广义连续格的结构     

邓自克 《湖南农业大学学报(自然科学版)》2001,28(6)

以上（下）子格为工具建立广义连续格的诸结构定理，它们奠定这些格的完全链表现的基础。  相似文献   

水稻机械化喷直播技术的应用现状及对策     

黄宗飞  叶钊海 《中国农机化》2005,(1):35-36

分析了水稻机械化喷直播技术的特点和技术要求，介绍了水稻机械化喷直播技术的应用现状及其技术推广的制约因素．提出了推广水稻机械化喷直播技术的对策．  相似文献   

Weeding techniques in transplanted and direct wet-seeded rice in Pakistan     

MOHAMMAD SAFDAR BALOCH  GUL HASSAN  TETSUO MORIMOTO 《Weed Biology and Management》2005,5(4):190-196

Field studies were undertaken to explore the weed management strategies for transplanted and direct wet-seeded rice in the Dera Ismail Khan district of North-west Frontier Province, Pakistan. The experimental design was a randomized complete block with a split plot arrangement. The main plots consisted of two planting techniques (transplantation and direct seeding), while weed control practises assigned to the subplots included the use of the granular herbicide Sunstar 15WG (ethoxy sulfuron), Machete 60EC (butachlor), conventional hand weeding, and the weedy check (untreated control). Data were recorded on weed dynamics and the agronomic parameters of the rice crop. Economic analyses on the data were also run. The weed density and biomass were lower in the transplantation plots than the direct-seeding plots. The herbicides ethoxy sulfuron and butachlor reduced the density over the weedy check, with a density comparable to hand weeding in 2002, but slightly higher in 2003. As a result of weed management by hand weeding and herbicides, the paddy yield and its components were significantly higher for the transplanted method compared to the direct-seeded method. The comparable yield of herbicides with hand weeding offers an option for the use of herbicides as an alternative management tool. In light of our findings, it is concluded that for good economic returns, rice crops may be transplanted rather than direct-seeded. The herbicides ethoxy sulfuron and butachlor offer a weed control cover comparable with hand weeding under the transplantation method, while butachlor is good for controlling weeds even under the direct-seeded conditions in the agroclimatic conditions of the area.  相似文献   

Cell direct reprogramming：a new technique for treating diabetes     

REN Li-wei  YANG Xiao-fei  LI Fu-Rong 《园艺学报》2014,30(12):2284-2288

Diabetes is characterized by an absolute or relative deficiency in β-cell mass, which cannot be reversed with existing therapeutic strategies. The restoration of the endogenous islet β-cells can stabilize the level of blood glucose. The islet β-cells can be obtained from the directional differentiation of stem cells, but the process is complex and has the risk of teratomas generation. Cell direct reprogramming, one terminal differentiated cell can transdifferentiate into another kind of terminal differentiated cell, which is other than directional differentiation from stem cells. Direct reprogramming gives rise to the generation of islet β-cells from one terminal differentiated cell, may be preferable for diabetes therapy because of its unique advantage.  相似文献   

机械化直播油菜的优点及高产栽培技术     

顾宗福  孙华  邵慧霞  仲嘉  穆晓伟 《安徽农业科学》2016,44(14):27-28

针对近年来油菜生产机械化程度低、用工多、成本高、效益低、面积逐年萎缩的情况,通过多年试验与总结,探索与完善了机械化直播油菜的高产栽培技术,实现了省工节本、提高机械化水平的目的,也为大面积油菜生产提供技术参考。  相似文献   

调环酸钙25%悬浮剂对直播稻抗倒伏和产量性状的影响     

郑先福  ;郑昊  ;骞天佑  ;刘彦涛  ;万翠  ;禹震洋 《农药科学与管理》2014,(9):59-62

为了研究新型植物生长调节剂调环酸钙在直播稻上的应用效果,本研究设计了调环酸钙25%悬浮剂在直播稻武运粳8号上的田间试验,用来了解其对直播稻的抗倒伏性状和产量性状的影响。试验结果表明:在直播稻武运粳8号的分蘖期使用调环酸钙25%悬浮剂12~15g/667m2均能够显著降低水稻的株高,缩短茎基部节间长度,提高水稻的抗倒伏能力,同时也能显著提高水稻产量。  相似文献   

The influence of feeding and gastroprotectant medications on the Factor Xa inhibitory activity of orally administered rivaroxaban in normal dogs     

Alex M. Lynch  Laura K. Ruterbories  Emily Griffith  Rita M. Hanel  Alyssa P. Stablein  Marjory B. Brooks 《Journal of Veterinary Emergency and Critical Care》2021,31(1):59-65

  相似文献   

Influence of HVDC System on the Shaft of Hydro-generator Unit     

XU Yuan-yuan  LIAO Yon  CHEN Guo-qing  XlANG Da-wei 《保鲜与加工》2006,(1):36-40

Widely concerns of the influence of the HVDC system on the Three Gorges power station have been shown so far. Based on the understanding of the mechanism of the non-characteristic harmonics introduced by HVDC system, the influence of interharmonics on the shaft of hydro-generator unit is studied. A MATLAB simulation model for the Three Gorges hybrid AC and DC transmission system with considering the effect of generator-unit shaft is established. Through time-domain simulation, the influence of the minor-associated component of interharmonics on the generator-unit shaft is analyzed, which arise from the asynchronous operation of the HVDC system. Also, the complex torque coefficient method in frequency-domain is used to analyze this problem. Same conclusions can be drawn from the results of timedomain and frequency-domain analyses.  相似文献   

STATE VARIABLE METHOD FOR DYNAMIC SIMULATION OF HVDC SYSTEMS     

Zhang Wei Ren Zhen Qin Yihong Liao Qing 《保鲜与加工》1990,(1):56-62

A flexible mathematical model used for dynamic simulation studies of HVDC systems which is based on the stale variable method is presented, and the correspongding computer program has been implemented. Generality, easy to use, and suitable to run on microcomputers are the main features of the model and the computer program. Therefore the model is easy to be extended for application. An example is given in the paper to verily the coneclness of the model and the program.  相似文献   

Recommendations on Shrinkage and Temperature Reinforcements in Concrete Slabs     

LI Lei 《保鲜与加工》2004,(4):45-50

The mechanism of shrinkage cracking is discussed with a simple member, which is fully restrained and subjected only to an axial restraining force caused by shrinkage, while a simple procedure is presented for the determination of the number and spacing of the cracks and the average crack width. With the simple model, some examples are shown to compare the provisions for minimum shrinkage and temperature reinforcement in GB 50010-2002 Code, ACI 318-02 Code and AS 3600-1988 Code. The results show that the provisions in GB 50010-2002 Code are too weak in comparison with the others. Finally, some recommendations are proposed.  相似文献