干旱

Agricultural drought on farmland or basin,which restricted by climate, geo logy,hydrography, soil moisture,plants, cultivation and water allocation etc.,is a complicated system.

农业干旱模型可用于农业干旱评价。本文对辽河流域六个区，海滦河流域九个区，黄河流域三个区，长江流域九个区P=50%，P=75%，保证率下农业干旱状况进行评价。

The 250 mm isohyet is used as the climatic boundary line between arid and semiarid region and it shifts at a maximum distance of 110-130 km during the extreme dry and wet year.

干旱半干旱过渡带是生态环境变化的敏感和脆弱地带，气候的波动性和人口压力是生态脆弱的根本原因，干旱和半干旱区交界线在丰枯年份的空间摆动幅度最大达110-130km。

Jack pine had higher rate of gas exchange and water use efficiency than black spruce when seedlings were well watered.

解除干旱胁迫后，黑云杉的气孔敏感性、光合能力及水分利用效率的恢复都要比北美短叶松更快。轻度的干旱胁迫锻炼可以帮助北美短叶松在更严重的干旱胁迫下保持固有而强劲的耐旱能力。

Desertification is land degradation occurs in arid, semi-arid and subhumid regions, which is one of the he environmental problems human society generally concerned in the context of global change, has a direct relationship with the survival and development of their own humanity.

沙漠化即发生在干旱、半干旱及半湿润干旱地区的沙质荒漠化，是全球变化背景下，人类社会普遍关注的环境问题之一，与人类自身的生存和发展有着直接的关系。

In Huang-Huai-Hai region, the focus was to strengthen the cultivation and management to reduce yield gap between test and field production, because there were a high scientific and technological level but shortage of water, etc. In middle and lower reaches of the Yangtze River region, the focus was to strengthen the ability of drainage and avoided water-logging etc. In north-eastern region, the focus was to avoid drought and high-temperature damage, sometimes spike-sprouting caused by rain pre-harvest.

黄淮海优势区灌溉水短缺，干旱、干热风等自然灾害频发，但小麦科技实力较强，育种和栽培研究水平相对较高，要加强栽培管理缩小试验地产量与大田产量的差距；长江中下游小麦优势区排涝和降渍能力比较弱，渍害、穗发芽时有发生；东北小麦优势区干旱和高温频发、收获前常遇阴雨导致穗发芽；西北小麦优势区土壤瘠薄、干旱少雨；西南小麦优势区日照不足、雨多雾大晴天少，易旱易涝等。

Using the concept of soil-moisture-balance suggested in Palmer-drought-model for reference, daily available water content in upper and lower levels of soil is simulated with daily maximum temperature and rainfall data. Drought dynamic index, I, defined by AWC of lower level soil, with definite physical meaning and data acquirability, is presented in the paper, by which a drought course can be depict in detail, and how a drought course occurs and develops can be monitored and evaluated dynamically.

借鉴帕默尔早度模式中的土壤水份平衡概念，采用逐日气温和降水量资料，对土壤有效含水量（分上、下2层）进行了逐日滚动模拟，提出了以下层土壤有效含水量构建逐日干旱动态强度指数I(下标 D，该指数物理意义明确，实时资料可得，能够刻画干旱过程的丰富细节，实现对干旱发生、发展及其强度的逐日动态监测与评估。

Drought and water shortage are worldwide problems in 21st century. Controlling of soil water evaporation and collecting of aerial water have become significant approaches to improve water shortage in droughty region.

