物体基视频编码中的运动物体分割

针对物体基视频编码应用 ,提出了一种基于运动的图像序列分割方案 ,它同时结合了亮度和运动信息 ,使用重构式开 -闭形态滤波器等形态变换工具。此外 ,还提出了一种区域生长型的分水岭算法 ,它直接对要分割的图像而不是其形态梯度信号进行分割 ,克服了传统形态分割方法使用形态梯度信号而导致轮廓信息丢失的缺点。在具体实现算法时 ,文中采用了一种基于分级队列结构进行图像扫描的巧妙方法 ,大大提高了算法的效率。模拟结果表明 ,该方案的主要优点是分割出的物体具有一致运动矢量的特征 ,并且能精确定位运动物体的边缘。

适应于极低传输码率的物体基图像编码

本文介绍了物体基编码的基本方法、算法流程及其关键技术。该编码方法的重要特点是既考虑到所处理对象的一般性，又利用了一定的先验知识，因此可用于极低传输速率的图像编码（６４ｋｂｉｔ／ｓ以下），是电视电话中的一种很有应用前景的编码方法。

对非细胞生物及生物体基本结构单元的认识

我们所看到的中学生物学教材，在谈到生物体所具有的特征及生物体组成的基本结构单元时，大多以“除病毒以外，生物体都是由细胞构成”来阐述。我们认为这一认识值得进一步讨论及思考。

基于立体三角形网络建立模型物体的方法

本文探讨一种在模型基图象编码中建立模型物体的方法，主要途径是双阈值处理的外轮廓提取，多层轮廓曲线族生成与多边形逼近，椭圆距离变换，立体三角形网络生成．

MPEG-4视频验证模型中基于内容的编解码算法

ＭＰＥＧ－４是一个正在制定的编码标准，除了具有 ＭＰＥＧ－１和 ＭＰＥＧ－２标准的基于“帧”的功能以外，ＭＰＥＧ－４视频编码算法还支持多媒体环境中对视频景物内的“物体”进行存取与操纵。文中描述了第四版ＭＰＥＧ－４视频验证模型的结构及其提供的主要编码工具和算法。

用质心运动定理解某些变质量物体运动的问题

在一般理论力学教材中，对变质量物体的运动问题，都采用变质量物体基本运动方程即宿舍尔斯基方程求解．本文提出了用质心运动定理求解该类问题中的一些典型例子，对理论力学教材中缺少质心运动定理某些应用题的情况是个补充．

Syntheses,structures,and properties of three coordination polymers based on 5⁃ethylpyridine⁃2,3⁃dicarboxylic acid and N⁃containing ligands

Three coordination polymers[Mn(epda)(2,2'⁃bipy)(H_(2)O)](1),[Mn(epda)(phen)](2),and[Co_(2)(epda)2(bpe)2(H_(2)O)_(4)]·5H_(2)O(3)(H2epda=5⁃ethyl⁃pyridine⁃2,3⁃dicarboxylic acid,2,2'⁃bipy=2,2'⁃bipyridine,phen=phenanthroline,bpe=1,2⁃bis(4⁃pyridyl)ethylene)were synthesized by solvothermal reactions and characterized by single⁃crystal X⁃ray diffraction,thermogravimetric analyses,IR spectroscopy and elemental analysis.1 displays a 1D chain struc⁃ture,and these chains are joined by O-H…O hydrogen bonding andπ⁃πstacking interactions to generate a 2D layer structure.2 displays a 2D layer structure,and adjacent layers are generated 3D architecture throughπ⁃πstacking interactions.3 displays a 1D chain structure,and adjacent chains are generated double layer structure through O-H…O hydrogen bonding.The fluorescent properties of 1 and 3 indicate that they can potentially be used as a luminescent sensor.1 was highly selective and sensitive towards o⁃nitrophenol through different detection mechanisms,however,3 was highly selective and sensitive towards 2,4,6⁃trinitrophenol.In addition,the magnetic behavior of 2 has also been investigated.CCDC:2172533,1,2355773,2,2355774,3.

