Analysis of Elevated Structure Radiated Noise with BEM-FEM Method     

GAO Fei  XIA He  CAO Yan-mei  AN Ning 《保鲜与加工》2012,(1):42-46

Urban rail transit is becoming an important means of transportation and elevated structure is one important part of urban rail transit. So the radiation noise induced by elevated structure attracts more and more attention. Based on the theory of Helmholtz integral equation of BEM and fluid-structure coupling system of FEM, the sound pressure transmission vector reflecting the relation between structural vibration acceleration and radiation of sound pressure is derived and solved by the element radiation superposition method. The calculated results are in good agreement with the experimental data from a viaduct section of the Beijing airport rapid rail transit.  相似文献   

Nonlinear Creep Damage Model of Water Bearing Carbonaceous Slate and Its Application     

ZHANG Yongxing  WANG Gengfeng  ZHOU Xiaoping  XIONG Xiaohui  WANG Guilin  HUANG Da 《保鲜与加工》2012,(3):1-9

Triaxial compression rheological experiments on carbonaceous slate specimens of deep buried tunnel were carried out on the rock rheology testing machine. Along with the increase of loading stress level and the improvement of moisture conditions, the initial attenuation creep phase, the stabilization creep phase, and the speedup creep phase were produced. By connecting Burgers model and the nonlinear viscoplastic body consisted of nonlinear viscous component η(n,t) parallel connected with the plastic component in series, the improved model could describe the speedup creep phase. Using this model to fit and analyze the rheological parameters of different moisture conditions, it is shown that η〖KG0.005mm〗 M、E M、E K and η〖KG0.005mm〗 Kwill decrease with negative exponential trend. Then water damage D(w) was introduced, and through deriving damage evolution equation, the nonlinear viscoelasticplastic model with water damage effect was established. Finally, the time effect deformation of surrounding rock under different times and different moisture conditions was studied by numerical simulation, and the results show that primary support should close in 168 h, and the best construction time for secondary lining is 360 h after the primary support is closed.  相似文献   

Probability Statistics and Sensitivity Analysis of Parameters of Soil-Water Characteristic Curves   总被引：1，自引：0，他引：1  

TAN Xiaohui  LI Dan  SHEN Mengfen  HOU Xiaoliang  HU Na 《保鲜与加工》2012,(6):97-103

To study the characteristic of soil-water characteristic curves (SWCC) of several different types of soils, a number of data sets of matric suction-volume water content were studied for UNSODA clay, UNSODA sand, Guangxi expansive soil and Hefei expansive soil. Three types of Fredlund-Xing models and three types of van Genuchten models were used to study the influence of SWCC models, and three types of functions in the scientific programming language MATLAB were applied to analyze the effect of different fitting methods. Through the data fitting and statistic analysis, the probabilistic characteristics of the fitting parameters of SWCCs for the four types of soils were obtained. For analyzing the relative sensitivity of the normalized volume water content to the three fitting parameters of SWCC, a formula which considers the correlation of parameters was proposed. Through the data fitting of many data sets, it is found that the fitting methods influence the value of parameters of SWCC, while the influence is less than that of fitting models from the statistical point of view. The SWCCs of all the models are nearly the same when the suction is low. With the increase of the suction, the SWCCs of FX2 and VG2 are very close, and the SWCCs of FX3 and VG3 are the same. The sensitivity analysis shows that the normalized volume water content is more sensitive to parameters n and m than to parameter a.  相似文献   

黄瓜ζ-胡萝卜素脱氢酶基因克隆及表达分析     

王柬人  李锡香  王海平  邱杨  宋江萍  张晓辉  沈镝 《分子植物育种》2012,(5):520-527

以西双版纳黄瓜为试材,从黄瓜果肉中克隆ζ-胡萝卜素脱氢酶(ZDS)基因的cDNA序列,命名为CsZds。获得目的片段长度为1805bp,该序列具有完整的开放阅读框,位于31~1761bp,编码576个氨基酸。序列比对分析结果显示,该蛋白在氨基端变化十分明显,中部较为保守,存在一个特征序列。系统进化分析表明,推测的CsZDS蛋白与南瓜中ZDS蛋白同源性最高,达到91.84%。利用实时荧光定量PCR技术分析结果显示,随着果实成熟期的延长,西双版纳黄瓜CsZds基因的表达量呈明显上升的趋势,在转色期达到最大。在果实发育过程中,西双版纳黄瓜CsZds基因的表达量高于普通黄瓜。  相似文献   

沼液追肥对菇渣复合基质栽培生菜产量和品质的影响     

夏亚真  刘金  李胜利  孙治强 《河南农业大学学报》2012,46(4):397-401

为研究菇渣和沼液2种农业二次废弃物在蔬菜无土栽培中的配套应用技术,试验采用生菜为材料,以菇渣与草炭按体积比1∶1为栽培基质,研究了追施不同沼液浓度和追施方式对生菜产量和品质的影响.结果表明,追施适当浓度的沼液能够提高生菜的产量和品质,其中以叶面喷施沼液与水体积比为1∶4的处理效果最佳,其根际环境电导率较低且产量最高为6 607.39 kg·hm-3,Ve的含量为2 186.2 mg·kg-1比对照提高了20％且达到了显著水平,硝态氮含量为510.56 μg·g-1显著低于硝酸盐含量≤3 000 mg· kg-1的国家标准.  相似文献   

