小麦纹枯病发生与流行规律的研究

小麦纹枯病有两个明显的发生与流行时期:(1)小麦出苗到返青期;(2)小麦植株拔出第三个茎节(日平均气温在10℃以上)到成熟。返青后地上部症状消失,出现发病停滞期。病害的消长与小麦生育有密切关系。 施肥种类、小麦密度、降雨、土壤水分、日照等影响小麦纹枯病发生与流行程度。施入氮肥、油饼肥及大量农家有机肥料,密植等使植株生长茂密,发病重。适宜的土壤含水量,成株期降雨量多、雨日多、日照少,是加重纹枯病发生和流行的重要气象因子。     

小麦重大病虫害发生流行的气候影响评价

 为分析评价气候变化对小麦重大病虫害发生流行的影响,揭示全球变暖趋势下异常气候条件对病虫害时空演替和发生规律的作用机制,通过收集整合20个中国冬小麦主产省(区、市)经规范连续、广泛系统的测报调查所获得的病虫害发生数据,对应2009-2010冬小麦生育期间气候特点和极端气候事件,与历史常规年份的病虫害发生状况和气候条件进行比较.结果表明,在该生长季,由于初冬强降温、春季持续低温以及西南麦区秋冬春三季连旱等异常天气气候条件的影响,小麦重大病虫害发生时期推迟,其中条锈病扩展流行范围小、发生轻,纹枯病和白粉病扩展流行范围广、发生中等,麦蜘蛛等前期虫害发生较轻,赤霉病、蚜虫等穗期病虫害发生严重.从而得出,影响不同种类病虫害发生流行的关键时期、关键气象因子有所不同,这为病虫害预测预报分类指导和关注重点提供了依据;为做好预测预报、评估气象灾害对病虫害发生的影响,应做到“大小兼顾、长短结合,分类关注、抓住关键”.     

石河子冬小麦生长阶段与气象服务要点分析

小麦是新疆的主要粮食作物,北疆沿天山一带的石河子垦区,是冬、春小麦兼种区,安集海至石河子市沿线一带冬季积雪形成早且稳定,适合种植冬小麦,冬小麦的种植,不但提高了小麦的单产,而且又改善了面粉的品质。乌兰乌苏农业气象试验站长期以来一直开展气象和农业气象观测,并为安集海片区各农牧团场的农业生产提供气象服务。根据多年观测冬小麦的发育期特点来分析农业气象条件对冬小麦生长发育和产量形成及品质的影响,总结冬小麦主要发育期的气象服务要点,为高产、优质、高效农业提供更好的气象服务。     

中国作物填图——冬小麦潜在分布

作为一个发展中国家,中国面临着巨大的粮食安全问题.中国作物填图一冬小麦潜在分布是中国作物填图的重要组成部分,实现中国冬小麦潜在分布图的绘制,缓解中国粮食压力.运用CropMap系统的概念和原理,收集环境条件数据和冬小麦生长相关数据,以GIS为主要技术手段,建立起区域气象、地形、土壤等空间数据库.借助基于GIS的多标准评价(MCE),得到冬小麦潜在分布图.冬小麦在中国适宜分布区为:河南,江苏(上海),辽宁,山东,天津,陕西,四川,北京,重庆,吉林,宁夏安徽,云南,山西,黑龙江,河北,贵州,湖北,台湾,甘肃.全国最适宜种植区域的面积约374257 km2;较适宜种植的面积约1659270 km2;中等适宜种植的面积约2983960 km2.中国冬小麦潜在分布图与冬小麦实际种植区的符合度相当高,可以用来指导政府的宏观调控和农民的投资方向,消除在农业投资上的盲目性,提高投资收益.     

