查询词典 planar developable surface

The history and representative work of methods of the developable surface modeling and surface development in the field of CAGD are briefly reviewed.

二、推导出了三次C-B？zier曲线导矢计算的简洁公式，证明了B？zier曲线的速端曲线性质对C-B？zier曲线不成立。

A surface that can be unfolded or unrolled into a flat plane or sheet without stretching, tearing or shrinking is called a 'developable surface'.

一个可以在没有拉伸、撕裂或收缩的情况下展开为一个平面或平面区域的面，被称为可展面。

Finally, the complex surfaces are developed by partition of the surfaces into small surface segment ,and approximation of the small segment with the developable surface between two Bezier curves.

最后，采用分片与近似的思想，给出了复杂曲面展开的算法，并提出由曲面面积和曲面展开面积的相对误差调节分片程度来满足精度要求。

In wire-cutting manufacturing of the top and bottom different curve,accomplishing cutting way of ellipse bias changing curved surface which between two plane curve into developable surface in order to calculate NC program of four axis ganging.

在上下异型工件的线切割加工中，宜采用椭圆偏置切割法，即将上、下两平面曲线间的曲面变成可展直纹面，进而计算四轴联动的数控程序，可保障加工的效率与效益。

Though the analysis of the convexity of the front surface, this paper gained some terse and practical results.We can control the shape of developable surface through adjusting corresponding plane curves.

本文通过对上述两种可展B样条曲面进行保凸分析，得到了一些简洁，适用的结论：只要调整相应平面曲线，就能控制可展面的形状。

Bout this Aumann[8] has provided some methods,connecting lines between two boundary curves,shaping ruled surface, and adding some developable conditions to ruled surface.

umann提出的方法是在两边界曲线之间连直线，形成直纹面，然后给直纹面加上可展条件。

Notch and groove were produced on fiber's surface by plasma's pHysical bump and corrasion, meanwhile oxygenic or nitrogenic radicals were also grafted on the surface. Through hydrolyzation, acetate fiber's surface will be denuded by cellulase enzyme. Surface of the fiber will be granulated and specific surface area will be enlarged by plasma and enzyme treatment, therefore obviously improve fiber's surface performance.

等离子体对纤维的物理撞击和表面刻蚀使纤维表面产生凹坑和沟槽，同时可在纤维材料表面引入含氧或含氮基团；而纤维素酶对纤维素的水解作用，促使纤维表面被剥蚀；等离子体与生物酶处理都能使纤维表面粗糙化，比表面积增加，使纤维的表面性能得到明显改善。

Remove row and column' and 'put a big number' have been used for the first boundary;a continuous Regional Identification Function is used on the basis of non-variant nodal virtual flux method for the free surface boundary;Gauss formula is used to make the curved surface integral of the free surface boundary transformed as the difference between volumn integral and other curved surface integral to calculate the integral item on boundaries, which avoiding finding the position of free surface, while the continuous Regional Identification Function is applied to calculate volumn integral and surface integral;Crout and PCG method is used for solusion.

对于已知水头边界，采用"去行去列法"和"置大数法"进行处理；对于自由面穿过的单元，在固定网格节点虚流量法的基础上，引入连续的区域识别函数；对于非稳定渗流中自由面边界积分项，采用高斯公式将求自由面的面积分转化为求体积分与其他面积分之差，避免了求自由面的具体位置，同时在计算体积分和面积分时采用连续的区域识别函数；在解法上，采用直接解法和PCG法。

In this paper, an iterative approach to potential field continuation from curved surface to plane is proposed. The continuation of potential field data from a curved surface to a plane can be viewed as an inverse problem of upward continuation of plane potential field data, getting a linear integral equation. Through viewing the potential field data on the curved surface as the data on the average elevation plane of the curved surface, then using the wavenumber domain generalized inverse algorithm to downward continue the data from the average elevation plane to a given plane, and a topography correction based on the change of curved surface relative to its average elevation is implemented to the downward continued data on the given plane, finally the downward continued data plane is upward continued to the curved surface.

本文提出一种位场数据曲化平的迭代方法，即通过把位场数据曲化平视为平面位场数据向上延拓的反问题，得到曲化平的线性积分方程，再把曲面上位场数据视为曲面平均高程面上的位场数据，利用向下延拓的波数域广义逆算法把平均高程面上的位场数据向下延拓到设定平面上，再根据曲面和其平均高程面的相对起伏对设定平面上的向下延拓数据进行起伏校正，最后再把所得平面上的位场数据向上延拓得到曲面上的位场数据，并进行迭代。

