临界值

Their structures were confirmed by IR, and the properties of these surfactants such as acid number, interfacial tension, and critical micelle concentration and so on were studied.

通过红外光谱确定了产物的结构，并对有机硼表面活性剂的酸值、表面张力以及临界胶束浓度等性能进行了研究。

The dissolubility of PPLA in water was (2.16～4.32)×10－2 mg·mL－1 according to eye judgment. The critical micelle concentration was 2.16×10－2 mg·mL－1 obtained from a fluorospectrophotometer. The self-assembled aggregates of PPLA in water were nanoscale spheres observed by a transmission electron microscope. The particle size and zeta potential tests by dynamic light scattering revealed that during preparation, the ratio of hydrophilicity/hydrophobicity, the aqueous medium and the pH had great influences; while dilution, freezing and pH change to basic condition had no effect after preparation, but pH change to acidic condition made the nanoparticles precipitate.

目测法得到其溶解度为(2.16～4.32)×10－2 mg·mL－1；荧光法得到聚合物的临界胶束浓度为1.12×10－3 mg·mL－1；透射电子显微镜观察显示该聚合物在水中的自组装聚集体为纳米级球形；动态激光光散射测试微球的粒径和Zeta电位发现，在微球的制备过程中，聚合物的亲/疏水性比例、水相介质及水溶液的pH值对它影响显著；而制备后，稀释和冷冻对它无显著影响，改变微球的环境pH值至酸性，出现聚集，至碱性无影响。

Based on analysis and comparison of the principle, method and form of train mass calculation and the correlative" select-judge value" for raising speed train,a change of particular attention from train mass to train speed is recommended in this paper,and the second critical gradient between the recommendatory maximum speed method and the traditional calculative speed method is established to the "select-judge value".

本文在分析与比较提速列车质量计算的原则和方式方法以及相关的选择判别值的基础上，提出应从传统的侧重列车质量的方式转向侧重运行速度的方式，并最终确立第二临界坡度为推荐的最高速度法与传统的计算速度法的选择判别值。

The computational complexity has been reduced about 5 times over against the original one. Moreover, the interpolation and quantization processing of CW is more reasonable; 2. A secondary power normalization algorithm is proposed in this dissertation. This normalization algorithm ensures that the energy sum of SEW and REW is 1. So, the energy ratio of SEW and REW can be achieved only by using SEW energy. This ratio is applied in REW quantization and CW composition; 3. For more efficient quantization for Slowly Evolving Waveform magnitude, Rapidly Evolving Waveform magnitude and power parameters, firstly, by applying the Equivalent Rectangular Bandwidth theory, classifiable multi-codebooks method, analysis-by-synthesis approach and so on, a predictive AbS multi-codebooks SEW magnitude quantization scheme is proposed. In the scheme, pitch information is exploited to determine which codebook is searched; secondly, for REW magnitude quantization, this dissertation proposed a DCT-matrix multi-codebooks quantization scheme. The classification in muti-codebooks is based on pitch and quantized SEW power. The multi-codebooks structure may offer more the information in quantization and solve the problem of the bit requirement limits in quantization by consuming some extra storage space; Furthermore, for the switch quantization of CW gain, a new classified parameter is proposed.

本文的主要贡献体现为如下几方面：一、为了减少WI模型的计算复杂度，提出了基于快速傅立叶变换、三次B样条插值和周期延拓技术的特征波形(Characteristic Waveform，CW)表示和对齐的快速算法，与原方法相比，计算量下降到原方法的1/5，同时也使得CW在插值和量化时更合理；二、为了严格保证SEW与REW的能量和为1，提出了一种特征波形的二次功率归一化算法，仅需要SEW能量就可以算出二者的能量比，并可应用到后续的REW的分类量化和CW合成中；三、为了对慢渐变波形(Slowly Evolving Waveform，SEW)幅度、快渐变波形(Rapidly Evolving Waveform，REW)幅度和特征波形功率进行有效量化，本文首先采用临界频带理论、分析合成技术、感觉加权技术以及预测式矢量量化技术，提出了一种基于基音周期分类的SEW分析合成预测式多码书量化方法；其次，本文根据基音和量化后SEW的功率信息对REW幅度进行分类，提出了一种基于离散余弦变换的REW矩阵多码书量化方法。

Parameters based on chemical shift indicate that methyl is a substituent with electron-withdrawing inductive effect and poor electron-donating conjugative effect. Perhaps its conjugative effect is on critical point. Methyl is electron-withdrawing for benzene relative to H. Otherwise, methyl has strong p-position and weak o-position orientation effect.

