高铁动车组惰行试验与应用实践

动车组具有优异的惰行性能,给接触网故障临时抢通设置无电区、降弓区创造了条件。通过组织动车组惰行试验和对试验数据统计分析,初步掌握了不同速度、不同坡度条件下动车组惰行规律。结合高铁线路实际,制定每个供电单元(供电臂)惰行方案,对高速铁路利用动车组惰行实施接触网故障快速抢通进行了有益的尝试与实践。

6分钟步行试验对慢性心衰患者心功能的评估

本文对用6分钟步行试验的方法评价慢性充血性心力衰竭患者心衰严重程度、治疗效果和其可靠性及重复性的情况进行了简要综述。提出6分钟步行试验是一种简单、易行、价廉的评价心功能的方法,尤其适用于年老体弱、肥胖以及严重心功能不全的患者。

451号紫花苜蓿株行系鉴定试验

经引种筛选出适应性强、抗病性好的紫花苜蓿"盛世"为亲本材料,先选出31个优良植株,再经继代连续株选获得15个株系材料,通过设置株行系试验,采用判别分析、生产性能比较,筛选出综合性状优于亲本的451号品系7个,编号为1,2,3,4,5,6,11号;12月进入留种期至翌年5月中旬收种,未发现病害,产种后197 d内刈割5次,干草产量达到12 683.67 kg/hm2,所选株系抗逆性好,并具有高产性。

慢性心力衰竭患者行6分钟步行试验的综合护理干预

慢性心力衰竭患者行6分钟步行试验的综合护理干预。方法:对照组进行常规护理,观察组通过6分钟步行试验分级后按分级护理进行各阶段不同的综合护理干预。结果:经对比实验组心功能评分符合率较高,且实验组经此次治疗后疗效、再次入院率及患者总满意度均显著优于对照组(P<0.05)。

皖油27优质高产制种技术行比试验

该文阐述了皖油27优质高产制种技术的行比试验结果表明:父本:母本为1:5最佳高产制种行比。

不育系繁殖父母本行比试验初报

不育系繁殖随着行比的扩大,母本有效穗增加,在一定范围内单产也随之提高,但随着行比的进一步扩大,父本有效穗减少,母本结实率下降。为了确定适宜的行比,使母本有效穗和结实率均达到较大值,1992年我们在繁殖基地进行了行比试验。 1 试验材料和方法 1.1 供试材料:协青早A、B。 1.2 试验设计:共设五个处理,即父母本行比分别为Ⅰ(1:6)、Ⅱ(1:8)、Ⅲ(1:10)、Ⅳ(1:12)。

新型半主动悬挂系统装车试验结果分析

为研究改善高速列车乘坐舒适度,在山阳新干线500系电动车组上对新型半主动悬挂系统进行了走行试验。试验结果证实了其减振效果等于或高于现行半主动悬挂系统。

A coupled strain softening and hardening model for completely weathered granite in a fault zone

his study focused on exploring the specificity of mechanical behavior for completely weathered granite,as a special soil,by consolidated drained triaxial tests.The influences of dry density(1.60,1.70,1.80 and 1.90 g/cm^(3)),confining pressure(100,200,400 and 600 kPa),and moisture content(13.0%,that is,natural moisture content)were investigated in the present work.A newly developed Duncan-Chang model was established based on the experimental data and Duncan-Chang model.The influence of each parameter on the type of the proposed model curve was also evaluated.The experimental results revealed that with varying dry density and confining pressure,the deviatoric stress–strain curves have diversified characteristics including strain-softening,strain-stabilization and strain-hardening.Under high confining pressure condition,specimens with different densities all showed strain-hardening characteristic.Whereas at the low confining pressure levels,specimens with higher densities gradually transform into softening characteristics.Except for individual compression shear failure,the deformation modes of the specimens all showed swelling deformation,and all the damaged specimens maintained good integrity.Through comparing the experiment results,the strain-softening or strain-hardening behavior of CWG specimens could be predicted following the proposed model with high accuracy.Additionally,the proposed model can accurately characterize the key mechanical indicators,such as tangent modulus,peak value and residual strength,which is simple to implement and depends on fewer parameters.

