虎林市水稻稻瘟病发生的原因分析

1 引言 虎林市是水稻生产大市,水稻种植面积现已达6×10^4 hm^2,占全市种植面积的54%。稻瘟病是危害水稻最严重的病害之一。稻瘟病的发生主要是气象原因,其危害程度因品种、栽培技术以及气候条件不同而有差异,流行年份一般减产10%～20%,严重的达40%～50%,甚至绝产。稻瘟病发病轻时,谷粒不饱满,品质下降;严重时,可使水稻成片枯死,颗粒无收。近几年来,虎林市水稻发生稻瘟病最严重的是2005年。本文分析2005年稻瘟病的发病症状、病菌来源和发病原因。     

辽宁水稻主产区稻瘟病发生特征分析

利用1999-2012年辽宁省8个水稻主产区（17个观测点）的稻瘟病资料,分析辽宁省水稻主产区稻瘟病的发生特征及发展趋势。结果表明：2001年、2003年和2010年辽宁地区水稻产量显著下降,水稻生产受稻瘟病影响较大。2011年辽宁水稻种植主要集中在沈阳、盘锦、铁岭、辽阳、丹东和营口地区,其余地区也有少量种植。2001年辽宁稻瘟病（主要为穗颈瘟）发生严重,发病率为27.7 %。稻瘟病主要在新宾和清原发生严重,平均发病率分别为17.0 %和16.4 %。辽宁不同熟期水稻以中早熟品种稻瘟病发生严重,平均发病率为10.1 %。辽宁不同区域以辽东地区水稻稻瘟病发生严重,平均发病率为11.2 %。     

气象因子对稻瘟病的影响及预报

通过对水稻稻瘟病的观测,找出温度、湿度、光照和风对稻瘟病流行的影响,和水稻返青期、抽穗前期稻瘟病的预测方法,建立了稻瘟病年发生的预报方程。     

重庆万州区稻瘟病发生发展与气象条件关系分析

利用万州1996—2007年气象资料及同期水稻稻瘟病病虫害资料,运用相关分析,筛选出与水稻稻瘟病密切相关的气象因子,分析其对稻瘟病发生发展的影响。结果表明:6月上旬≥0.1mm的降雨日数、6月下旬—7月上旬≥35.0℃的天数及7月中、下旬阴雨寡照天气与万州水稻稻瘟病的发生发展有紧密关系。另外分析发现:水稻稻瘟病的发生发展除气象因子这个主要原因外,还与水稻品种抗性、病源基数有关。     

2005年四川省水稻稻瘟病发生条件分析

稻瘟病是四川省水稻生产上的一种重要流行性、灾害性病害,稻瘟病的爆发流行严重威胁着水稻产量的提高.本文针对导致2005年四川省稻瘟病的发生流行的菌源、品种抗性、气象条件进行分析,为农业气象服务对稻瘟病发生条件分析提供思路.     

2005年四川省水稻稻瘟病发生条件分析

稻瘟病是四川省水稻生产上的一种重要流行性、灾害性病害，稻瘟病的爆发流行严重威胁着水稻产量的提高。本文针对导致2005年四川省稻瘟病的发生流行的菌源、品种抗性、气象条件进行分析，为农业气象服务对稻瘟病发生条件分析提供思路。     

稻瘟病发生发展气象条件等级业务预报技术研究

从稻瘟病发生机理出发,通过筛选满足稻瘟病病菌侵入寄主的气象因子条件,即水稻稻瘟病的促病气象指标:日平均气温20～30℃,日最低气温<20℃,空气相对湿度≥90%,日照时数≤1h,日降水量≥1mm,建立了水稻稻瘟病发生发展的气象条件促病指数Z,在相关分析的基础上确立了稻瘟病发生发展气象条件预报等级指标,通过1984-2006年历史回代检验,准确率为74%～78%.2007年实际业务服务应用,服务效果很好.     

