速率

By use of titration analysis, the thesis investigated various factors such as isocyanate, PE molecular weight, reacting substance molecular ratio, reacting temperature and time etc. influencing upon prepolymerization step. It was found that 2, 4-tolulene diisocyanate and 4, 4'diphenylmethane diisocyanate is more rapidly reacted with PE600 than HDI. With PE molecular weight increasing, the reacting temperature or time should be raised or extended relevantly. Thus PE2000+2HDI pre-polymerization should be better carried out under some catalyst, for example, Triethylene diamine , Dibutyltin dilaurate and Tin octoate were used.

首先采用滴定分析方法对WRPU预聚反应的影响因素进行了研究：芳香族二异氰酸酯TDI、MDI比脂肪族二异氰酸酯HDI反应活性高，其中TDI在反应初始阶段的反应速率比MDI快，不过随着反应的进行，MDI比TDI反应速率加快，这主要是因为TDI分子中的两个-NCO反应活性差异大所致；二元醇分子量越大，反应速度越慢；聚醚二元醇比聚酯二元醇的反应速度快；当分子量超过2000的二元醇与HDI进行预聚反应时，需借助适当的催化剂来加快反应速度，从而使预聚反应能够顺利进行，分别选择DABCO、TOA和DBDTL三种催化剂进行催化反应，发现不同的催化剂，其催化效果相差较大。

Of course, unlike the Ogallala, most aquifers are naturally "recharged"—replenished by rain and runoff—but even these are being depleted dramatically, as the rate of withdrawal easily surpasses the recharged amount.

当然，和奥加拉拉蓄水层不同的是，大多数蓄水层可以天然&充水&——由雨水和径流补给，即便如此，由于抽用速率轻而易举就超过了补给速率，这些蓄水层也在急剧衰耗。

The results showed that organic manure combined with constant chermical NPK fertilizer continually increased the content of soil organic carbon, readily oxidable organic carbon, humus cat.n, and their proportion in total organic carbon, HAC, FAC and HAC/FAC, but decreased Kos progressively.

结果表明，采用有机肥料配施常量NPK化肥，土壤有机碳、易氧化有机碳、腐殖酸碳及其占总有机碳比率、HAC、FAC和HAC／FAC不断提高，Kos持续下降，其变化速率表现为递减；长期不施肥和单施常量NPK化肥则造成Kos持续上升，其余指标以递减速率下降。

The method of series rate is used to study the linear growth order of ammonium paratungstate crystal.

将结晶成核期后晶体的生长阶段作为线生长速率测定的时间范围，采用&串联速率法&研究了仲钨酸铵的晶体线生长级数。

The response of gas exchange parameters such as net photosynthesis rate, transpiration rate, water use efficiency of leaf, stomatal conductance and intercellular CO2 concentration of 2-years old Periploca sepium Bunge to different soil water content were studied in Loess Plateau with CIRAS-2 portable photosynthesis system.

在半干旱黄土丘陵区，采用CIRAS-2型光合作用系统，在不同土壤水分条件下，对2年生杠柳的净光合速率、蒸腾速率、叶片水分利用效率、气孔导度和胞间CO2浓度等叶片气体交换参数的日变化进行了研究。

It is researched the influence of cooling rate and the content of silicon and manganese alloy on peritectic reaction and position of peritectic point in Fe-C alloy.

研究了冷却速率和硅、锰合金元素含量对Fe-C合金的包晶反应和包晶点位置的影响；由于CSP薄板坯冷却速率快，Fe-C相图向左下方移动，包晶反应区域的碳含量为0。

The rate constant of thereaction of pyrocatichol with organic peroxyl radicals is about 1～2 orders higher thanits reaction with superoxide anion radical.

邻苯二酚与有机过氧自由基的反应速率要比与超氧阴离子自由基的反应速率高1～2个数量级。

The relativity analysis indicated that the net photosynthetic rate of F.cymosum had a positive correlation to the stomatal conductance,photosynthetically active radiation,transpiration rate and water utilization efficiency,and negative to the intercellular CO2 concentration.

相关性分析表明，金荞麦叶片净光合速率与气孔导度、光合有效辐射、蒸腾速率和水分利用效率等呈正相关，与胞间CO2浓度呈负相关。

Stomatal conductance,photosynthetically active radiation and transpiration rate were the main environment factors that affected the net photosynthetic rate of F.cymosum .

金荞麦为阳生植物，气孔导度、光合有效辐射和蒸腾速率是影响金荞麦叶片净光合速率的主要环境因子。

Diaminodiphenylmethane and phthalic anliydride etc., were studied by means of differential scanning calorimetry.

DSC测得的数据表明，反应速率的最大值并不出现在t=0的时刻，而在转化率为40％左右时反应速率最大，所以服从自催化反应历程。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。