查询词典 developable surface

For a general parametric curve/surface, we usually cannot compute its exact implicit form. Even though its exact implicit form can be computed, the curve/surface implicitization involves relatively complicated computation and the degree is higher. Moreover, it may have unexpected components and self-intersections. All these unsatisfied properties limit the applications of the exact implicitization. So finding curve/surface approximate implicitization has become a practical problem. In this paper, we present an algorithm to solve the approximate implicitization of a given parametric curve by using a quadratic algebraic spline curve.

由于精确隐式化过程不一定可以实现，即使可以实现隐式曲线曲面的阶数高计算复杂，并且具有不希望的自交点和奇异分支，从而限制了隐式化的运用，所以寻求参数曲线曲面的近似隐式化问题成为很实际又重要的问题，提出利用二次代数样条曲线来实现一般平面参数曲线近似隐式化的一种算法。

In this paper,we propose a concept called interval implicitization of rational bézier surfaces,that is ,finding an interval algebraic surface with lower degree which bounds a given parametric rational bézier surface such that some objective function involving the width and the tention term of the interval algebraic surface is minimized.

本文提出有理Bézier曲面的区间隐式化的概念，即找到一条较低次的区间代数曲面使得给出的有理Bézier曲面落在该区间代数曲面内，并使得一包含区间代数曲面的宽度和张量项的目标函数达到最小。

The action mechanism that (NaPO3)6 depresses almandine is two sides: one is that (NaPO3)6 is chemical adsorbed firmly on the surface of almandine and lead to almandine strong hydrophilic. The other is that (NaPO3)6 selectively dissolves Ca(superscript 2+) on almandine surface and makes the surface cations act with the collector lessening.

NaPO36对石榴石的抑制作用存在两种机理：其一，(NaPO3)6与石榴石表面Fe(上标 2+)发生化学键合导致其牢固吸附而使石榴石表面强烈亲水：其二，(NaPO3)6选择性溶解石榴石表面Ca(上标 2+)导致石榴石与捕收剂作用的表面活性质点减少。

Moreover, it was successfully linked with lactobionic acid through amine groups on the surface of particles, and used to recognize living liver cells successfully.(3) In order to simplify the proceeding of preparation of silica-coated qdots, a novel one-pot method using 3-mercaptopropyl-trimethoxysilane as a capping molecule was proposed for the first time. Furthermore, amine and phosphonate groups were also modified on the surface of silica-coated qdots simultaneously. This was the first time the synthesis and the surface modification of qdots were performed in the same system.

3在前一部分工作的基础上，进一步简化量子点的合成与包壳步骤，以MPS为稳定剂，制备了硅壳包被的CdTe量子点，并在硅壳外同步修饰氨基及磷酸基团，首次成功实现了量子点的合成与表面的功能化修饰在同一体系中进行，从而制得了水溶性的、表面带有氨基和磷酸基团的硅壳型CdTe量子点。

The polymethyl methacrylate material with super-hydrophobic surface of the invention is prepared in the following steps: 1 the polymethyl methacrylate material is first put into diamine solution, so that the ester group on the surface of the material has ammonolysis reaction with diamine molecules; 2 and then, the product of the step 1 is put into long chain fatty acid solution to be treated and the solvent is volatilized, so as to obtain the polymethyl methacrylate material with super-hydrophobic surface.

本发明具有超疏水表面的聚甲基丙烯酸甲酯材料，是按照如下步骤进行制备的：1将聚丙烯酸甲酯材料先置于二胺溶液中使聚丙烯酸甲酯材料表面的酯基与二胺分子发生氨解反应；2然后，将其置于长链脂肪酸溶液中进行处理，挥发掉溶剂，得到具有超疏水表面的聚甲基丙烯酸甲酯材料。

The structural parameter including span, height of north wall, angle of elevation of north slope, angle of south surface, project width of south surface, height of the greenhouse, shape of south surface were optimized.

日光温室是一种在室内不加热的温室，即使在最寒冷的季节，也只依靠太阳光来维持室内的温度水平，以满足蔬菜作物生长的需要[1]。

Poly is a kind of membrane material with excellent characteristics, in order to improve its surface hydrophilicity, so as to increase its antipollution ability, surface modification of PVDF hollow fiber porous membrane has been studied, on the bases of reviewing all kinds of modification methods, the modification method of chemical grafting onto hollow fiber membrane surface was determined.

聚偏氟乙烯是一类性能优良的膜材料，为了改善膜表面的亲水性，提高其抗污染性能，必须对膜表面进行改性，本课题在充分考察各类改性方法的基础上，采用在膜表面接枝共聚的方法对PVDF中空纤维膜表面进行改性。

The composite interface space of the place could be associated with the vertical surface of architecture and ereate a new design technique: the composite design of the vertical surface of architecture—the composite vertical surface of architecture.

场所的复合界面空间可以与建筑立面相结合，形成一种的设计手法建筑立面的复合化设计——建筑的复合立面。

The unsaturated and compacted soil triaxial test result under constant suction describes the unsaturated soil critical state surface in p-q-s three dimensional space: in p - q plane, the slope M of critical state line is independent of suction; the cross line of LC yield surface and critical state surface is a curve with extremum in three dimensional stress space, and its projection in p-s plane is located in quadrant 1 in triaxial compression state; its projection in q-s plane has asymptote, and there should also be asymptote in respect of the curve that stands for the function relationship between cohesive and suction.

基于局部变形测量的常吸力非饱和压实土三轴剪切试验结果，全面描述了非饱和土p—g—s三维应力空间中临界状态面的合理形态：在p—q平面，临界状态线斜率M是与吸力无关的物理量；临界状态面与LC屈服面交线在三维应力空间中是一条存在极值的曲线；该交线在p—s平面的投影曲线在三轴压缩应力状态下应位于第一象限；该交线在q—s平面的投影曲线应存在渐近线；反映凝聚力与吸力关系的函数曲线也应存在渐近线。

The diameter of nano-particle is small and its surface energy is high. Atomic valence bond of particle surface is not saturation and surface atoms have extremely physical and chemical activity. So, nano-particle is apt to agglomerate to make difficult to bring its excellent properties to completely play and to modify polymer.

纳米粒子粒径小，表面能大，且粒子表面的原子价健处于不饱和状态，表面原子有极大的物理与化学活性，因此纳米粒子非常易于团聚和吸附，而使得其拥有的性能难以充分发挥，从而失去应有的对高分子材料的改性作用。

Many will continue to choose to live in duality and in conflict.

许多人将继续选择活在二元对立性和冲突中。

I find that students of the University of Physical Education all wear sportswear at first sight.

我发现：体育大学的学生乍一看，都是穿运动衣，大家都一样