丹东春季回流天气最高气温预报方法研究

分析了丹东地区近50年春季(3~6月)最高气温南北偏差5℃以上的回流天气的气候特征,重点分析了2014年春季丹东地区回流天气的特征,根据地面形势将回流天气分成了2种典型类型。中央指导预报产品对丹东地区回流天气预报误差比较大,运用T639数值预报产品对中央指导报进行订正,可以极大地提高预报准确率。     

Staying alive – is cell death dispensable for plant disease resistance during the hypersensitive response?

Probably the most known and best studied type of plant resistance to pathogenic infections is the hypersensitive response (HR), a form of localized programmed cell death associated with restriction or killing of pathogens that often leads to macroscopically visible localized tissue necrosis. It is generally assumed that cell death and resistance within the HR are physiologically and genetically linked. However, there has been considerable speculation about whether cell death is an absolute requirement for resistance conditioned by the HR. This review discusses the relation of cell death and resistance in the HR, in particular, the importance of cell death in this process. We intend to focus on the increasing amount of research evidence showing that in several plant-pathogen interactions, the two main components of the HR – resistance and cell death – can be physiologically, genetically and temporally uncoupled. In other words, HR should be considered as a combination of resistance and cell death responses, where cell death may be dispensable for plant disease resistance. The varying contribution of these two components (i.e. cell death and resistance) generates an array of defense strategies differing in efficiency. Thus, a very early and rapid defense response seems to contribute to the development of macroscopically symptomless (extreme) resistance, while a moderately early defense response results in resistance with the concomitant development of controlled and limited cell and tissue death (HR). Accordingly, a delayed and failed attempt by the host to elicit resistance responses would result in massively stressed plant tissues (e.g. “systemic HR”) and a partial or almost complete loss of control over pathogen invasion. The dynamic nature of resistance responses in plants implies that resistance can be effective with or without cell death but its outcome and efficiency may depend primarily on the timing and speed of the host response.     

使用JDBC实现自动气象站要素信息检索

介绍了使用JDBC实现自动气象站分中心站的气象要素信息检索，程序运用B／S体系结构，遵循MVC设计思想，采用Model2模式进行开发，为了提高程序的运行速度，在数据库中创建了存储过程。     

Impact analysis of climate data aggregation at different spatial scales on simulated net primary productivity for croplands

For spatial crop and agro-systems modelling, there is often a discrepancy between the scale of measured driving data and the target resolution. Spatial data aggregation is often necessary, which can introduce additional uncertainty into the simulation results. Previous studies have shown that climate data aggregation has little effect on simulation of phenological stages, but effects on net primary production (NPP) might still be expected through changing the length of the growing season and the period of grain filling. This study investigates the impact of spatial climate data aggregation on NPP simulation results, applying eleven different models for the same study region (∼34,000 km²), situated in Western Germany. To isolate effects of climate, soil data and management were assumed to be constant over the entire study area and over the entire study period of 29 years. Two crops, winter wheat and silage maize, were tested as monocultures. Compared to the impact of climate data aggregation on yield, the effect on NPP is in a similar range, but is slightly lower, with only small impacts on averages over the entire simulation period and study region. Maximum differences between the five scales in the range of 1–100 km grid cells show changes of 0.4–7.8% and 0.0–4.8% for wheat and maize, respectively, whereas the simulated potential NPP averages of the models show a wide range (1.9–4.2 g C m⁻² d⁻¹ and 2.7–6.1 g C m⁻² d⁻¹ for wheat and maize, respectively). The impact of the spatial aggregation was also tested for shorter time periods, to see if impacts over shorter periods attenuate over longer periods. The results show larger impacts for single years (up to 9.4% for wheat and up to 13.6% for maize). An analysis of extreme weather conditions shows an aggregation effect in vulnerability up to 12.8% and 15.5% between the different resolutions for wheat and maize, respectively. Simulations of NPP averages over larger areas (e.g. regional scale) and longer time periods (several years) are relatively insensitive to climate data aggregation. However, the scale of climate data is more relevant for impacts on annual averages of NPP or if the period is strongly affected or dominated by drought stress. There should be an awareness of the greater uncertainty for the NPP values in these situations if data are not available at high resolution. On the other hand, the results suggest that there is no need to simulate at high resolution for long term regional NPP averages based on the simplified assumptions (soil and management constant in time and space) used in this study.     

Application of the Cropping System Model (CSM)‐CROPGRO‐Soybean for Determining Optimum Management Strategies for Soybean in Tropical Environments

The determination of optimum crop management practices for increasing soybean production can provide valuable information for strategic planning in the tropics. However, this process is time consuming and expensive. The use of a dynamic crop simulation model can be an alternative option to help estimate yield levels under various growing conditions. The objectives of this study were to evaluate the performance of the Cropping System Model (CSM)‐CROPGRO‐Soybean and to determine optimum management practices for soybean for growing conditions in the Phu Pha Man district, Thailand. Data from two soybean experiments that were conducted in 1991 at Chiang Mai University and in 2003 at Khon Kaen University were used to determine the cultivar coefficients for the cultivars CM 60 and SJ 5. The CSM‐CROPGRO‐Soybean model was evaluated with data from two experiments that were conducted at Chiang Mai University. The observed data sets from farmers’ fields located in the Phu Pha Man district were also used for model evaluation. Simulations for different management scenarios were conducted with soil property information for seven different soil series and historical weather data for the period 1972–2003 to predict the optimum crop management practices for soybean production in the Phu Pha Man district. The results of this study indicated that the cultivar coefficients of the two soybean cultivars resulted in simulated growth and development parameters that were in good agreement with almost all observed parameters. Model evaluation showed a good agreement between simulated and observed data for phenology and growth of soybean, and demonstrated the potential of the CSM‐CROPGRO‐Soybean model to simulate growth and yield for local environments, including farmers’ fields, in Thailand. The CSM‐CROPGRO‐Soybean simulations indicated that the optimum planting dates from June 15 to July 15 produced maximum soybean yield in a rainfed environment. However, the planting date December 15 produced the highest yield under quality irrigation. Soybean yield was slightly improved by applying nitrogen at a rate of 30 kg N ha^?1 at planting. Soybean yield also improved when the plant density was increased from 20 to 40 plants m^?2. The results from this study suggest that the CSM‐CROPGRO‐Soybean model can be a valuable tool in assisting with determining optimum management practices for soybean cropping systems in the Phu Pha Man district and might be applicable to other agricultural production areas in Thailand and southeast Asia.     

