双承载缆索在特大桥吊装工程上的设计与应用   总被引：1，自引：0，他引：1  

罗仙仙  周新年  胡永生  郑丽凤  李纲  冯建祥  陈永祥 《福建林学院学报》2003,23(4):305-308

本着技术可行、经济合理、安全适用的原则,对京福高速公路上洋特大桥的双承载缆索吊装进行设计,包括索道总体布置,承载索与工作索计算,并进行支架稳定性、生产率的验算.  相似文献   

甘草悬浮培养细胞与甘草草药、植株中甘草酸的检测     

李楠高广瑞  魏景芳李冬杰刘颖  薛志忠 《华北农学报》2007,22(B08):197-199

采用不同的萃取剂从甘草的根、茎、叶、草药和甘草悬浮培养细胞中萃取甘草酸。结果表明,选择含氨0.5%、浓度为10%的乙醇溶液作为萃取剂,萃取得到的甘草酸粗品含量均高于50%乙醇萃取的萃取含量,检测出在优选甘草悬浮培养细胞中所含的甘草酸铵的含量高于其他材料,其中通过细胞悬浮培养,获得的甘草酸铵含量最高可达160.81 mg/g。  相似文献   

水稻胚性悬浮细胞系建立过程中生理生化变化——Ⅱ.氨基酸、多胺及内源激素的变化     

向太和  梁海曼  钟华鑫  颜秋生  张雪琴 《作物学报》1997,(3)

以水稻广亲和中粳品系02428为材料,分析了其胚性悬浮细胞系建立过程中氨基酸、多胺及内源激素的变化。结果表明:1.游离氨基酸的总量是FP_(15)>MP_(45)>LP_(90),其中FP_(15)游离精氨酸的含量很高,而在MP_(45)和LP_(90)中含量剧降。蛋白质氨基酸和蛋白质合成能力正好和游离氨基酸的总量变化相反。2.从FP_(15)→MP_(45)→LP_(90),腐胺含量呈上升、精胺含量呈下降趋势。腐胺/(精胺 亚精胺)上升了近20倍。悬浮细胞经脱壁而成游离原生质体后,其总多胺、尸胺和腐胺的含量与悬浮细胞相比均大幅度下降,而精胺和亚精胺则有所升高。3.植物内源激素IAA、2ip的含量是LP_(90)>MP_(45)>FP_(15),ABA、ZRs的含量是FP_(15)>MP_(45)>LP_(90)。上述变化在一定程度上解释了胚性悬浮细胞即后期悬浮细胞适合于进行原生质体培养的生理生化机理。  相似文献   

Optimization of Vehicle Frontal Wheel Orientation Parameters     

CHU Zhi? gang  DENG Zhao? xiang  HU Yu? mei  XIONG Wei 《保鲜与加工》2003,(2):86-89

Based on the theory of multi body dynamic, the paper established the front suspension model of vehicle. The uniform optimization object function, including the tolerance of front wheel orientation angles' practical value and set value under full load, and the changing value of each parameter during wheel fluctuating is put forward. Utilizing this model, the original suspension is optimized and the variation of each parameter with front wheel fluctuation is calculated. The optimized driving operation performance resulted from the analysis and application.  相似文献   

Continuous Plant Regeneration from Established Embryogenic Cell Suspension Cultures of Italian Ryegrass and Tall Fescue   总被引：8，自引：0，他引：8  

Sahondra Radilofe  Rajoelina  Gilbert  Alibert Claude  Planchon 《Plant Breeding》1990,104(4):265-271

The suitability of different protocols was compared for entire plant regeneration by somatic embryogenesis, of the forage plants Lolium multiflorum Lam. (Italian ryegrass) and Festuca arundinacea Schreb. (tall fescue). In the first protocol, miniature embryos were used as starting material, while mature seeds were retained in the other two. Whichever the considered protocol, undifferentiated calli were produced on Murashige and Skoog MS medium supplemented with 2,4-D. The calli were subcultured in the dark on solid MS agar medium, containing 5 mg/1 2,4-D (protocol 2) or on solid MS medium followed by transfer to a rotated liquid MS medium with 2 mg/1 2,4-D (protocol 1). In these conditions, induction of somatic embryogenesis occurred, and whole plants were regenerated during a limited lapse of time, upon transfer in the light, to MS medium supplemented with BAP but devoid of 2,4-D. The simultaneous elimination of 2,4-D and transfer to light appeared essential for full regeneration of the plants. Using this characteristic, an additional step was added to a new protocol (protocol 3) in which microcalli, cultured on liquid MS medium containing 5 mg/1 2,4-D, were transferred to the same medium with 2 mg/1 2,4-D, in the dark. In these conditions, the suspensions kept their embryogenic potential for months. In all cases, plantlets were successfully transferred into the soil. An evaluation of the somaclonal variation potential of the plants issued from each protocol is now underway.  相似文献   

