无特性的

In most meshless methods based on weights with compact support, difficulties arise in nonconvex bodies such as bodies containing crack.

大多数的无单元方法都使用具有紧支集特性的权函数。当求解域是非凸区域的时候，无单元的近似函数不能准确的描述裂缝带来的场函数不连续。

Hairy roots were induced from tobacco leaves with Agrobacterium rhizogenes LBA1334 harboring agropin type PRil855 and binary vector PIG121HM carrying a kanamycin resistant gene nptll and GUS gene and the good hairy root clones were selected. The root with many root hairs and branches grew vigorously toward all the direction on MS medium without plant hormone and on kanamyain containing medium (km:30mg/L). The structure of the hairy root tip is different from that of ordinary root. Witch was not typical root cap maybe the main cause of losing the geotropism of hairy root. Plantlet regenerated from hairy root when cultured on Ms medium without plant hormone. The nicotine content of the hairy root was little higher than that in the natural roots.

本研究通过发根农杆菌工程菌LBA1334(含有野生型pRi1855质粒和pIG121HM双元载体质粒，编码NPTⅡ基因和GUS基因)转化烟草沙姆逊，获得了具有卡那霉素抗性烟草发状根，并筛选出良好的单克隆株系，该发状根具有典型的发状根特性(多根毛、多分支、在无激素培养基上快速生长)，通过根尖压片分析，烟草发状根不具备典型的根冠；发状根中烟碱含量1.61％稍高于与天然栽培品种母体根的含量(1.5％左右)，发状根向培养液中释放烟碱，释放量最多时占总烟碱量的81.1％；在无激素的培养基上获得了再生植株。

The main results can beexpressed as follows:(1)Based on πtheory, some affected factors about wave forces are given, and therelation between affected factors and wave forces is analysised by experimentalresults.(2) The distribution of wave press at representative time and reflection nature aregiven and their variety charactes are discussed by experimental results.(3)By comparing the wave forces of quarter-circular breakwater and semi-circularbreakwater under the same wave conditions,some approximately wave forcesexpressions of quarter-circular breakwater are given.(4)Based on VOF method to trace water free surface,solve numerical value ofRANS equation,and get the distributions of flow field and wave press ofquarter-circular breakwater at the same time during one period,the mechanism ofwave force is also discussed elementarily.(5) Based on the result that RANS equation of numerical simulation agree wellwith experimental results,a new approach to study hydraulic natures of quarter-circular breakwater is provided.

其主要结论如下：一、通过π定理，确定影响波浪力的无因次参变量，根据试验结果对其影响因素进行分析；二、基于模型试验，给出典型时刻圆弧面防波堤的同步波压分布和反射特性，讨论它们的变化特点；三、通过相同条件下圆弧面防波堤与半圆型防波堤两种堤型试验波浪力的比较，给出了圆弧面防波堤波浪力的近似方法；四、利用VOF法追踪自由水面，数值求解RANS方程，得到圆弧堤堤体周围的流场和压力场，初步分析了速度涡流与压力场的相互影响；五、对比数值分析与试验结果，探讨数值方法研究圆弧面防波堤水力特性的可行性，提供新的研究途径

Convention V-belt Continuously Variable Transmission, shifts gears the travel mechanism property fixed constraint, unable full into full play initiative control advantage, to engine and Transmission on the go to hold optimum match, Also takes into consideration acceleration and fuel consumption performance, so this paper research Motorcycles with an Electronically-Controlled Continuously Variable Transmission shift gears planning, to use motor power screw, we shall revolve motion changes rectilinear motion, to push driving sheaves achieved to change speed ratio; Comparison between analysis convention CVT speed ratio shift gears curves of acceleration and fuel consumption performance optimum curves, use engine can hold high performance output or low fuel consumption region run.

中文摘要传统皮带式无段变速器(Continuously Variable Transmission， CVT)，换档行程由於机械特性的限制，无法完全发挥主动控制的优点，让引擎与变速器随时保持在最佳的匹配状态，同时顾及加速性能与燃油消耗，所以本文主要研究机车用电子控制式无段变速系统(Electronically Controlled Continuously Variable Transmission， ECVT)最佳换档规划，利用马达与动力螺杆，将旋转运动改变为直线运动，以推动主动滑轮达到改变减速比；分析传统CVT减速比换档曲线与最佳化曲线之加速性能及燃油消耗比较，使引擎能够保持较高性能输出或较低油耗区间运转。

In view of the four plants have characteristics of autonomous seed set at first female ear of the every plant,short husk,yellow silk,thin cob,purple anther as well as unhealthy to rootage development and so on ,which are different completely from to their parents.