体内自由基的产生机制

生物体内可产生多种自由基,而研究最多、医学上占有重要地位的是氧自由基。机体每天吸入氧的98％是通过细胞色素氧化还原生成水。

Investigation of bioactivity and biodegradability of Mg-bioceramic implants:An in vitro study for biomedical applications

In this study,Mg-based composites,by the addition of ZnO,Ca_(2)ZnSi_(2)O_(7),Ca_(2)MgSi_(2)O_(7),and CaSiO_(3)as bioactive agents,were fabricated using friction stir processing.The microstructure and in vitro assessment of bioactivity,biodegradation rate,and corrosion behavior of the resultant composites were investigated in simulated body fluid(SBF).The results showed that during the immersion of composites in SBF for 28 d,due to the release of Ca^(2+)and PO_(4)^(3-)ions,hydroxyapatite(HA)crystals with cauliflower shaped morphology were deposited on the surface of composites,confirming good bioactivity of composites.In addition,due to the uniform distribution of bioceramic powders throughout Mg matrix,grain refinement of the Mg matrix,and uniform redistribution of secondary phase particles,the polarization resistance increased,and the biodegradation rate of composites significantly reduced compared to monolithic Mg matrix.The polarization corrosion resistance of Mg-ZnO increased from 0.216 to 2.499 kΩ/cm^(2)compared to monolithic Mg alloy.Additionally,Mg-ZnO composite with the weight loss of 0.0217 g after 28 d immersion showed lower weight loss compared to other samples with increasing immersion time.Moreover,Mg-ZnO composite with the biodegradation rate of 37.71 mm/a exhibited lower biodegradation rate compared to other samples with increasing immersion time.

立体图像序列的压缩方法

首先介绍了立体视觉的基本原理,然后对立体图像的压缩方法分四类进行了综述。对其中用于立体图像序列的两种主要方法:基于“块”匹配的立体图像压缩方法和基于物体的立体图像压缩方法进行了深入探讨。通过对已有成果进行总结和分类,剖析了两种方法的优、缺点,并提出了一些还需要深入研究的问题,如:残差图像编码、遮挡检测、更精确的场景分割等。

MPEG-4视频验证模型

ＭＰＥＧ４是一个正在制定的编码标准，除了具有ＭＰＥＧ１和ＭＰＥＧ２标准的基于“帧”的功能以外，ＭＰＥＧ４视频编码算法还支持多媒体环境中对视频景物内的“物体”进行存取与操纵。概述了ＭＰＥＧ４视频编码标准将支持的新功能，并描述了第４版ＭＰＥＧ４视频验证模型的结构。

Self-adapting extraction of matrix mineral bulk modulus and verification of fluid substitution

Gassmann＇s equations are commonly used for predicting seismic wave velocity in rock physics research.However the input matrix mineral bulk modulus parameters are not accurate,which greatly influences the prediction reliability.In this paper,combining the Russell fluid factor with the Gassman-Biot-Geertsma equation and introducing the dry-rock Poisson＇s ratio,we propose an effective matrix mineral bulk modulus extraction method.This method can adaptively invert the equivalent matrix mineral bulk modulus to apply the Gassmann equation to fluid substitution of complex carbonate reservoirs and increase the fluid prediction reliability.The verification of the actual material fluid substitution also shows that this method is reliable,efficient,and adaptable.

Effect of thermal stabilization on microstructure and mechanical property of directionally solidified Ti-46Al-0.5W-0.5Si alloy

Effect of thermal stabilization on the microstructure and mechanical property of directionally solidified Ti-46Al-0.5W-0.5Si （mole fraction, %） alloy was investigated. The specimens were thermal stabilized for different time （t） and directionally solidified at a constant growth rate of 30 μm/s and temperature gradient of 20 K/mm. Dependencies of the primary dendritic spacing （λ1）, secondary dendritic spacing （λ2）, interlamellar spacing （λL） and microhardness （HV） on holding time were determined. The values of the λ1, λ2 and λL increase with the increase of t, and the value of HV decreases with the increase of t. The increase of t is helpful to obtain a good directional solidification structure. However, it reduces the mechanical property of the directionally solidified TiAl alloy. The optimized value of t is about 30 min.

Effects of Material Physical Properties on White-rot Fungi Mycelial Growth

[ Objective] The research aimed to study effects of material physical properties on white-rot fungi mycelial growth and provide theoretical basis for further expanding the application range of white-rot fungi. [ Method Four common species of white-rot fungi were cultivated by wood meal fowl dung mixture in test tube and culture dishes. The relationship between physical properties of culture material and the growth of these mycelials were studied. [Result] The results showed the water retention capacity of culture material was decreased with the increasing of its grain size and porosity, but the decrease of its specific gravity reduced the material water retention. And the dehydration rate of medium prepared with these materials at the same moisture conditions tended to increase. These physical properties of material, such as grain size, specific gravity, porosity, water retention and water drainage, influenced the growth of white-rot fungi mycelial by affecting the moisture and ventilation condition of media. The results hinted that above material physical properties had feedback effects on the growth of white-rot fungi mycelia. [ Conclution] Physical properties of culture material have significant effects on the growth of white-rot fungi mycelial.