灰色拓扑方法在广元稻瘟病预测中的应用

病虫害预测预报是粮食安全风险管理的重要内容之一,灰色理论用于病虫害预测是一项有益的探索。以水稻稻瘟病预报为例,本文详细阐述灰色系统理论的建模方法,利用广元市近20年水稻稻瘟病发生面积资料,建立了1个GM (1,1)拓扑预测模型,用于稻瘟病趋势预测,并取得了较为满意的结果。      

安顺1999年水稻稻瘟病发生的气象条件分析

分析了 1999年安顺地区水稻稻瘟病发生、发展的气象条件 ,得知春季低温、干旱是造成水稻苗瘟和叶瘟的主要气象条件 ;夏季低温阴雨的气温变幅大 ,诱发了水稻节瘟、穗颈瘟、谷粒瘟。提出了稻瘟病的防御措施。     

安顺1999年水稻瘟病发生的气象条件分析

分析了１９９９年安顺地区水稻稻瘟病发生、发展的气象条件,得知春季低温、干旱是造成水稻苗瘟和叶瘟的主要气象条件;夏季低温阴雨的气温变幅大,诱发了水稻节瘟、穗颈瘟、谷粒瘟。提出了稻瘟病的防御措施。     

加强业务管理提高测报质量

我局从1999～2003年,测报工作连续4年未出现错情,在此期间共有1个250个班,9个百班无错通过上级业务部门验收.在仪器保管、使用、维护上符合要求,对外报送的各种表、簿都能做好出门合格.     

Addressing the necessity of the registration of the effects of causal mechanics in the example of a simple barotropic model of the atmosphere

Summary Considering the effects of causal mechanics on geophysical problems enables us to explain a number of phenomena, which cannot be explained from conventional positions. This paper shows that the introduction of the force of causality in a simple barotropic hydrodynamic model of weather forecasts results in the outcomes, which, on the one hand, can not be described from the positions of classical hydro-thermodynamics, whilst on the other hand, exist in nature.     

Modeling the evolution of the family of Mediterranean cyclones using the regional model of the atmosphere

Due to the complex orography and the presence of the moisture-saturated air, the Mediterranean region is characterized by the increased baroclinic and convective instability, that leads to the sudden cyclogenesis and the formation of dangerous weather phenomena. The results are given of the investigation of formation mechanisms of Mediterranean cyclones, peculiarities of stages of their evolution and dynamical processes, which occur throughout the atmosphere, using the regional numerical ETA model of the atmosphere by the example of individual cases of the cyclogenesis over the Mediterranean Sea. It is revealed that the cold Arctic air outbreak (the intrusion of the cold Arctic air) to the south of the Western Europe, leading to the formation of the areas of the baroclinic instability and the increased moisture content of the air in the area of the vortex origin, favors the cyclogenesis. The use of the vertical coordinate η in the model enabled to compute more precisely the vertical wind speed, therefore, the influence of the orography on the moisture content and precipitation increase became pronounced. The transformation of the structure of meteorological fields in the course of the development of vortexes is considered. The computation of the helicity is made, and it is shown that this characteristic can be one of the earliest predictors of cyclogenesis.     

Analysis of the Characteristics of the Low-level Jets in the Middle Reaches of the Yangtze River during the Mei-yu Season

Here, we analyze the characteristics and the formation mechanisms of low-level jets(LLJs) in the middle reaches of the Yangtze River during the 2010 mei-yu season using Wuhan station radiosonde data and the fifth generation of the European Centre for Medium-Range Weather Forecasts(ERA5) reanalysis dataset. Our results show that the vertical structure of LLJs is characterized by a predominance of boundary layer jets(BLJs) concentrated at heights of 900–1200 m.The BLJs occur most frequently at 230...     

流场配置及地形对西南低涡形成的动力作用

本文采用定常二层模式讨论较小地形及高、低层流场配置对西南低涡形成的动力作用。指出了西南低涡的形成是与盆地、河谷以及其上气流分层有关的一种定常态.在上、下为西风分层时期,低层的浅薄暖湿西风有利于西南低涡的形成.在上、下为东、西风分层时期,上层浅薄东风亦有利于西南低涡的形成.小型的凸起山脉对西南低涡的形成没有作用.     

