底的

Suitable substrates were the key factors for xylanases production. XylanaseB was produced mainly when corn starch or beechwood xylan was used as the inducing substrate.

发酵底物是产生木聚糖酶的重要影响因素，在以玉米淀粉或山毛榉木聚糖为底物时，产生的木聚糖酶主要是木聚糖酶B，而以廉价的麦麸为底物则主要产生木聚糖酶G和B。

On the basis of the kinetic equation of substrate reaction in the presence of urea or guanidine hydrochloride, all microscopic kinetic constants for the free enzyme and enzyme-substrate binary and ternary complexes have been determined. The results of the present studies indicate that:①In the presence of urea or guanidine hydrochloride, enzyme-substrate complexes lose their activity less rapidly than the free enzyme. Therefore, both substrates, NADPH and 7, 8-dihydrofolate, protect dihydrofolate reductase against inactivation.②The denaturation of dihydrofolate reductase by urea follows single-phase kinetics, and changes in enzyme activity and tertiary structure proceed simultaneously in the unfolding process, so it may be an"all or none"process.③The GdnHCl-induced unfolding of the dihydrofolate shows a biphasic transition, while the change in the enzyme activity is a single exponential process. The rate constant of inactivation is consistent with that of the fast conformational change. Therefore, the kinetic intermediate of protein unfolding should be a partially folded and inactive form.

我们根据在脲或盐酸胍存在下的底物反应动力学方程求得游离酶和酶底物二元、三元复合物的微观动力学常数，结果表明：①酶-底物二元、三元复合物的失活速度明显慢于游离酶，说明两个底物二氢叶酸和NADPH对酶的失活都具有一定程度的保护作用；②在脲作用下，酶的失活和构象变化均为单指数项过程，而且酶的活力丧失和三级结构变化是同时发生的，说明二氢叶酸还原酶的脲变性可能是一个"全或无"的两态过程；③在盐酸胍作用下，酶的构象变化为两相过程，而失活则是单指数项过程，酶分子构象变化的快相速度常数与失活速度常数基本一致，因此我们认为二氢叶酸还原酶的盐酸胍变性过程中存在一个没有活力、但仍具备一定空间结构的变性中间体。

The number of the species of macrofauna of the Lotus flower bridge mudflat in the spring, summer, autumn and winter were respectively 19, 20, 20 and 12, respectively.

结果在两地共发现大型底栖动物38种，分别隶属于4门5纲24科，其中澳门莲花大桥滩涂的大型底栖动物有4门5纲23科34种，占两个湿地总种数的89%；路凼湿地大型底栖动物有3门4纲15科21种，占两个湿地物种数的55%。

This article analyses Thucydides' narration of the beginning of Peloponnesian War, and compares it with IR scholars' interpretation of Thucydides.

200字本文分析了修昔底德关于伯罗奔尼撒战争起因的论述，并将修昔底德本人的论述和国际关系学者对修昔底德的解读进行了比较。

Based on a hypothesis of function-equivalence which occurred not only in the mental folding but also object folding for individuals, this research indicated that individuals will search a fixed undersurface to fold up adjacent surfaces. Therefore, the type of unfold cube which had less undersurfaces and more adjacent surfaces could be more quickly for individuals to identify its undersurface, complete the mental folding and have better performance.

研究者以个体心像摺合时会与实物摺合存在功能相等性的假设，认为个体在心像摺合时会先寻找一个固定底面，再一起摺合所有邻面，因此底面数较少、邻面数较多的展开图类型会较快判定底面并完成心像摺合，而有较佳的表现。

Brey's (1990) empirical formula was used to calculate the secondary production and P/B ratio of macrobenthos according to macrobenthos biomass and abundance obtained in Shenhu Bay. The results showed that the mean annual secondary production and P/B ratio were 0.599g/(m^2a) and 1.561 respectively.

根据各个季节获得的大型底栖动物栖息丰度和生物量，采用Brey (1990)的经验公式进行了大型底栖动物次级生产力和P/B值的计算，得出深沪湾潮下带大型底栖动物年平均次级生产力和P/B值分别为0.599g/和1.561。

An hot simulation experiment has been made to investigate the process of forming mushroom above outlet of bottom bloving nozzel in combined blowing converter , and the relation between the temperatures of bottom bloving nozzel as well its peripheric refractory lining, and the temperature of hot metal as well the flowrate of bottoin blowing gas.

