Kinematic and Dynamic Characteristics Analysis of Bennett's Linkage

Bennett's linkage is a spatial fourlink linkage,and has an extensive application prospect in the deployable linkages.Its kinematic and dynamic characteristics analysis has a great significance in its synthesis and application. According to the geometrical conditions of Bennett 's linkage,the motion equations are established,and the expressions of angular displacement,angular velocity and angular acceleration of the followers and the displacement,velocity and acceleration of mass center of link are shown. Based on Lagrange's equation,the multi-rigid-body dynamic model of Bennett's linkage is established. In order to solve the reaction forces and moments of joint,screw theory and reciprocal screw method are combined to establish the computing method.The number of equations and unknown reaction forces and moments of joint are equal through adding link deformation equations. The influence of the included angle of adjacent axes on Bennett 's linkage 's kinematic characteristics,the dynamic characteristics and the reaction forces and moments of joint are analyzed.Results show that the included angle of adjacent axes has a great effect on velocity,acceleration,the reaction forces and moments of Bennett's linkage. The change of reaction forces and moments of joint are apparent near the singularity configuration.

Hospitalized prevalence and 5-year mortality for IBD:Record linkage study

AIM:To establish the hospitalized prevalence of severe Crohn's disease(CD) and ulcerative colitis(UC) in Wales from 1999 to 2007;and to investigate long-term mortality after hospitalization and associations with social deprivation and other socio-demographic factors.METHODS:Record linkage of administrative inpatient and mortality data for 1467 and 1482 people hospitalised as emergencies for ≥ 3d for CD and UC,respectively.The main outcome measures were hospitalized prevalence,mortality rates and standardized mortality ratios for up to 5 years follow-up after hospitalization.RESULTS:Hospitalized prevalence was 50.1 per 100 000 population for CD and 50.6 for UC.The hospitalized prevalence of CD was significantly higher(P < 0.05) in females(57.4) than in males(42.2),and was highest in people aged 16-29 years,but the prevalence of UC was similar in males(51.0) and females(50.1),and increased continuously with age.The hospital-ized prevalence of CD was slightly higher in the most deprived areas,but there was no association between social deprivation and hospitalized prevalence of UC.Mortality was 6.8% and 14.6% after 1 and 5 years follow-up for CD,and 9.2% and 20.8% after 1 and 5 years for UC.For both CD and UC,there was little discernible association between mortality and social deprivation,distance from hospital,urban/rural residence and geography.CONCLUSION:CD and UC have distinct demographic profiles.The higher prevalence of hospitalized CD in more deprived areas may reflect higher prevalence and higher hospital dependency.

Complete Real Solution of the Five-orientation Motion Generation Problem for a Spherical Four-bar Linkage

For a spherical four-bar linkage,the maximum number of the spherical RR dyad（R：revolute joint）of five-orientation motion generation can be at most 6.However,complete real solution of this problem has seldom been studied.In order to obtain six real RR dyads,based on Strum＇s theorem,the relationships between the design parameters are derived from a 6th-degree univariate polynomial equation that is deduced from the constraint equations of the spherical RR dyad by using Dixon resultant method.Moreover,the Grashof condition and the circuit defect condition are taken into account.Given the relationships between the design parameters and the aforementioned two conditions,two objective functions are constructed and optimized by the adaptive genetic algorithm（AGA）.Two examples with six real spherical RR dyads are obtained by optimization,and the results verify the feasibility of the proposed method.The paper provides a method to synthesize the complete real solution of the five-orientation motion generation,which is also applicable to the problem that deduces to a univariate polynomial equation and requires the generation of as many as real roots.

