降水

A comparative study of pollen floras between two cores: Core 17940 from the northern slope of the South China Sea and a core from the Toushe Basin in central Taiwan Province, reveals that there were three different vegetation types around the two areas during 15-40kaBP. The first type is characterized with the subtropical evergreen broadleaved forest during MIS2 (20-15kaBP). The second is the Pinus/Alnus-dominated woody plant communitites, corresponding to an interstadial summer monsoon dominated warm and humid climate and higher sea/lake level. The third is the Artemisia/Poaceae-dominated herb communities, corresponding to a stadial winter monsoon dominated warm and dry climate and lower sea/lake level.

根据南海北部17940孔和台湾中部头社孔孢粉序列对比结果，首次提出了华南地区15-40kaBP期间的三个具代表性植物群：1以青栲类为主的亚热带常绿阔叶林为第1植物群，该植物群在MIS2阶段(20-15kaBP)，为南海北部周边地区和台湾中部头社盆地周围地带性植被；2以松属或桤木属为主的木本植物为第2植物群，对应于间冰阶，夏季风盛行，降水充沛，气候暖湿，高海面；3以蒿属或以禾草为主的草本植物为第3植物群，对应于冰阶，冬季风盛行，降水少，气候暖干，低海面。

Through analysis of potential vorticity in isobaric surface field, in high-troposphere a positive potential vorticity disturbance before rainstorm generation;positive potential vorticity disturbance in high-troposphere downward, form one vertical disturbance column, now corresponding precipitation develop stage;When near ground arises negative potential vorticity disturbance, precipitation also weaken.

通过对等压面的位涡分析，发现在暴雨发生发展时，在对流层高层有正位涡向下扰动，在暴雨的发展鼎盛阶段，从对流层中高层到地面形成一个垂直扰动柱；位涡柱对地面气旋的发展有较好的指示性，位涡柱形成时刻前后降水达到最强；当近地面出现负的位涡扰动时，降水随之减弱。

Analysis of lag correlation suggests that minimum cloud hydrometeors leads the maximum precipitation rate by 4-5 hour, and maximum cloud hydrometeors lags maximum precipitation rate by 1-2 hour.

滞后相关分析表明，降水率的峰值到来之前4-5小时云中水凝物含量最少，降水率的峰值到来之后1-2小时，云中水凝物含量最多。

In the 54th years, the lapse rate of precipitation during JJA over the SH is 0.12mm/a, just half as much as that over the NH.

在54年的时间段内，南半球6~8月降水的递减速度为0.12mm/a，仅为北半球同期降水减幅(0.24mm/a)的一半。

Since Doppler weather radar can detect the radar echo reflectivity factor and the radial velocity of precipitation at the same time, it has considerably deepened our understanding of the physical mechanism of precipitation and the rainstorm dynamics, and can largely improve the warning and nowcasting capacity of rainstorms, hails, squall line and tornadoes with its wide use.

多普勒天气雷达能够同时测量降水的雨强分布和目标的运动速度，使得人们在降水物理和风暴动力学方面的认识有很大提高，它的广泛使用会大大改善暴雨、冰雹、雷雨大风和龙卷等灾害性天气的警戒和短时预报能力。

Pass the analysis of pair of sensitivity test results, making clear flux of lunt of face of bureau ground underlay is the intensity that through changing low layer atmospheric the layer writtens guarantee the structure will affect precipitation and main precipitation period of time.

通过对敏感性试验结果的分析，表明局地下垫面水汽通量是通过改变低层大气的层结结构来影响降水的强度和主要降水时段的。

Contemporary artificial rainfall is artificial rainfall basically is principle of basis nature rainfall, launch activator from the ground through the plane is spread or using tall artillery piece, rocket, wait like silver iodide, dry ice, liquid nitrogen, drop cloud layer temperature thereby, form supersaturation lunt; to perhaps condense to the boardcast sowing in the cloud layer that contains supersaturation lunt nucleus, increase the ice crystal amount in the cloud, increase the amount of drip-drop and diameter then, raise cloud precipitation change rate, achieve the goal that raises precipitation of bureau ground nature thereby.

二、现代的人工降雨人工降雨主要是依据自然降雨原理，通过飞机播撒或利用高炮、火箭从地面上发射催化剂，如碘化银、干冰、液氮等，从而降低云层温度，形成过饱和水汽；或者向含有过饱和水汽的云层中撒播凝聚核，增加云中的冰晶数量，进而增加雨滴的数量和直径，提高云降水的转化率，从而达到增加局地自然降水的目的。

This showed that capacity of water-holding in biological soil crusts were obvious improve,and effected precipitation permeate or water second distribute process.The study results of"fertile islands"formation mechanism in biological crusts showed that biological crusts layer cover could increased nutrients content for below sand soil through precipitation permeate washing,and it promoted plants assimilate more nutriment.The matter import ways of biological soil crusts fertility island had many ways,including the effection of living macrobiotics metabolism in crusts levels,wind-sand flow of near surface,dust deposition and plants decomposition course,etc.Source of particle matter in biological soil crusts was wind-sand flow of near surface,and not dust deposition.Biological crusts layer cover had preserved effection for nature water content in 0-5cm soil layer,compared with the sand of no biological crusts layer,effecting precipitation permeate,and could not obvious restrained from the water evaporate process indoor experiment.

生物结皮层肥岛形成机制的研究结果表明：生物结皮层覆盖能够通过降水淋溶作用而增加下层土壤养分的含量，进而促进植物对养分的吸收；生物结皮层养分输入有结皮生物代谢、降尘、风沙流和植物分解矿化作用等多(来源：A73e3B3eC论文网www.abclunwen.com)种途径，但生物结皮层的颗粒物质来源主要是近地表风沙流，而不是大气降尘；生物结皮层覆盖对0-5cm土层自然含水量有一定的保护作用，并影响降水向深层渗透，不能有效的阻止表层水分的蒸发进程；研究表明采取人工促进技术能够在流动沙丘上形成生物结皮层，实现流动沙地的快速治理。

The nutrints imported from rainfall,and ratio between nutrient content and total nutrient content in macroelement and microelement,and changes in month and year were analyzed.

本文就寒温带大兴安岭林区兴安落叶松原始林生态系统降水输入总养分含量、大量元素和微量元素的养分含量占总养分含量的比值、降水输入养分含量月际变化和年内分配等进行了分析。

The initial conditions created by the precipitation data assimilation experiment make an adjustment on the temperature and humidity fields to improve the heavy rainfall forecast.

降水资料的同化场主要通过对温度场和湿度场的调整来影响对强降水的模拟。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。