高速公路养护生产管理系统,动态、形象地观察公路技术状况,定期评价路况水平和预测变化趋势,合理安排养护生产计划并随时统计完成情况,及早发现并精确定位病害缺陷,快速确定维修方案和组织施工作业,准确验收计量作业数量,不断积累和完善病害处治技术工艺对策,从而推动和支撑公路日常养护管理与生产作业的科学决策、规范运行、精细操作、标准考核。

Zuogui Jiangtang Jieyu Formula ameliorating hippocampal neuronal apoptosis in diabetic rats with depression by inhibiting JNK signaling pathway

Objective To investigate the effect of Zuogui Jiangtang Jieyu Formula(左归降糖解郁方,ZJJF)on hippocampal neuron apoptosis in diabetic rats with depression and to ascertain whether its mechanism involves the regulation of JNK signaling pathway.Methods(i)A total of 72 specific pathogen-free(SPF)grade male Sprague Dawley(SD)rats were randomly divided into six groups,with 12 rats in each group:control,model,metformin(Met,0.18 g/kg)+fluoxetine(Flu,1.8 mg/kg),and the high-,medium-,and low-ZJJF dosages(ZJJF-H,20.52 g/kg;ZJJF-M,10.26 g/kg;ZJJF-L,5.13 g/kg)groups.All groups except control group were injected once via the tail vein with streptozotocin(STZ,38 mg/kg)combined with 28 d of chronic unpredictable mild stress(CUMS)to establish diabetic rat models with depression.During the CUMS modeling period,treatments were administered via gavage,with control and model groups receiving an equivalent volume of distilled water for 28 d.The efficacy of ZJJF in reducing blood sugar and alleviating depression was evaluated by measuring fasting blood glucose,insulin,and glycated hemoglobin levels,along with behavioral assessments,including the open field test(OFT),forced swim test(FST),and sucrose preference test(SPT).Hippocampal tissue damage and neuronal apoptosis were evaluated using hematoxylin-eosin(HE)staining and terminal deoxynucleotidyl transferase-mediated dUTP nickend labeling(TUNEL)staining.Apoptosis-related proteins Bax,Bcl-2,caspase-3,and the expression levels of JNK/Elk-1/c-fos signaling pathway were detected using Western blot and real-time quantitative polymerase chain reaction(RT-qPCR).(ii)To further elucidate the role of JNK signaling pathway in hippocampal neuronal apoptosis and the pharmacological effects of ZJJF,an additional 50 SPF grade male SD rats were randomly divided into five groups,with 10 rats in each group:control,model,SP600125(SP6,a JNK antagonist,10 mg/kg),ZJJF(20.52 g/kg),and ZJJF(20.52 g/kg)+Anisomycin(Aniso,a JNK agonist,15 mg/kg)groups.Except for control group,all groups were established as diabetic rat models with depression,and treatments were administered via gavage for ZJJF and intraperitoneal injection for SP6 and Aniso for 28 d during the CUMS modeling period.Behavioral changes in rats were evaluated through the OFT,FST,and SPT,and hippocampal neuron damage and apoptosis were observed using HE staining,Nissl staining,TUNEL staining,and transmission electron microscopy(TEM).Changes in apoptosis-related proteins and JNK signaling pathway in the hippocampal tissues of rats were also analyzed.

EFFECT OF TOOL-PATH ON MILLING ACCURACY UNDER CLAMPING

To resolve the deformation problem for thin-walled aero-parts in the actual production, this paper simulates the effect of the tool-path on the machining accuracy of the thin-walled frame. The frame is shaped in the part milling under a given clamping condition by using the three-dimensional finite element method （FEM）. Result shows that the sidewall deformation has a big difference if only the tool-path changes. When the tool-path from the outside to the inside is used, the machining deformation is smaller than another three kinds of toolpaths. Simulation results are compared with experimental data, and the correctness of the simulation is verified.Reasonable processing paths can be found by FEM.

Photo-Controlled MOBILE's

A novel optoelectronic functional circuit with heterojunction phototransistors (HPTs) and resonant tunneling diodes (RTDs) is described,which presents the function of both photocurrent switching and photo-current latching.These behaviors have been demonstrated by simulating experiments and circuit simulation.Furthermore,basing on photo-current latching behavior,various photo-controlled basis logic elements such as delayed flip-flop (DFF) can be designed and fabricated.

