On The Values of Natural Resources

This paper discussed whether natural resources have values from Labor Theory of Value and Utility Theory of Value at first, then its values are defined and its are methods of classification summarized. It is definite that values of natural resources include economic value, social value, and ecological value, and representations of all these values are commodity value and service value. Evaluating natural resources scientifically, especially its service value, and establishing reasonable strategy of utilizing and protecting natural resources are a very important task for sustainable using of natural resources.     

超临界CO_2流体萃取天然植物香精研究进展

天然香精是从芳香植物中用物理方法提取的有机混合物,具有独特、自然、舒适的香气和香韵,在香料工业、日化、食品等领域有广泛应用,但利用传统方法萃取易使其原有香味失真;超临界CO2流体萃取是一种新型分离技术,特别适于不稳定及热敏性天然产物的萃取,利用该技术萃取天然香精可得到高品质高价值的产品。概述了超临界CO2流体萃取技术,介绍了近几年该技术萃取植物天然香精及其与其他分离技术结合的相关研究,探讨了该技术在应用中存在的问题及其发展前景,旨在为该技术萃取天然香精的进一步应用提供参考。     

普通小麦×八倍体小黑麦杂种F1代与亲本的形态学、细胞学和超微形态比较分析

以普通小麦京冬8号为母本,八倍体小黑麦劲松5号为父本,杂交获得杂种F1代。在对杂种F1代和亲本进行形态学和细胞学鉴定的基础上利用扫描电子显微镜对亲本和杂种F1代的叶表皮及气孔亚显微形态进行比较,得知3种供试材料叶表皮亚显微形态共同的特征是有气孔器、长细胞和毛细胞,细胞排列与叶脉平行,但母本普通小麦的叶表皮细胞轮廓清晰,排列较为整齐、光滑,气孔排列呈直线,哑铃状的保卫细胞有长短不一的刺毛;父本八倍体小黑麦的气孔周围有横向和纵向排列的嵴状凸起,气孔呈长方形、较大,排列方式总体也呈直线型,保卫细胞非常明显,但刺毛极少且短;杂种F1代无论是叶表面还是气孔的亚显微形态都与父本更相似,所不同的是叶表皮有刺毛,气孔大小介于两亲本之间。杂种F1代与双亲在形态学、叶表皮及气孔超显微形态特征上均有明显差异;超显微形态学指标也可以作为区分、鉴定远缘杂种和亲本的一项依据。     

中国虫茶现状及其研究开发思路

虫茶在我国有悠久的历史,其由来众说纷纭,无从考证。虫茶具有奇特的冲泡特点以及多种营养保健功能,广受东南亚、港澳华侨的青睐。虽然对虫茶的研究越来越多,但还有许多关键问题亟待解决。介绍了虫茶的现状和存在的问题,并进一步提出了用现代理念开发加工虫茶的一些思路。     

门架式抗滑桩结构模型试验研究

为了对门架式抗滑桩的结构特性有进一步的认识和提升,进行了门架式抗滑桩三维地质力学模型试验与门架式抗滑桩结构模型试验。通过在桩身内部贴置应变片以及桩身的关键位置处放置千分表,来测量在推力荷载施加过程中,门架式抗滑桩的桩身应力变化特点及关键位置点的位移变化特征。试验结果表明：门架式抗滑桩桩前、后排桩桩顶位移大于滑动面处位移,后排桩桩身位移大于前排桩桩身位移;前、后排桩桩身内力均呈现明显的“s”型分布,桩顶应力不为零,其数值随着推力荷载的增大的而增大。     

Global Attractors for a Class of Pattern Formation Equations

A class of pattern formation equations is treated, the existence of its global attractor is considered and some estirnates of its dimension are given. This sort of pattern formation equations relate to turbulence phenomenon in chemistry and combustion, so it is of great physical importance. Besides, its important theoretical value lies in that the equation contains differential operator of the fourth order in space. The global attractor exists after a series sophisticated estimates by the means of interpolation inequity and embedding theorems in sobolev spaces. Furthermore, some estimates on its fractal dimension are given.     

