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1.
根据广西池塘底质偏酸、水浅等特殊养殖条件,进行一次性进水消毒、肥塘放苗,利用添加淡水进行养殖水体的排换,避免从外海直接进排水,有效利用沸石粉、生石灰、CIO2等进行水质的改善及消毒,使养殖水体的交换与外海相对隔绝,养殖过程处于相对封闭状态,切断由外海带来的病害水平感染途径,减少病害的危害.在1999年4月15日~10月16日进行的低产池塘、旧塘改造健康养殖生产实验中,养殖斑节对虾(Penaeusmonodon)的面积7hm2共3口池,第1茬收虾6683kg,平均每1/15hm2产虾61.3kg,第2茬收虾7469kg,平均每1/15hm2产虾68.5kg.  相似文献   

2.
通过在民勤沙漠绿洲边缘进行紫花苜蓿的适应性栽培及品种对比试验研究,表明"甘农3号"、"中苜1号"、"德宝"、"三得利"、"兰热莱恩德"5个紫花苜蓿品种是适宜民勤荒漠绿洲栽培的优良紫花苜蓿品种,年可刈割3~4茬,年风干草产量分别为20775kg/hm2、18793kg/hm2、18300kg/hm2、20199kg/hm2、24875kg/hm2、24822kg/hm2;比我国优良地方苜蓿品种"新疆大叶苜蓿"分别提高16.62%、5.50%、13.39%、2.73%、39.64%、39.34%,表现出较强的适应性、抗逆性和较好的营养价值。  相似文献   

3.
采用“3414“二次回归最优设计试验方案, 研究N、P、K肥配施对紫花苜蓿(Medicago sativa)当年草产量的影响,结果表明:施尿素0.0 kg/hm2、过磷酸钙302.6 kg/hm2、硫酸钾440.0 kg/hm2,3种苜蓿均获得最高产量 ,其中阿尔冈金77167 kg/hm2,WL232HQ 77200 kg/hm2,敖汉苜蓿66166 kg/hm2.  相似文献   

4.
为优化种植结构,提高中药材种植效益,我中心通过近三年的试验示范,逐步总结出了黄芪与油菜套种的成功栽培技术,该技术的好处有三点:一是油菜较黄芪出苗早,可以满足黄芪幼苗期喜潮湿凉爽的生长条件,从而有效地解决了黄芪苗难全的问题;二是提高了黄芪的产量。实行套种的黄芪产量7279.5kg/hm2,校单种的增产2481kg/hm2;三是增加了一茬油菜收入,油菜产量2793kg/hm2,达到了增产增效的目的。加之黄芪在国内外市场上走俏,此种模式可以推广,现将栽培技术介绍如下:1 选用良种 黄芪选用膜荚黄芪和内蒙古黄芪,因两个品种幼苗主根光洁,…  相似文献   

5.
采用四因素二次通用旋转组合设计研究氮,磷,钾,硫(N,P,K,S)的肥施用效果。结果表明:在大通长宁地区获得紫花苜蓿粗蛋白含量最高的N、P、K、S肥施用量的最优组合为尿素300 kg/hm2,过磷酸钙225 kg/hm2,加拿大钾肥225 kg/hm2,硫磺粉15 kg/hm2,结合播种前整地施入。  相似文献   

6.
杂交水稻冈优725高产栽培技术初步研究   总被引:2,自引:0,他引:2  
采用四因素二次回归正交旋转组合设计,建立了水稻冈优725产量(Y)与施氮量(X1),施磷量(X2),施钾量(X3)和密度(X4)的数学模型,经因子水平选优,得出产量在9750-11250kg/hm2间的栽培模式,施氮肥85-177kg/hm2,施用P2O5为40-85kg/hm2,施用K2O为125-202.5kg/hm2,密度20.5-27万窝/hm2。  相似文献   

7.
通过二年试验结果表明 ,棉花喷洒“丰满乐”蕾铃宝和缩节胺 ,均能抑制棉花营养生长 ,增强生殖生长 ,减少蕾铃脱落 ,增加单株成铃和单铃重 ,籽棉单产比对照提高361.5kg/hm2 和223.5kg/hm2,增产8.5 %和5.3 % ,增值1265.25元/hm2 和782.25元/hm2,其效果是蕾铃宝第一 ,缩节安第二  相似文献   

8.
每次用2 .1kg/hm2 奇丽施喷洒棉花 ,增产效果最好 ,经济效益最高。其它按增产高低依次为每次用2 .4kg/hm2、1 .8kg/hm2、1 .5kg/hm2、1 .2kg/hm2。  相似文献   

9.
棉花每次喷洒750kg/hm2的劲康霖作物营养剂,增产效果最好,经济效益最高。其它每 次用量的增产增收效果分别为825 kg/hm2、900 kg/hm2、675 kg/hm2、600 kg/hm2。  相似文献   

10.
每次用1.5kg/hm2 利果美喷洒棉花 ,增产效果最好 ,经济效益最高 ,其次为每次用1.8kg/hm2、1.2kg/hm2、0.9kg/hm2  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

15.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

16.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

17.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

18.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

19.
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that  相似文献   

20.
For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the  相似文献   

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