但是长期以来利用近缘野生种向栽培玉米转移无融合生殖特性的研究，仍未能达到预期的目标[4，10]为此，我们于1990～2003年进行了诱导玉米无融合生殖体的研究，并获

Secondly, when kalman filter has reached steady state its error covariance will have a very small stationary value, namely filter dropping off'. Thirdly, the traditional kalman filter cannot adjust its filter parameters with statistic characteristic of the noise. To overcome the deficiency of kalman filter, an SVD-based adaptive kalman filter is put forward in the paper. The filter restrains the filter divergence by matrix singular value decomposition. The eigenvalues and eigenvectors of the matrix are insensitive to tiny change of matrix element and acceptable error.

然而，传统的卡尔曼滤波器存在以下问题：问题一，因噪声统计特性估计不准确和计算机舍入误差引起的滤波发散现象；问题二，在卡尔曼滤波器达到稳态时，其误差方差阵将饱和使其对信号的突变变得不敏感，问题三，传统的卡尔曼滤波器对滤波参数无自适应能力，不能随着噪声统计特性的改变而调整自身的滤波参数。

The characteristics of clonal growth and resources sharing were important to keep stability of community. The transpiration and the stomatal conductance of stolon with and without adventitious roots were same. But the water potential of stolon without adventitious roots was higher than that with adventitious roots.

臭柏克隆生长和资源共享特性在维持群落稳定中起着重要作用，来源于同一上级枝的匍匐茎，有不定根的和无不定根的日平均蒸腾速率和气孔导度没有差异，但无不定根匍匐茎的叶水势比有不定根的高。

Study on manufacture and properties of binderless board from steam exploded Phyllostachys heterocycla var.

研究了22、26、33 kg/cm2爆破压力，5 min蒸煮时间对毛竹无胶粘剂蒸爆板的制造和特性的影响，结果表明，无胶板的静曲强度、弹性模量和内结合强度与板材密度普遍呈紧密的线性正相关。

According to the definition and the distribution of VSR's voltage space vector, the introduction of a rule-based SVPWM current control strategy, with non-fixed switching frequency and dual hysteresis loops, that obviously improves the performance of current control. Based on two kinds of control strategies of VSR under unbalanced grid condition, the introduction of a new VSR control strategy featuring undamped-oscillation that simplifies the controller structure and effectively improves VSR's performance under unbalanced grid condition. A systematic description of the state switching in trilogic PWM signal generation of threephase CSR by using the conversion between bilogic and trilogic switching functions.

作者在如下工作的基础上对PWM整流器的一些关键问题提出了自己的研究思路、观点和方法：根据PWM整流器网侧矢量关系，直观地描述了其四象限运行的基本原理及特征；定量分析了VSR、CSR的PWM换相过程及波形特征；引入等效变压器模型并详细分析了VSR、CSR基于d—q模型的动、静态特性；提出了满足四象限有功、无功运行指标时的VSR交流侧电感设计方法；并提出了依据控制系统跟随性和抗扰性性能指标设计VSR、CSR直流侧储能元件的参数计算方法；在研究了VSR电流控制策略基础上，提出了影响VSR电流控制的几个要素，并进行了定量分析；根据VSR空间电压矢量的定义及分布，提出了基于规则控制的不定频滞环空间矢量PWM电流控制策略，并由此提出了具有双滞环特性的不定频滞环优化SVPWM电流控制策略，有效地改进了滞环PWM电流控制性能。

A univariate ANOVA is executed to analyze the influencing factors of the production cost by dividing it into direct material, direct labor cost, indirect cost and total cost separately. It is found that the variables of farm scale and crop type show significant impacts in the direct labor cost and total production cost. The one-crop farming variable makes significant difference in the total production cost; whereas different planting ways differentiates the indirect cost. In addition, years of farming, farmer's age, and full-time status all make no significant difference in all aspects of production cost.

此外，将农场生产成本分为直接材料、直接人工、间接成本、总生产成本四面向进行多因子变异数分析，结果发现耕作面积、作物类型变项仅在有机农场的直接人工和总生产成本中有显著差异；有机农场是否为单一经营在总生产成本上有显著差异；不同栽培方式的有机农场仅在间接成本的高低上有显著差异；此外，而耕作年数变项因本研究有机农场耕作年数较高之样本特性影响，导致该变项对生产成本并无显著的差异；年龄、专兼业经营等变项在生产成本上高低并无显著差异。

Neither the killing of Mr Zarqawi nor any breakthrough on the political front will stop the insurgency and the fratricidal murders in their tracks.

在对危险的南部地区访问时，他斥责什叶派民兵领导人对中央集权的挑衅行为。

In fact,I've got him on the satellite mobile right now.

实际上 我们已接通卫星可视电话了