利用共轭梯度法反演钢包内钢液温度分布

为提高钢铁生产中浇铸的命中率,需对钢包内钢液温度进行测量,传统方法是用热电偶直接测量,但热电偶易损坏、成本高,且测点数目有限,不能完全反应钢液温度分布情况。针对上述问题,提出使用共轭梯度法（CGM）反演钢液温度分布。建立钢包的二维稳态传热模型,采用有限元法对钢包传热模型进行离散,获得钢包传热系统温度场;通过构建误差信息最小化函数,建立反演模型,利用CGM对刚包内钢液温度分布情况进行反演。并对某80t钢包模型仿真试验。试验证明,利用上述传热学反问题能够有效的对钢包内钢液的温度分布情况进行辨识,证实了通过传热学反问题方法辨识钢包内钢液温度分布的有效性,为钢包内钢液温度的准确识别提供新的技术手段。     

高校产学研一体化发展的实践与前瞻

本文探讨我国高校产学研一体化发展的必要性、可行性及其前景。从人类社会发展的历史特点入手，并借鉴了美国硅谷发展的经验和我国改革开放推进社会主义市场发展的需求，对高校产学研一体化发展的道路作了论述。针对目前高校产学研一体化中存在的问题，作者提出了加速高校产学研一体化发展的四条建议：1，高校产学研一体化发展必须转变观念，积极参与社会大循环；2，推进高校产学研一体化要有过硬的产品和准确的市场定位；3，高校产学研一体化发展要依托高科技园区，切实解决经费投入问题；4，高校产学研一体化发展要突出以人为本的思想，努力造就发明家和企业家。     

大型直线振动筛横梁结构动力学分析

针对某大型直线振动筛频繁出现横梁断裂问题,应用ANSYS软件,对横梁结构进行了模态分析和谐响应分析,指出结构设计中存在问题。提出横梁结构改进方案,对改进后结构动力学性能进行分析,并与原设计横梁结构的动力学性能进行比较。结果表明：横梁断裂属于低应力断裂;横梁结构静力分析与动力分析的应力值差异较大,采用静力准则的结构设计不能保证结构可靠性;改进后的横梁结构应力状态得到改善,疲劳寿命提高。     

非对称双向中继X网络中基于最大化和速率的干扰对齐与中继处理算法

双向中继X网络相对于传统无线通信网络可以实现更高的自由度.然而,基于迫零算法的中继处理算法仅考虑了消除干扰成分,忽略了对期望信号的影响,从而使得网络的和速率有待提高.特别地,当用户发送功率越低,其和速率劣势越明显.针对上述问题研究其干扰对齐方案,并给出了优化的联合考虑期望信号和干扰信号的中继处理算法.首先,通过利用用户矢量信号之间的空间关系,给出网络和速率的数学模型;其次,通过矩阵分析及数值分析理论将最大化网络和速率的中继预编码设计问题转化为线性搜索最优值问题,并用极限值方法近似网络目标函数;再次,进一步将双向网络的目标函数近似为单向网络用户参数的线性组合,大大降低算法复杂度;最后,基于优化的线性搜索最优值问题,得到最大化网络和速率的中继预编码矩阵.仿真结果表明:相较于现有的中继处理方案,本文方案明显改善了网络和速率,同时还简化了最大化网络和速率带来的算法复杂度.     

Stock market volatility and the forecasting performance of stock index futures

This study attempts to apply the general equilibrium model of stock index futures with both stochastic market volatility and stochastic interest rates to the TAIFEX and the SGX Taiwan stock index futures data, and compares the predictive power of the cost of carry and the general equilibrium models. This study also represents the first attempt to investigate which of the five volatility estimators can enhance the forecasting performance of the general equilibrium model. Additionally, the impact of the up‐tick rule and other various explanatory factors on mispricing is also tested using a regression framework. Overall, the general equilibrium model outperforms the cost of carry model in forecasting prices of the TAIFEX and the SGX futures. This finding indicates that in the higher volatility of the Taiwan stock market incorporating stochastic market volatility into the pricing model helps in predicting the prices of these two futures. Furthermore, the comparison results of different volatility estimators support the conclusion that the power EWMA and the GARCH(1,1) estimators can enhance the forecasting performance of the general equilibrium model compared to the other estimators. Additionally, the relaxation of the up‐tick rule helps reduce the degree of mispricing. Copyright © 2008 John Wiley & Sons, Ltd.     

