使转化

In this dissertation the"Penalty"finite element method was employed to compute the velocity of the three-dimensional flow of power-law fluid in a profile die. In order to decrease the needed computer memory and raise the stability of numerical simulation, a set of decoupled methods such as PFEM, pseudo-body force method and transformation of momentum equation to the elliptic equation was developed to establish the general finite element equations to compute the distributions of velocity and viscoelastic stress of the three-dimensional viscoelastic flow of the Phan ThienTanner fluid in a profile die. During numerical simulation of the extrudate swell of the PTT fluid, the flow in the die and out of the die was analyzed separately, which demands less computer memory. The key techniques used in numerical simulation of the three-dimensional extrusion from dies such as decision of boundary conditions, creation of initial velocity field, selection of penalty factor, high Weissenberg number problem , regeneration of the free surface were studied in detail.

中文题名聚合物异型材口模挤出三维流动研究副题名外文题名 Study on three-dimensional flow of polymer melts during the process of profile extrusion from dies 论文作者涂志刚导师柳和生包忠诩教授学科专业材料加工工程研究领域\研究方向学位级别博士学位授予单位南昌大学学位授予日期2001 论文页码总数148页关键词挤出成型聚合物材料挤出口模聚合物异型材馆藏号BSLW /2003 /TQ320 /9 本文建立了求解挤出口模内幂律流体流动速度场的通用三维罚有限元模型；对于非线性粘弹性的Phan Thien-Tanner流体，为了降低模拟计算对计算机硬件的要求，并使模拟计算更加稳定，采用了一种去耦算法，包括罚有限元方法、拟体力方法和动量方程的椭圆类方程转化方法，并建立了求解速度场和粘弹性应力场的总体有限元方程；对于PTT流体的挤出胀大问题，提出了挤出胀大熔体口模内外分离模拟法，这样可以显著降低数值模拟对计算机硬件的要求。

The results show that nonlinear dry friction between mandril and tube conduces to the self excited vibration of tube and the drawing speed is the main factor which determines whether the mandril static balance is stable.

分析结果表明，抖纹产生的主要原因是芯棒与钢管之间的非线性干摩擦力导致芯棒产生自激振动；钢管的拉拔速度及钢管表面润滑层的好坏是决定芯棒的静平衡位置是否稳定的关键因素，提高拉拔速度可将干摩擦阻尼转化为粘性阻尼，同时也使拉拔速度远离临界速度，从根本上消除抖

The corrosion behavior of the specimens with and without conversion film was investigated by methods of collecting hydrogen gas and potentiodynamic polarization in neutral 3.5wt% NaCl solution and 0.15moldm^(-3)H3BO3/0.05moldm^(-3)Na2B4O7 solution.

在3.5%NaCl溶液和0.15mol/L H3BO3/0.05mol/L Na2B4O7缓冲溶液中的动电位极化测试表明，最佳条件下铈盐转化处理可使合金的腐蚀电位正移，腐蚀电流密度明显降低，起到一定的防护作用。

After different sediments ignitions, S was 1.64~2.25 times of that of raw sediment, higher obviously than the sediments without ignition. The aerating pretreatments of sediment and water caused the transformation of bioavailable form to nonavailable form. The bioavailable phosphorus decreased 7.02% and 0.23% respectively compared with that before pretreatment, but the bioavailable phosphorus of the blank test sediment increased 4.85%.

不同底泥灼烧后，最大吸附量为天然底泥的1.64~2.25倍，且明显高于未灼烧底泥对底泥曝气与对水曝气预处理使易被生物利用态磷向难被生物利用态磷转化，易被生物利用态磷较预处理前分别减少了7.02%和0.23%，而空白试验底泥的易被生物利用态磷则增加了4.85%。

State Key Laboratory of Pollution Control and Resources Reuse, Tongji University, Shanghai 200092, ChinaSoil and sediments are anoxic and anaerobic environment, often containing high levels of Fe due to the interaction of iron reducing bacteria with iron oxide minerals which are widely present in subsurface.

在土壤和沉积物的自然厌氧环境中，铁氧化物可被铁还原菌等微生物异化还原产生Fe，形成的Fe/铁氧化物表面结合铁系统具有还原活性，可使有机污染物还原转化。

Hardener :硬化剂 are used to achieve a certain hardness of water which is required for the conversion of Na-soap into stable micells of lime soap by which the ink particles can be fixed on the air bubbles e.g.

用于使水达到一定的硬度，是钠皂转化成稳定的胶态钙皂的必需品。

These compounds inhibit an enzyme called angiotensin--converting enzyme, which is responsible for making the muscle cells in blood vessels contract, which drives blood pressure up.

这些化合物能抑制一种叫血管紧张肽—转化酶的酶，这种酶使血管肌细胞收缩，从而驱使血压上升。

In this paper, the technology of Se centent of the yoghourt in Se-enriched and activated Lactobacillus was studied.

本研究将亚硒酸钠添加在活性乳酸菌发酵剂中，通过活性乳酸菌的生物转化，使活性乳酸菌发酵剂富集有机硒，再用活性乳酸菌发酵剂和鲜乳等加工制成富硒功能性酸乳。

This study has provided first molecular evidence that the mRNA expression of CYP1A was significantly induced in response to domoic acid. We suggest that phaseⅠxenobiotic metabolizing enzymes CYP1A, instead of phaseⅡxenobiotic metabolizing enzymes GST, might be major detoxified enzymes in the metabolism of amnesic shellfish poisoning toxin, domoic acid.

我们认为第Ⅰ时相去毒酶CYP1A是DA代谢的关键的酶，它可通过生物转化降低DA的毒性，而第Ⅱ时相去毒酶GST在DA代谢过程中的作用不显著，使毒素不能被有效地排出体外。

Must fully note this time high school as the teacher newborn to appear not the indication,promptly does an inspection to analyze the unsuitable reason,and has pointed in the investigation and study foundation takes the measure,the practice proved: promptly on own initiative finishes the guard,unblocks with transition-period and so on transformation works,effectively prevented the polarization phenomenon,can cause the student to eliminate unsuitably,the smooth transition as soon as possible,simultaneously for constructed the harmonious teachers and students relations extremely essential function.

作为教师要充分注意到这一时期高中新生出现的不适应症，及时巡查剖析不适应的原因，并在调查研究的基础上有针对性地采取措施，实践证明：及时主动地作好防范、疏导和转化等过渡期工作，有效防止两极分化现象，能使学生尽快消除不适应，顺利过渡，同时为构建和谐的师生关系起到了非常关键的作用。

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