区域农牧业可持续发展决策支持系统研究   总被引：1，自引：0，他引：1  

姚艳敏  王立刚  陈仲新  唐华俊  李文科  王毅敏  马成龙  白锐峥  陈敦善  费健雄 《地域研究与开发》2007,26(2):112-116,123

以区域农牧业可持续发展为研究对象,采用地理信息系统(GIS)、遥感(RS)、全球定位系统(GPS)的"3S"技术和数据库技术,建立了区域资源环境、社会经济空间和属性数据库.通过计算机技术、GIS技术和数据库技术构建了区域农牧业可持续发展决策支持系统,集成了耕地利用评估模型和草地建设管理模型,并进行了山西省雁门关生态畜牧经济区的实证研究.区域农牧业可持续发展决策支持系统将为农业结构调整、农牧业可持续发展提供决策支持.  相似文献   

Aeolian construction and alluvial dismantling of a fault‐bounded intracontinental aeolian dune field (Teruel Basin,Spain); a continental perspective on Late Pliocene climate change and variability     

JUAN PEDRO RODRÍGUEZ‐LÓPEZ  CARLOS L. LIESA  JAN VAN DAM  PALOMA LAFUENTE  LUIS ARLEGUI  LOPE EZQUERRO  POPPE L. DE BOER 《Sedimentology》2012,59(5):1536-1567

An aeolian dune field migrating to the east encroached on the toes of alluvial fans in the Teruel Basin (eastern Spain) during a short interval in the Late Pliocene (ca 2·9 to 2·6 Ma), when Northern Hemisphere glaciation and strong glacial–interglacial cycles began. Preservation of the dune field was controlled by syn‐sedimentary activity of a normal fault. Ephemeral water discharge eroded aeolian sands and formed V‐shaped channels in which aeolian sandstone blocks accumulated. The incorporation of loose aeolian sand in wadi waters modified the sediment/water ratio, changing the physical properties of the flows as they penetrated the aeolian dune field. The erosion and cover of aeolian dune foresets by sheetflood deposits suggest that dune‐damming caused the intermittent ponding of water behind the dunes and its flashy release. The arid climate in the Late Pliocene western Mediterranean realm favoured the transport of windblown sediments from northern Africa and western Mediterranean land masses into the Mediterranean. The formation of the studied aeolian dune field (2·9 to 2·6 Ma) and possibly others (for example, the Atacama, Namib and Sahara deserts) correlates with a strong increase of the influence of obliquity, which can be attributed to the combination of a regional expression related to the reduced effect of precession due to a minimum in the long‐period (2·3 Ma) eccentricity cycle and a remote expression of the onset of the Northern Hemisphere glaciation.  相似文献   

EFFECTS OF SOIL FAUNA ON LITTER DECOMPOSITION     

ZHANG Xue－ping  Zhang Si－cong  HUANG Chu－long 《中国地理科学(英文版)》2001,11(3):283-288

１ＩＮＴＲＯＤＵＣＴＩＯＮＦｏｒｅｓｔｌｉｔｔｅｒｗｈｉｃｈｉｓｔｈｅｐｈｙｓｉｃａｌｍａｋｅｕｐｐａｒｔｏｆｆｏｒｅｓｔｅｃｏｓｙｓｔｅｍｐｒｅｓｅｎｔｓｍａｎｙｉｍｐｏｒｔａｎｔａｃｔｉｏｎｓｕｐｏｎｅｃｏｓｙｓｔｅｍ．Ｈｏｗｅｖｅｒｉｆｆｏｒｅｓｔｌｉｔｔｅｒｉｓａｃｃｕｍｕｌａｔｅｄｔｏｅｘｃｅｓｓｉｔｗｉｌｌｐｒｏｄｕｃｅｓｏｍｅｎｏｎｎｅｇｌｉｇｉｂｌｅｎｅｇａｔｉｖｅｉｎ-ｆｌｕｅｎｃｅｗｈｉｃｈｃｏｕｌｄｂｅｔｈｅｃａｕｓｅｏｆａｆｏｒｅｓｔｆｉｒｅｏｒｔｈｅｉｍｐｏｒ…  相似文献   