《上海市人民政府关于由中国(上海)自由贸易试验区临港新片区管理委员会集中行使一批行政审批和行政处罚等事项的决定》的政策解读

为进一步促进临港新片区高质量发展,近日,市政府印发了《关于由中国(上海)自由贸易试验区临港新片区管理委员会集中行使一批行政审批和行政处罚等事项的决定》。现就有关内容解读如下:一、出台背景根据《中国(上海)自由贸易试验区临港新片区总体方案》《中国(上海)自由贸易试验区条例》《中国(上海)自由贸易试验区临港新片区管理办法》《关于促进中国(上海)自由贸易试验区临港新片区高质量发展实施特殊支持政策的若干意见》。

高空零压气球上升过程的运动特性研究

飞行在20km～100km高度的临近空间浮空器,在区域监视、侦查、应急通信与科学实验等领域具有独特的优势。高空零压气球是常见的临近空间浮空平台之一。对其上升过程运动特性的研究有利于增加驻空时间、减少横向漂移距离。文章通过建立零压气球充气量模型和气球上升过程中的动力学模型,对气球上升过程中动力学模型进行仿真分析,结合高空飞行试验数据,验证了所建模型的准确性。在模型的基础上对比了不同浮升气体对气球上升速度以及驻空高度的影响;研究了浮升气体充气量对载荷总量的影响,并分析了气球在上升过程中的体积变化以及驻空高度与浮升气体质量的关系,最后讨论了影响气球上升特性的关键因素。可以得到零压气球上升过程运动特性与浮升气体种类、充入气体量、气球规格、载荷质量有关,假设气球可无限膨胀不发生爆炸,浮升气体密度越小,充入气体量越多,载荷质量越轻,气球的驻空高度就越高,达平衡所需时间越少;实际工程应用中,气球受材料限制不可无限膨胀,面密度小的气球,可能在上升到驻空高度前发生爆炸,要使气球携带一定质量载荷在某一高度范围驻空,其充气量不能过多,需与一些物理量满足一定关系。

Research on Manipulation Strategy of Quad Tilt-Rotor

Aiming at the complex tilting process of quad tilt-rotor(QTR)transition mode,this paper studies the manipulation strategy in transition mode to solve the problem of manipulation redundancy and coupling in transition mode of quad tilt rotor.The variations of the manipulation derivative are analyzed in the tilting process.Through the flight control simulation and flight test of the quad tilt-rotor,the validity of the control system and the rationality of the manipulation strategy are verified.

The Nonlinear Interaction Process in the Wave Assimilation Model and Its Experiments

This paper presents a composite interaction formula based on the discrete-interaction operator of wave-wave nonlinear interaction for deriving its adjoint source function in the wave assimilation model. Assimilation experiments were performed using the significant wave heights observed by the TOPES/POSEIDON satellite, and the gradient distribution in the physical space was also analyzed preliminarily.

Designing similarity measurement with distance measure and application on laterally directional mode flight test

Similarity measure construction has been proposed as fault detection of flight test method in order to obtain the primary control surface stuck and the combination stuck of primary control.Similarity measures were obtained through analyzing the certainty and uncertainty of fuzzy membership functions,which were designed based on well-known Hamming distance.It was applied to the fault detection of primary control surface stuck of uninhabited aerial vehicle(UAV).At post-failure control surface,if the UAV is controllable and trimmable using other control surfaces,the UAV is able to fly or return to the safety region through reconfiguration of flight control system.To detect the fault,similarity measure computations were carried out.This result could be applicable with the real-time parameter estimation method.By monitoring the value of coefficients due to the control surface deviation,it becomes aware that the control surface fault occurs or not.The control surface stuck position and value were separated by comparing the trim value with the reference value.This is the advantage of increasing in reliability without adding sensors or with additional low cost.