As a whole,the notable characteristic of primary productivity in size-fractioned structure was that nanoplankton occupied comparatively significant advantage in Beibu Gulf.Nanoplankton has the largest contribution to gross primary productivity,and picoplankton was the secondary contributor,while microplankton the least.The contribution of microplankton for primary productivity in the north Gulf was more than that in the other waters.Nanoplankton and picoplankton contribute more to the gross primary productivity in offshore deep waters than in inshore shallow waters3.The Beibu Gulf can be divided into three ecoregions:Region-Ⅰis the ecoregion in inshore shallow waters of the north Gulf.In average,the water depth is 18m,DIN is 1.88μmol/L,DIP is 0.20μmol/L,N:P is 9.4:1,dissolved silicate is 5.17μmol/L,the Chl a conentration in surface layer is 2.27mg·m~(-3),the assimilation index in surface layer is 3.80mg/,the primary productivity is 198.78mgC/(m~2·d), and potential fishery production is estimated to be 0.24gC/(m~2·a) according to the primary productivity.The ecoregion is mainly affected by the northern coastal water systems,and may be fit for aquaculture;Region-Ⅱis the ecoregion in offshore deep waters of the north Gulf and the coastal shallow waters to the west Hainan Island.In average,the water depth is 35m,DIN is 2.01μmol/L,DIP is 0.18μmol/L,N:P is 11.2:1,disovled silicate is 4.23μmol/L,the chlorophyll a of surface layer concentration is 1.45mg·m~(-3),the assimilation index of surface layer is 4.12 mg/,the primary productivity is 276.60mgC/(m~2·d),and the estimated potential fishery production is 0.34gC/(m~2·a) according to the primary productivity. The ecoregion was mainly influenced by ocean current from the South China Sea, rivers in the west coast of Hainan Island and the water from Qiongzhou Strait.It may be fit for aquaculture and fishery;Region-Ⅲis the ecoregion in offshore deep waters of the mid and south Gulf.In average,the water depth is 75m,DIN is 0.77μmol/L, DIP is 0.15μmol/L,N:P is 5.1:1,disovled silicate is 3.05μmol/L,the chlorophyll a of surface layer concentration is 0.70mg·m~(-3),the assimilation index of surface layer averaged is 3.69mg/,the primary productivity is 350.89mgC/(m~2·d),and the estimated potential fishery production is 0.43gC/(m~2·a) according to the primary productivity.The ecoregion was mainly affected by the circulation inside Beibu Gulf, and may be fit for fishery.

初级生产力的粒级结构的一个显著特点是总体上微型浮游生物在全调查海区均占较明显优势，对总初级生产力的平均贡献最大；微微型浮游生物对初级生产力的平均贡献次之；小型浮游生物对总初级生产力的平均贡献最小；湾北部小型浮游生物对初级生产力的平均贡献高于湾中部和湾南部，而湾中部和湾南部微型和微微型浮游生物对初级生产力的平均贡献高于湾北部，远岸深水区高于近岸浅水区。3、北部湾可以分为三个生态区：湾北部近岸浅水区，该区的环境主要特点是平均水深19m，DIN浓度平均值为1.88μmol/L，DIP浓度平均值为0.20μmol/L，N：P为9.4：1，硅酸盐浓度平均值为5.17μmol/L，表层叶绿素a平均值高达2.27 mg·m~(-3)，表层同化指数平均为3.80 mg/，初级生产力平均值198.78mgC/(m~2·d)，根据初级生产力计算潜在渔业资源碳生产量平均为0.24 gC/(m~2·a)，该区主要受湾北部沿岸水系影响，适合作为水产养殖区；湾北部深水区和海南岛西部沿岸浅水区，该区的环境主要特点是平均水深35m，DIN浓度平均值为2.01μmol/L，DIP浓度平均值为0.18μmol/L，N：P为11.2：1，硅酸盐浓度平均值为4.23μmol/L，表层叶绿素a平均值1.45 mg·m~(-3)，表层同化指数平均为4.12mg/，初级生产力平均值276.60 mgC/(m~2·d)，根据初级生产力计算潜在渔业资源碳生产量平均为0.34 gC/(m~2·a)，该区主要受南部湾口区海流向湾内延伸，沿岸海南岛河流注入湾内和琼州海峡过道水的影响，适合作为渔业作业区和水产养殖区；湾中部和南部远岸深水区，该区的环境主要特点是平均水深75m，DIN浓度平均值为0.77μmol/L，DIP浓度平均值为0.15μmol/L，N：P为5.1：1，硅酸盐浓度平均值为3.05μmol/L，表层叶绿素a平均值0.70 mg·m~(-3)，表层同化指数平均为3.69 mg/，初级生产力平均值350.89 mgC/(m~2·d)，根据初级生产力计算潜在渔业资源碳生产量平均为0.43 gC/(m~2·a)，该区主要受北部湾环流影响，适合作为渔业作业区。

A backer of an Afghan law that critics say legalizes marital rape has rejected the international outcry as foreign meddling.

饱受批评的一项法律的拥护者说合法化的婚内暴力不会受国际舆论的干涉。

Years ago, a ancient Egyptian fleet went to the Land of punt for seeking a kind of flavor named "myrrh", and aromatic plants which has dense exotic style for the queen Hatshepsut.

3500年前的一个古埃及的舰队到&彭特之地&寻找一种叫没药的香料。