Nonlinear Seismic Response Analysis of Long- span CFST Arch Bridge

The non-linear seismic response behavior of concrete filled in steel tube(CFST) arch bridge subjected to synchronous seismic excition and multi-support seismic excitation is studied in this paper.The non-linear seismic response of CFST arch bridge is calculated by time-history analysis method,and the effect of geometric nonlinear to long-span CFST arch bridge is studied.The influence of internal-force and deformence under dead-load,multi-support seismic excitation,etc to nonlinear seismic response behavior of CFST arch bridge is analysed.The result show that the effect of geometric nonlinear to long-span CFST arch bridge is obvious.     

Operational Bridge Responses due to Road Surface Profile Spectral Excitations

Random spectrum excitation samples of a road surface profile are investigated. The displacements, velocities, accelerations of a vehicle and a bridge structure are discussed using certain samples. The road excitations are numerically simulated by the random phase cosine method of the power spectral density. The vehicle bridge system responses are obtained using the vehicle bridge differential equations for different road surface profiles. It is concluded that the random phase has critical effects on the road surface profile curve shape, and the power spectral density on the curve value. The random samples possesses the same statistical characteristics. The system response values are affected more by the road surface profiles, and the response shapes are affected more as the vehicle velocity varies. Some engineering advice is proposed based on the numerical calculation with the different random excitation inputs for their significant differential responses.     

Response Spectrum Method for Seismic Response Calculation of Pipeline System Multiply Supported on Structures

In order to ensure the function of building in the earthquake, reduce economic losses and facilitate post-disaster relief, it is necessary to accurately evaluate the seismic performance of pipeline system on the structure under seismic excitation. Considering this practical need, seismic response calculation methods of piping systems on structures were systematically studied. Firstly, theoretical derivation was performed based on the pseudo-excitation method for seismic response of pipeline system. It is found that the formula in previous studies has obvious defect: the accurate relative displacement values of degree of freedom near the supports can not be obtained in the formula. Thereby, the theoretical basis for derivation was mended to correct the defect, and the uniform combination expressions available for pipeline's seismic response calculation which is in the form of ground response spectrum or floor response spectrum were presented. Moreover, the simplified formulas and calculation method of correlation coefficients in the obtained expressions were put forward according to the assumption of white noise earthquake excitation. Finally, case studies were adopted to verify the proposed method's effectiveness and applicability in the seismic response calculation of pipeline system.     

刚性连体位置对非对称双塔连体结构动力可靠度的影响

考虑地震动的非平稳性,变化连体位置,对非对称双塔连体结构运用虚拟激励法进行非平稳随机激励下的动力可靠度研究。采用刚度退化的Bouc-Wen模型模拟塔楼各楼层的滞变特性,建立非线性化动力方程。运用混合精细积分法对每一时刻的响应进行求解,得到连体位置变化时非对称连体结构在非平稳随机激励下的时变方差。基于首次超越破坏准则与Markov假定,研究非平稳随机地震激励下连体结构的动力可靠度。运用上述理论,在8度罕遇地震作用下对某非对称双塔连体结构进行随机地震响应与动力可靠度分析。研究结果表明,地震作用下结构的层间位移响应呈现强烈的非平稳性,变化连体位置对连体结构的随机地震响应与动力可靠度将产生显著影响。     

Wind-induced Response Analysis on a Large-span Membrane Roof by Considering Non-gaussian Stochastic Wind Pressure Field

The stochastic fluctuating wind pressure field acting on a large-span membrane roof consists of Gaussian and non-Gaussian regions in the sense of statistics. Simulation of this stochastic field is presented based on the zero memory nonlinearity (ZMNL) transformation method. A case study is then given to show that the stochastic wind pressure field samples generated by the proposed method can well represent the specified statistical characteristics of data from the wind tunnel experiment. After that, the wind-induced response analysis is conducted on a membrane roof structure using the Gaussian/non-Gaussian composed wind pressure field samples generated by the proposed method and the Gaussian samples by the traditional method, respectively. Results indicate that response values of some components of the structure induced by the Gaussian samples are lower than those by the Gaussian/non-Gaussian composed wind pressure samples, which means the non-Gaussian characteristics of the stochastic wind pressure should not be ignored. Meanwhile, the total gust response factors of the components caused by the wind excitation are given to meet with the requirement of the designers.     

