查询词典 derivative

At last,a convergent and general protocol to marine natural product,as demonstrated by the enantioselective total synthesis of malyngamides O,P,Q,R, 5"-epi-Q and 5"-epi-R bearing terminal vinylic chloride structure,was developed in detail.E,(7S)-7-methoxytetradec-4-enoic acid was prepared using the above described Johnson-Clainsen rearrangement,the terminal vinyl chloride was constructed using Wittig reaction as key step,the pyrrolidone derivative was constructed using L-serine as natural chiral pool.Starting from the synthesis of malyngamides O and P to explore the general route,an aldol reaction of methyl acetate with the vinyl chloride part in the presence of LDA gave the skeleton of amine portion,followed by amidation with the fatty acid finished the synthesis of malyngamide P.

先以malyngamides O和P为试点探索通用合成路线，将乙酸甲酯和烯氯部分在LDA存在下进行aldol反应得到氨部分的骨架，再将手性不饱和脂肪酸和氨部分进行酰胺化反应完成了malyngamide P的合成，将P在碱性条件下进行烯醇甲基化反应完成了malyngamide O的全合成。

Derivative is a four-letter wod now,but as the Chinese currency opens up,there will be more need for sophisticated hedging products simply to allow Chinese companies to be competitive.

现在衍生产品只是一个四字词语，但是当人民币汇率更加灵活时，为了让中国公司更具竞争力，对复杂对冲产品的需求将增加。

Derivative is a four-letter wod nowbut as the Chinese currency opens upthere will be more need for sophisticated hedging products simply to allow Chinese companies to be competitive.

现在衍生产品只是一个四字词语，但是当人民币汇率更加灵活时，为了让中国公司更具竞争力，对复杂对冲产品的需求将增加。

The change for substitute group on chlorin ring of chlorophyll-a derivative and the effect on their visible spectra is discussed and summarized according to relation of electron effect and substituted position of different groups with conjugated region.

根据不同取代基的电子效应、取代位置与分子共轭区域的联系，提出二氮杂轮烯和四氮杂轮烯组成的非等原子芳香体系结构，总结了卟吩大环上的化学结构变化对其可见光谱的影响。

The high level cheats of the consuming society recruited the best men to do brain storming, to invent the " derivative financial goods " that even debts can be securitilized; they were roaming around to suck the money, to pay the commissions, rewards and others by the principals, and the break appeared immediately to form the black hole of finance.

消费型社会的高层骗徒则召募最顶尖的人才，挤尽脑汁，发明了所谓的「衍生性金融商品」，连债务都可以证券化；他们飞来飞去吸金，吸入本金用以支付佣金、奖金、其它支出---等等，马上出现缺口，形成一个金融黑洞。

A part of microbial cells would autolyzed to release the intercellular alkanedegrading enzymes when they were cultured on alkane. Thus alkane could be degraded and synthesized alkane derivative with surface activity extracellularly. This surface-active agent would improve alkane emulsifying, and those unautolyzed cells could utilize the emulsified alkane sequentially.

微生物细胞在烃类基质中培养时，为了适应其疏水性环境以更好地摄取烷烃，会通过一部分细胞的自溶解体而使得胞内烃类代谢酶等释放，这样烃类在胞外被代谢生成具有表面活性的烷烃衍生物，该表面活性产物将促进烃类的乳化，使得剩余的未自溶解体的细胞可以借助生物表面活性剂而摄取降解烃类。

The method colligates weighting moving average residual within L time window to detect multi-type sensor fault,and uses neural network technique to online re-construct sensor signal,and achieves the tolerant proportional integral derivative control.

该方法应用加权移动平均残差技术对传感器故障进行检测，并利用神经网络建模技术在线重构故障传感器信号，重组PID控制器反馈回路，实现容错PID控制。通过在三水箱过程设立多种不同类型的传感器故障，进行仿真研究。

After convolving the image model with the edge detection operators of second derivative model, a plane fitting in the least squares sense is used to detect the zero crossing points as edge points.

使用二阶导数型边缘检测算子对图象模型进行卷积后，用均方误差最小的准则对卷积后的图象进行平面拟合，并求出零交点作为图象的边缘点。

Image is processed by using median filter and unsharp mask. The infrared image intensity surface is fitted by Haralickd discrete orthogonal polynomial basis function,and then the maximum points are detected on the fitted intensity surface by convolving the image with the second order directional derivative operators.

中文摘要：提出一种红外弱小多目标图像检测方法，图像先经过中值滤波、高提升滤波增强处理，再用基于Haralick离散正交多项式曲面拟合图像，拟合曲面的极大值点即目标点，可以利用导出的二阶方向导数算子与图像进行卷积得到。

It was found that the PCCG of the derivative could be 31.32% when 3 g starch and 3 g maleic acid were initiated by both 0.009 85 mol/L Fe2+ and 4.412 mol/L H2O2 and copolymerized at 60 ℃ for 5 h.

将中性的淀粉转化为含羧基的阴离子型聚电解质，是赋予淀粉功能性而提升其价值的一种有效途径。

It has been put forward that there exists single Ball point and double Ball points on the symmetrical connecting-rod curves of equilateral mechanisms.

从鲍尔点的形成原理出发，分析对称连杆曲线上鲍尔点的产生条件，提出等边机构的对称连杆曲线上有单鲍尔点和双鲍尔点。

The factory affiliated to the Group primarily manufactures multiple-purpose pincers, baking kits, knives, scissors, kitchenware, gardening tools and beauty care kits as well as other hardware tools, the annual production value of which reaches US$ 30 million dollars.

集团所属工厂主要生产多用钳、烤具、刀具、剪刀、厨具、花园工具、美容套等五金产品，年生产总值3000万美元，产品价廉物美、选料上乘、质量保证，深受国内外客户的青睐