On China's Foreign Trade Development and Linkage with the Customary Rules of International Trade

Although great differences exist between the trade systems of different countries,internationaltrade must go on in line with the customary international trade rules.As China’s economy developsand the socialist market economic system emerges,China is basically qualified to link up withcustomary international trade rules.In the Ninth Five-Year Plan period,China’s reform of its foreigntrade system aims at setting up a trade system that conforms with international trade practice.Forthe purpose,the author of this article suggests that a neutral trade policy should be adopted inaccordance with the international practice since it does not hinder exports,nor restrict imports toan excessive degree.

A generalization of Kempe’s linkages

A new, general type of planar linkages is presented, which extends the classical linkages developed by Kempe consisting of two single-looped kinematic chains of linkages, interconnected by revolute hinges. Together with a locking device, these new linkages have only one degree of freedom (DOF), which makes them ideal for serving as deployable structures for different purposes. Here, we start with a fresh matrix method of analysis for double-loop planar linkages, using 2D transformation matrices and a new symbolic notation. Further inspection for one case of Kempe’s linkages is provided. Basing on the inspection, by means of some novel algebraic and geometric techniques, one particularly fascinating solution was found. Physical models were built to show that the derivation in this paper is valid and the new mechanisms are correct.

一类Chebyshev行列式的计算

研究了一类 Ｃｈｅｂｙｓｈｅｖ多项式 Ｔ_ｎ（ｘ）及 Ｕ_ｎ（ｘ）组成的特殊行列式 Ｑ_ｎ（ｍ，ｋ）、Ｃ_ｎ（ｍ，ｋ）、Ｃ_ｎ（ｍ，ｋ）的计算问题，得到了两个有趣的恒等式及一个推论．

关于Chebyshev函数的加权Landau’s型不等式

本文在L^2上建立了关于Chebyshev多项式T_n(x)的Landau's型不等式。利用T_n(x)的正交性,建立了代数多项式p_n(x)的加权Landau's型不等式,并指出其不等式的系数在某种意义上是最好可能的。

圆管O-S方程的Chebyshev多项式方法

采用一般形式的Ｃｈｅｂｙｓｈｅｖ多项式展开方法，对圆管Ｐｏｉｓｅｕｉｌｅ流的Ｏ－Ｓ方程进行数值模拟．发现所有特征值的虚部都小于零，因此，验证圆管Ｐｏｉｓｅｕｉｌｅ流对于轴对称的小扰动来说是线性稳定的，结果还表明应用Ｃｈｅｂｙｓｈｅｖ多项式在计算结果精度方面有较大的优越性．

一族带有两参数的修正型Chebyshev-Halley迭代方法（英文）

应用(2,1)阶Padé逼近方法,得到不需要计算二阶导数求解非线性方程的修正型Chebyshev-Halley方法的新两参数族,证明该族方法是至少三阶收敛。该族方法的每步迭代需要计算两个函数和一个一阶导数,数值实验表明,该族迭代方法与其它方法相比,在许多方面得到了更好的数值结果。

圆管流动稳定性O—S方程的CHEBYSHEV多项式展开方法

对圆管poiseuille流动稳定性O—S方程,采用CHEBYSHEV多项式直接进行数值模拟,得到其展式方程。

Rearrangement Inequality and Chebyshev＇s Sum Inequality on Positive Tensor Products of Orlicz Sequence Space with Banach Lattice

Let φ be an Orlicz function that has a complementary function φ＊ and let lφ be an Orlicz sequence space. We prove a similar version of Rearrangement Inequality and Chebyshev＇s Sum Inequality in lφ FX, the Fremlin projective tensor product of lφ with a Banach lattice X, and in lφ iX, the Wittstock injective tensor product of lφ with a Banach lattice X.

An Extension of Chebyshev's Maximum Principle to Several Variables

In this article, we generalize Chebyshev＇s maximum principle to several variables. Some analogous maximum formulae for the special integration functional are given. A sufficient condition of the existence of Chebyshev＇s maximum principle is also obtained.

