Aeroelastic modeling of wind loading on a cable-net supported glass wall

Wind loading study on a cable-net supported glass wall is conducted by means of wind tunnel tests. An equiva- lent aeroelastic model is designed and constructed. Response of displacements of the wall is measured and analyzed. In order to design a glass wall under wind loading, the ＂wind- vibration factor＂ is estimated and discussed. In fact, the mech- anism of wind acting on the wall is commonly known not only as positive pressure, but also as negative pressure caused by the flow separation on the corners of the building. Due to the diffidence in the mechanism of wind acting, two typi- cal response cases are classified. The results show that the dynamic response of the structure caused by the negative pressure is stronger than that of the positive pressure case. To determine the aerodynamic wind loading on a flexible part of structure on a building, wind tunnel study may be useful and play an important role.

EXACT SOLUTION FOR RECTANGULAR SLAB WITH THREE EDGES SIMPLY-SUPPORTED AND OTHER FREE

In this paper,we give all-sided pastic analysis of the rectangular slab with three edges simply-supported and other free.Here we discuss the following four cases:(1)The uniformly distributedload over the area a slab.(2).A concentrated load act at midpoint of free edges slab.(3)A concen-trated load act at the center a slab.(4)The line load act along free edge of slab.

A Novel Way to Prepareγ-A1_2O_3 Supported SO_4^(2-)/ZrO_2 Solid Superacid Catalysts for n-Butane Isomerization

Highly active solid superacid catalysts for n-butane isomerization, SZ/A1_2O_3-P, were prepared by supporting SO-(4-2)/ZrO2, (SZ) on y-A1_2O_3 carrier using a precipitation method. The activities of some catalysts were enhanced significantly j The activity of the most active sample. 60%SZ/Al_2O3-P, was even about 2 times more active than that of the SZ catalyst.

NEW SOLID BASE DERIVED FROM AIPO4-5 SUPPORTED KF

Dispersion of KF on AlPO4-5 molecular sieve created basic sites and caused 1654 cm- band of bidentate carbonate in CO2 adsorption.After pre-treated above 823K. 5%KF/AlPO4-5exhibited basic catalytic activity in the isomerization of butenes at 273K. and the activity increasedwith the pre-treatment temperature up to 923K.

Iterative FEA Method for Load Distribution of Flexible Supporting Thin-section Ball Bearing

To figure out the load distribution of thin-section rolling bearing supported by flexible structure with squirrel cage and the distribution's influence on bearing life,an iterative FEA method is proposed to use the result calculated from the Quasi-Dynamic model based on the rigid support hypothesis. The contact angle,contact position and stiffness of equivalent spring are modified during the iterative FEA to optimize the FEA model,and then the bearings' life can be predicted when the error is below 0.5%. It can be concluded that from the analysis results the load distribution under flexible support is more uniform than that of the rigid support,while the maximum load decreases by 11.2% and bearing life increases by 14.7%. The analysis result of different values of thickness of bearing house,rings and hollow shaft demonstrates the thicknesses of bearing house and hollow shaft have a greater influence on the load's uniformity and bearing's life than those of the rings.

Effect of temperature difference load of 32 m simply supported box beam bridge on track vertical irregularity

In order to study the effect of temperature difference load （TDL） along the vertical direction of a simply supported beam bridge section on the vertical irregularity, a rail-bridge-piers calculation model was established. Taking 32 m simply supported box beam bridge which is widely used in the construction of pas- senger dedicated line in China as an example, influences of the temperature variation between the bottom and top of the bridge, temperature curve index, type of temperature gradient, and beam height on track vertical irregularity were analyzed with the model. The results show that TDL has more effects on long wave track irregularity than on short one, and the wavelength mainly affected is approxi- mately equal to the beam span. The amplitude of irregu- larity caused by TDL is largely affected by the temperature variation, temperature curve index, and type of temperature gradient, so it is necessary to monitor the temperaturedistribution of bridges in different regions to provide accurate calculation parameters. In order to avoid the irregularity exceeding the limit values, the height of 32, 48, and 64 m simply supported box beam bridges must not be less than 2.15, 3.2, and 4.05 m, respectively.