On the physiology of metazoa

The problem of integration and control of the various processes of the metazoan organism is a major challenge to the physiologist. The traditional research strategy in dealing with the problem is neuron-oriented and its roots extend back into the last century when knowledge of hormones was lacking. In the present article, the traditional strategy is analyzed in the light of available data and its logical basis is questioned. Different levels of communication are supposed to occur in the animal or human body. Circulating hormones are responsible for the highest level of communication that occurs between organs or tissues. The central concept in the article is that regulation of circulating hormones constitutes a higher level of control relative to regulation of intercellular hormones. This is regardless of whether the latter occurs in the nervous system or elsewhere. The approach is utilized in defining the mechanism that integrates and controls the part processes of the body. The mechanism is defined as endothelial; the vascular endothelial system is the controlling part and the nervous system is one of the subordinate parts. Thanks to the new approach, meaningful biological explanations of major psychiatric disorders are now possible.     

Impulse propagation from the SA-node to the ventricles

Normally the pacemaker of the mammalian heart is located in the sinus node. In the rabbit the sinus node can be subdivided into two regions, the center of the node where the impulse originates and the border zone through which the impulse is conducted towards the atrium. Conduction properties of both regions were investigated. It appeared that conduction velocity increases and refractoriness decreases when one goes from the nodal center towards the atrium. The tissue mass of the atrium is large in comparison to the sinus node and normally the resting membrane potential of atrial fibers is more negative than that of nodal fibers; consequently, a potential difference exists causing a current flow between both areas. Evidently this hyperpolarizing current flow depresses impulse formation in the border zone fibers which have better intrinsic pacemaker properties than fibers in the nodal center. If the impulse has reached the atrium it is conducted with a relatively high safety factor and will reach the AV node in principle without difficulty. The AV node, if deprived of sinus nodal dominance, develops spontaneous activity originating from the lower nodal fibers. Also in this structure, electrotonic depression by surrounding tissue causes deceleration of the pacemaker.     

Stimulating determinants of the secondary mixed lymphocyte reaction (MLR-II)]

An anti-Ia immune serum (A . TL anti-A . TH) directed to the antigens of the stimulating cell, blocked the MLR-II. A significant correlation was observed between the anti-Ia reactivity of the immune serum, studied against a panel of eleven original H-2 haplotypes and the reactivity against the same panel of the in vitro primed responding cells (A . TL anti-A . TH). These results confirm the hypothesis that Ia antigens are the structures stimulating the MLR-II.     

Focus on molecular events in the anterior chamber leading to glaucoma

Primary open-angle glaucoma is a multifactorial disease that affects the retinal ganglion cells, but currently its therapy is to lower the eye pressure. This indicates a definite involvement of the trabecular meshwork, key region in the pathogenesis of glaucoma. This is the first target of glaucoma, and its functional complexity is a real challenge to search. Its functions are those to allow the outflow of aqueous humor and not the reflux. This article describes the morphological and functional changes that happen in anterior chamber. The “primus movens” is oxidative stress that affects trabecular meshwork, particularly its endothelial cells. In these develops a real mitochondriopaty. This leads to functional impotence, the trabecular meshwork altering both motility and cytoarchitecture. Its cells die by apoptosis, losing barrier functions and altering the aqueous humor outflow. All the morphological alterations occur that can be observed under a microscope. Intraocular pressure rises and the malfunctioning trabecular meshwork endotelial cells express proteins that completely alter the aqueous humor. This is a liquid whose functional proteomics complies with the conditions of the trabecular meshwork. Indeed, in glaucoma, it is possible detect the presence of proteins which testify to what occurs in the anterior chamber. There are six classes of proteins which confirm the vascular endothelium nature of the anterior chamber and are the result of the morphofunctional trabecular meshwork decay. It is possible that, all or in part, these proteins can be used as a signal to the posterior pole.     

Site of sex pheromone biosynthesis in the female housefly,Musca domestica L.

