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1.
LIUHaixia YANYongnian XIONGZhuo CHENGJie WANGXiaohong LINFeng WANGChangyong 《科学通报(英文版)》2005,50(8):830-832
Tissue loss and end-stage organ failure has been an emergent problem for humanity. Solving this problem at the most basic level is currently an area of great interest to many.researchers. At the end of the 20th century, tissue engineering technology began using formed scaffolds to indirectly control the assembly of cells. This technology has resulted in a new way to artificially fabricate tissues.But the method has been limited to simple tissue types,such as bone, skin, muscle and tendon. The fabrication of complex organs by this technology is still not possible.A possible alternative is assembling cells directly into a viable and predefined structure. 相似文献
2.
Modular structure reengineering is a design approach conforming to the mobile exhibition features in nature and giving full play to the flexibility, convenience, and environmental protection of the mobile exhibition modes. The objective of this paper on modular reengineering study is to analyze the innovative applications of modular design in small mobile exhibition. Firstly, the modular design in the domestic small mobile exhibition was investigated in this paper, and then the significance of modular design in small mobile exhibition was proposed via combining the design and future orientation of small mobile exhibition modes. The conclusion is that modular multi-functional small mobile exhibition is the inevitable direction of the future development of the exhibition industry, as this design mode solves a series of problems including resources intensification, structure rationalization, and cost reduction in a foreseeable scope to facilitate sufficient utilization and development of the small mobile exhibition modes. 相似文献
3.
The age of the plant fossil assemblage in the Liuqu Conglomerate of southern Tibet and its tectonic significance 总被引:1,自引:0,他引:1
FANG Aimin YAN Zhen LIU Xiaohan PAN Yusheng LI Jiliang YU Liangjun HUANG Feixing TAO Junrong 《自然科学进展(英文版)》2006,16(1):55-64
The Liuqu Conglomerate, situated to the south of Yarlung Tsangbo Suture Zone (YTSZ), is a suit of molasse formed in a foreland basin of the Himalayan orogenic belt after the collision between the two plates of the Indian and Eurasion. It is of great significance in constraining the younger limit time of the collision of the two plates and providing stratigraphic evidence to reveal the post?collisional tectonic evolution and uplifting history of the Tibet plateau. However, the age of this molasse suit and its correlation to other synchronous strata distributed in southern Tibet have been in great disputes for a long time. Especially in recent years, argues on its ages are growing violently with the recognition of the great sedimentary tectonic significances of this molasse. During the field work carried out recently on this molasse suit, a lot of plant fossils were found preserved in fairly good conditions in the upper part of this strata, which is of great help in determining its age. By identification, the assemblage of the plant fossils belongs to a tropic to subtropic flora developed in the southern margin of the Northern Hemisphere supercontinent during the Middle to Later Eocene, which can provide good constraint on its formation age. This paper is to give a brief introduction of the plant assemblage and its age, and to discuss their tectonic significances. 相似文献
4.
A scheme of chaotic secure communication based on the parameter modulation and the inversion of a chaotic dynamical system is analyzed.According to this schems,information signal is modulated by a bifurcation parameter of the transmitter,which is in chaotic state.In the receiver,a proportional-integral feedback demodulator is used to demodulate the information signal,which only uses the available synchronizing error as well as stateness of receiver,The purpose of this demodulator is proposed to overscome the influence of differentiation operation,nonlinear part and singularities in chaotic system.Numerical simulation is proposed to show the effectiveness of this demodulator. 相似文献
5.
Theodore Dreiser relates a story of Carrie's rise from a poor country girl to a Broadway star in Sister Came. An attempt is made in this paper to analyze the cold society. By way of analyzing this unequal and cruel reality to prove: in the world only the fittest can survive, the standards and requirements of morality are challenged and the traditional value is suspected. In the cold reality, any way that can protect oneself or survive in. the world is sensible, morality and traditional value are weak and meaningless. 相似文献
6.