Estimation of genetic parameters and breeding values in shrimp Fenneropenaeus chinensis using the REML/BLUP procedure     

ZHANG Tianshi  KONG Jie  LUAN Sheng  WANG Qingyin  LUO Kun  TIAN Yi 《海洋学报(英文版)》2011,30(1):78-86

An analysis of a selection experiment was used to assess the impact of various animal model structures on REML estimates of variance components.The analyses were carried out based on 162 d body mass (BM) of 1 287 animals from 21 paternal half-sib groups of Fenneropenaeus chinensis.Estimated breeding values (EBV) of BM of all individuals were estimated using eight statistical models (A,AB,ABC,ABDC,ABMFC,ABMDC,ABFDC and ABMFDC) and BLUP (best linear unbiased prediction).These models were designed involving factors such as sex,spawn date as fixed effects,maternal genetic effects,full-sib family effects as random effects,mean BM of families at tagging and age at recording (covariate).The results demonstrate the importance of correct interpretation of effects in the data set,particularly those that can influence resemblance between relatives.The data structure and the particular model that was applied markedly influenced the magnitude of variance component estimates.Models based on few effects obtained upward biased estimates of additive genetic variance.The accuracy of genetic parameters and breeding value estimated by ABFDC model was higher than other models.The results imply that additive genetic direct value,full-sib family effects,and covariance effects besides sex and spawn date as fixed effects were very important for estimating genetic parameters and breeding value of body mass.This model had a heritability estimate of 162 d BM of 0.44.The comparison of the efficiency of selection based on breeding values or phenotypic value revealed great difference:average breeding value of the best 24 families selected by the 162 d BM breeding value and phenotype were 0.577 g and 0.366 g,respectively,representing a 36.57% higher efficiency in the former.In conclusion,selection based on breeding value was more effective than selection based on phenotypic value.Our results indicate that effects influencing the magnitude of estimates should be taken into account when estimating heritability and breeding values for BM.  相似文献   

海洋动物标准物质的研制及其技术流程     

吕海燕  王正方  周青松  刘际弟 《海洋学研究》2011,29(1):104-108

以缢蛏为例,详细介绍了海洋动物标准物质的研制及其技术流程,对研制过程中候选物的确定,以及标准物质所必须具备的特性量值等进行了全面叙述.海洋动物标准物质制备的技术流程主要包括:均匀性、稳定性和准确性的检验,定值分析方法、数据的统计分析以及定值数据结果的表达.有证标准物质的包装运输、认定证书和标签等方面的操作也都应按照规定...  相似文献   

Modelling to analyse the impacts of animal treading effects on soil infiltration     

Y. Q. Tian  R. McDowell  Q. Yu  G. W. Sheath  W. T. Carlson  P. Gong 《水文研究》2007,21(8):1106-1114

Animal treading can change soil physical properties, and thus is an important factor in hydrological modelling. We investigated the impacts of animal treading on infiltration by using a series of rainfall simulation experiments at Whatawhata Research Center, Waikato, New Zealand. The study identified significant variables for estimating soil steady‐state infiltration at a micro‐site (0·5 m²) and fitted the Green and Ampt equation by modifying or including variables for soil and water parameters and animal activities on grazing paddocks. A regression function for estimating steady‐state infiltration rate was created for each of four scenarios: between tracks (inter‐track), track, easy slope with ash soil, and easy slope with clay soil. Significant variables included the number of days after treading, antecedent soil moisture, field capacity, percentage of bare ground, bulk density, and the high degree of soil damage (damage not compacted). Regression models explained more than 71% of the variance in steady‐state infiltration for three scenarios, but only 53% for the easy slope with clay soil. The remodified Green and Ampt equation provided satisfactory estimation of infiltration for all scenarios (accuracy > 80%), and thus enables us to use the modified model for Waikato hill country pastures of different topography, soil physical condition, season and grazing management. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   

Effects of Replacing Fishmeal with Animal By-products Meal Supplementation in Diets on the Growth and Nutrient Utilization of Mangrove Red Snapper   总被引：1，自引：0，他引：1  

Khalid Jamil Ghulam Abbas Rukhsana Akhtar LIN Hong LI Zhenxing 《中国海洋大学学报(英文版)》2007,6(3):292-298