Summary The primary site of sex pheromone biosynthesis in the female housefly is the abdominal integument tissue, whereas the contribution of the legs is relatively minor. A substantial portion of the sex pheromone components are, however, transferred from the abdomen to the legs, probably as a result of grooming.Acknowledgment. This work was supported by the Science and Education Administration of the U.S. Department of Agriculture under grant No. 7801064 from the Competitive Research Grants Office. Contribution of the Nevada Agricultural Experiment Station, Journal Series No 524. Housefly pupae were kindly supplied by Dr Ted Shapas, S.C. Johnson and Son, Inc., Racine, Wisconsin.Author for correspondence.     

Beyond Mendelism and Biometry

Historiographical analyses of the development of genetics in the first decade of the 20th century have been to a great extent framed in the context of the Mendelian-Biometrician controversy. Much has been discussed on the nature, origin, development, and legacy of the controversy. However, such a framework is becoming less useful and fruitful. This paper challenges the traditional historiography framed by the Mendelian-Biometrician distinction. It argues that the Mendelian-Biometrician distinction fails to reflect the theoretical and methodological diversity in the controversy. It also argues that the Mendelian-Biometrician distinction is not helpful to make a full understanding of the development of genetics in the first decade of the twentieth century.     

Evidence for the metabolism of phospholipids and triacylglycerols in humanAscaris lumbricoides

Summary HumanAscaris lumbricoides has the necessary mechanism for the biosynthesis and degradation of phospholipids and triacylglycerols, as in most other species. Piperazine decreases the level of triacylglycerols of this parasite by stimulating the activity of lipase and partially inhibiting the activity of phosphatidate phosphatase.Acknowledgments. Thanks are due to the University of Kerala for facilities provided, Dr T. Ramasarma of the I.I. Sc., Bangalore for help in the labelling studies, Dr. G. D. Cain of the University of Iowa for valuable comments and Dr P. Vijayagopal of ANU for the gift of CDP-choline.     

Bovine pituitary intraglandular colloid fraction F5 localized in the rat endocrine pancreas

Summary Bovine pituitary intraglandular colloid thought to be a waste product, is the holocrine secretion of intermediate lobe cells. It is housed in the intraglandular lumen (residual lumen) and is extruded into the venous circulation of the cavernous sinuses via clefts in the capsule of the gland aligned with the intraglandular lumen. Intraglandular colloid, fraction F₅ (mol.wt 34,000), radiolabeled with (¹²⁵I)Na and injected (0.15 ml) into the right internal jugular vein of male Wistar rats, accumulated in the endocrine pancreas. Autoradiographs showed that the material had specifically localized in the capillary network of the endocrine pancreas. Since the intermediate lobe is poorly vascularized, intraglandular colloid is considered to be the transport medium for intermediate lobe materials.This study was supported by a grant from the Natural Sciences and Engineering Research Council of Canada.I would like to thank S. Choles and J. Bennett for their technical expertise with the help of P. Galvin and W. Halina. I thank members of the Central Animal Facilities, McMaster University Medical Centre, Hamilton, Ontario, for labeling the intraglandular colloid and for counting the decay rate of the tissue. I would also like to thank Drs. A. deBold and J. Kraicer, Faculty of Medicine, Queen's University, Kingston, Ontario, for their interest in this study.     

Role of FGFRL1 and other FGF signaling proteins in early kidney development

The mammalian kidney develops from the ureteric bud and the metanephric mesenchyme. In mice, the ureteric bud invades the metanephric mesenchyme at day E10.5 and begins to branch. The tips of the ureteric bud induce the metanephric mesenchyme to condense and form the cap mesenchyme. Some cells of this cap mesenchyme undergo a mesenchymal-to-epithelial transition and differentiate into renal vesicles, which further develop into nephrons. The developing kidney expresses Fibroblast growth factor (Fgf)1, 7, 8, 9, 10, 12 and 20 and Fgf receptors Fgfr1 and Fgfr2. Fgf7 and Fgf10, mainly secreted by the metanephric mesenchyme, bind to Fgfr2b of the ureteric bud and induce branching. Fgfr1 and Fgfr2c are required for formation of the metanephric mesenchyme, however the two receptors can substitute for one another. Fgf8, secreted by renal vesicles, binds to Fgfr1 and supports survival of cells in the nascent nephrons. Fgf9 and Fgf20, expressed in the metanephric mesenchyme, are necessary to maintain survival of progenitor cells in the cortical region of the kidney. FgfrL1 is a novel member of the Fgfr family that lacks the intracellular tyrosine kinase domain. It is expressed in the ureteric bud and all nephrogenic structures. Targeted deletion of FgfrL1 leads to severe kidney dysgenesis due to the lack of renal vesicles. FgfrL1 is known to interact mainly with Fgf8. It is therefore conceivable that FgfrL1 restricts signaling of Fgf8 to the precise location of the nascent nephrons. It might also promote tight adhesion of cells in the condensed metanephric mesenchyme as required for the mesenchymal-to-epithelial transition.     