《科技信息》2008,(27)
W.J.F.jenner is a well-known English writer and translator, whose English version Journey to the West was published by Foreign Language Press in 1984. ﹙first edition ,1982. second edition, 1984.﹚The writing in the English version is pure and fluent, and the selection of word is concise and precise .On top of this ,the English version is loyal to the content and style of the original book .Besides, Jenner's Translation is flexible according to different context . For example , the two Chinese Word "泼猴"appear many times in the first eight chapters in the original book , but Jenner translated them each time differently,as well as marvelously and appropriately . The flexibility of transition matches the concrete context and it is not only loyal to the original language, but it corresponds to the style of English language. All this is what we should learn from in our practice of translation. 相似文献
7.
Foreignization and domestication as two major translation techniques have long been the focus of the debate in translation circles. The paper reviews the history of the dispute by introducing some essays on domestication and foreignization published in key translation jour- nals in China. The ultimate aim of this dissertation is to propose that domestication and foreignization co-exist and a good translation contains both strategies. So it is unnecessary to argue which one is better. As the number of the example in this paper is limited, its credibility needs further investigation and research. 相似文献
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9.
Chao Li Nicholas Johnson Victor Ostanin Andrew Shevchuk Liming Ying Yuri Korchev David Klenerman 《自然科学进展(英文版)》2008,18(6):671-678
Microscopy is an essential technique for observation on living cells. There is currently great interest in applying scanning probe microscopy to image-living biological cells in their natural environment at the nanometer scale. Scanning ion conductance microscopy is a new form of scanning probe microscopy, which enables non-contact high-resolution imaging of living biological cells. Based on a scanned nanopipette in physiological buffer, the distance feedback control uses the ion current to control the distance between the pipette tip and the sample surface. However, this feedback control has difficulties over slopes on convoluted cell surfaces, which limits its resolution. In this study, we present an improved form of feedback control that removes the contribution of up to the third-order slope from the ion current signal, hence providing a more accurate signal for controlling the distance. We show that this allows faster and lower noise topographic high-resolution imaging. 相似文献
10.
In this study, we used the stop-action technique to experimentally investigate the material flow and microstructural evolution of alclad 2A12-T4 aluminum alloy during refill friction stir spot welding. There are two material flow components, i.e., the inward- or outward-directed spiral flow on the horizontal plane and the upward- or downward-directed flow on the vertical plane. In the plunge stage, the flow of plasticized metal into the cavity is similar to that of a stack, whereby the upper layer is pushed upward by the lower layer. In the refill stage, this is process reversed. As such, there is no obvious vertical plasticized metal flow between adjacent layers. Welding leads to the coarsening of S (Al2CuMg) in the thermo-mechanically affected zone and the diminishing of S in the stir zone. Continuous dynamic recrystallization results in the formation of fine equiaxed grains in the stir zone, but this process becomes difficult in the thermo-mechanically affected zone due to the lower deformation rate and the pinning action of S precipitates on the dislocations and sub-grain boundaries, which leads to a high fraction of low-angle grain boundaries in this zone. 相似文献
11.
三维散射问题通常采用电场积分方程(EFIE)结合矩量法(MOM)来求解,为了消除基于双线形4边形的混合域基函数在伽列金-矩量法的应用中所出现的积分奇异性,采用了参数坐标变换、相对坐标变换和奇异值提取相结合的技术,有效地消除了被积函数中出现的奇异性,并降低了原4维奇异性积分的维数,实例计算结果表明,该处理方法是正确和有效的。 相似文献
12.
本文从最大后验概率估值的角度讨论了语音信号识别中的时间规整问题,讨论了由此导出的方法与常用的动态时间规整方法之间的关系,并对这一方法的普遍意义及其在语音识别中的应用提出了看法。 相似文献
13.
施秉喀斯特位于我国贵州省黔东南州境内,区内拥有古老、完整、全球罕见的白云岩喀斯特地貌,因其具有超乎寻常的美学、生态和科研价值。该区域内地形崎岖,气候湿润温和,人为干扰少,水质洁净,森林茂密,生境多样,生物种类繁多。研究历经3年对该区域的植物进行鉴定整理得到该区域常见栽培植物名录,以期对该区植物资源综合开发利用提供参考。 相似文献
14.