化学位移值表示的诱导效应参数表明甲基具有吸电子诱导效应，经校正后的化学位移值表示的共轭效应参数表明甲基具有微弱的给电子共轭效应，甚至其共轭效应有可能正处于给电子和吸电子的临界状态，总之相对于氢原子，甲基具有吸电子效应。

The results were found as following:(1) The damage value increases more significantly with the increase in PVF before 30% PVF, beyond which the increasing trend becomes gradually gentle.(2)Keeping the interphase strength and PVF unchanged, the damage increase with increasing moisture concentration in a nearly linear relation.(3)The results generated from the FCC model with consideration of the interphase debonding are in good agreement with the experimental data, meanwhile, the FCC model is also capable of predicting the critical load for the damaged and the undamaged dental composite subject too the 3-point flexural test.4 A 3D-fmite element analysis has been successfully exploited to examine the mechanical behavior of the restoration-tooth structure under the polymerization shrinkage and water sorption. It was found:(1) The low stiffness of the composite has the effect to limit the displacement occurring in the remaining tooth tissue. For lower interphase, the cuspal flexures are litter higher. The high interphase modulus acts as a \'shielding effect\' for stress transfer.

得到如下结论：(1)相同的吸湿性，在30％PVF(颗粒体积分数：Particle volume fraction，PVF)前增加PVF，层间脱胶损伤值显著增加；此后损伤值的增加趋于平缓；(2)保持层间强度和PVF不变，层间脱胶损伤随吸湿率的增加而接近线性增加；(3)FCC(面心立方：Face-centred cubic，FCC)模型层间脱胶损伤的预测结果和实验数据基本吻合；同时此模型可以用于预测牙齿填充材料三点弯曲实验的临界载荷。4、建立理想牙齿修复结构，利用有限元方法研究了同时考虑聚合收缩和吸湿膨胀耦合作用下的填充修复材料和粘结界面层材料性能对牙齿修复结构的力学行为的影响，得到如下结论：(1)低弹性模量的牙齿填充修复材料能限制天然牙组织的位移，但天然牙组织的位移与粘结界面层的弹性模量无关。

The experimental values of the critical concentration were in agreement with the calculated ones based on the Khokhlov-Semenov-Odijk theory, which indicated that the lyotropic behavior of chitosan in dichloroacetic acid can be well described with wormlike chain model.

临界浓度的实验值与根据Khokhlov-Semenov-Odijk理论预示的值比较一致，说明蠕虫链模型可以很好地描述壳聚糖分子链在二氯乙酸中的溶致液晶行为。

The effects of main test parameters on the process of pitting potential of carbon steels have been studied by quasi-steady-state polarization technique and metallographical analysis technique.

采用准稳态的极化试验研究了各主要试验参数对碳钢在3%NaCl溶液中点蚀电位的影响，结果表明：3种碳钢钝化的临界pH值约为8 0 ；当T =2 0℃～35℃时，点蚀电位值Eb10 0 随温度的降低而变正；当电位变化速度慢于30mV/ 30s时，Eb10 0 随电位变化速度的减小而变负；试验面的粗糙度越大，点蚀电位越

The results of simulations performed at nearly zero temperature demonstrate that stress-induced phase transitions from body-centered cubic to face-centered cubic and hexagonal close-packed structures take place during the deformation process of both Fe and Ta, and the maximum fraction of FCC atoms varies linearly with the tensile strength, from which we can conclude that a critical stress exists for the phase transition to take place.

低温模拟结果表明，纳米晶铁和钽在变形过程中都出现了应力诱导的相变，其中FCC结构含量的最大值和抗拉强度成线性关系，并由此可以推出相变发生的临界应力值。

Use bifurcation curve and analyze the effect on voltage stability by static load model,propose that critical voltage decrease with the constant impedance ratio increasing.

使用分岔曲线，分析了负荷静态模型对系统电压失稳临界点电压值的影响，得出系统发生电压失稳时临界电压值随负荷模型中恒阻抗负荷比例的增加而降低，并对北京电网进行实例分析。

In the negative and interrogative forms, of course, this is identical to the non-emphatic forms.

。但是，在否定句或疑问句里，这种带有"do"的方法表达的效果却没有什么强调的意思。

Go down on one's knees;kneel down

屈膝跪下。。。下跪祈祷