干旱缺水已成为21世纪和未来的世界性难题，减少土壤水分蒸发、收集空气中的水分，已成为缓解干旱、半干旱地区水资源紧缺的重要途径。

Seven grapevine cultivars originated from different regions, i. e.'Carbernet Sauvignon' and'Queen of Vineyard'(two members of the Western Europe Cultivars Group),'Rizamat'(a member of the East Cultivars Group),'Red Double Taste'(a hybridized cultivar from Vitis vinifera L. and V. labrusca L.),'1103Paulsen','Red Globe'and 'Autumn Royal'(two new hybridized cultivars between cultivars groups which were warmly planted in recent years) were selected. After different drought stress, a combined measurement of gas exchange and chlorophyll fluorescence was conducted to evaluate the effects of drought stress to photoinhibition, as well as the role of photorespiration and xanthophyll cycle in photoprotective mechanism. After photorespiration and xanthophyll cycle were separately inhibited, the complementary effect of these two photoprotective pathways was discussed. Detached leaves of different grapevine cultivars, i. e.'Cabernet Sauvignon','Cabernet Franc','Merlot', and a rootstock,'1103Paulsen'were selected as materials, and photoinhibition degree, photorespiration activity as well as its photoprotective function under drought stress were studied. The results are as follows: 1. Under the same drought stress treatment, different photoinhibition degrees formed in different grapevine cultivars.

本研究选择不同起源地的葡萄品种－－包括西欧品种群的赤霞珠和葡萄园皇后、东方品种群的里扎马特、欧美杂种红双味、美洲种砧木1103Paulsen，以及近年来发展较快的品种群间杂交新品种红地球和皇家秋天等七个品种盆栽苗，在进行不同程度的干旱胁迫处理后，利用气体交换参数和叶绿素荧光参数同步测定的方法，研究干旱对其光抑制程度的影响，以及光呼吸和叶黄素循环组分在其光保护中的作用；并在分别抑制光呼吸和叶黄素循环的基础上，探讨了赤霞珠葡萄两种光保护机制的互补效应；同时选择不同的酿酒葡萄品种赤霞珠、品丽珠、梅鹿辄和砧木1103Paulsen的叶片，研究其离体干旱条件下光抑制程度、光呼吸活性及其光保护作用，结果发现： 1。

This conclusion is based on three groups of experiments with detached root tips of wheat seedlings: By following the time course changes of NO synthase , superoxide synthase and ABA accumulation under dehydration stress, we found that ABA accumulation was preceeded by the changes of NOS and superoxide synthase. ABA accumulation induced by dehydtrion stress and osmotic stress can be blocked by NO scanvegers and NOS inhibitors, while only dehydration stress-induced ABA accumulation can be blocked by ROS scanvegers. Exogenous applied NO or ROS induced ABA accumulation in root tips of wheat seedlings, and synergistic effects were found between NO and NO. The in planta expereiments also proved that ROS and NO are involved in water stress-induced ABA accumulation.Ⅱ.

证据主要来自以离体根尖为材料的实验：(1)通过检测干旱胁迫下小麦根尖NOS活性、O〓合成酶活性和ABA积累的时间变化进程，发现ABA积累滞后于ROS和NO的变化；(2)抑制剂实验表明，NO清除剂和NOS抑制剂可以抑制自然干旱胁迫及渗透胁迫诱导的小麦根尖ABA积累，ROS清除剂抑制自然干旱胁迫诱导的ABA积累而不抑制渗透胁迫诱导的小麦根尖ABA积累；(3)在非胁迫条件下施加外源的ROS或NO可以诱导小麦根尖积累ABA，ROS和NO之间具有协同作用。

When the relative soil water content were 55%-40%, the main reasons of the photosynthetic rate declined were stomatic limitation. When the relative soil water content were 20%, the main reasons of the photosynthetic rate declined were nonstomatic limitation.

干旱胁迫下，光合速率的下降是气孔因素与非气孔因素双重作用的结果：轻度干旱胁迫下（土壤相对含水量55%~40%）气孔限制是光合速率下降的主要原因，而严重干旱胁迫下（土壤相对含水量20%）非气孔限制是光合速率下降的主要原因。

Neither the killing of Mr Zarqawi nor any breakthrough on the political front will stop the insurgency and the fratricidal murders in their tracks.

在对危险的南部地区访问时，他斥责什叶派民兵领导人对中央集权的挑衅行为。

In fact,I've got him on the satellite mobile right now.

实际上 我们已接通卫星可视电话了