DEVELOPING EXPERT DECISION SUPPORT SYSTEM WTH VP-EXPERT AND LOTUS 1-2-3 IN RE-BLENDING BY USE

An expert decision support system (EDSS) for multi-bins balance and contro1 of orequality in production ore bins of some large-scale open pit iron mine in China has been developed byexpert svitem tool software VP-EXPERT and integration software LOTUS 1-2-3 in this paper. Itis known by practicing that a medium-scale EDSS constructed on microcomputer is completcly, feaasible by means of VP-EXEPERT to construct knowledge base system (KBS), LOTUS 1-2-3 tomake decision support system (DSS) and link them with BAT.

基于整体-局部技术的鼠笼式弹性支承疲劳强度分析

基于M sc.Patran/Nastran有限元分析软件,使用从整体到局部的有限元分析方法,对某型航空发动机减振用鼠笼弹性支承进行了疲劳强度分析。该分析方法克服了传统方法中对有限元模型的规模与精度难以兼顾的缺点,为分析工程中复杂构件的强度提供了1条新的思路。

笼形聚肟偕亚氨二乙酸钒(Ⅳ)-硫脲体系引发丙烯腈聚合的研究

研究了笼形聚肟偕亚氨二乙酸钒(CPV)-硫脲(TU)体系在硝酸溶液中引发丙烯腈(AN)聚合反应.表观聚合速度(R_P)是 R_P=1.0×10~8e^(-10.500/RT)[AN]^(1.0)[CPV]^(1.0)[TU]^(1.5)[HNO_3]^(3.0) 聚合诱导期(τ)随反应温度和物料浓度发生变化,可表示为 1/τ=5.2×10~9e^(-12.800/RT)[AN]~1.0[CPV]~1.0[TU]~1.5[HNO_3]~3.0实验结果表明,聚合反应以单基终止为特征,可能是和高分子载体较大的空间位阻有关.

Yield Increasing and Quality Improving Effects of Smash-ridging Method("4453" Effects) and Its Potential in Benefiting the Nation and the People

Yuan Longping proposed that smash-ridging technology could be extend-ed widely nationwide. ln the research, smash-ridging technology reconstruct cultiva-tion layers with loose soils in agricultural fields, creating ＂4453＂ effects, as fol ows： ＂Four increases＂ include to increase loosen soil quantity in cultivation layers, soil nutri-ents use, ＂water pool＂ in soils, and ＂oxygen pool＂ in soils. Four reductions are to reduce soil erosion, carbon emission, salt content and heavy metal in soils. Five resistances refer to improve crop resistance capacity in terms of drought, high tem-perature, lower temperature, disease and lodging. Three improvements indicate to enhance photosynthetic efficiency over 10%, yield in 10%-30% and quality over 5%. lt is researched that without additional chemical fertilizer, yield could increase by 10% by labor force, animal, tractor or smash-ridging machine. What’s more, by smash-ridging cultivation, the depth can be 20 times or higher compared with tractor cultivation, with looser soils. lt is estimated that if smash-ridging cultivation is applied once in agricultural lands in China, present soil layers can be twice as deep as present. Specifical y, the thickness of loose soil-layers could be extended from 10-18 cm at present to 25-35 cm, and natural rainfal would increase by 40 bil ion cm3. After vitalization of soil nutrients, chemical fertilizer would decrease by 7 bil ion kg, and the increased c rops would feed more than 300 mil ion population as per yield at 7 50 kg/hm2.

Key technologies and equipment for a fully mechanized top-coal caving operation with a large mining height at ultra-thick coal seams