秦州区小麦白粉病发生流行规律及其监测预报因子分析探讨

近年来，小麦白粉病在秦州区呈加重趋势，已上升为影响小麦安全生产的重要病害之一。对小麦白粉病进行及时准确的监测预报，是科学指导大田防治，抗灾保产的关键。通过对十多年来病害发生流行规律的总结及其流行因子的分析，提出了秦州区小麦白粉病的监测预报应以春季温度、雨量、日照为主导因子，以越冬菌源基数及冬温、积雪等为辅助因子。     

淮阴小麦赤霉病发病原因及防治

小麦赤霉病是典型的气候型病害,其流行程度主要取决于三个方面的因素,即气候条件,菌源数量和感病期及其吻合程度,其中,气候条件是决定流行与否的主导因素,另外还受品种抗性及栽培生态环境及管理措施等因素影响。扬花期是小麦最易感病的生育期,扬花期遇连阴雨有利于病菌侵入,灌浆期遇连阴雨有利于病害扩展,小麦抽穗扬花期高温、多雨、高湿、寡照是造成小麦赤霉病流行的主要原因。防治对策主要是加强预警、选育品种、田间管理、喷药防治。了解和认识小麦赤霉病的发病症状,流行规律及危害性,对今后做好小麦赤霉病预报和防治工作具有积极意义。     

农民的“知心平台”--记滨州市农业信息化平台

今年6月2日，滨州市高新区小营潘家村村民彭吉昌家小麦麦穗干枯现象严重，非常着急。一个电话后，滨州市农业局信息中心及时组织农技站副站长和植保站副站长奔赴该村进行现场出诊。经现场调查和诊断，该村民种植的小麦麦穗干桔为小麦赤霉病所致，赤霉病病株率占到2％左右，同时还伴有白粉病发生，周边大约100亩小麦都有不同程度发生这两种病害。     

基于MaxEnt模型的青钱柳潜在适宜栽培区预测

【目的】 青钱柳是集药用、材用和观赏价值于一身的多用途树种。通过应用贡献率、置换重要值比较以及Jackknife检验等综合分析方法,评价制约青钱柳现代地理分布的主要因子,可为青钱柳资源的科学保护和合理利用提供理论依据。【方法】基于183个青钱柳地理分布记录和8个气候环境因子数据,采用MaxEnt模型软件对青钱柳潜在适宜分布区进行预测,并在此基础上划分适宜栽培区。【结果】采用MaxEnt模型预测青钱柳潜在适宜分布区准确度极高,受试者工作特征曲线下的面积(AUC值)达0.964±0.006。目前,青钱柳高度适宜分布区为浙江南部、福建西北部、安徽南部、湖北东部、江西东部和西部、湖南东部和西部、贵州东部、重庆东部、陕西南部和四川东北部; 随着未来气温的升高,青钱柳有向高纬度和高海拔地区迁移的趋势。【结论】 影响青钱柳分布的主要气候因子是温度,包括年均温、季节温度变异系数和平均日温差,其中年均温为最主要因子。     

开发区经济增长要素分析及发展建议 ——基于苏南、苏中、苏北的面板证据

依据江苏省各地区所有开发区数据,利用面板数据从苏北、苏中、苏南三个角度,检验影响开发区经济增长的主要因素,通过对比分析得出三个地区在发展方式上的异同以及各影响要素对不同地区经济增长的贡献率。结果表明,自主创新和开放水平能够大力带动江苏省所有地区的开发区经济,苏北的发展要义在于加大环境保护力度,苏中的发展重点在于提高集约水平,苏南的发展模式较为成熟,应着重提高管理水平。     

开发区经济增长要素分析及发展建议 ——基于苏南、苏中、苏北的面板证据

依据江苏省各地区所有开发区数据,利用面板数据从苏北、苏中、苏南三个角度,检验影响开发区经济增长的主要因素,通过对比分析得出三个地区在发展方式上的异同以及各影响要素对不同地区经济增长的贡献率。结果表明,自主创新和开放水平能够大力带动江苏省所有地区的开发区经济,苏北的发展要义在于加大环境保护力度,苏中的发展重点在于提高集约水平,苏南的发展模式较为成熟,应着重提高管理水平。     

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.     

Features of Women's language

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.     

An Analysis of Catherine＇s Character——Wuthering Heights

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.     

Lower Paleozoic oil relationships within Williston Basin, Canada

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.     

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.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

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