查询词典 derivative

Series of β-sitosterol derivative are synthesized in order to select the more effective insecticide and to study the relationship between molecular structure and insecticidal activity.

为筛选更有效的杀虫剂，探明β谷甾醇的分子结构与杀虫活性之间的关系，合成了一系列的β谷甾醇衍生物。

Keywords β-sitosterol;β-sitosterol derivative;synthesis;structure characterization

谷甾醇；β-谷甾醇衍生物；合成；结构表征

The synthesis of the pentacyclic skeleton of Et-743 and the construction of the five chiral centers thereof.1. The core pentacyclic skeleton of phthalascidin was constructed with L-dopa as the starting material via thirteen steps. First, two basic synthons, the C-1 functionalized tetrahydroisoquinoline compounds 8 and N-protected Z-dopa derivative 9, were prepared from L-dopa. They were coupled via amide bond to form the dipeptide compounds 10, which were the first key intermediates. Then the primary hydroxyl groups were transformed into the corresponding amino aldehydes 11 via Swern oxidation. Followed by the intramolecular Pictet-Spengler cyclization, the pentacyclic compounds 12 were synthesized.

五环骨架的构建及五个正确手性中心的确立：1.1我们以L-多巴为起始原料，经过多步官能团保护和转化合成了基本结构单元8然后和苯丙氨酸衍生物9，通过缩合反应生成酰胺中间体10，经Swern氧化得到醛化合物11，然后再次利用分子内改良的Pictet-Spengler反应一步构建c，d两环，得到五环骨架化合物12，最后，实现了21-位羰基向氰基的转化，得到了C-1位官能化的化合物14，化合物14不但具有和Et-743一致的五环骨架，而且分子中五个手性中心立体构型也与其完全相同：其中，3，位和13，位的手性中心由原料L-多巴带入，而1，位，11，位和21，位手性中心则通过不对称诱导而确立。

Reliability of the nonlinear and complex performance function of slope stability can be got without doing derivative.

对于功能函数的非线性和复杂性，避免了有时比较繁琐的求导工作，通过编制通用程序直接计算出可靠度指标，试验点坐标和失效概率。

First of all, modeling image by fractional-order derivative and negative Sobolev space, this paper presents a fractional-order multi-scale variation PDE model, and the proposes the adaptive parameter selection method and obtains the field and scale adaptively algorithm for SAR image denoising.

首先利用分数阶导数以及负指数Sobolev 空间对图像进行建模，建立了分数阶多尺度变分PDE 模型，然后给出了模型参数自适应选择方法，并在此基础上提出了区域、尺度自适应的SAR 图像去噪算法。

B Unless otherwise specified by us in this Software or pursuant to separate licence granted by us, you are not allowed to sell, upload, post, publish, reproduce, transmit or distribute in any way any component of this Software itself or create derivative works with respect thereto as this Software is copyrighted under applicable laws.

b 除非我们在本软件中另有订明，或我们另外给予特许，否则阁下不得上载、下载、张贴、发布、复制、传送或以任何方式分发本软件任何元件或创立衍生作品，因本软件获得适用法例的版权保障。

G upload, post, publish, transmit, reproduce, or distribute in any way, any component of this Software itself or any Information obtained through this Software which is protected by copyright, or other proprietary right, or create derivative works with respect thereto, without our prior written permission unless otherwise specified by us in this Software or pursuant to separate licence granted by us

g 未得我们书面批准﹙除非我们在本软件中另有订明，或我们另外给予特许﹚而上载、张贴、发布、传送、复制或以任何方式分发本软件任何元件或通过本软件取得的任何受版权或其他专利权保障的资料，或创立衍生作品；阁下对该等资料并不拥有任何权利，除该等使用条款所允许者外，以及/或除我们另外给予特许外，阁下不得另外使用该等资料。

Based on a graphical stability criterion in parameter space, the range of proportional-gain is given. For both stable and unstable open-loop plants, the stabilizing region in integral derivative space is plotted and determined directly, not to be calculated mathematically.

基于参数空间的图解稳定性准则，在已知比例增益范围的前提下，针对稳定和不稳定开环对象，直接在积分－微分参数空间绘制和确定稳定区域，避免了复杂的数学计算。

Sales of its products include: LM series of precision rails, precision Ball Spline, precision ball screw and associated support components, precision cross-roller working platform, rail actuators, Zhixian Qiu Waterloo Block, guided packages, and various derivative - Spherical and even the axis of linear motion products such as grease.

其销售产品包括： LM系列精密导轨、精密滚珠花键、精密滚珠丝杆及配套支撑部件、精密交叉滚子工作平台、导轨引动器、直线球滑座、导套、导柱及各种球面连轴节和直线运动产品润滑脂等。

The results as follows,maximum of the derivative was significantly greater(P.01)and value Kof sphygmogram area was less(P.1)in young than elderly group.

结果如下：脉搏波导数最大值是年轻组明显大于年老组(P.01)，波图面积的K值是年轻组小于年老组(P.1)。

Finally it offers the analysis of the fault-tolerance system as well as its test verification.

这样，运行于空间环境中的系统的设计目标就是在保证系统实时性

However, it is still difficult to find out the real reason of the increase of the keratinized gingiva during the orthodontic extrusion whether it is due to the proliferation of the gingival tissue or to its elastic nature, that is because the proliferation of the fibroblasts as well as the connective tissue changes in volume and the intra-fibers spaces were all immeasurable in most of the studies.

然而，仍然难以找到真正的原因增加的角化牙龈在正畸挤压它是否是由于扩散的牙龈组织或其弹性性质，这是因为增殖的成纤维细胞以及作为结缔组织的变化量和内部纤维空格都是不可估量的，大多数的研究。