Thick and ultra-thick coal seams are main coal seams for high production rate and high efficiency in Chinese coal mines, which accounts for 44 % of the total minable coal reserve. A fully mechanized top-coal caving mining method is a main underground coal extraction method for ultra-thick coal seams. The coal extraction technologies for coal seams less than 14 m thick were extensively used in China. However, for coal seams with thickness greater than 14 m, there have been no reported cases in the world for underground mechanical extraction with safe performance, high efficiency and high coal recovery ratio. To deal with this case, China Coal Technology ＆ Engineering Group, Datong Coal Mine Group, and other 15 organizations in China launched a fundamental and big project to develop coal mining technologies and equipment for coal seams with thicknesses greater than 14 m. After the completion of the project, a coal extraction method was developed for top-coal caving with a large mining height, as well as a ground control theory for ultra-thick coal seams. In addition, the mining technology for top-coal caving with a large mining height, the ground support technology for roadway in coal seams with a large cross-section, and the prevention and control technology for gas and fire hazards were developed and applied. Furthermore, a hydraulic support with a mining height of 5.2 m, a shearer with high reliability, and auxiliary equipment were developed and manufactured. Practical implication on the technologies and equipment developed was successfully completed at the No. 8105 coal face in the Tashan coal mine, Datong, China. The major achievements of the project are summarized as follows： 1. A top-coal caving method for ultra-thick coal seams is proposed with a cutting height of 5 m and a top-coal caving height of 15 m. A structural mechanical model of overlying strata called cantilever beam-articulated rock beam is established. Based on the model, the load resistance of the hydraulic support with a large mining height for top-coal caving method is determined. With the analysis, the movement characteristics of the top coal and above strata are evaluated during top-coal caving operation at the coal face with a large mining height. Furthermore, there is successful development of comprehensive technologies for preventing and controlling spalling of the coal wall, and the top-coal caving technology with high efficiency and high recovery at the top-coal caving face with a large mining height. This means that the technologies developed have overcome the difficulties in strata control, top-coal caving with high efficiency and high coal recovery, and enabled to achieve a production rate of more than 10 Mtpa at a single top-coal caving face with a large mining height in ultra-thick coal seams; 2. A hydraulic support with 5.2 m supporting height and anti-rockburst capacity, a shearer with high reliability, a scraper conveyor with a large power at the back of face, and a large load and long distance headgate belt conveyor have been successfully developed for a top-coal caving face with large mining height. The study has developed the key technologies for improving the reliability of equipment at the coal face and has overcome the challenges in equipping the top-coal caving face with a large mining height in ultra-thick coal seams; 3. The deformation characteristics of a large cross-section roadway in ultra-thick coal seams are discovered. Based on the findings above, a series of bolt materials with a high yielding strength of 500-830 MPa and a high extension ratio, and cable bolt material with a 1 × 19 structure, large tonnage and high extension ratio are developed. In addition, in order to achieve a safe roadway and a fast face advance, installation equipment for high pre-tension bolt is developed to solve the problems with the support of roadway in coal seams for top-coal caving operation with a large mining height; 4. The characteristics of gas distribution and uneven emission at top-coal caving face with large mining height in ultra-thick coal seams are evaluated. With the application of the technologies of gas drainage in the roof, the difficulties in gas control for high intensive top-coal caving mining operations, known as ＂low gas content, high gas emission＂, are solved. In addition, large flow-rate underground mobile equipment for making nitrogen are developed to solve the problems with fire prevention and safe mining at a top-coal caving face with large mining height and production rate of more than 10 Mtpa. A case study to apply the developed technologies has been conducted at the No. 8105 face, the Tashan coal mine in Datong, China. The case study demonstrates that the three units of equipment, i.e., the support, shearer and scraper conveyor, are rationally equipped. Average equipment usage at the coal face is 92.1%. The coal recovery ratio at the coal face is up to 88.9 %. In 2011, the coal production at the No. 8105 face reached 10.849 Mtpa, exceeding the target of 10 Mtpa for a topcoal caving operation with large mining height performed by Chinese-made mining equipment. The technologies and equipment developed provide a way for extracting ultra-thick coal seams. Currently, the technologies and equipment are used in 13 mining areas in China including Datong, Pingshuo, Shendong and Xinjiang. With the exploitation of coal resources in Western China, there is great potential for the application of the technologies and equipment developed.