Adomian Modification Methods for the Solution of Chebyshev’s Differential Equations

The current study examines the important class of Chebyshev’s differential equations via the application of the efficient Adomian Decomposition Method (ADM) and its modifications. We have proved the effectiveness of the employed methods by acquiring exact analytical solutions for the governing equations in most cases;while minimal noisy error terms have been observed in a particular method modification. Above all, the presented approaches have rightly affirmed the exactitude of the available literature. More to the point, the application of this methodology could be extended to examine various forms of high-order differential equations, as approximate exact solutions are rapidly attained with less computation stress.

Wilson病与微卫星DNA的连锁分析

目的探索国人Ｗｉｌｓｏｎ病（ＷＤ）基因位点（ＷＮＤ）与ＡＦＭ２３８ｖｃ３、Ｄ１３Ｓ３０１、Ｄ１３Ｓ３１６、Ｄ１３Ｓ２９６、及ＡＦＭ０８４ｘｃ５等５个微卫星ＤＮＡ（ＳＴＲ）之连锁关系，对ＷＮＤ进行精确定位。为ＷＤ基因克隆奠定基础。方法对２０个ＷＤ家系１１３名成员及１００名正常对照组成员的ＤＮＡ进行５个ＳＴＲ的聚合酶链反应（ＰＣＲ）扩增片段长度多态性分析；对ＷＮＤ及５个ＳＴＲ进行二点配对及多点连锁分析。结果ＷＮＤ与Ｄ１３Ｓ３０１、Ｄ１３Ｓ３１６、Ｄ１３Ｓ２９６呈紧密连锁，与ＡＦＭ２３８ｖｃ３及ＡＦＭ０８４ｘｃ５呈中度连锁。

基于B/S模式的高职毕业生就业数据管理系统的设计与实现

为了实现对高职毕业生就业数据的信息化管理,为班主任方便、准确、快捷地录入就业数据提供服务,特别是为各职能部门及时、方便地了解学校就业情况,提出构建基于Web的高职毕业生就业数据管理系统。基于三层的B/S体系结构,采用ASP.NET(C#)+SQL Server 2000等网站开发技术,设计系统总体架构、功能模块和后台数据库,给出安全访问控制、DropDownList无刷新三级联动显示数据、导入导出数据、自动统计就业率等关键问题解决方案,实现集班主任就业数据录入和各类就业率查询统计为一体的网络应用平台。

GSTM1基因编码区SNP位点T1270533G与鼻咽癌的相关性

目的通过筛查GSTM1基因SNPs位点,研究该基因编码区单核苷酸多态位点T1270533G与鼻咽癌易感性和临床表型的关系。方法用PCR方法对中国人群27个个体DNA标本进行扩增、纯化及测序,从中获得GSTM1编码区、调控区和侧翼区及部分内含子区SNP位点,所获数据进行LD分析。选择编码区多态性位点T1270533G(该位点在中国人群罕见等位基因频率为22.2%),用tetra-Primer ARMS-PCR结合测序方法对鼻咽癌患者和对照人群进行相关性分析。结果通过测序共获取29个SNPs;其中13个SNPs位点之间均呈高度连锁不平衡;编码区多态性位点T1270533G的变异与鼻咽癌临床表型之间无明显关联(RR=0.170,95%CI=0.95-0.306 for homozygoteTT)。结论编码区多态位点T1270533G虽然发生了碱基顛换,产生了错义突变,导致了氨基酸的改变,但并没有影响其解毒功能。该位点在鼻咽癌患者和对照人群中等位基因型频率差别很小,与中国广东地区鼻咽癌易感性无明显关联。

