黄土丘陵区不同植被类型根际微生物群落功能多样性研究

为了解生态恢复过程中土壤微生物功能特征,采用Biolog-Eco微平板法分析了黄土丘陵区人工灌木(柠条 Caragana korshinskii、沙棘 Hippophaer rhamnoides)、人工草地(沙打旺 Astragalus adsurgens、柳枝稷 Panicum virgatum)和天然草地(阿尔泰狗哇花 Heteropappus altaicus、茵陈蒿 Artemisia capillaries)的根际微生物碳源代谢多样性特征。结果表明:柠条、阿尔泰狗哇花和茵陈蒿的根际微生物对糖类的代谢能力显著高于沙棘、沙打旺和柳枝稷;阿尔泰狗哇花和茵陈蒿对氨基酸类、酚酸类和聚合物类的代谢能力较高。茵陈蒿和阿尔泰狗哇花的微生物代谢功能多样性高于其他4种植物。柠条、阿尔泰狗哇花和茵陈蒿具有相似的根际微生物代谢功能。黄土丘陵区植被类型显著影响微生物群落碳源利用能力,天然草地根际微生物群落代谢功能多样性优于人工灌木和人工草地。     

Chemical changes of kenaf core binderless boards during hot pressing (I): influence of the pressing temperature condition

Self-bonding is the main factor of the performance expression of binderless boards, and therefore its clarification is considered to be an important issue. For this purpose, a series of chemical analyses were conducted on kenaf core binderless boards and their chemical changes during the hot-pressing process are discussed in this article. First of all, binderless boards were prepared from kenaf core powder at different pressing temperatures (without steam-explosion process) and were used for chemical analyses after they were reduced into powders and extracted with methanol. To investigate their chemical changes, lignin, holocellulose, and neutral sugar contents were determined, Fourier transform infrared (FTIR) spectra were recorded, and the nitrobenzene oxidation procedure was applied. As a result, it was found that parts of lignin and hemicelullose were decomposed during the hot-pressing process; however, the contribution of the resulting fractions to selfbonding was not observed. In addition, progress of condensation reactions in lignin and the formation of chemical bonds by low molecular weight conjugated carbonyl compounds in methanol extractives were observed. Thermal softening of lignin is also suggested to play an important role in the expression of board performance.     

对森林生态共享数据问题的初探

共享数据可以为我国经济社会可持续发展指标研究提供丰富的支撑。可持续发展指标的系统调查已经成为各级行政主管部门的经常性工作,数据的获得成为很容易的事情,并且形成惯例成为数字化产品序列,使指标的实施有了可操作的定量化方法。     

国土资源信息化对土地可持续发展利用的作用

国土资源信息是国民经济信息中不可或缺的、重要的土地信息资源,在国家经济和社会发展中具有重要的公益性、战略性和基础性作用。文章就加强国土资源信息化建设的必要性进行了分析,并提出了具体的发展措施,以促进土地管理科学化进程,提高土地可持续发展利用。     

八个竹种海涂引种试验报告

本文从土壤含盐量着手对八个竹种在引种成活率、新竹抽发数及其质量、角竹笋产量等方面进行了较系统的研究。结果表明,土壤盐分影响竹子的生长发育,此影响一般随含盐量的增加而增加;不同竹种对土壤盐分的适应能力不同;角竹笋能获得高产,单产达20800kg/ha。参照产地母竹和引种地新竹的生长情况,我们建议:海涂地区发展竹子时可选用角竹、桂竹和红竹。     

基于键合图理论的动力稳定装置轮轨间动态特性分析

考虑动力稳定装置的轮轨非线性接触、轮轨间的间隙传动、夹钳油缸和水平油缸的等效刚度建立了动力稳定装置动态特性键合图模型.使用分段函数表达式实现了轮轨间的间隙传动.针对不同夹持力对于能量的传递效率与作业效果进行了深入分析与探究,确定了所需最小的水平油缸的推力.     

Statistical Model on the Time and Time Difference Error of Arrival in TDOA Location Estimation

Additional time delay of arrival resulted from non-line of sight(NLOS)propagation and muti-path effect in(cellular) environment is the dominant factor resulting in TDOA location error,study on the statistical property of TDOA error is useful for improving the accuracy of TDOA location.Based on the exponential distribution property of NLOS propagation delay,and considering the system error resulted from the signal detection,the authors establish a statistical model of arrival time and a model of TDOA error distribution by statistics when non-light of sight and multi-path propagation exist.The models reflect the statistical property of arrival time and TDOA error in cell network,the simulation shows that the proposed models have a good accuracy and a satisfactory behavior.     

丽水市责任山产权登记现状分析与探讨

通过对浙江省丽水市责任山产权登记现状的调查,分析各县、市、区存在登记差异的原因,并提出了解决问题的建议。     

浅谈武穴旅游业发展构想

指出了武穴市位于湖北省东部,隶属于湖北省黄冈市,其地理位置优越,交通便利,旅游资源丰富,但由于是个农业县经济不发达,而且存在着缺乏主题文化及特色旅游活动等问题,严重制约了其旅游发展,使这些年来旅游发展毫无起色。鉴于此,提出了打造“佛国广济,洞天武穴”、大力开发具有武穴乡土特色旅游活动等构想以达到促进武穴市旅游发展的最终目的。