Fire Environment Mechanism of Lightning Fire for Daxing''''an Mountains

Lightning fire is one of natural fires; its mechanism is very complex and difficult to control. Daxing'an Mountain is the main region that lightning fires occur in China. Research on lightning fires indicates that special fuel, dry-storm weather and high altitude form the lightning fire environment. Lightning fires have close relation with lights. When lightning occurs, especially dry-lightning which brings little precipitation with surface temperature growing and fuel dehydrating, these often lead to lightning fires. Lightning fires have characteristics of geography, time and topography. The higher altitude forest region in Daxing'an Mountain, the more lightning fires occur. Valley with altitude above 800 m in the north of 51.N and Larix gmelinii-Pinus pumila, Pinus sylvestris var. mongolica -Pinus pumila forests on the top of mountain are the most concentrating region where lightning fires occur. One serial dry-storming can ignites many lightning fires, the furthest between them is as long as 150 km.     

Enhancing the Simplified Surface Energy Balance (SSEB) approach for estimating landscape ET: Validation with the METRIC model

Evapotranspiration (ET) can be derived from satellite data using surface energy balance principles. METRIC (Mapping EvapoTranspiration at high Resolution with Internalized Calibration) is one of the most widely used models available in the literature to estimate ET from satellite imagery. The Simplified Surface Energy Balance (SSEB) model is much easier and less expensive to implement. The main purpose of this research was to present an enhanced version of the Simplified Surface Energy Balance (SSEB) model and to evaluate its performance using the established METRIC model. In this study, SSEB and METRIC ET fractions were compared using 7 Landsat images acquired for south central Idaho during the 2003 growing season. The enhanced SSEB model compared well with the METRIC model output exhibiting an r² improvement from 0.83 to 0.90 in less complex topography (elevation less than 2000 m) and with an improvement of r² from 0.27 to 0.38 in more complex (mountain) areas with elevation greater than 2000 m. Independent evaluation showed that both models exhibited higher variation in complex topographic regions, although more with SSEB than with METRIC. The higher ET fraction variation in the complex mountainous regions highlighted the difficulty of capturing the radiation and heat transfer physics on steep slopes having variable aspect with the simple index model, and the need to conduct more research. However, the temporal consistency of the results suggests that the SSEB model can be used on a wide range of elevation (more successfully up 2000 m) to detect anomalies in space and time for water resources management and monitoring such as for drought early warning systems in data scarce regions. SSEB has a potential for operational agro-hydrologic applications to estimate ET with inputs of surface temperature, NDVI, DEM and reference ET.     

冷锋云系的多普勒雷达反射率因子特征总结

[目的]总结冷锋云系的多普勒雷达反射率因子特征。[方法]从反射率因子特征上来研究冷锋云系,利用2002～2007年哈尔滨新一代天气雷达资料,总结了冷锋云系的反射率因子特征。[结果]冷锋所产生的云总体上说呈带状,但其间云体有间隙,且强度分布不均匀;多数移动快的冷锋为长而窄的回波带,移动缓慢的冷锋或弱冷锋,则呈宽广的片状或片絮状回波;面积大的冷锋云系通过测站基本都可以分析出径向速度由西北风转为西南风;随着月份的不同,反射率因子特征也有很大的变化。在冬季,冷锋云表现为层状云,反射率因子特征非常弱,一般面积较大,呈片状,但结构松散,回波间有间隙,其中夹杂着几块比较强的回波;在冷锋两侧易产生强度大的对流单体回波,一般会随着整体云带移动,移速、移向基本一致;干冷锋移过时,易局地产生强对流,以对流云为主,回波面积较小,一般从径向速度图中分析不出风向转变,但单体的强度特征明显,一般有＂三体散射＂、＂旁瓣＂、＂弱回波区＂特征,具有超级单体的特征。[结论]该研究为多普勒雷达在黑龙江省监测灾害天气的应用上起到了积极作用。     

安徽省极端降水事件的判别分析

利用安徽省68个台站近40年的日降水资料,运用累积频率法判别分析基于日资料的极端降水事件,给出了安徽省各台站降水极端事件的阈值.着重分析了阈值的空间分布,出现最大和最小阈值站点的降水时间序列特征及夏季暴雨多发地带的区域极端降水的特征.同时运用一元线性回归和滑动平均分析了暴雨多发地带的区域降水变化趋势.     

烟草野火病“天气促病指数”表解模型的建立

在对野火病各流行环节定量研究的基础上，提出了可以进行烟草野火病短期预测的“天气促病指数表解模型”。这种模型是建立在对植物病原细菌从植物体内经雨露浸出到植物体表，再进一步侵染新的寄主植物健康部位这一过程的逼真模拟基础上，所以它具有机理模型的特点和优点，这种模型虽不能进行数值预测，但可以进行较为的病情发展趋势，而且不需要计算机，只要查表就可以进行预测的有关运算，是一种较有应用潜力的模型。