ANALYSIS OF GEOSYNTHETICS REINFORCED EMBANKMENT ON SOFT SOIL BY FEM

The reinforcement effects of geosynthetics in thick soft subsoil case and thin soft subsoil case are studied in this paper,and a Duncan Chang nonlinear numerical model based on the finite element method (FEM) is developed.Moreover,an important conclusion that the thickness of soft subsoil affects greatly the geotechnical behavior of geosynthetic reinforced embankments is drawn.A series of embankment built on soft subsoil is calculated using the FEM program.The results of the computer program,such as the lateral displacements,settlements,and stress level and shear stresses in the subsoil,are presented in great detail and the comparison of those results disposes clearly the huge discrepancy of reinforce benefit between the thick subsoil embankment and thin subsoil embankment.Reinforcement mechanism of geosynthetics is also discussed in this paper and several conclusions are reached.This paper also gives recommendations for design.

用事实阐明观点——从古代记事文学习新闻写作之二

写文章、作演说都有一个重要的要求,就是尽力做到观点和材料的统一。新闻更是如此。新闻必须"用事实说话"。它应该既是客观的,又是观点鲜明的。客观主义地罗列事实,或者由作者站出来叽哩哇啦地大发议论、指手划脚都是不足取的。当然,对有些新闻报道,先讲清事实,然后借"此间观察家指出"等名义来指出其意义和影响,也是可以的。但是,对于大多数新闻报道来说,还是以寓观点于事实的叙述中为好。在这方面,我国古代的记叙文中,也有不少可供学习和借鉴的东西。

Optimization method for evacuation zone with network reconfiguration based on dynamic simulation

Abstract： With a determinate danger zone and evacuation demand caused by an emergency, an optimization method for the evacuation zone with network reconfiguration based on dynamic simulation is proposed. The method contains three modules. First, the network in the evacuation zone is optimized by a model with the integrated strategy of lane reversal and intersection conflict elimination. Secondly, the dynamic evacuation simulation model based on the cell transmission model is applied to simulate the dynamic propagation process of evacuated vehicles in the network in the evacuation zone. The evacuation time for all evacuated vehicles leaving the danger zone is obtained and the setting of the current evacuation zone is fed back. Thirdly, the arrival distributions of evacuated vehicles at critical intersections of the evacuation zone are also obtained to estimate the delay at critical intersection to determine whether the intersection should be taken as the critical intersection in the next iteration. The evacuation zone is expanded gradually through iteration, and the reasonable evacuation zone and the optimal evacuation network is confirmed. Based on the survey of the parking lot and urban street network around Nanjing Olympic Sports Center, the models and the iterative algorithm were applied to obtain the optimal plan of the evacuation zone with network reconfiguration in an evacuation situation to verify the validity of the proposed method.

Critical load position for cavities beneath CRCP slab under vehicle loading

In order to study the critical load position that causes cavities beneath the continuously reinforced concrete pavement（ CRCP） slab under vehicle loading, the elliptical load is translated into the square load based on the equivalence principle.The CRCP slab is analyzed to determine the cavity position beneath the slab under vehicle loading. The influences of cavity size on the CRCP slab＇s stress and vertical displacement are investigated. The study results showthat the formation of the cavity is unavoidable under traffic loading, and the cavity is located at the edge of the longitudinal crack and the slab corner.The cavity size exerts an obvious influence on the largest horizontal tensile stress and vertical displacement. The slab corner is the critical load position of the CRCP slab. The results can be used to assist the design of CRCP in avoiding cavities beneath slabs subject to vehicle loading.

Response mechanism for widened pavement structure subjected to ground differential settlement

By the use of a large-scale ground differential settlement simulator, a full-size model test is performed to study the strain response and the deformation behavior of both the wearing course of asphalt cement and the base course of cement-stabilized gravel. Moreover, with the differential settlement at the bottom of the pavement structure as the constraint condition, a plane finite element model is established, which is used to study the stress variation of different pavement layers in response to the differential settlement of varying magnitudes. It shows that, under the effects of the ground differential settlement, the wearing course is subjected to the tensile stress while the base course to the compressive stress and the maximum additional tensile stress and compressive stress occur in the area of 1 m from the splicing joint between the new and the old subgrade. Plastic deformation develops in both layers when the ground differential settlement reaches 14 cm. When the differential settlement at the bottom of the pavement goes up to 1 cm, the maximum additional stress in the surface of the base course will reach 0. 28 MPa, which surpasses 0.276 MPa that is specified in the current specifications as the maximum splitting tensile strength for cement-stabilized base material.

A Novel Charge-Transfer Matching Cell for High-Precision Correlation and Low-Power

A novel matching cell circuitry using charge transfer circuit technique for high precision correlation calculation is presented.The cell calculates the absolute value of the difference between two analog input voltages and amplifies the result.Amplification gain can be designed by the capacitance size in the cell and threshold voltage mismatch can be canceled automatically,thus high precision operation of the circuit is achieved.The circuit can be operated with low power dissipation of about 12μW at a frequency of 50MHz.Because of its simple structure and small silicon area,the matching cell is suitable to realize the correlation dealing with many template vectors that have many elements in a chip.