面对庞大的GSM用户数,如何平稳地向3G过渡是国内甚至世界上每一个运营商都将面临的问题,TSM标准在这种情形下应运而生。在简单介绍TSM标准由来的基础上,将深入研究TSM系统中RR连接建立的过程,简要分析、比较该过程在TSM与GSM系统中的不同之处,接着描述了TSM系统RR连接建立过程中RRM子层所需完成的其他任务,最后给出了TSM系统RR连接建立过程的消息流程图。 相似文献
15.
线性代数课程是工科各专业学生必修的一门公共基础课程,行列式的定义、计算和应用是线性代数课程的重要内容之一。对于学生而言,行列式定义很难理解和掌握,从而导致很多学生对该门课程的学习产生了畏惧和厌倦心态,甚至部分学生产生了放弃的想法。根据多年的教学实践经验,该文对行列式一章教学内容进行了适当的增减优化,并采用问题式教学方法,教学实践证明,效果令人满意。 相似文献
16.
系统分析阶段是管理信息系统 (MIS)设计开发的起步阶段 ,也是设计过程中的关键一步 ,在该阶段建立逻辑模型的传统方式是采用面向处理的功能分解法。本文先讨论了该方法所存在的局限性 ,然后探讨了另外一种设计方法———面向对象设计方法 ,并将该方法应用于MIS系统的建模当中。 相似文献
17.
电力系统规划Hopfield优化模型的模拟退火算法 总被引:4,自引:0,他引:4
Hopield模型用于电力系统规划问题求解时,可能陷入局部最小点而无法得到全局最小点。本文提出了一种改进方法,即在陷入部最小点后,引入模拟退火技术,可使网跳出局部最小点而向全局最小点收敛,算例证实例了方法的可行性。 相似文献
18.
提出一种新的有限元子结构并行算法。本方法利用改进的Choleski分解进行静凝聚以求得有效刚度阵和载荷阵。计算结果表明,本方法的运算速度优于矩阵分解法和传统的子结构方法。 相似文献
19.
LI Yan LI XiaoLi OUYANG GaoXiang GUAN XinPing 《科学通报(英文版)》2007,52(14):2006-2011
Estimating the interaction among neural networks is an interesting issue in neuroscience. Some methods have been proposed to estimate the coupling strength among neural networks; however, few estimations of the coupling direction (information flow) among neural networks have been attempted. It is known that Bayesian estimator is based on a priori knowledge and a probability of event occurrence. In this paper, a new method is proposed to estimate coupling directions among neural networks with conditional mutual information that is estimated by Bayesian estimation. First, this method is applied to analyze the simulated EEG series generated by a nonlinear lumped-parameter model. In comparison with the conditional mutual information with Shannon entropy, it is found that this method is more successful in estimating the coupling direction, and is insensitive to the length of EEG series. Therefore, this method is suitable to analyze a short time series in practice. Second, we demonstrate how this method can be applied to the analysis of human intracranial epileptic electroencephalogram (EEG) recordings, and to indicate the coupling directions among neural networks. Therefore, this method helps to elucidate the epileptic focus localization. 相似文献
20.
抚顺矿区煤层气资源条件综合分析 总被引:1,自引:0,他引:1
通过对抚顺矿区煤层气地质特征、储层特征及煤层气资源量的系统而深入分析,认为该区煤层气资源条件良好,主煤层巨厚而集中、煤阶相对较高、煤岩类型有利于煤层气的生成、主煤层顶板的巨厚油页岩有利于煤层气的保存、且含气量相对较高、渗透性好、1200m以浅的煤层气资源量还有41.65×108m3。同时对矿区井下瓦斯抽放利用和煤层气利用的下游市场进行了评述,指出抚顺矿区是使我国煤层气产业走出困境,寻求突破的最佳试验战场。 相似文献