Real-time crash prediction on freeways using data mining and emerging techniques

Recent advances in intelligent transportation system allow traffic safety studies to extend from historic data-based analyses to real-time applications. The study presents a new method to predict crash likelihood with traffic data collected by discrete loop detectors as well as the web-crawl weather data. Matched case-control method and support vector machines （SVMs） technique were employed to identify the risk status. The adaptive synthetic over-sampling technique was applied to solve the imbalanced dataset issues. Random forest technique was applied to select the contributing factors and avoid the over-fitting issues. The results indicate that the SVMs classifier could successfully classify 76.32% of the crashes on the test dataset and 87.52% of the crashes on the overall dataset, which were relatively satisfactory compared with the results of the previous studies. Compared with the SVMs classifier without the data, the SVMs classifier with the web-crawl weather data increased the crash prediction accuracy by 1.32% and decreased the false alarm rate by 1.72%, showing the potential value of the massive web weather data. Mean impact value method was employed to evaluate the variable effects, and the results are identical with the results of most of previous studies. The emerging technique based on the discrete traffic data and web weather data proves to be more applicable on real- time safety management on freeways.

鼠笼弹支-金属橡胶阻尼器刚度阻尼优化设计

将一种鼠笼弹支-金属橡胶阻尼器装置应用于磁悬浮转子系统振动的抑制。基于有限元分析软件ANSYS Workbench的Design Exploration模块,以系统的不平衡响应为目标函数,利用多目标遗传算法对该装置的刚度阻尼进行优化设计。从仿真结果来看,优化后的阻尼器装置使转子系统平动及一弯振幅分别降低60.1%,41.2%,可以有效抑制系统振动。

Stable CuO/La_(2)Sn_(2)O_(7) catalysts for soot combustion:Study on the monolayer dispersion behavior of CuO over a La_(2)Sn_(2)O_(7) pyrochlore support

To understand the dispersion behavior of metal oxides on composite oxide supports and with the expectation of developing more feasible catalysts for soot oxidation,CuO/La_(2)Sn_(2)O_(7)samples containing varied CuO loadings were fabricated and characterized by different techniques and density functional theory calculations.In these catalysts,a spontaneous dispersion of CuO on the La_(2)Sn_(2)O_(7)pyrochlore support formed,having a monolayer dispersion capacity of 1.90 mmol CuO/100 m^(2) La_(2)Sn_(2)O_(7)surface.When loaded below this capacity,CuO exists in a sub-monolayer or monolayer state.X-ray photoelectron spectroscopy(XPS),Raman spectroscopy,and Bader charge and density of states analyses indicate that there are strong interactions between the sub-monolayer/monolayer CuO and the La_(2)Sn_(2)O_(7)support,mainly through the donation of electrons from Cu to Sn at the B-sites of the structure.In contrast,Cu has negligible interactions with La at the A-sites.This suggests that,in composite oxide supports containing multiple metals,the supported metal oxide interacts preferentially with one kind of metal cation in the support.The Raman,in situ diffuse reflectance infrared Fourier transform spectroscopy,and XPS results confirmed the formation of both O2^(-)and O2^(2-)as the active sites on the surfaces of the CuO/La_(2)Sn_(2)O_(7)catalysts,and the concentration of these active species determines the soot combustion activity.The number of active oxygen anions increased with increase in CuO loading until the monolayer dispersion capacity was reached.Above the monolayer dispersion capacity,microsized CuO crystallites formed,and these had a negative effect on the generation of active surface oxygen sites.In summary,a highly active catalyst can be prepared by covering the surface of the La_(2)Sn_(2)O_(7)support with a CuO monolayer.

鼠笼式弹性支承-圆柱滚子轴承-转子系统振动分析

考虑圆柱滚子轴承非线性接触力、保持架能量、鼠笼刚度、转子不平衡以及它们之间的力学耦合关系,基于拉格朗日方程建立鼠笼式弹性支承-圆柱滚子轴承-单转子系统动力学分析模型,结合龙格库塔数值积分方法,并对该模型动力学仿真分析,分析了不同转速区域鼠笼式弹性支承-滚动轴承-转子系统振动响应的分岔特性,结果表明:两支点的鼠笼式弹性支承-圆柱滚子轴承-单转子系统受到组合支承非线性支承力的激励作用下,呈现丰富多样的运动周期变化,相比于高转速区域的系统振动响应,低转速区域的系统振动响应混沌现象更易出现。高转速区间可以对系统建模分析进行线性近似处理,更方便地对系统振动进行控制与优化。