进入细胞世界

细胞是生命活动的基本单位，一切有机体都由细胞构成。除病毒外的所有生物，都由细胞构成。自然界中既有单细胞生物，也有多细胞生物。细胞是生物体基本的结构和功能单位。因此，了解细胞，认识细胞的功能是非常重要的。

Cloning of the Full-length Gene for Tobacco Ethylene Receptor NTHK2 and Characterization of Its Kinase Domain

Previously the partial sequence of an ethylene receptor gene NTHK2 was isolated from tobacco (Nicotiana tabacum L. var. Xanthi) plants and it was wound and drought inducible. In the present study full-length cDNA of NTHK2 was cloned by 5'-RACE method. NTHK2 gene has 3 216 bp, with 509 bp of 5'-non-coding region and 427 lip of 3'-non-coding region, and encodes an ethylene-receptor homolog of 760, amino acids. NTHK2 protein has a putative signal peptide, three transmembrane domains, a histidine kinase domain and a receiver domain. In the putative histidine kinase domain, the histidine at the phosphorylation site was replaced by an asparagine. To study the biochemical property of NTHK2, its kinase domain was expressed as a fusion protein with glutathione S-transferase (GST) using yeast Schizzosaccharomyces pombe as an expression system. In vitro kinase assay showed that NTHK2 kinase domain can autophosphorylate in the presence of Mg2+, indicating that NTHK2 may function as a kinase. Further studies will elucidate the function of NTHK2 in plant.

Calculations of rock matrix modulus based on a linear regression relation

The rock matrix bulk modulus or its inverse, the compressive coefficient, is an important input parameter for fluid substitution by the Biot-Gassmann equation in reservoir prediction. However, it is not easy to accurately estimate the bulk modulus by using conventional methods. In this paper, we present a new linear regression equation for calculating the parameter. In order to get this equation, we first derive a simplified Gassmann equation by using a reasonable assumption in which the compressive coefficient of the saturated pore fluid is much greater than the rock matrix, and, second, we use the Eshelby- Walsh relation to replace the equivalent modulus of a dry rock in the Gassmann equation. Results from the rock physics analysis of rock sample from a carbonate area show that rock matrix compressive coefficients calculated with water-saturated and dry rock samples using the linear regression method are very close （their error is less than 1%）. This means the new method is accurate and reliable.

Genetic Analysis of a Biomass Mutant in Oryza sativa

[ Objective ] The study aimed to reveal the genetic model of a biomass mutant in Oryza sativa. [ Method ] In the process of screening and identification of Bar-transgenic rice, a biomass mutant was found in 10 lines of T1 progenies. The mutant was investigated for genetic analysis and agronomic traits by herbicide spraying and PCR amplification. [ Result] The segregation ratio is consistent with mendelian law（3：1）. The mutant assumed not only higher plant height, wider straw and earlier florescence, but also more tillers, bigger spikes and resultantly higher biomass. PCR detections indicated that no co-segregation was observed between mutant traits and target gene（Bar） in the T-DNA inserted, proving that the mutant is not caused by the insertion of T-DNA containing target gene （Bar）. [ Conclusion] Our study may avail to understand the cloning of mutant gene and the mechanism of the mutant gene on biomass.

Chloroplast Genetic Engineering in Higher Plants

Chloroplast genetic engineering, with several advantages over nuclear genetic engineering, is now regarded as an attractive new technology in basic and applied research, including deepening our understanding of plastid genome, engineering plant metabolic system, generating transplastomic plants with higher resistance to insect, disease, drought and herbicide and bioproducing of antibodies and vaccines. In this review, the principle and operating system for chloroplast genetic engineering and its application in higher plants have been discussed.

Impact of Copy Number on Transgene Expression In Tobacco

对农杆菌介导法获得的转 β_葡糖醛酸酶 (β_glucuronidase ,GUS)基因 (uidA)烟草 (NicotianatabacumL .)进行GUS表达分析 ,发现部分转基因植株无GUS活性。进一步Southern杂交结果发现 ,GUS基因失活植株的基因组中整合了多个uidA拷贝 ,而GUS活性高的转基因植株多为uidA单拷贝整合 ,表明uidA基因失活与基因多拷贝整合有关。Northern杂交结果显示 ,失活植株无特异uidARNA杂交带 ,而GUS活性高的植株可检测到明显的杂交信号 ,说明多拷贝引起的基因失活发生在RNA水平。