Analysis of Seismic Dynamic Responses of Tunnel throughFault Zone in High Earthquake Intensity Area

Based on dynamic time history analysis, dynamic response behavior of an un supported tunnel through fault zone which was simulated by interface and solid elements was studied under uniform input earthquake wave excitation. The analyses of response behaviors, including displacement difference, acceleration magnification, and plastic zones and so on, were carried out when earthquake wave excitation was input along transverse, longitudinal and vertical of tunnel respectively. The results show that simulation method for fault zone is effective; the earthquake causes obvious displacement difference at fault zone and surrounding rock contacting part. The maximal displacement difference reaches to 51.8mm under transverse uniform input earthquake wave excitation. And the displacement difference under vertical and longitudinal is only 44.3% and 23.1% of the transverse value, respectively; the acceleration magnification in fault zone is significantly greater than that in surrounding rock. Shear failure zone appears at the fault zone and surrounding rock contacting part, and it is especially prominent under input longitudinal earthquake wave excitation. It is proposed that fault zone has significantly influence on the dynamic performance of tunnel. The fault zone and the transitional zones are the control zones of seismic design when tunnel passes through fault zone, thus, the study on the anti seismic measures should be further strengthened.     

Analysis and test on vibration and acousticnoise of GWC6066 marine gearbox

The mesh stiffness of gear tooth is simulated by spring elements, the connected bolt between various housings are simplified as bar elements, and the sliding bearing and rolling bearing are simplified as spring dumping elements. Based on them, the gear-shaft-bearing-housing coupled finite element model and boundary element model of GWC6066 marine gearbox are established. Finally, the dynamic response under internal dynamic excitation is analyzed and the vibration severity, structural-borne noise and air-borne noise of the gear system are forecasted. Through the experimental modal analysis of gear system, and the test of vibration response and air pressure, the natural frequencies, vibration severity, structural-borne noise and air-borne noise are obtained. Compared with numerical results, two results show good agreement.     

Numerical simulation of dynamic response and radiation noise of gearbox

Considering the internal dynamic excitation produced by stiffness excitation, error excitation and mesh impact excitation, a dynamic finite element model of transmission system and structure system of gearbox is established. The normal mode and the dynamic responses of gearbox under the internal dynamic excitation are calculated by using the numerical simulation software ANSYS. Based on the result of dynamic responses, the boundary excitation condition is determined, and then the acoustic boundary element model is built. With the software of SYSNOISE, the surface acoustic pressure of gearbox and the radiation noise of field points are solved by the direct boundary element method. The test of airborne noise is carried out. The computational results obtained are in a good agreement with the data of experimental test.     

Wind Vibration Analysis on the Large -span Curtain Wall

The large-span structure requires wind vibration analysis when computing the wind load;however,the formula in current code on wind vibration coefficient can hardly be applied in large-span structure,making its computation difficult and troublesome.This paper makes wind vibration analysis on the large-span curtain wall combined with certain engineering background in the methods of both time domain and frequency domain,and then the derived results are compared.The analytical results demonstrate identical distribution and contiguous numerical value of wind vibration coefficient concluded from the two varied methods;furthermore,even if the method in time domain is higher in computational complexity,more data on the response of structure under wind can be obtained,which provides reference for the theoretical analysis and engineering design.     

Self Excitation Simulation for Hydro-Synchronous Generators

The capacity,voltage,and length of modern electric power system are increasing ceaselessly.Synchronous generators will cause self excitation with the help of armature reaction,its stator current and voltage will increase.The self excitation conditions and the transient process are two aspects for studying self excitation.Now,self excitation conditions are mathematical formulas under certain postulate.The model of transient process of self excitation is linear.The conditions of self excitation are presented based on simulation,and the results of self excitation effected by the electromagnetic parameters of hydro generators operating extra high voltage long transmission line are simulated,based on a saturation model of hydro generators.The conclusions are very helpful for operation and design of hydro generators.     

小冰麦(Triticum aestivum -Agropyron intermedium)对盐胁迫和碱胁迫的生理响应

将两种中性盐（NaCl和Na₂SO₄）和两种碱性盐（NaHCO₃和Na₂CO₃）按摩尔质量比1∶1混合,在60~300 mmol L^-1盐浓度内模拟出5种强度的盐胁迫条件,在30~180 mmol L^-1盐浓度内模拟出6种强度的碱胁迫条件,并以此对小冰麦苗胁迫处理12 d。测定相对生长率（RGR）、含水量、丙二醛（MDA）、电解质外渗率、叶绿素、类胡萝卜素6项胁变指标和Na⁺、K⁺、脯氨酸、甜菜碱、有机酸5种溶质含量。结果表明,碱胁迫下小冰麦的各项胁变反应均明显大于盐胁迫下。在本试验条件下,小冰麦可耐受的最高盐胁迫浓度为300 mmol L^-1,而碱胁迫仅为150 mmol L^-1。碱胁迫造成小冰麦光合色素含量急剧下降,可能是其危害甚于盐胁迫的原因之一。碱胁迫下有机酸大量积累可能是小冰麦响应碱胁迫的特殊生理机制。试验结果证明盐、碱胁迫是两种性质不同的胁迫,不仅对植物的作用机制不同,而且植物的适应机制也不同。     