通过热态模拟试验，研究了复吹转炉底吹喷枪出口端生成蘑菇头的过程以及底吹喷枪温度、周围耐火材料内的温度与铁水温度、底吹气体流量之间的关系。

Therelationship between the turbulent kinetic energy and its dissipation rate,whichis widely used to parameterize the dissipation rate in turbulence closure models,is found to hold well for both reversing and rotating flows,but with differentcoefficients.Microstructure profiling measurements at two comparative stations (a deepercentral basin and a local shelf break) in the stratified Yellow Sea are analyzed,with emphasis on tidal and internal-wave induced turbulence near the bottomand in the pyenocline.The water column has a distinct three-layer thermohaline structure,consisting of weakly stratified surface and bottom boundary layers anda narrow sharp pycnocline.Turbulence in the surface layer is controlled by thediurnal cycle of buoyancy flux and wind forcing at the sea surface.while thebottom stress induced by barotropic tidal eurrents dominates turbulence in thebottom boundary layer.The maximum level at which the tidally enhanced mixingcan affect generally depends on the magnitude of the tidal current,and it canbe up to 10-15 m in the Yellow Sea.This suggests that,in the deeper regionsof the shelf seas,turbulent dissipation and mixing are very weak at the levelsbetween the near-bottom tidally enhanced layer and the pycnocline.Therefore,these levels provide a significant bottle neck for the vertical exchanges.In theshallow regions,however,the tidally-induced turbulence can occupy the wholewater colum below the pycnocline.A quarter-diurnal periodicities of the turbulentdissipation rate and eddy diffusivity are found at different heights with evidenttime lag.In the relatively flat central basin,the pycnocline is essentially non-turbulent and internal-wave activity is very weak.Therefore,vertical fluxes acrossthe pycnocline decreased to molecular levels.In contrast,internal waves of variousperiods can be always found near the local shelf break.

对强层化季节黄海两对比性站位(分别位于中央海盆区与局地陆坡区)处层化、内波以及湍流混合特征的研究结果表明：1、强层化季节的陆架海水体一般呈现显著的三层热盐结构，在水体近乎混合均匀的上混合层与潮流底边界层之间为强跃层；2、近表层水体的湍流混合强度主要由海表浮力通量的日变化与海表风强迫控制，而在潮流底边界层内，潮混合是水体热量、物质、动量与能量垂直交换的主要机制；3、潮混合影响的深度由潮流大小决定，在黄海，一般可达10-15 m，因此，在水深较深的区域，在跃层与潮混合所至深度范围的上界之间存在湍流混合非常弱的区域，这显著抑制水体内物质的垂直通量，为物质垂直交换的瓶颈，而在水深较浅的区域，潮混合影响范围可至跃层底部，因此物质在跃层以下整个水体中混合非常均匀，当跃层内间歇性强混合发生时，可以产生显著的跨跃层物质输运；4、近底潮致强湍流耗散缓慢地向上传播，底上不同深度处垂直湍扩散系数也具有显著的位相差异，且二者均随时间呈现四分之一周日周期的变化；5、在地形较为平坦的中央海盆区，内波活动非常微弱，因此跃层内湍流混合非常弱，垂直扩散系数为分子扩散水平，跨跃层物质通量受到显著抑制，而在地形变化较为显著的局地陆坡区，内波活动非常活跃，除内潮的影响外，高频内波与内孤立波的影响也很显著，因此跃层内存在很强的间歇性强混合，内孤立波存在的区域，水体湍流混合显著增强。

Hisun's emulsion sealer R810 is a sealer based on acrylic resin. Applied on the surface as an ideal primer in paint system.

产品说明 DESCRIPTION 海生牌乳胶封闭底漆R810是一种丙烯酸树脂为基料的封闭底漆，专用于涂在施工表面为整个油漆配套提供一个理想的底漆。

The esterification reaction was carried out in isooctane solvent at 50℃, with 0.15mol/L of substrate and 1:1.4 of acid-alcohol molar ratio.

研究了反应温度、溶剂、底物浓度、底物摩尔比、吸水剂用量等因素对酯化反应的影响，确定了正戊酸异戊酯的最佳合成条件为：反应温度为50℃，异辛烷为反应介质，底物浓度为0.15mol/L，酸醇摩尔比为1：1.4。

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。