Network Virus and Means of Its Prevention

More and more people are caring about network virus because of its enormous devastation lately. After introducing the development course of network virus and its main characters and analyzing its spreading path, the authors put forward ten means of prevention according to their work and experience.     

甘薯无土培育体系的研究与应用

甘薯(Ipomoea batatas)是一年生蔓生草本植物, 具地下块根, 原产于热带中美洲, 是中国重要的旱粮作物, 并有鲜食、 菜用、 观赏等多种类型。随着无土栽培技术的不断发展, 其在甘薯栽培上的应用也越来越广泛。综述了甘薯无土培育体系建设方面的研究进展和成果, 包括甘薯水培模式以及国内外有关甘薯水培的研究内容, 阐述了无土培育体系在甘薯育苗、 繁种、 生产、 绿化等方面的应用。提出了甘薯无土培育体系存在的问题并展望其发展前景。     

城市化进程中的农村居民点用地变化分析 ——以广州市为例

随着社会经济的发展,在区域建设用地变化中,占重要地位的农村居民点用地变化,已经成为城乡一体化进程中值得关注的问题。以城市化为角度对广州市农村居民点用地现状和变化进行了分析,研究发现在1997~2002年间,广州市的城市化水平综合指标由68.28增加到75.28,年平均增长的比率为1.92 %,而农村居民点用地的变化非常平稳,在6年间共增长了 796.67 hm2,年平均增长的比率为0.47 %。以上数据反映广州市农村居民点用地变化滞后于经济发展和城市化。广州的城市化是以自组织为主的城镇化,产业与居住的分散化决定了小城镇发展呈现均衡性特征。这样实质上把有限的农村空间割裂为多个不大的发展中心。这种多中心往往导致无中心,即建设无重点、发展无中心、各乡镇过度竞争,造成区域内资源的不合理流动与低效率配置,影响资源向优势区位的流转,无法形成土地资源的集约利用,最终导致农村居民点用地变化滞后于经济发展和城市化。针对农村居民点用地状况,当前对策主要是依托城市化对农村居民点进行土地整理规划使其用地变化向规模减少、集约利用发展。广州市有农村居民点的各区(县级)市,发展情况各不相同,根据不同的社会经济发展条件和地理条件可以对上述区域进行分类,分别采用适合的模式。     

The Aesthetical Characters of Traditional Buildings of Tujia Nationality in the Western of Hubei Province

Tujia nationality is a nation which has a long history and cultural traditions.The art of folk-house in the western of Hubei province is a typical representation of its national culture.Both its external form with the inner dealings and its fit for the nature are not only the results of the perfect combination of practicality and aesthetic as well as the combination of buildings and environment,but also embody Tujia people's understanding of life and beauty.This article tries to found deep-seated cultural foundation and spirits of Tujia traditional housing by researching and analyzing its aesthetical characters on architectural form,and Absorb its essence on design for modernization.     

魔芋葡甘聚糖化学结构及生理功能研究进展

为了更好地开发利用魔芋葡甘聚糖(KGM),阐明了KGM独特的结构、优良的理化性质,综述了其生物活性的研究进展,分析了其结构与性能的关系,探讨了KGM的研究方向及其应用前景。     

凝固型酸奶感官品质的控制

分析了凝固型酸奶的常见感官缺陷,并提出了生产中的控制方法,为凝固型酸奶的质量控制提供依据。     

烟草起垄施肥机的研究设计

系统地研究设计了烟草起垄施肥机,提出了烟草起垄施肥机的总体方案。分析了排肥机机构,提出了排肥机的结构设计方案。确定了设计烟草起垄施肥机关键的技术参数,设计了烟草起垄施肥机的主要部件,提出了具体实施方法。     

Parameter uncertainty analysis for probability distribution of bulk power systerm reliability

Component reliability parameters are of uncertainty and are affected by the component type, operation time, and weather conditions. So do the reliability indices of bulk power systems. The calculation of its probability distributions and its alteration law affected by parameters uncertainty are researched to provide practical engineering reference with exploring the impact of the parameter uncertainty on reliability assessment. The point estimate method is firstly proposed based on the two-loop Monte-Carlo simulation, and then the improved Monte-Carlo simulation is presented to enhance the calculation efficiency further. Moreover, their theories, merits and faults are explained in detail. It can be seen from the evaluation results for the RBTS power systems that the accuracy of the three methods are similar but the improved Monte-Carlo simulation has the highest efficiency, followed by the point estimate method. The IEEE-RTS 79 power system is evaluated by using the improved Monte-Carlo simulation, and the results verify its validity.     