Nickel-binding proteins

Nickel enzymes are a relatively new class of metalloenzymes. The seven known nickel enzymes are urease, hydrogenase, CO-dehydrogenase, methyl-coenzyme M reductase, Ni-superoxide dismutase, glyoxalase I and cis-trans isomerase. The requirement for nickel implies the presence of a nickel-processing system, since free transition metals are harmful to the cell. A nickel-processing system involves the recognition and transport of nickel into the cell and the handling of the nickel once it enters the cell until it is inserted into the nickel enzyme. Several mechanisms for nickel transport have been identified and will be reviewed here. Accessory proteins required for the biosynthesis of the nickel active site have been identified. Accessory proteins bind the nickel when it enters the cell and are proposed to assist with the insertion of nickel into the enzyme. The function of the characterized nickel-processing proteins is described, and models for nickel insertion into the nickel enzymes are presented.     

New inversion of the pair no. 3 chromosome in a black rat

Summary A Japanese black rat (Rattus rattus tanezumi) with a subtelocentric pair no. 3 chromosome was found in Gotenba, Japan. By comparison of the length in both members of the chromosome pair, and from the G-ban pattern, the subtelocentrics seemed to have developed from the original acrocentrics by the pericentric inversion.The author wishes to express his sincere thanks to Dr. K. Moriwaki for the help of the collection of the material and also for the skilful technical help of Miss Y. Ochiai. Supported by a grant-in-aid from the Ministry of Education, Science and Culture of Japan (Nos 111510 and 111506). Contribution No. 1125 from the National Institute of Genetics, Japan.     

Reflex motility of the stomach evoked by electrical stimulation of the hepatic vagus nerve

Summary Electrical stimulation of the cranial end of the cut hepatic branch of the vagus nerve produced an increase in the motility of the empty stomach in the rat, whereas systemic injection of insulin produced a gradual increase in the motility.Acknowledgment. The authors are indebted to Dr K. Yamaguchi and Prof. A. Niijima for their encouragement of the project.     

吴家沟赤泥尾矿库初期坝稳定性分析

吴家沟尾矿库初期坝包括下部天然岩土体初期坝和上部土石混填初期坝两部分。在分析初期坝基本特征的基础上,把初期坝视作重力式档土墙结构,采用极限平衡法计算堆积坝对初期坝的静止土压力和主动土压力,应用抗剪强度公式分析上部初期坝与基岩之间坝基面的抗滑稳定性,得到无水和有水工况下静止土压力和主动土压力作用下坝基面抗滑稳定安全系数,其安全系数值明显大于规范规定的安全系数。采用ABAQUS有限元软件对初期坝应力特征进行分析,初期坝(包括天然坝体和堆石坝体)的最大剪应力及最大竖向应力分别小于坝体的抗剪强度和抗压强度,初期坝是稳定的。     

汶川特大地震灾后职业教育对经济增长贡献预测及其重构

分析汶川地震灾区职业教育损失状况和灾区职业教育发展问题及特征.通过大量的实证研究和数据分析,在解析职业教育重建体系中相关因素对灾后重建社会经济体系影响力的基础上,基于教育的外溢率构建社会经济增长的生产函数模型,得出职业教育对经济重建的贡献率,从而证明了职业教育正的外部性及职业教育投资的比例.在灾区技能人才需求预测的基础上,修正原有的职业教育体系结构,借助人-机结合的定性分析和定量分析方法,构建灾后职业教育重建体系.在这个过程中,也对职业教育发展中出现的问题进行了分析,并提出了具有可行性的改进办法.