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阿魏属和独活属都是伞形科中具有重要药用价值的植物。但是由于伞形科的分类系统是建立在典型的伞形花序和带有特殊分泌管的果实的基础之上的,使得分类学者在亚科、族、属和种的设立和分类方面存在分歧,实验主要针对阿魏属和独活属的花粉形状进行研究,对阿魏属和独活属植物的分类提供一些基础数据。利用光学显微镜和扫描电子显微镜拍摄了伞形科阿魏属5种和独活属3种植物的花粉照片,进行了花粉形态的比较研究。结果表明,阿魏属花粉形状为长球形,而独活属花粉为超长球形;2属花粉外壁均具有网状纹饰,3孔沟。阿魏属和独活属植物的极轴平均长度分别为29.67μm和34.07μm,秩和检验表明二者差异显著;赤道轴平均长度17.07μm和15.65μm,差异不显著;极轴长/赤道宽的平均值分别为1.76和2.19,差异显著。 相似文献
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中国城市市花市树研究 总被引:1,自引:0,他引:1
市花市树往往是一个城市的象征,反映城市市民的文化传统、审美观和价值观。调查了当前全国各省地级市及直辖市市花市树评选情况,分析了所选用市花市树的种类状况和特征及不足,发现292个城市中有167个城市评选了市树,209个城市确定了市花;所选的植物种的重复率较高,平均3个城市选用的市花或市树雷同,市花市树分布48个科,76个属,106种;市民对市花市树的认知不够,对市花市树的宣传不足,多数城市的市花市树缺少植物学名,主要以俗称为主等情况。剖析了目前这种状况的背景与原因.并为如何充分开发市花市树提出了建议。 相似文献
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云南省楚雄州自然分布(少数几种为栽培)的双子叶植物有2939种(含种以下单位),隶属170科914属。本文对其区系成分进行了统计分析,结果表明双子叶植物科的分布类型主要是以热带——亚热带分布型(41科,占24.18%)和热带——温带分布型(31科,占18.24%)为主。属的分布类型主要以泛热带分布型(243属,占26.59%)、东亚分布型(112属,占12.25%)和北温带分布型(94属,占10.28%)为主。楚雄州双子叶植物区系特征有以下显著特点:①植物种类丰富;②区系成分复杂、起源广泛;③热带、亚热带成分突出。 相似文献
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Linkage control of fire-fighting electrical equipment effectively and reasonable design, installation and debugging of power supply and distribution are increasingly important to ensure the safety of underground space. As the linkage control systems associated with the fire control electrical equipment are very complicated, and the distribution of installation and debugging are very professional, there are many hidden troubles of safety in the whole life cycle process. On the basis of analysis of characteristics of underground space of fire, underground fire-fighting electrical equipment and the requirement of power supply system are expounded, hidden dangers on linkage control of electrical devices and design installation and debugging of power supply and distribution underground space are analyzed, and some suggestions and countermeasures are provided for relevant departments as decision-making reference. 相似文献
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For a reinforce concrete frame structures which is not satisfied the standard for seismic appraiser of building, viscidity dampers are used to retrofit the structure. Four reinforce schemes are selected in which six same viscidity dampers are located at different position of the structure. Compared seismic performance of the retrofited structure with unretrofited one, an optimum scheme where viscidity dampers should better set is obtained. Then the number and technical parameter of viscidity dampers are adjusted, and seismic performance of the structure are calculated. The results are compared and a more economic scheme is obtained because the cost is lowest and the displacement of the structure under earthquakes is satisfied the standard for seismic appraiser of building. Several rules and advices are gotten about how to use the viscidity dampers to retrofit reinforce concrete frame structures. The conclusion about viscidity dampers are useful for similar actual engineering. 相似文献
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由于卧龙山庄原规划已时过境迁,已经不能满足需要,因而急需进行重新规划和对规划后的方案进行系统评价。该文通过实地调查、GPS定位相结合的方法查清了现有旅游资源并在此基础上进行了规划,然后运用景观生态学方法对规划后的方案进行了评价。该文规划种植了酸枣、冬枣、梨枣、月光枣、野菜、柿子、欧李,改变了蔬菜园的种植种类;增加了杜梨、栾树和红叶臭椿的种植面积;规划了生态集雨工程示范点、火箭消雷展览室、卧龙禅寺、金鱼池、观鱼长廊、商店、观景亭、道路、停车场和厕所等。用斑块水平和景观水平上的景观指数作为规划方案评价的数量指标,对规划后的效果进行评定,认为规划后虽然景观破碎化指数提高了,但景观类型集中度加强;景观多样性指数、优势度指数、丰富度均提高了,美学质量得到改善,旅游设施更为完善,游览期更长;同时认为这种评价方法在规划方案筛选中具有一定的可行性和参考性。 相似文献
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The term Cleaner Production(CP)and Estimation of Cleaner Production Potential are introduced, meanwhile their importance are pointed out. Three kinds of cleaner technologies are put forward-Best Available Technology(BAT), Best Economic Attractive Technology(BEAT), and usually used new technology, combined with some CP casesat home and abroad. several cleaner technologies are compared, and the results show that the implementation of CP can greatly reduce consumption of resource and energy and pollution emission, There are obvious environmental, economic and social benefits. The great potential of CP in industrial pollution control are estimated and demonstrated ultimately. 相似文献