On the determination of the height of the Ekman boundary layer

The heighth of the Ekman turbulent boundary layer determined by the momentum flux profile is estimated with the aid of considerations of similarity and an analysis of the dynamic equations. Asymptotic formulae have been obtained showing that, with increasing instability,h increases as ¦¦^1/2 (where is the non-dimensional stratification parameter); with increasing stability, on the other hand,h decreases as ^–1/2. For comparison, a simple estimate of the boundary-layer heighth _u determined by the velocity profile is given. As is shown, in unstable stratification,h _u behaves asymptotically as ¦¦^–1, i.e., in a manner entirely different from that ofh .     

接地降阻剂的PH值的探讨

1引言我国执行接地降阻剂测试的技术标准是全国电力系统起草的:“接地降阻剂暂行技术条件修改稿”。在技术要求中要求接地降阻剂的酸碱值应在7￣12范围内。在实际使用中发现该技术要求对接地降阻剂的酸碱值要求范围并不合理,需要分析和讨论。2接地降阻剂的PH值接地降阻剂的酸碱性对地网的使用寿命至关重要,为了不让接地降阻剂腐蚀接地体或者减弱接地降阻剂对接地体的腐蚀,在接地降阻剂测试的技术要求中,对接地降阻剂的酸碱度有一定的限制。国内各厂家用于生产接地降阻剂的偏弱酸的盐类进行了对镀锌钢材腐蚀的试验,结果是这些镀锌钢材均受到…     

阴山山脉对内蒙古中部地区气象要素影响初探

文章选用阴山山脉山北乌拉特后旗、白云、达茂旗、苏尼特左旗、化德,山南杭后旗、包头、呼和浩特、察右前旗、兴和1971—2000年气温、降水量、天气现象等资料进行对比分析,得到阴山山脉对内蒙古自治区中部地区气象要素影响初步结论。     

2003年黑龙江省主要灾害性天气及其对作物生长发育和粮食产量的影响

利用40年气温、降水资料和历史上千旱、低温严重的年份与2003年进行对比分析．评估黑龙江省2003年发生的严重灾害的分布范同,灾害程度,及其对主要粮食作物生长发育和产量的影响。得出2003年的灾害是30年未遇的全省性严重灾害年,各种灾害对各种作物都产生了不同程度的影响,受害最重的作物是小麦。     

On the forecast of the onset and end of the convective season in the Amazon

Summary ?Some features of the climate system that can be considered predictors of the onset and end of the convective season over the Amazon were identified using one-month lag correlations and field composites. The fields analyzed were sea surface temperature (SST), outgoing long-wave radiation (OLR), vertical velocity and upper tropospheric winds. Warm (cold) anomalies in the SST in the tropical North Atlantic and the Caribbean Sea tend to be associated with delayed (early) onsets. Likewise, there is a tendency towards a delayed (early) end of the convective season with cold (warm) anomalies in these ocean regions. In addition, the SST in the cold tongue region of the equatorial Pacific is negatively, though weakly correlated with the onset date. The signal of this SST is more evident in the case of the end date, which is earlier with respect to its mean date in most of El Ni?o cases. The convective activity intensity itself conditions the onset and the end of the convective season, as it is evidenced by the behavior of the OLR and the vertical velocity fields. The more (less) intense the convective activity over South America during the preceding month, the earlier the onset and the later the end of the convective season on the Amazon region. The prediction of the onset and end dates of the convective season in the Amazon region was explored using a simple multiple regression technique based on the variables that have shown precursor signals with respect to these dates. The correlation coefficient between the predicted and the observed onset date is 0.81, and in the case of the end date, it is 0.76. The skill to predict early, delayed and normal categories was high, since in more than two thirds of the cases the category was successfully predicted, and there were no predictions of categories opposed to those observed. Received July 23, 2001; revised February 22, 2002; accepted April 26, 2002