极端暴雨条件下黄土丘陵沟壑区土壤蓄水能力和入渗规律

黄土高原退耕还林还草工程实施后,下垫面环境条件的变化可能对流域水文过程、水文通量、水量平衡以及生态系统产生十分重要的影响。研究极端暴雨条件下剖面土壤蓄水能力和入渗规律,对于阐明流域产汇流过程和影响机制具有重要的科学价值。采用土壤墒情仪对陕北"7·26"特大暴雨事件下黄土丘陵沟壑区草地剖面土壤水分进行了实时动态监测,分析了极端暴雨条件下剖面土壤水分的动态变化和蓄水过程,利用Horton入渗模型模拟了剖面土壤水分湿润锋的运动过程,揭示了极端暴雨条件下剖面土壤水分的入渗规律。结果表明:(1)极端暴雨条件下,黄土丘陵沟壑区坡面草地不同深度层次土壤水分与降雨过程的响应不同,具有层次性和明显的滞后效应,其中,0～140 cm是影响该地区土壤水文过程的关键层次;(2)土壤水分再分配结束时,湿润锋最深深度达140 cm,土壤蓄水量达225.99 mm,较降雨前95.37 mm增加了1.37倍;(3)极端暴雨过程中湿润锋的运动随时间呈对数递减关系,其稳渗速率随容重增加而减小,呈指数函数递减;(4)极端降雨过程中该地区坡面草地的产流机制仍以超渗产流为主,对于揭示流域的产汇流机制和完善水文预报模型具有重要的科学意义。     

The use of urban organic wastes in the control of erosion in a semiarid Mediterranean soil

Abstract. A two year field experiment was carried out in a semiarid Mediterranean area in order to evaluate, the effect on soil erosion of adding different urban organic wastes: a stabilized municipal waste (compost), an unstabilized municipal waste, and an aerobic sewage sludge. All the treatments significantly reduced soil erosion, compared to the control soil. The soil amended with compost was the most effective treatment, reducing soil loss by 94% and runoff by 54%.     

小麦条锈病流行程度趋势预测专家系统雏型

本文运用知识工程语言 M·1构造了一个用于小麦条锈病流行程度趋势预测的专家系统雏型。专家的知识用产生式规则来表示。知识库中的知识规则可相对独立,便于知识库的扩充和完善。     

GI PiCO2: Tissue Specific Monitoring For Improving Patient Outcomes

Improvements in human patient monitoring despite their development in animals, do not always find their way into veterinary clinical use due to financial constraints. Gastrointestinal intraluminal CO₂ partial pressure (Gip₁CO₂) monitoring, however, is not only proving very beneficial in human trauma and critical patient care but is also very likely to become relatively inexpensive. By providing information on the perfusion adequacy of a high risk, critically important tissue, the GI mucosa, GI P₁CO₂ monitoring offers an easily accesible indicator of the efficacy and adequacy of resuscitative interventions. The potential for decreasing morbidity and mortality is enormous. Therefore, the practicing veterinarian should become familiar with GI P₁CO₂ monitoring theory and technology so he or she can be better prepared to incorporate it into practice when in becomes available.     

应用积分GM(1,1)模型进行杉木炭疽病预测预报的研究

以积分生成代替传统的累加生成方法 ,并用双向差分建立积分GM (1,1)灰色预测模型进行杉木炭疽病预测预报的研究 ,结果表明积分GM (1,1)模型能较好地预测杉木炭疽病在三明市的发生     

旱地保护性耕作地表径流和土壤水分平衡模型

在田间试验和对现有径流模型及土壤水分平衡模型改进的基础上，建立了适用于保护性耕作的地表径流和土壤水分平衡模型。该模型以日为步长，根据气象数据、土壤水分状况、作物生长发育及耕作管理措施，模拟不同耕作管理体系下地表径流和田间水分平衡的变化。针对保护性耕作的特点，主要对径流曲线数字(USDA—Curve Number)法进行了改进，在PERFECT模型的基础上增加了坡度和降雨强度两因素的影响，从而使模型较全面地考虑了残茬覆盖、耕作、坡度及降雨强度等多种因素对径流的影响；采用简单实用的Priestley—Taylor公式计算潜在蒸散量，并考虑作物覆盖与残茬覆盖对土壤蒸发与作物蒸腾的影响。通过田间径流试验和根层有效贮水量测定数据的验证，证明了地表径流和土壤水分的模拟值与实测值比较接近。     

Predicting the spatial distribution of ground flora on large domains using a hierarchical Bayesian model

Accomodation of important sources of uncertainty in ecological models is essential to realistically predicting ecological processes. The purpose of this project is to develop a robust methodology for modeling natural processes on a landscape while accounting for the variability in a process by utilizing environmental and spatial random effects. A hierarchical Bayesian framework has allowed the simultaneous integration of these effects. This framework naturally assumes variables to be random and the posterior distribution of the model provides probabilistic information about the process. Two species in the genus Desmodium were used as examples to illustrate the utility of the model in Southeast Missouri, USA. In addition, two validation techniques were applied to evaluate the qualitative and quantitative characteristics of the predictions.This revised version was published online in May 2005 with corrections to the Cover Date.     

全球气候暖干化对秦岭南北河流径流泥沙的影响研究

以秦岭南侧汉江和北侧渭河多年的径流泥沙观测资料，分析了全球气候暖干化对秦岭南北径流泥沙的变化。分析指出在80年代后，由于全球气候变化的影响，秦岭南北河流年均径流量均减少，与1935－1980年相比，汉江河流年均径流量减少1.9%，渭河河流年均径流量减少27.4%；同时汉江河流泥沙含量明显减少，但渭河河流泥沙含量呈增加趋势，是汉江河流泥沙含量133倍，表明了秦岭南北两侧在全球气候暖干化表现出明显的区域响应性。     

新亚欧大陆桥新疆段受损区段的灰色预测

在对新亚欧大陆桥新疆段受损区段、受损长度及受损频率和受损密度详尽分析的基础上，揭示了陆桥新疆段受损区段的时空分布规律。并依据灾害的时序分布特征，运用灰色原理和方法，根据受损区段数确立阈值和相应的年份序列，分别建立GM（1，1）模型，求出年份序列的序号响应式，并对实际值和理论预测结果进行了拟合检验，模型群的原点误差范围为0.198-1.314之间，平均误差为0.823-1.917，并同时预测了陆桥新疆段2001－2005年间可能的受损区段数。