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A great deal of electronic documents will be produced in enterprises, many of which in the form of disk files are stored in the computers of each department. Some are shared through the sharing mechanism, but they are difficult to manage and maintain. Security problems and information-isolated island may occur for some of these documents. A new technology of electronic document administration are introduced, in which authorized administration mechanism are taken and the documents are classified, encrypted, compressed and then transported via intranet and stored in database. Its application in enterprises has proved that documents can be shared and queried dynamically, conveniently and reliably by using the technology. 相似文献
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研究国内外学者关于利他行为的思想、观点,总结利他行为的发展和争鸣,为后人研究利他行为提供理论依据和借鉴。本文在相关文献资料的基础上,采用实证描述和规范研究的分析方法,探讨了亲缘利他、互惠利他和纯粹利他等利他行为,并从自然选择、群体选择、基因选择、亲缘选择、互惠利他、自私基因、囚徒困境、纯粹利他等理论视角对利他行为进行解读和讨论。 相似文献
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The finite element model involving geometric large deformation,materials and contact nonlinearity is established.Specimens of cold-formed steel quadruple-C built-up section members are simulated and the finite element models are proved to be valid.Then,numerical analysis on the behavior of specimens with different slenderness ratio and flange flakiness ratio are carried out,and then the axial bearing capacities of specimens are obtained.Based on effective width method and direct strength method (DSM) in related codes,two design methods of cold-formed steel quadruple-C built-up section members under axial compression are proposed:effective length method and correction factor method.It is shown that:the final failure characteristics of all specimens are local buckling and distortional buckling.In the case of not considering the reduction of effective length,the results calculated by each code are slightly lower than those of test and FEM when the slenderness ratio is less than 50,while the results are too conservative when the slenderness ratio is more than 50. 相似文献
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Luc Baudouin Claire Baril André Clément-Demange Thierry Leroy Didier Paulin 《Euphytica》1997,96(1):101-114
The recurrent selection schemes recommended by CIRAD for 6 tropical tree crops are presented and compared. Breeding programmes
are carried out under cooperation between CIRAD and its partners in regions where the crops are grown. The crops are cacao,
coffee, rubber tree, oil palm, coconut and eucalyptus. After a short look at the background, the reasons behind the options
chosen are given and the main characteristics of the schemes are described and illustrated. The state of progress and some
major results are discussed. Over and above the differences linked to plant biology, the genetic diversity available and the
type of varietal output, common characteristics are emphasized. The time taken for each generation means simplifying the intercrossing
phases between successive breeding cycles, and thus, the parents tested are heterozygous: whenever possible, a clonal varietal
output is an additional source of progress. The use of biotechnologies to study diversity is a valuable asset, and their application
for early selection (QTL) is also promising. The preponderance of combining ability coexists with marked heterosis, which
poses the problem of the latter's origin. As a result, all of the schemes described, but one, are reciprocal recurrent selection
schemes.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
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Sun Renbo Wang Daiyu 《保鲜与加工》1988,(4)
In this paper, the solution of cylindrical bending problem for rectangular plates supported by elastic and tensile supports on particular deformation condition are derived from practical engineering problem. By examples, some considerable matters of analysing prismatic structures are suggested. The solutions are also studied when the tensions are to be determined. the results are simple and easy to be used. 相似文献
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Four sigmoid growth functions and two exponential functions are described. Relevant values are calculated for estimated functions and presented in tables. Six examples are presented and interpreted. Estimated functions and contour plots for the rate of relative growth are shown in figures. Functions are estimated with SAS 6.12 and STATISTICA 5.0. 相似文献
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根据食用植物油中的特征物质、甘三酯及脂肪酸组成的不同,研究了一些食用植物油的掺假检测,分析了这些检测方法的优缺点及影响因素,并对掺伪检测技术的发展方向进行了展望。 相似文献