共生理论视角下全日制教育硕士“U-S双实基地”双边联动培养模式建构

全日制教育硕士"U-S双实基地"双边联动培养模式是指大学(University)和中小学(School)通过合作,分别在其内部设置教育教学实验基地和教育教学实践基地,以此联动培养教育硕士的一种教育模式。在共生理论视角下,该模式实为大学与中小学以培养全日制教育硕士为中介而形成的一种共生结构,其共生单元为大学和中小学;共生模式为"U-S双实基地"双边联动;共生环境为当前的教育政策与信息技术条件。在该培养模式运行过程中,大学与中小学这两个共生单元的质参量相容构成该模式动力机制;"U-S双实基地"为该模式提供联动共生运作平台;约束条件下的连续共生性协议制度与信息技术条件为该模式提供共生环境保障。

多位点连锁分析检测Wilson病基因携带者及症状前患者

应用Ｓｏｕｔｈｅｍ余交技术，以ＷＮＤ位点两侧的四个ＤＮＡ多态标记一Ｄ１３Ｓ１（ｐ７Ｆ１２／ＴａｑＩ）、Ｄ１３Ｓ３１（ｐＣＲ１３２４／Ｔａｑ１和ｐＣＲＩ３２４／ＰｖｕⅡ）、Ｄ１３Ｓ２６（ｐＨ２１０／ＥｃｏＲＩ）对１０个Ｗｉｌｓｏｎ病家系的５４名个体进行多位点限制性片晰长度多态性（ＲＦＬＰ）连锁分析，检出２例症状前患者，１１例肯定携带者及５名正常纯合子，证实它们用于Ｗｉｌｓｏｎ病的症状前诊断及杂合子筛选是有效可靠的。

修正后的N-S方程研究微流动的稳定性

研究了克努森数不是特别大的微流动的稳定性,这种流动处于N-S方程适用的临界处。考虑到壁面对流体的作用力,修正流体的黏性系数,然后用修正后的N-S方程研究微流动的稳定性。类比于势能的幂函数衰减形式,本文也定义了一个黏性系数的幂次衰减模型并讨论了模型参数对稳定性的影响。用切比雪夫配置点法解模型中的微分方程,用QR法分析流动的稳定性。在所研究的流动尺度内,受壁面的影响,失稳雷诺数减小。从速度分布图上看,出现了拐点,这种拐点越明显,流动越容易失稳。

毛白杨S-腺苷高半胱氨酸水解酶基因PtSAHHA的克隆、表达及SNP关联分析

组合运用分子生物学及生物信息学方法,首次从毛白杨成熟木质部中分离出编码S-腺苷高半胱氨酸水解酶基因PtSAHHA的cDNA克隆。序列分析表明,毛白杨PtSAHHA cDNA片段全长为1 935 bp,其内部含有大小为1 458 bp的完整开放阅读框架,可编码含有485个氨基酸残基的蛋白质。组织特异性Realtime-PCR结果显示,PtSAHHA在木质部中表达丰度最高,在形成层和老叶中表达丰度中等,在嫩叶中表达丰度最低。在此基础上,组合利用MAGE5.0和DnaSP5软件对毛白杨自然群体中45株基因型个体的PtSAHHA序列进行对比和分析,共检测到166个单核苷酸多态性(SNP)位点,SNP频率为1/15 bp,多样性指数πT为0.010 58。在外显子区域共检测到88个SNP位点,其中同义突变位点34个,错义突变位点53个及1个无义突变位点;同义突变的核苷酸多样性πSynonymous=0.024 91,是非同义突变核苷酸多样性πNonsynonymous=0.002 33的10倍,推测毛白杨PtSAHHA基因编码区在毛白杨物种演化过程中受到较强的纯化选择压力。对PtSAHHA基因内的SNPs连锁不平衡分析结果表明,随着核苷酸序列长度增加至800 bp,即r2<0.1,SNPs的连锁不平衡水平已衰退至不明显。在此基础上,在由426株毛白杨基因型个体组成的关联作图群体内,对频率大于10%的42个常见SNP标记位点与6个木材品质性状进行关联分析,检测到3个SNP标记与3个表型性状显著关联。研究结果为基于分子标记的毛白杨优良木材品质性状定向辅助育种提供理论依据。