三化螟种群数量变动情况分析

根据汕头市１９７４－１９９８年三化螟发生危害的测报调查资料，分析水稻三化螟的种群数量构成及其变化特点，明确造成三化螟种群数量下降的主要原因是耕作制度和作物栽培措施变化，科学施用农药和“抓前压后”的防治策略，以及无敌因素等。     

芜湖市郊区三化螟卵寄生蜂自然寄生情况初步调查

芜湖地区水稻由于受三化螟为害,每年都有不同程度的损失,一般年分约减产一、二成,严重受害年分如1965年和1970年部分社队单、双晚稻减产高达五成以上。因此,三化螟是芜湖地区水稻生产的重大威胁。考虑到长期单纯应用化学防治容易造成农药公害,从而在水稻害虫综合防治的总体中,积极开展稻螟生物防治,研究利用螟卵寄生蜂防治三化螟是一个很有希望的方法。这就必须首先查明芜湖地区三化螟卵寄生蜂的种     

生物源农药防治水稻害虫

阿维菌素防治水稻三化螟 ,亩用 0 .75克 ,防治二化螟亩用 1.5克 ;防治稻飞虱亩用 0 .5 4克。多杀霉素防三化螟 ,亩用 1.6 5克 ,防治二化螟亩用 2 .5克 ,防治稻纵卷叶螟亩用 1克 ,防治稻飞虱亩用 0 .5克。楝素防治稻纵卷叶螟亩用 5 0 PPm。藜芦碱醇防治纵卷叶螟亩用 0 .5— 0 .6 2 5克。 Bt防治水稻二化螟、三化螟防效低。     

X—射线对三化螟蛹的辐射生物效应

本文就X—射线辐射三化螟蛹,对其羽化率、交配、产卵孵化等方面,以及所产生的辐射生物效应和利用性不育法防治三化螟等害虫的可能性,作了初步探讨。     

积极开展水稻害虫防治试验

为了使教学、科研为生产服务,建立教学、科研和生产劳动三结合基地,生物系组织专人成立水稻害虫防治实践小组,与芜湖市郊区赭山公社赭山大队阡坡山生产队固定联系,组织师生以该生产队为基地,开展水稻害虫防治实验。除已进行三化螟卵寄生蜂自然寄生情况的调查和害虫虫情测报、预报外,还应用杀螟杆菌对三代三化螟为害双季晚稻所造成的枯心苗,进行了大田防治试验。据去年八、九月间对面积共8.9亩、六块大     

关于螟卵啮小蜂(Tetrastichur schoenobii Ferriere)生物学特性的初步探讨

1972——1973年,我们对本省水稻三化螟虫卵寄生蜂作了初步普查,着重对防治水稻三化螟虫效果较好的啮小蜂进行了引种,省内普查以及生物学特性等方面的初步研究。现将两年来试验观察的有关材料整理于后。     

生物防治作物病虫害动态

上海昆虫研究所寄生蜂组自一九六七年开始,进行了寄生蜂防治农作物害虫的研究。五年多来,他们在上海、太湖流域和两广稻区对水稻三化螟卵的寄生峰种类和自然杀伤害虫作用进行了调查和利用啮小蜂防治三化螟的研究。通过调查,初步掌握了上海、太湖和两广一些地区螟卵寄生蜂的一些分布情况,为开展以虫治虫提供了一些科学数据;在此基础上,着重对螟卵啮小蜂接种培养、寄主情况和放蜂治螟等进行了试验,对利用螟黄赤眼蜂防治稻纵卷叶螟和     

几种农药的药效试验

在党的“九大”团结、胜利路线指引下,温州地区农科所于1971年对18种杀虫剂和杀菌剂防治三化螟、稻纵卷叶螟、稻叶蝉、褐稻虱及稻小粒菌核病进行了大田示范试验。据试验,50%杀螟腈乳剂对稻纵卷叶螟、稻飞虱、稻叶蝉和三化螟等多种害虫均有很好的防治效果,对稻纵卷叶螟尤为显著;50%6711乳剂每亩2—3两加水泼浇,防治三化螟、稻飞虱和稻叶蝉等有良好的效果;50%硫特普乳剂及35%硫环磷乳剂等,对稻纵卷叶螟、稻     

“7216”细菌农药治虫效果好

天台县红旗公社微生物实验站,于1979年春从湖北省天门县微生物研究所引进苏芸金杆菌天门变种,土法生产“7216”细菌农药,在室内和大田开展“以菌治虫”试验,经过两年实践证明,防治稻纵卷叶螟的效果达91.78％,防治三化螟效果为70.53％,防治玉米螟的效果达85.7％,防治萍灰螟的效     

三化螟发生趋势的灰色预测

本文应用灰色系统理论的GM(1,1)建模方法,对丰城县26年的虫情历史资料,应用电子计算机组建了该地区三化螟发生趋势的预测模型: 模型Ⅰ x(t+1)=71.2131e~(0.1136t)-68.2131 模型Ⅱ x(t+1)=58.2206e~(0.1254t)-55.2206 经检验,两模型合格,并用此模型对1985—2000年丰城地区三化螟危害比较严重的年份进行预测,其结果将有助于该地区的螟害防治。     

Markedness and its Interpretation in Language Use

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.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

低渗透非均质砂岩油藏启动压力梯度研究

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。     

On Tragic Consciousness In The Works By Ernest Hemingway

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.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

Achieving Unusual States of Matter Under High Pressure

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-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

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-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

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     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

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