杂交水稻制种提高结实率的研究     

许琨  舒昆 《种子》1997,(1):17-20

杂交水稻制种不同于水稻栽培、其结实由柱头外露结实和非柱头外露结实两部分构成；空壳中90％以上是由于没有授粉受精造成的：90％以上的受精拉都能正常发育结实。柱头外露率和受精率与结实率呈显著正相关。后期施肥、父本大龄秧和机械授粉能有效地提高柱头外露率、花遇优度和结实率及制种产量。  相似文献   

Dropwise Condensation Heat Transfer Coefficient on the Horizontal Circular Surface with Radial Gradient Surface Energy     

GU Yang-biao  LIAO Qiang  ZHU Xun  WANG Hong 《保鲜与加工》2006,(5):48-51

A theoretical model is developed for the dropwise condensation heat transfer on the horizontal circular surface with radial gradient surface energy based on the heat transfer model of individual condensate drop and the size distribution model of condensate drop on homogeneous condensation surface.The effect of variation of contact angle on the gradient surface on condensation heat transfer and condensate drop size distribution is taken account of in this model.The theoretical calculation method was obtained to predict the dropwise condensation heat transfer coefficient on the horizontal circular surface with radial gradient surface energy under various wall subcooled temperature,contact angle profile on wall surface,and working fluid.The effects of surface energy gradient,wall subcooled temperature,and thermophysical properties of condensate on the condensation heat transfer are discussed respectively.The calculation results show that the condensation heat transfer coefficient increases slightly with the increase of wall subcooled temperature.As latent heat and surface tension increasing,the condensation heat transfer coefficient increases.A larger surface energy gradient induces a larger condensation heat transfer coefficient.  相似文献   

Intensity Comparative Analysis Based on Ideas Between Involute Gear and Double Involute Gear     

ZHANG Guang-hui  TAO Ling-feng  LIU Wen 《保鲜与加工》2005,(11):1-4

Modeler and simulation modules in Ideas software are used to build the finite element models on involute gear and double involute gear with accurate tooth shape, and with the same design parameters and under the same loads, finite element contact analysis has been done. At last, the contact stress and bending stress on the two types gear transmission at the different meshing positions are solved out, and comparative analysis and study have been done. At the same time, that the ladder-shape tooth on the double involute gear how to influence contact stress and bending stress is emphatically analysed. All above offer the theoretical foundation that bring the double involute gear with ladder-shape tooth into the industry.  相似文献   

Comparative Experiment Research on Seismic Behavior of New Reinforcement Scheme Coupling Beam with Slab     

PI Tian-xiang  LIU Guang-wei  FU Jian-ping  BAI Shao-liang 《保鲜与加工》2007,(8):107-113127

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Asymmetric Exhaustive Service Polling System with Bernoulli Feedback     

SUN Rong-hen 《保鲜与加工》2001,(2):127-131

This paper studies asymmetric exhaustive service polling system with Bernoulli feedback,gives the distributions of queue lengths and sojoun times,and obtains some other results,in stationary condition.  相似文献   

Optimization of Worm Gearing''s Geometric Parameters Under the Condition of the Errors and the Load     

XU Wu-jiao  QIN Da-tong  SHI Wan-kai ongqing  Chin 《保鲜与加工》2004,(4):24

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Studies on the Oxidation of Weathered Coal with Nitric Acid     

Liang Renjie  Yao Shusen  Zhang Shilin  Hu Daiying  Wang Nanmu 《保鲜与加工》1996,(3):79-83

A raseach has been done on the possibility of producing nitriochumic acid fromweathered coal of Nantong,Sichuan,oxidised by nithic acid.The optimun reacting conditions,whichare found through the way of orthogonal experiment,are suggested as follows:concentration ofHON3 35%,rate of HON3 to coal 3.5,reacting take 15 min,and reaction temperature 369 K. Thecomposition of product is Wf 2. 91 %;Ag 14.06%;HAg 78.28%;Ng 1.62%.  相似文献   

Ecological Technology Strategy-the Typologic Analysis and Research of Double-Skin Facade     

WANG Xue-song 《保鲜与加工》2003,(6):5-9

As a renovation envelope, double-skin facade has the characteristics of environmental function and unique aesthetic effect. In this paper, the composition and functional characteristics of double skin facade is introduced briefly, its development history and a detailed typologic analysis combined with typical cases is reviewed. It is pointed out that the double skin facade has a bright future in 21~(st) century and the function and aesthetics are the footstone for its typologic research.  相似文献   

THE INDUSTRIAL ORGANIZATIONS AND THE L-S-BUSINESS STRATEGIES     

He Zonglu 《保鲜与加工》1992,(4):111-117

This papar presents an evolution model in business behaviors-the L-S Business Strategies,gives some examples and predictions which support these strategies,and analyzes the relationship between the industrial organizations in China and the L-S Business strategies.  相似文献   

COUPLING ANALYSIS METHOD FOR INTERACTION BETWEEN FOUNDATION WITH CAVERN AND FRAME STRUCTURE     

Luo Jizhang Chongqing Institute of Architecture  EngineeringLiu Zhengbao Nanyang University 《保鲜与加工》1991,(2)

In this paper,the interaction between foundation withcavern and frame structure is studied by the coupling methods of BEMand FEM.On the interface between the foundation and structure,thecoupling analysis needs to satisfy both the condition of displacementcompatibility and force equilibrum.A calculating program for two-dim-ensional problem is worked out in the computer,SIEMENS 7570C.Twoengineering examples are calculated and the results are compared withthose obtained by the comventional simplified method and with the observedresults from the engieering structures.It indicates that it is necessaryfor the weak rock foundation with shallow cavern,in the buried depth,to take the interaction into account.  相似文献