LATERAL STABILITY VERIFICATION OF A CANARD AIRPLANE WITH AND WITHOUT A VERTICAL PANEL

The lateral stability of Velocity-173, canard-pusher type airplane, has been investigated with and without an extended vertical panel. It is well known that Velocity-173 has an excellent longitudinal stability but a relatively poor lateral stability. To improve the lateral stability, two types of composite sandwich panel have been designed and attached to the vertical tail of Velocity-173. A series of flight test has been performed to measure the effects of the extended vertical tail. Analytical methods, such as maximum likelihood estimation method and real-time parameter estimation method, have been used to extract lateral controllability/stability derivatives from flight test data. This work validates the effects of an extended panel to the lateral stability.

Serial observations on an orthotopic gastric cancer model constructed using improved implantation technique

AIM:To establish a gastric cancer nude-mouse model with improved orthotopic implantation and investigate its biological characteristics at different time points.METHODS:Human gastric cancer SGC-7901 cell suspensions were injected subcutaneously into a nude mouse to develop solid tumors,and the tumor tissue pieces were implanted under the serous coat.The nude mice were then euthanized in group every two weeks to observe the primary tumor growth and metastases.RESULTS:Within 2-4 wk,there were no obvious chang-es about the primary tumor in stomach.At the sixth week,the primary tumor began to grow fast,resulting in incrassation of the gastric wall and stenosis of the gastric cavity,and metastases into the liver and lymph nodes were detected.The tumor,which compressed the adjacent organs,gradually became bigger and bigger followed by stenosis or vanishment of the gastric cavity from 8 to 12 wk.There were massive metastases,and the rate of metastasis was 58%in lymph nodes,78%in liver,39%in kidney,and 81%in peritoneum or septum.CONCLUSION:A gastric cancer model is established,which can simulate the clinical tumor behavior and provide experimental carrier for clinical trials of gastric cancer treatment.

Simulation study of plane motion of air cushion vehicle

This research is on horizontal plane motion equations of Air Cushion Vehicle (ACV) and its simulation. To investigate this, a lot of simulation study including ACV's voyage and turning performance has been done. It was found that the voyage simulation results were accorded with ACV own characteristic and turning simulation results were accorded with USA ACV's movement characteristic basically.

Engineering behavior and sedimentation behavior of lead contaminated soil-bentonite vertical cutoff wall backfills

Soil-bentonite （SB） vertical slurry cutoff wall is a useful treatment for urban industrial contaminated sites. Due to the clay-heavy metal interaction, significant changes would occur in the engineering behavior of SB cutoff walls. However, previous study is limited to kaolinitic soils or montmorillonitic soils along using solidum chloride and/or calcium chloride as target contaminant. In this work, a series of oedometer tests were conducted to investigate the effects of lead （Pb） on the compressibility and the permeability of kaolin-bentonite （KB） mixtures, a simplified model of in-situ SB cutoff wall backfills. In addition, sedimentation tests were conducted to interpret the mechanism controlling the change of compressibility and permeability from the perspective of soil fabric. The Pb-contaminated KB mixtures for oedometer tests and sedimentation tests were prepared with bentonite contents of 0, 5%, 10%, and 15% by dry mass, and they were mixed with pre-determined volume of lead nitrate solution based on designed Pb concentration and solid-to-solution ratio. The Pb concentration was controlled as 0, 0.1, 0.5, 1.0, 5.0, 10, and 50 mg/g with a solid-to-solution ratio of approximate 0.5. The prepared KB mixtures with bentonite contents of 0, 5%, and 10% were chosen for the sedimentation tests. They were freeze-dried and mixed with DDI with a solid-to-solution ratio of 10 g/100 mL. The results indicate that pH, compressibility, and permeability of KB mixture changed considerably with respect to Pb concentration. It is concluded that the fabric of KB mixture, depending on the particle-particle interaction subjected to different ranges of pH and Pb concentration, governs the sedimentation behavior and permeability. The results of liquid limit （WE） cannot be explained in terms of the sedimentation behavior since it is only ionic-dependent.