隧道管棚支护承载特性及支护参数试验研究

为探究隧道管棚注浆钢管不同支护参数对管棚支护承载能力的影响,引入Pasternak双参数模型构建出更符合实际情况的管棚支护力学模型,通过多组室内试验,对管棚在不同注浆钢管管径、壁厚、注浆饱满度及加设钢筋笼条件下的承载能力进行定量研究。研究表明:1)管棚注浆钢管支护参数中,对管棚承载能力的影响排序为:管径>注浆饱满度>壁厚>钢筋笼。2)增大管棚注浆钢管管径可大幅提高管棚的承载能力,相比管径为108 mm的管棚,管径为159、219、299 mm时管棚承载能力分别增大183.58%、398.62%、874.86%。3)管棚钢管注浆不饱满会较大程度削弱管棚的承载能力,钢管注浆饱满度由100%降至75%、50%时,管棚承载能力分别降低29.8%、34.5%,注浆饱满度为50%时管棚的承载能力与未注浆时相差不大。4)管棚钢管壁厚和钢筋笼加设与否对管棚的承载能力影响较小。因此,在实际工程中,可通过增大管棚钢管管径提升管棚的承载能力,通过减小管棚钢管壁厚及不加设钢筋笼节约用钢量。

Formation of Hybrid Ring Structure of Cyanurate/Isocyanurate in the Reaction be-tween 2,4,6-Tris(4-Phenyl-Phenoxy)-1, 3,5-Triazine and Phenyl Glycidyl Ether

Reaction products of 2,4,6-tris(4-phenyl-phenoxy)-1,3,5-triazine derived from 4-phenylphenol cyanate ester and phenyl glycidyl ether were analyzed. In addition to an isocyanurate compound and an oxazolidone compound which were well known as reaction products of cyanate esters and epoxy resins, compounds with hybrid ring structure of cyanurate/isocyanurate were determined. Gibbs free energies of the compound having hybrid ring structure of cyanurate/isocyanurate with two isocyanurate moiety were found to be lower than that of the compound with cyanurate ring structure through calculations. Calculation data supported the existence of hybrid ring structure of cy-anurate/isocyanurate. It was revealed that isomerization from cyanurate to isocyanurate occurs via hybrid ring structure of cyanurate/isocyanurate in the reaction of aryl cyanurate and epoxy.

Shape optimization of 3D curved slots and its application to the squirrel-cage elastic support design

The squirrel-cage elastic support is one of the most important components of an aero-engine rotor system.A proper structural design will favor the static and dynamic performances of the system.In view of the deficiency of the current shape optimization techniques,a new mapping approach is proposed to define shape design variables based on the parametric equations of 3D curves and surfaces.It is then applied for the slot shape optimization of a squirrel-cage elastic support.To this end,an automatic design procedure that integrates the Genetic Algorithm (GA) is developed to solve the problem.Two typical examples with different shape constraints are considered.Numerical results provide reasonable optimum designs for the improvement of stiffness and strength of the squirrel-cage elastic support.

西安国家版本馆隔震建筑施工技术的研究与应用

针对传统隔震支座施工工艺工效低、施工缓慢且质量难以达标的问题,论文对隔震支座的关键施工技术进行了深入分析,并提出了一种新型施工方法。该方法通过运用标准化、工具化的工艺技术路径以及建筑信息模型软件,实现了隔震支座的高效和高精度施工。工程应用实例表明,所提隔震支座施工方法的效果达到了单体水平度小于1.5 mm,整层小于3 mm,远优于国家标准。这一研究结果有望应用于解决隔震支座高精度快速施工的难题,进而推动隔震建筑的发展。

核电站带支撑笼架的钢衬里模块吊装研究

结合某核电站机组安全壳钢衬里模块吊装工程,研究支撑笼架与环向钢筋对钢衬里模块整体吊装的影响。论文介绍钢衬里模块的概况,分析介绍吊索具方案,通过有限元软件进行建模分析4种工况下钢衬里模块及环形吊具的应力应变。结果显示,增加支撑笼架与环向钢筋对钢衬里模块整体吊装是有利的。