The influence of nitrogen and phosphorous status on glyphosate hormesis in Lemna minor and Hordeum vulgare

The herbicide glyphosate has been shown to stimulate growth and photosynthetic capacity of barley and other plant species. The growth increase, however, only takes place under certain, yet undefined, growth conditions. We hypothesise that glyphosate growth stimulation only takes place, when growth is nutrient limited. Nutrient limitation was induced in this study by limiting nitrogen and phosphorous availability. The experiments were performed on hydroponically grown lesser duckweed and barley and on barley in the field. Hydroponic duckweed and barley grown under a range of N- and P-availabilities displayed glyphosate induced growth increases in plants which were slightly stressed by N-deficiency, but not in response to P-deficiency in the case of barley. The growth increase found for P-deficient duckweed was hypothesised to be caused by glyphosate derived P, acting as a nutrient source. No growth increase was found in the 2012 field experiment, which was in contrast to earlier year’s findings. Our hypothesis that nutrient limitation makes plants susceptible to glyphosate induced growth was only confirmed for nitrogen but not for phosphorous and not under field conditions in 2012. Mechanisms related to high C:N ratios might be of importance, as this trait varies depending on N- and P-availability during plant growth.     

Seismic Responses of Cylindrical Reticulated Mega-structure under Traveling Wave Excitations

Considering the significant influence of spatial correlation in long-span spatial structures, seismic response analyses of traveling wave excitations in cylindrical reticulated mega-structure were conducted under one-dimensional and multidimensional severe earthquake by using dynamic time-history method. Elastoplastic displacement and stress, stress range, distribution and development of yield members of the structure under traveling wave excitations were researched via inputting horizontal transverse wave and longitudinal wave separately firstly. Then traveling wave effects of the structure were studied under different dimensional earthquake inputting and different spans. It is shown that the response effects under traveling wave excitations differ from that under simple support excitations and the diversity changes under different earthquake inputting and different span, which proves that the effect of traveling wave excitations should be taken into account under different earthquake inputting in long-span spatial structures.     

甜菜M14品系BvM14-Dof3.4基因的克隆及响应盐胁迫表达分析

为进一步研究BvM14-Dof3.4基因响应盐胁迫的功能,以甜菜M14品系根为材料,通过PCR技术获得BvM14-Dof3.4基因cDNA全长序列并进行生物信息学以及盐胁迫应答分析。结果表明：该基因最大ORF为408 bp,编码135个氨基酸,蛋白分子量为12646.63 Da,理论等电点为4.68,为亲水性蛋白;BvM14-Dof3.4蛋白质二级结构和三级结构主要由延伸链和无规卷曲组成;BvM14-Dof3.4蛋白氨基酸序列与NCBI数据库中甜菜(Beta vulgaris)的氨基酸序列相似度为99.26%;系统进化分析表明BvM14-Dof3.4蛋白与菠菜(Spinacia oleracea)Dof3.4蛋白亲缘性较高。结合实验室前期盐胁迫下甜菜M14品系根的转录组数据分析,BvM14-Dof3.4基因参与甜菜M14品系应答盐胁迫过程,在200 mmol/L NaCl处理下上调2.05倍,在400 mmol/L NaCl处理下上调1.41倍。实验成功获得BvM14-Dof3.4基因cDNA全长,并确定该基因响应盐胁迫,该结果对挖掘甜菜M14品系优质基因和提高栽培甜菜抗逆性等方面具有重要意义,为后续进一步开展BvM14-Dof3.4基因响应盐胁迫功能研究提供参考。     

生物炭的施入对Cr(Ⅵ)胁迫条件下玉米幼苗的生理响应及铬吸收的影响

为了研究生物炭的施入对Cr(Ⅵ)胁迫条件下玉米幼苗的生理响应及铬吸收的影响。以玉米为供试作物,试验设5个处理,测定了玉米苗的地上和地下生物量,叶片丙二醛含量、脯氨酸含量、可溶性糖含量、可溶性蛋白含量、超氧化物歧化酶活、过氧化物酶活、过氧化氢酶活等生理生化指标,并测定了玉米根系、地上部分的Cr含量。试验结果表明:在Cr(Ⅵ)胁迫条件下,地上部分鲜重相对于CK1增幅分别为12.73%、32.73%、38.40%,其中BC450、BC600处理相对于CK1达到显著性差异(P<0.05);BC600处理根系铬含量仅为1.258 mg/kg,相对减少铬吸收量65.75%,同时地上部分铬含量仅为0.36 mg/kg;丙二醛、脯氨酸、CAT酶活、POD酶活、SOD酶活等指标随明显增加(P<0.05);其中BC600的处理相对于铬胁迫CK1明显降低丙二醛、脯氨酸含量、POD、CAT、SOD酶活(P<0.05),而使可溶性蛋白、可溶性糖含量明显增加(P<0.05)。通过综合评定,施用生物炭处理,玉米苗期受到的Cr(Ⅵ)胁迫程度低于对照,生物炭对Cr(Ⅵ)具有一定的固定效应,其中BC600处理最为明显。     