Analytical model of shear mechanical behaviour of bolted rock joints considering influence of normal stress on bolt guide rail effect

Rock bolts have been widely used in slopes as a reinforcement measure.Modelling the shear mechanical behaviours of bolted rock joints is very complicated due to the complex factors that affect the axial force and shear force on the bolts.Rock bolts under shear action exhibit the guide rail effect;that is,the rock mass slides along the rock bolt as if the rock bolt is a rail.The normal stress can inhibit the guide rail effect and reduce the axial force on bolts.However,this factor is not considered by the existing analysis models.Shear tests of bolted joints under different normal stresses were carried out in the laboratory.During the test,the axial force on each point monitored on the bolt was recorded by a strain gauge,and the attenuation trend of the strain was studied.An analytical model that considers the inhibition of the bolt rail effect due to an increase in the normal stress was proposed to predict the shear mechanical behaviour of rock bolted joints.The new model accommodates the bolt shear behaviours in the elastic stage and plastic stage,and the estimated values agree well with the results of the direct shear tests in the laboratory.The validation shows that the proposed model can effectively describe the deformation characteristics of the bolts in the shear tests.

Post-fire cyclic behavior of reinforced concrete shear walls

The effects of fire exposure,reinforcement ratio and the presence of axial load under fire on the seismic behavior of reinforced concrete(RC) shear walls were investigated.Five RC shear walls were tested under low cyclic loading.Prior to the cyclic test,three specimens were exposed to fire and two of them were also subjected to a constant axial load.Test results indicate that the ultimate load of the specimen with lower reinforcement ratio is reduced by 15.8%after exposure to elevated temperatures.While the reductions in the energy dissipation and initial stiffness are 59.2%and 51.8%,respectively,which are much higher than those in the ultimate load.However,this deterioration can be slowed down by properly increasing reinforcement due to the strength and stiffness recovery of steel bars after cooling.In addition,the combined action of elevated temperatures and axial load results in more energy dissipation than the action of fire exposure alone.

Enrichment planting in a logged-over tropical mixed deciduous forest of Laos

Enrichment planting is commonly used for increasing the density of desired tree species in secondary forests often characterized by a prevalence of low commercial species. The objectives of the study were to identify the optimal enrichment planting method vis-à-vis gap and line planting, and to evaluate the performance of two dipterocarps （Vatica cinerea and Dipterocarpus alatus） and three legumes （Afzelia xylocarpa, Pterocarpus macrocarpus, Dalbergia cochinchinensis） planted in logged-over mixed deciduous forest of Laos. The enrichment planting trial was arranged in a randomized complete block design with seven replica-tions. Survival, height and diameter were measured seven years after planting and subjected to analysis of variance. Survival rate of planted seedlings did not vary between enrichment planting （p 0.05）. However, diameter and height growth was favored more in gaps than in planting lines. This was related to rapid canopy closure in both gaps and lines, albeit more remarkable in planting lines. Significant inter-species varia-tion was detected for survival rate, height and diameter. The shade-tolerant dipterocarps had better survival and growth than the light-demanding leguminous species （p 0.0001）. The size class distribution of individuals was irregular, accentuating uneven light condition in the understory. Given the difficulty to maintain constant line width and even light condi-tion, the cost of annual clean operation and the rigid geometric patterns of planting lines, the use of logged-over gaps for enrichment planting is recommended. Dipterocarpus alatus and V. cinerea are recommended for enrichment planting in mixed deciduous forests. A. xylocarpa, D. cochi-chinensis and P. macrocarpus can be planted in wider gaps, lines and open sites as plantation of mixed species or under canopy of young swidden forests.