灌水和施用钾肥对玉米果穗叶片光合特性及产量的影响

在玉米生育期间进行灌水和施用钾肥，对玉米果穗叶片的叶绿素含量、光合强度和玉米籽粒灌浆及最终的籽粒产量均有明显的促进作用；灌水与施用钾肥之间有一定的互作效应；钾肥（K2O）的适宜施用量在90—135kg／hm^2为宜。     

新营养健康资源:白背天葵的研究进展

本文介绍了白背天葵的基本概况,包括生物学特性、来源与分布、栽培种植技术,系统地综述了营养价值、活性物质组成及生物学功效,并从中医学理论对其药理作用进行了阐述。此外,全面分析了白背天葵的研发现状及存在的问题,并对其研究前景进行了相应的展望,以期为白背天葵的研发利用提供理论依据,为食品工业的发展提供新的动力。     

The Kinetic Study of Adsorption of Methane on Anthracite and Its Char

The adsorption quantities of methane on anthracite and its char at different tem-perature and time were measured by using volumetric niethod. The corresponding adsorption formula-is presented. The experimental results have shown that the diffusion acti-vation energies of methane in the anthracite and its char are 14.3 kJ/mol and 26. 3 kJ/mol.It issuggested that the diffusion process of methane could be the flow through the micropores in the an-thracite and its char.     

Present Research Progress of Active Vibration Control for High rise and Flexible Civil Infrastructures

The necessity,basic concepts and its key techniques of active vibration control for high rise and flexible civil infrastructures are expounded and the current research situation and its problems that still existed are introduced,and it is pointed out that making structures smart/intelligent is a new important way to ensure the structures safe and durable.     

转基因食品的安全性

转基因食品与普通食品的主要差异在于前者含有采用DNA重组技术导入的外源基因.由于近年来随着转基因作物商业化进程的加快,转基因食品的安全性引起了人们越来越多的关注.在综述了转基因食品的安全性问题以及引起争论的基础上,讨论了转基因食品的发展前景.     

Theoretical Analysis and Numerical Simulation of Variable Curvature Friction Pendulum Isolation Bearing

The basic structure of Variable Curvature Friction Pendulum Isolation Bearing (VCFP) is introduced. Based on the principle of mechanical equilibrium, theoretical analysis on two types of VCFP which are Variable Frequency Pendulum Isolation Bearing (VFPI) and Conical Friction Pendulum Bearing (CFPI) are conducted. The stiffness of each VCFP is derived, and the recovery characteristics were discussed and the computing formula of maximum residual displacement was deduced as well. Moreover, with the use of ABAQUS software, the models with solid element of each VCFP are built, and the hysteresis property under low cyclic loading and recovery characteristic are simulated. The comparative analysis of VCFP and Friction Pendulum Bearing (FPB) are also conducted. The results show that: 1) the numerical simulation results are identical to the theoretical analysis; 2) according to its plump hysteresis loops, the hysteresis property of VCFP is favorable, further more, its effective viscous damping ratio and coefficient of energy dissipation are higher than FPB, which indicates its greater ability in energy dissipation; 3) the stiffness of the VCFP is determined by curvature radius, that is, sliding surface function. And its stiffness decreases with the increase of bearing displacement through rational design. And then its isolation period increases as the displacement increases and the low frequency resonance problem of isolated structures can be well solved; 4) compared with FPB, the softening mechanism of stiffness can make the shear force transferred to superstructure decrease; 5) the maximum stress of bearing appears when the bearing reaches its designed displacement, and in general it may situate in the edge of ball joint surface of slider or bearing plate 6) the maximum residual displacement of VCFP depends on both friction coefficient and the parameters of sliding surface function, therefore, parametric design based on analysis or simulation is necessary so as to control the maximum value in an acceptable range in engineering.