Accelerated recurrent selection

In Accelerated Recurrent Selection (ARS) schemes, selection is based on the predicted performance of progeny families, estimated as the average of the parental families. These schemes can halve cycle time compared to simple recurrent selection methods. They also have a lower requirement for evaluation of families in yield trials, although they do require more seed production. ARS therefore provides options in cycle time, effective population size, response to selection and cost which have not been available before. Example schemes are compared by computer simulation with truncation selection and with optimal family selection, where contributions of families to the next generation are optimised to give the maximum response to selection at a specified effective population size. In many circumstances, ARS schemes compare favourably. Difficulties in combining estimates of selection intensity and of effective population size when comparing the merits of different breeding schemes are discussed. It is suggested that unless one is interested in response to selection over periods greater than 50 years, the weight given to effective population size in ranking different schemes should be small.     

密植条件下4个春玉米品种物质生产性能对施氮水平的响应

为了探讨密植条件下春玉米物质生产性能对氮肥水平的响应,为研究区高产高效的氮素养分管理提供理论指导,于2012年在内蒙古民族大学试验农场,在8.25万株/hm2的密度下,研究了不同施氮水平下4个当地主推高产春玉米品种的物质生产性能。结果表明,4个品种的产量均以N2(300 kg/hm2)处理下最高,这一施氮水平下‘伟科702’、‘先玉335’、‘郑单958’和‘金山27’分别较各自N0(CK)增产25.9%、24.8%、14.1%和11.1%。4个品种的叶面积指数和光合势均随施氮水平的增加而增加,均随生育进程的推移呈单峰曲线变化;干物质最大积累速率和最大积累量以N2处理下最大,CK最低。同一品种不同施氮水平下,经济系数均以N2处理下最大;同一施氮水平下,各品种的经济系数以‘伟科702’最大。     

Method for Calculating Steady Vibration Response of Shafting with Local Nonlinearity

A method which is used for calculating steady vibration response of shipping propulsion shafting connecting with a coupling with nonlinear hysteresis characteristics are studied. On condition that the nonlinear dynamic stiffness and hysteresis damping of the coupling be considered, on the basis of GLM(Galerki Levenberg Marquard) method, a method called SSGILM(Separate System Galerkin and Improved Levenberg-Marquardt)to be used for calculating steady vibration response of propulsion shafting with local nonlinear dynamic stiffness and hysteresis damping, is proposed. A simple example is given out and the analyses show that it is effective to calculate steady vibration response of the shafting with local nonlinear dynamic stiffness and hysteresis damping by SSGILM method. From initial response values given arbitrarily, the automatic search algorithm in SSGILM method can converge the given initial response values to the response values accorded with required accuracy quickly; nonlinear dynamic stiffness and hysteresis damping of the coupling have different effect on vibration response of the shafting at different range of frequency. At the area of close nature frequency of the shafting ,displacement amplitude of the shafting is bigger. Beyond the range, the characteristics of the coupling have restraint effect on vibration of the shafting.     

Farquhar模型在覆盖措施下春小麦光合光响应曲线分析中的应用

采用Farquhar数学模型对3种覆盖措施下春小麦的光响应曲线进行了模拟分析,并计算了不同覆盖措施下春小麦光合特征参数。模拟结果显示：RMSE的变化范围为0.29~0.59,R²的变化范围为0.99,拟合效果极佳。春小麦光合特征参数显示,地膜覆盖措施较其他覆盖措施更有利于提高春小麦的最大净光合速率,且具有最高的光饱和点和较低的光补偿点,并使春小麦暗呼吸速率消耗减小,是春小麦光合产量累积的最佳种植方式。     

离体胚培养途径探索东北刺人参种子的休眠原因

为深入探索东北刺人参（Oplopanaxelatus Nakai）种子休眠的原因,在WPM培养基上对经过不同处理的东北刺人参种子胚进行离体萌发试验.结果表明：由于胚乳的存在,即使种胚已经完成了形态后熟,胚仍然不能萌发;种子胚在尚未分化完全时处于休眠状态,在离体条件下不能萌发;当胚完成分化以后,胚本身不是休眠的,在适宜的离体条件下能正常萌发,而且胚发育越接近成熟其萌发力就越强.在一定的范围内,外源激素对离体胚萌发有促进作用.