变变

Through analysis to multilevel invertor a method of switching angle control for Diode-clamping Multilevel Inverter is introduced. The quantity of wave for output voltage is improved and the content of harmonics is reduced. And a design is carried on to realize the control mode based on TMS320F2407DSP.

通过分析多电平逆变器的拓扑结构，选择二极管箝位型多电平逆变器为研究对象，提出在二极管箝位型逆变电路中实现开关角控制的方法，该方法减少了谐波的含量，改善了输出电压的波形，并以TMS320F2407DSP为平台进行了设计实现了该控制策略。

Comparing with water, the optimal heat transfer enhancement is achieved near the critical micelle concentrations of surfactants. The degree of heat transfer enhancement is different with different surfactants and is influenced by solubility characteristic, ionic nature and chemical structure of surfactants. Boiling in surfactant solutions, when compared with that in water, is observed to be more vigorous with smaller-sized, more regularly shaped and faster departure frequency bubbles, but the surfactant solutions of Triton X-100 and Triton X-114 become cloudy for the cloud point of surfactants.

和水相比，表面活性剂强化池内核态沸腾换热的最佳浓度为临界胶束浓度；不同种类表面活性剂强化换热程度不同，它们与表面活性剂的溶解特性、离子类型和化学结构有关；溶液沸腾时，沸腾汽泡的脱离直径变小，脱离频率变快和更不易聚集，但非离子表面活性Triton X-100和Triton X-114由于存在浊点其沸腾溶液变浑浊。

During the next few years it grew grayer and grayer until it attained an even pepper-and-salt iron-gray, when it ceased turning.

以后数年中，头发越变越灰，变得像胡椒盐似的铁灰色，颜色就不再变了。

By investigating Newton\'s Problem of the Solid of Least Resistance,John Bernoulli\'s Brachystochrone Problem and Jacob Bernoulli\'s Isoperimetric Problem, the physics and Calculus background of the calculus of variations is illustrated,the fundamental thought together with the patterns of solutions are summarized,and the ideas and the interaction of the pioneers,such as the Bernoullis and B.

通过考察牛顿最小阻力体问题、约翰·伯努利最速降线问题和雅可布·伯努利等周问题等问题的提出过程及解决方法，深入探究了变分法诞生的深刻背景，提炼和概括出了伯努利兄弟和泰勒等先驱者解决变分问题的基本思想和求解模式，追溯了其微积分渊源，并分析了三位先驱(来源：ABCbc论文64网www.abclunwen.com)者之间的变分法思想传承及相互影响。3。

Associated signs of kwashiorkor, which do not always occur, include hair changes (color becomes lighter, curly hair becomes straight, hair comes out easily with a gentle pull) and skin changes (dark skin may become lighter in places, skin may peel off, especially on the legs, and ulcerations may occur).

其他与浮肿型营养不良相关的症状还包括发质改变（颜色变浅；卷发变直；轻易脱发）和肤质改变（深色皮肤的某些地方变浅；皮肤，尤其是腿部表皮脱落；溃疡）。

Phase change materials investigation is the first step of developing a latent heat storage system and thus is always the focus in related research.

相变材料是开发相变储能系统的前提，因而相变材料的研究一直是这一领域中心课题之一。

The key points of research and development of latent heat storage are selection or compound of high effective phase change materials, and enhancement of the heat transfer performance of storage systems.

研究和开发利用相变储热的关键是选择或合成高效的相变材料和增强相变储热系统的传热性能。

Shape memory alloy with thermoelastic martensite metallography transform represents absolute shape memory effect, for matrix metallography lattice orientation selectivity in reverse metallography transform.

具有热弹性马氏体相变的形状记忆合金，在逆相变中必定会选择相变前母相的晶格位向，表现出完全的形状记忆效应。

The formation of martensite is accomplished by the immigration of well-defined glissile interface (121)fcc type and its misfit dislocations can produce the lattice invariant deformation on the basis of phenomenal theory of martensitic crystallography, however, LID is retarded slightly after the migration of interphase (121)fcc, i.e.a thin plate-like zone exists without LID in martensite near the well-defined interface. When the temperature reduces to the Ms point, the lattice parameter of austenite matrix is √3/2 times that of the martensite without LID. This critical condition for spontaneous transformation agrees with that the stack fault energy in matrix is less than zero according to Olson and Cohen's nucleation model.

通过模型分析表明：fcc/bcc马氏体形核与长大过程是通过(121)fcc型择优界面推移进行的，界面上的错配位错可以完成马氏体晶体学唯象理论要求的点阵不变变形，但LID要稍滞后于界面迁移，即在马氏体形核与长大过程中推移界面新相一侧存在一未发生LID的新相薄区；当相变温度达到马氏体相变点Ms时，母相奥氏体与这一薄区的晶格常数比为√3/2，这一几何条件和Olson-Cohen形核模型中要求扩展位错层错区界面能γ≤0是等价的。

The main results were summarized as follows: 1 With the increase of cooling rate, full recrystallization during cooling became difficult to take place and the decrease in dislocation density became slow so that dislocation density in austenite remains higher before phase transformation occurred. 2 Compared with undeformed samples, the CCT diagram under deform conditions has a similar shape, but its position shifts leftwards.

计算结果表明：1随着冷却速率增大，低碳钢热变形后的冷却过程中再结晶变得越来越困难，位错密度的下降变慢，导致在相变前奥氏体中保留着较大的变形存储能；2奥氏体在经历热变形后的CCT曲线与未变形条件相比，明显向左上方偏移。

And Pharaoh spoke to Joseph, saying, Your father and your brothers have come to you.

47：5 法老对约瑟说，你父亲和你弟兄们到你这里来了。

Additionally, the approximate flattening of surface strip using lines linking midpoints on perpendicular lines between geodesic curves and the unconditional extreme value method are discussed.

提出了用测地线方程、曲面上两点间短程线来计算膜结构曲面测地线的方法，同时，采用测地线间垂线的中点连线和用无约束极值法进行空间条状曲面近似展开的分析。