Mechanical analysis of transmission lines based on linear sliding cable element

In order to study the sliding characteristics when the cable structures are connected with other rods, a string of sliding cable dements （SCE） consisting of one active threenode SCE passing through the sliding point and multiple inactive two-node SCEs is put forward. Based on the updated Lagrangian formulation, the geometric nonlinear stiffness matrix of the three-node straight sliding cable dement is deduced. The examples about two-span and three-span continuous cable structures are studied to verify the effectiveness of the derived SCE. Comparing the cable tension of SCE with the existing research results, the calculating results show that the error is less than 1%. The sliding characteristics should be considered in practical engineering because of the obvious difference between the cable tension of the SCE and that of the cable element without considering sliding characteristics.

A Novel NeuMOS Source Follower Cell with High Precision

A novel neuMOS source follower circuit is presented.The cell can complete the s ource follower function even if the input voltage is lower than the threshold of the source follower,thus high-precision operation of the circuit is achieved. The simulation and the measurement results show that its precision is higher tha n that of other neuMOS source follower circuits.

各种产品2008年10月价目表

由于生产成本原料上涨非常严重,我们对部分产品进行了调价。详见下表。

Reflective cracking viscoelastic response of asphalt concrete under dynamic vehicle loading

In order to investigate the mechanical response of reflective cracking in asphalt concrete pavement under dynamic vehicle loading, a finite element model is established in ABAQUS. The viscoelastic behavior is described by a prony series which is calculated through nonlinear fitting to the creep test data obtained in the laboratory. Based on the viscoelastic theory, the time-temperature equivalence principle, fracture mechanics and the dynamic finite element method, both the Jintegral and the mix-mode stress intensity factor are utilized as fracture evaluation parameters, and a half-sine dynamic loading is used to simulate the vehicle loading. Finally, the mechanical response of the pavement reflective cracking is analyzed under different vehicle speeds, different environmental conditions and various damping factors. The results indicate that increasing either the vehicle speed or the structure damping factor decreases the maximum values of fracture parameters, while the structure temperature has little effect on the fracture parameters. Due to the fact that the vehicle speed can be enhanced by improving the road traffic conditions, and the pavement damping factor can become greater by modifying the components of materials, the development of reflective cracking can be delayed and the asphalt pavement service life can be effectively extended through both of these ways.

FE Method of Analysing Detecting Electrode of Capacitance Proximity Fuze

The finite element method is first introduced into the design process of detecting electrodes of three electrode capacitance fuze, the mutual capacitance of the fuze and target is calculated by the finite element method, which provides the parameters for simulation circuit and design of detecting electrode. The finite element method pierces the traditional method of designing detecting electrode-design, test and adjustment. The system capacitance can be calculated accurately and the performance can be predicted in the design period of the detecting electrode, which saves a lot of research fee. The capacitances of a mortar shell fuze above ground 2 m and lower are given. After putting the computing data into simulating circuit, the demodulation voltage can be obtained, its changing trend is in agreement with the tested result.

Incremental Placement Algorithm for Standard-Cell Layout

A new algorithm W ECOP is presented to effect incremental changes on a standard cell layout automatically.This algorithm deals with cell inserting and cell moving based on rows instead of on cells as most placement algorithms usually do.An integer programming problem is formulated to minimize the adjustment on the initial placement and a heuristic method is presented to search for a shifting path so as to optimize the wirelength.Test of W ECOP on a group of practical test cases shows that the algorithm can successfully accomplish incremental placement with good quality and high speed.

BOOTSTRAPPING FOR EXTRACTING RELATIONS FROM LARGE CORPORA

A new approach of relation extraction is described in this paper. It adopts a bootstrap- ping model with a novel iteration strategy, which generates more precise examples of specific relation. Compared with previous methods, the proposed method has three main advantages: first, it needs less manual intervention; second, more abundant and reasonable information are introduced to represent a relation pattern; third, it reduces the risk of circular dependency occurrence in bootstrapping. Scalable evaluation methodology and metrics are developed for our task with comparable techniques over TianWang 100G corpus. The experimental results show that it can get 90% precision and have excellent expansibility.

Traffic Flow States in a Freeway with Bottleneck

The system of mixture of single lane and double lane is studied by a cellular automata model, which is developed by us based on the Nagel and Schreckenberg＇s models. We justify that the model can reach a stable states quickly. The density distributions of the stable state is presented for several cases, which illustrate the manner of the congestion. The relationship between the outflow rate and the total number of vehicles and that between the outflow rate and the density just before the bottleneck are both given. Comparing with the relationship that occurring in the granular flow, we conclude that the transition from the free traffic flow to the congested traffic flow can also be attributed to the abrupt variation through unstable flow state, which can naturally explain the discontinuities and the complex time variation behavior observed in the traffic flow experiments.