人参中人参多糖检测方法研究

目的测定人参中人参多糖的含量,并建立人参多糖的含量测定方法。方法采用紫外分光光度法,苯酚-浓硫酸比色法于波长486nm处测定吸光度。结果人参多糖含量为13.31g/100g,标准曲线的线性范围为0.9991~0.9998,平均加样回收率为98.2%,RSD=2.23%。结论苯酚-浓硫酸比色法测定人参中多糖含量,方法简便、准确、稳定性好。     

中子仪测定土壤水分方法的研究进展

中子仪测定土壤水分方法的核心内容是中子计数与土壤含水量的曲线标定,为了绘制精确的能够应用于不同土壤层次、土壤质地、土壤有机质含量和土壤剖面含水量变化等条件的标定曲线,通过对已取得的不同土壤条件下标定曲线文献的整理分析,从中子仪测水的工作原理出发,分析了影响中子仪测定土壤水分的主要因素,概括了测水所遇到的主要问题及其解决的方法,并对准确测定含水量层状变化土壤,提出标定曲线绘制的可行方法。根据中子计数值不仅与土壤容积含水量有关,而且还与水分和中子计数器的距离有关,提出了进一步准确标定曲线的研究方法。     

气液叉流下受热液膜的热质传递特性

采用VOF两相流模型研究了气液叉流条件下受热液膜热质传递特性,在模型中添加了表面张力源项和气液相间传质源项.为了验证所建立模型的可靠性,采用非接触式红外热成像测温方法,进行了相应的气液叉流试验.对叉流条件下受热液膜热质传递过程进行了试验和模拟计算,结果显示无量纲壁面温度计算结果与试验结果吻合很好.应用所建立的模型,模拟计算并分析了表面张力、固液接触角、液膜流量等因素对液膜流动侧形和热质传递性能的影响,结果表明：在其他参数保持不变的情况下,表面张力从0.014 N／m增大到0.072 N／m的过程中,液膜覆盖面积由82.7％减小到73.2％;固液接触角从30°增大到60°的过程中,液膜覆盖面积由80.6％减小到69.4％;液膜流量越小,液膜厚度越小,越有利于液膜的蒸发;相反,较高的液膜流量会使液膜厚度增大,阻碍了液膜蒸发,从而使外掠过液膜的单位体积空气含湿量减小.     

冲击条件对原木孔洞缺陷检测效果影响的研究

应用摆锤敲击装置,在实验室条件下研究冲击条件对原木内部孔洞缺陷检测效果的影响。摆锤冲击装置能以不同的速度敲击测试传感器,得到扰动信号在试样内的平均传播速度及原木孔洞缺陷区域的识别质量系数。研究结果表明,适当提高摆锤冲击速度,能够提高原木孔洞缺陷的检测效果。     

The Unloading Effect of Rock Samples and the Quality Evaluation of Engineering Rock Masses

For most evaluating methods of engineering rock mass, the integrality index is an important assessment factor. However, sometimes the value of integrality index would be more than 1.0 because of unloading effect of rock samples and differentia of frequency between the measurements of rock samples and rock mass. In order to solve this problem, unloading index and frequency correcting coefficient were put forward to revise the integrality index. Moreover, the BQ evaluating method proposed in the national standard (GB 50218-94) was improved with the revised method. With the case study of the project of water sealed underground oil tank in Huangdao, it was found that the quality of rock mass in the site was grade I or II.     

Spatial structure of deciduous forest stands with contrasting human influence in northwest Spain

Five contrasting deciduous forest stands were studied to characterize the spatial structural variability in human-influenced forests. These stands are representative of cultural forest types widely represented in western Europe: one plantation, two coppices, one wood-pasture forest and one high forest stand. All stems with DBH > 5 cm were measured and mapped, and stem DBH distributions, spatial structure of DBH, spatial point patterns and spatial associations were analysed. Spatial autocorrelation for DBH was calculated with Moran’s I correlograms and semivariograms. Complete spatial randomness hypothesis for spatial point patterns, and both independence and random labelling hypotheses for spatial associations were analysed using Ripley’s K function. The results showed that tree sizes were conditioned by particular former management systems, which determined unimodal symmetric, positively skewed or compound DBH distributions. Spatial structure was more complex when human influence became reduced. Coppice stands showed clumped spatial patterns and independence among size classes, as a consequence of sexual and vegetative establishment of new stems in open areas. The largest clumping intensity was observed in the wood-pasture with an intermediate disturbance frequency and low inter-tree competition. The high forest stand displayed spatial traits consistent with the gap-dynamics paradigm, such as clumping of smaller trees, random arrangement of larger trees, negative association between juveniles and adults, and high structural heterogeneity. It can be expected that after cessation of human interference, coppices and wood-pastures would evolve to a more heterogeneous structure, probably with a higher habitat and species diversity.     

撑绿竹赤霉病的病原菌鉴定及杀菌剂毒力测定

根据病原菌形态特征和致病性等特点,鉴定撑绿竹赤霉病的病原菌为子囊菌门肉座菌目肉座菌科的虱状赤霉(竹赤霉菌)Gibberella pulicaris(Fr.)Sacc..对10种杀菌剂抑菌效果筛选,10%世高、50%多菌灵、60%茄苯得、80%炭疽福美对菌丝的抑制效果均80%以上,其EC<,50>依次为0.033,310.88,528.98,770.68μg/mL.     

基于灰色系统的地下水动态研究

为了深入探求地下水动态变化规律,以陕西洛惠渠灌区实测数据为例,首先采用改进的灰色斜率关联法,对灌区自然-人工-生物条件下地下水动态敏感性因子进行研究,分析了各因子与地下水埋深的关系,并运用灰色动态模型对敏感因子进行灾变预测.结果表明:蒸发量是影响该灌区地下水动态的主要因子,而各因子之间相互作用影响,形成了复杂条件下的耦合关系;灰色动态模型对蒸发量的灾变预测精度较高,完善模型系统.将灰色系统理论应用到灌区地下水动态评价中是切实可行的,是对传统地下水动态研究方法的补充与完善,可为灌区管理和调控提供一定的依据.     

Effect of Microorganisms on Some Engineering Properties of Silt

The microbiology was introduced in foundation treatment. Several Carbonate mineralization microorganisms and polysaccharides viscose microorganisms were screened and the microorganisms No.ATCC 6453,3,polysaccharides viscose microorganisms 5 and 6 were used in silt modification. The engineering properties of silt before and after modification were compared by unconfined compressive strength test and indoor seepage test. The microstructures of silt incorporating different microorganisms were analysed by mean of scanning electron microscope and energy dispersive X ray (EDX) analysis. And the modification mechanism of silt has been revealed. These studies indicate that certain engineering properties of silt can be improved by incorporating microorganisms.     

基于回归分析建立补充耕地数量质量实行按等级折算数学模型的研究

目前,我国在执行占用耕地补偿制度中存在以数量进行平衡,而忽视质量平衡的问题,导致占用耕地与补充耕地质量不对等,土地综合生产力下降。本文以回归分析为原理,通过对自然质量等指数、利用等指数、经济等指数及其所对应的实际标准粮产量进行回归分析,建立了数学模型,计算出不同等别间的折算系数,为云南省补充耕地数量质量按等级折算提供依据。