A feeding trial was conducted for 75 d to evaluate the nutritive value of a mixture of animal by-products(MAB) as a possible protein source in diets for juvenile mangrove red snapper,Lutjanus argentimaculatus(mean initial body weight,30 g). Fish were fed one of five isonitrogenous diets(40% crude protein) replacing 0,25%(MAB25),50%(MAB50),75%(MAB75) and 100%(MAB100) of fish meal protein with similar percentages of MAB. The MAB consisted of 25% cow liver meal,20% leather meal,20% meat and bone meal,15% blood meal,10% APC(poultry feather meal),8% poultry manure dried,1.5% choline and 0.5% chromic oxide. After 75 d of feeding,fish fed with diets MAB50,MAB75 and MAB100 exhibited significantly lower growth per-formance than that of fish fed with control and MAB25 diets. The optimum level of MAB was estimated to be 23%. Replacement of fish meal by MAB23% showed the following performance:maximum weight gain,510%;SGR,2.39% and FCE,2.83%. The MAB substitution up to 75% of fish meal protein in diets did not show differences in apparent protein digestibility(83.6% for MAB25,79.2% for MAB50,78.7% for MAB75) compared with control(83.4%),whereas in MAB100 group digestibility(65.3%) was sig-nificantly lower than in other groups. The apparent phosphorus absorption of test diet groups was significantly higher(37.1% for MAB25,28.5% for MAB50,55.6% for MAB75 and 54.5% for MAB100) than that of control(11.2%). The levels of protein and ash in the whole body,carcass and viscera increased as MAB substitution in diets increased,whereas lipids and moisture remained con-sistent among all treatment groups. These results showed that approximately 23% of fish meal protein could be replaced by a mixture of animal by-products for juvenile snapper growing from 30 g to 167 g in 75 d without compromising growth performance and feed efficiency.  相似文献   

河南西峡含化石碎屑龟山组层位层序及时代探讨     

薛松鹤 《河南国土资源》1997,(1)

信阳群龟山组横贯北秦岭南缘及桐柏山—大别山，西延入陕西，为地质结构上的关键层位，部分地段为重要赋矿层位，因其为一套罕见化石的碎屑岩，故对其地质时代看法颇异。近年我队在西峡八庙矿区工作时，在岩石薄片中见有多门类化石碎屑，并作了报道。作者在报道的基础上，吸收前人和近年某些有关信阳群和刘岭组（群）的工作成果，就龟山组的层位、层序及时代进行探讨，并与邻区、邻省的相关层位进行对比：认为含动物化石碎屑的龟山组（周进沟组）与陕西省的牛耳川组及桐柏山—大别山北坡的大部分龟山组及二郎坪群和部分苏家河群的时代大体相当，其时代归属暂置早奥陶世—早泥盆世  相似文献   

C/S模式视频监控系统的设计与实现   总被引：5，自引：0，他引：5  

高焕兵 《成都信息工程学院学报》2003,18(4):386-389

随着网络技术的发展，计算机网络已越来越成为当今流行的计算环境。计算机的使用方法和体系结构也从早期的单一体系结构，发展成为现在比较流行的C／S体系结构。另一方面，随着社会经济的发展，智能交通系统也已经得到了广泛的应用。介绍了一个高速公路的视频监控系统，详细描述了自动报警功能的设计和实现。  相似文献   

The construction of human–animal relations: National Jumps Day 2013 at Te Rapa,Hamilton, New Zealand     

Phil McManus  Raewyn Graham  Karen Ruse 《New Zealand geographer》2014,70(3):190-200

New Zealand is an important place for thoroughbred breeding and racing. Most races are on the flat, but jumps racing is conducted in the cooler months. The 2013 National Jumps Day at Te Rapa, Hamilton, was a significant space for the construction of human–animal relations. Drawing on three bodies of accounts, we ask whether social media contributes to the realignment of perspectives or reinforces existing human–animal relations. We explore competing narratives and demonstrate how animals, people, activities and places are constructed, including making animal deaths unrecognisable to perpetuate activities that are questioned by contemporary animal geographies.  相似文献