嫁接棉苗对黄萎病的抗性及相关生理指标的变化   总被引：4，自引：0，他引：4  

张明菊  夏启中  吴冰 《华中农业大学学报》2012,31(4):414-418

以海岛棉海7124(R1)和Pima 90(R2)为砧木,以冀棉11(S1)和鄂棉22(S2)为接穗,利用贴接法得到嫁接苗(S1/R1,S2/R1,S1/R2和S2/R2),成活率均在60%以上,S2/R2的则达85%,表明选用的海岛棉品种与陆地棉品种具有良好的亲和性。抗性鉴定结果表明,S1/R1、S2/R1对黄萎病表现为抗病;S1/R2、S2/R2表现为高抗,说明利用合适的抗病砧木与感病的陆地棉嫁接,能有效地防治黄萎病。接种黄萎病菌3d后,叶片中SOD、POD活性均有加强,MDA含量均有提高。且砧木叶片中SOD、POD活性最高,接穗叶片中SOD、POD活性最低;4种组合的嫁接苗介于二者之间。而叶片中MDA含量则相反,以接穗中最高,砧木中最低,嫁接苗介于二者之间。表明嫁接增强植株的抗病性可能是通过增强防御自由基和活性氧伤害的酶系统、降低叶片细胞膜脂的过氧化作用、使膜的损伤程度减小而实现的。棉苗感染病原菌后PAL活性明显升高并表现出规律性的变化,即在侵染的第1天,酶活性上升较缓,随后急剧上升,酶活高峰出现在侵染后第3天,之后迅速下降,到第5天后与初始水平接近。不同抗性品种的PAL活性变化有显著差异。鄂棉22(S2)的PAL活性上升缓慢,峰值较小,Pima 90(R2)的PAL活性上升快,峰值最高。S2/R2嫁接棉苗的PAL活性介于两者之间,且峰值与Pima 90(R2)的接近。  相似文献   

微波及保鲜剂延缓狗蝇腊梅切枝衰老的研究     

夏晶晖 《西南大学学报(自然科学版)》2012,34(6):036-040

研究了保鲜剂(PS)、微波(MW)和保鲜剂复合(MW+PS)预处理对腊梅切枝瓶插生理特性的影响,结果表明:MW+PS预处理具有增效保鲜和加合效应,与CK相比在蛋白质含量、糖含量、鲜质量变化率、干鲜质量百分率、POD活性上分别提高42.18%,47.11%,1.28%,10.57%,75.12%;瓶插寿命延长5.65d;MDA含量及萎蔫脱落率分别降低19.11%,3.17%.MW+PS和MW预处理明显促进了花枝吸收水分,也促进了花枝水分丢失,能较好维持腊梅切枝水分代谢平衡.保鲜剂复合预处理总体优于单独微波预处理,表现了MW与PS的加合效应.  相似文献   

吉林省农村居民消费结构的研究     

孙晓慧  刘特  闫风格  于圭  林艳辉 《吉林农业科技学院学报》2012,(3):47-49

我国是农业大国,农业更是吉林省的主要产业,要保持吉林省经济的健康持续快速发展,对农村市场的开拓是非常有必要的。农村居民的消费结构能够充分的反映经济水平的状况,农村经济健康发展,离不开健康科学的消费方式。本文从吉林省农村居民消费方式的特点展开,研究影响农村健康消费的相关因素,并提出有效的对策措施,扩大农村居民消费,加快推进吉林省新农村建设进程。  相似文献   

盆炎丸治疗多重耐药解脲支原体感染的临床观察     

夏如意  谈珍瑜  刘文娥  邹芝香  左和宁   《勤云标准版测试》2012,32(3):53-55

目的观察盆炎丸治疗多重耐药支原体感染的临床疗效。方法将60例多重耐药支原体感染患者随机分为2组,治疗组30例口服盆炎丸,对照组30例口服强力霉素,14 d为1个疗程,两组均连续治疗3个疗程,观察2组治疗前后临床证候积分,判断其临床疗效。结果治疗组综合疗效总有效率为83.3%,对照组总有效率为63.3%,两组比较,差异无统计学意义(P>0.05)。在中医证候改善方面,治疗组明显优于对照组(P<0.01)。结论在综合疗效方面,盆炎丸治疗多重耐药支原体感染疗效与强力霉素相当,但在中医证候改善方面,盆炎丸有明显优势,值得临床推广。  相似文献   

不同产丝量家蚕品系后部丝腺的蛋白质组学分析     

张利平  钟晓武  聂红毅  王晨  荀利杰  赵萍  夏庆友 《蚕业科学》2012,(3):468-474

家蚕幼虫后部丝腺是合成和分泌丝素蛋白的重要器官。为从蛋白质水平探究不同家蚕品系产丝量差异的原因,应用蛋白质组学研究方法,选取3个产丝量有较大差异的家蚕品系Ndx、大造和21-872为材料,通过双向电泳和基质辅助激光解析电离飞行时间质谱(MALDI-TOF-MS)技术对各品系5龄第5天幼虫后部丝腺表达的差异蛋白进行鉴定,查找与丝蛋白合成相关的蛋白质。结果表明,茧丝突变品系Ndx后部丝腺的蛋白质表达水平与普通丝量品系大造和高丝量品系21-872有差异,差异表达蛋白种类主要为应激反应相关蛋白、能量相关蛋白、蛋白质合成相关蛋白和一些酶类,其中核糖体磷酸化蛋白P0和P2、蛋白质二硫化物异构酶、丝素轻链蛋白Fib-L以及丝素蛋白P25等在Ndx后部丝腺的含量明显低于其它2个品系。推测在茧丝突变品系Ndx的后部丝腺中,上述蛋白质表达量的变化可能是导致其不能正常吐丝结茧的原因。  相似文献