电析土壤微粒悬浮液的维恩(Wien)效应及其影响因子   总被引：5，自引：0，他引：5  

LI Cheng-Bao  S. P. FRIEDMAN  ZHAO An-Zhen 《土壤圈》2002,12(3):235-242

The electrical conductivity of suspensions and their supernatants from the electrodialyzed clay fractions of latosol, yellow-brown soil and black soil equilibrated with nitrate solutions were determined at different field strengths using a short high-voltage pulse apparatus to demonstrate the Wien effect in soil suspensions and to investigate factors affecting it. It was found that Wien effect was much stronger in suspensions with a clay content of 30 g kg-1 from the soils equilibrated with a 1 × 10-4 KNO3 solution than in their supernatants.The threshold field strength (TFS), at which the relative conductivity is equal to 1.05, i.e., the Wien effect begins to be obvious, of the yellow-brown soil suspensions (clay content of 30 g kg-1) equilibrated with different nitrate solutions of a concentration of 1 × 10-4/z mol L-1 , where z is the valence, varied with the type of nitrates, being lowest for NaNO3 (47 kV cm-1) and highest for Ca(NO3)2 (98 kV cm-1). At high field strengths (larger than 130 kV cm-1), the relative conductivities of yellow-brown soil suspensions containing different nitrates diminished in the order: NaNO3 ＞ KNO3 ＞ Mg(NO3)2 ＞ Zn(NO3)2 ＞ Ca(NO3)2. The rates and intensities of the Wien effect in the suspensions of the three soils equilibrated with 5 × 10-5 molL-1 Ca(NO3)2 solution were in the order of the yellow-brown soil ＞ the latosol ＞ the black soil. The results for the yellow-brown soil suspensions (clay concentration of 30 g kg-1) equilibrated with KNO3 solutions of various concentrations clearly demonstrated that the more dilute the solution, the lower the TFS, and the larger the relative conductivity of the suspensions at high field strengths. The results for yellow-brown soil suspensions with different clay concentrations indicated that as the clay concentration increased, the low field electrical conductivity, EC0, also increased, but the TFS decreased, and the Wien effect increased.  相似文献   

土壤悬浮液中溶解和吸附性铁离子对硫化物还原Cr(VI)的催化作用     

LAN Ye-Qing  YANG Jun-Xiang  B. DENG 《土壤圈》2006,16(5):579-586

The kinetics of Cr(Ⅵ) reduction by sulfide in soil suspensions with various pHs, soil compositions, and Fe(Ⅱ) concentrations was examined using batch anaerobic experimental systems at constant temperature. The results showed that the reaction rate of Cr(Ⅵ) reduction was in the order of red soil < yellow-brown soil < chernozem and was proportional to the concentration of HCl-extractable iron in the soils. Dissolved and adsorbed iron in soil suspensions played an important role in accelerating Cr(Ⅵ) reduction. The reaction involved in the Cr(Ⅵ) reduction by Fe(Ⅱ) to produce Fe(Ⅲ), which was reduced to Fe(Ⅱ) again by sulfide, could represent the catalytic pathway until about 70% of the initially present Cr(Ⅵ) was reduced. The catalysis occurred because the one-step reduction of Cr(Ⅵ) by sulfide was slower than the two-step process consisting of rapid Cr(Ⅵ) reduction by Fe(Ⅱ) followed by Fe(Ⅲ) reduction by sulfide. In essence, Fe(Ⅱ)/Fe(Ⅲ) species shuttle electrons from sulfide to Cr(Ⅵ), facilitating the reaction. The effect of iron, however, could be completely blocked by adding a strong Fe(Ⅱ)-complexing ligand, 1,10-phenanthroline, to the soil suspensions. In all the experiments, initial sulfide concentration was much higher than initial Cr(Ⅵ) concentration. The plots of lnc[Cr(Ⅵ)] versus reaction time were linear up to approximately 70% of Cr(Ⅵ) reduction, suggesting a first-order reaction kinetics with respect to Cr(Ⅵ). Elemental sulfur, the product of sulfide oxidation, was found to accelerate Cr(Ⅵ) reduction at a later stage of the reaction, resulting in deⅥation from linearity for the lnc[Cr(Ⅵ)] versus time plots.  相似文献   

超大跨悬索桥地震响应的综合最优控制研究     

王浩  李爱群  郭彤 《湖南农业大学学报(自然科学版)》2006,33(3)

超大跨缆索支承桥梁通常选择隔震体系以减小桥塔的地震内力,但隔震体系会使得结构在强震下的梁端位移很大,必须采取控制措施以保证整体结构的抗震安全性。本文以主跨1 490 m的润扬悬索桥为研究对象,在对其地震响应特性进行分析的基础上,从振动控制的原理出发,探讨了控制超大跨悬索桥地震响应的具体的措施及参数选择,结合改进的层次分析法提出了地震响应综合最优控制的概念,构造了综合最优控制效果评估模型,并给出了该桥在给定地震输入下的综合最优控制措施。结果表明,对于超大跨悬索桥,在塔、梁间设置弹性连接装置或阻尼器都能减小梁端位移响应,但综合考虑其它部位的响应,阻尼器的减震效果更为全面。  相似文献   

春石斛的工厂化快速繁殖技术研究   总被引：2，自引：0，他引：2  

廖飞雄  王恒明  黄群慧 《西南农业学报》2006,19(5):943-945

在附加6-BA和KT的MS培养基上,利用侧芽诱导了2个春石斛(Dendrobium nobileLindl)品种腋芽的再生。从再生芽基部成功地诱导了类原球茎的形成,1~3.0 mg.L-1KT对诱导类原球茎是有效的浓度。将类原球茎通过振荡悬浮培养诱导,结合固体培养增殖,可实现短时间内进行大量繁殖,建立了高效繁殖体系。振荡培养还可使类原球茎发育同步化。  相似文献   

水稻胚性悬浮细胞系建立的细胞学研究   总被引：3，自引：0，他引：3  

向太和  钟华鑫 《安徽农业科学》1993,21(1):1-6

胚性悬浮细胞是禾谷类作物原生质体培养的理想材料。本文研究了水稻广亲和中粳品系02428胚性悬浮细胞系建立过程中的细胞学动态变化,结果表明:建成的胚性悬浮细胞系(后期悬浮细胞系)和前、中期悬浮细胞系相比较,细胞团内细胞结合紧凑,细胞壁簿,细胞质浓厚,颗粒状内含物丰富,细胞活力强,质膜凹陷较浅,较平整,质膜强度高。本研究结果从细胞学角度初步探讨了水稻胚性悬浮细胞系适应于原生质体培养的机理。  相似文献