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1.
朱政  贺清云  朱翔 《人文地理》2016,31(3):74-80
农村社区的科学选址建设,是改善农民生产生活条件、降低建设与环境成本、提升农村基础设施与公共服务设施覆盖率的重要途径。根据国内外理论动态及我国农村实际情况,以株洲市云田镇为例,建立了一套完整的方法体系。该方法体系涵盖图面矢量化、六边形格网系统、空间标准化、因子分析、综合加权、两步聚类等要素。利用该方法体系,以及国标所规定的地形、水体、绿地、农田、道路、建成区、农村居民点、基础设施8项指标,对云田镇农村社区的选址适宜性进行综合分析。得出8项指标权重,并通过综合加权运算,得到最适宜、适宜、较适宜、不适宜、禁止选址区的分布等结果,以三维柱状图形式进行直观表达。本文的方法将为我国乡镇农村社区选址提供方法论支撑。  相似文献   

2.
The long-term grain requirements of the growing Soviet population are calculated. On the basis of the relationship between water use and grain yields by natural soil zones of the USSR, the authors show that the amount of water needed per unit of output declines with a growth of productivity, especially in the non-chernozem zone of the Soviet Union. It is therefore concluded that greater water savings might be assured by expanding grain production in zones with an adequate supply of natural moisture rather than by the use of artificial irrigation of arid lands.  相似文献   

3.
山东省人均粮食变化的时空差异研究   总被引:4,自引:0,他引:4  
刘兆德 《人文地理》2000,15(2):35-37,52
人均粮食占有量是反映粮食供给水平的重要指标。本文分析了山东省人均粮食占有量变化的时空差异研究,并探讨了其与粮食增产的关系,对因地制宜调控人粮关系有一定的参考价值。  相似文献   

4.
It is argued that variation in uncertainty about social program goals and causal processes should influence the selection of evaluation designs and methods. Eighteen prominent evaluation reports are examined to contrast predicted evaluation strategies derived from theory about organizational uncertainty with the actual evaluation methods used. It was found that the actual design, measurement, and analysis procedures were frequently different from procedures that were compatible with the kinds of program uncertainty described in the evaluation reports. It is suggested that theory and practice in program evaluation can be improved by systematically incorporating organizational concepts that would contribute to the selection of evaluation methods.  相似文献   

5.
A prominent analyst of Soviet agricultural developments examines the 1992 grain harvest in the former Soviet republics. Coverage includes selective attention to the effects of such factors as weather (both losses from drought and from winterkill), farmers' economic calculations (purchase prices, alternative markets, etc.), the availability of inputs, and measures undertaken at the local level to support the harvest. The assessment provided here indicates that earlier projections of a dramatically smaller 1992 grain harvest have been overstated and outlines measures that can be implemented to reduce dependency on grain imports.  相似文献   

6.
长江三角洲地区粮食安全性度量研究   总被引:4,自引:0,他引:4  
区域粮食安全问题是当前政府与学者关注的热点问题之一。长江三角洲地区高速的工业化、城镇化过程及快速增长的经济使维系粮食生产的耕地数量及质量发生剧烈变化,区域的粮食供需矛盾日益突出。文章对该区粮食生产与土地变化的相关性进行了分析,并阐述了近50年的粮食波动系数,通过预测分析长江三角洲地区粮食产量与消费状况,进一步对该区域粮食安全性进行度量研究。研究结果表明长江三角洲地区粮食缺口将逐年变大,粮食安全状况越来越差,有效的调控措施是实现区域粮食安全的保证。  相似文献   

7.
On the basis of a chronology of droughts in the grain-growing regions of the USSR, compiled from historical sources and the more recent period of instrumental observations, the author shows that the occurrence of drought may be regarded as a random process characterized as a quasi-stationary Poisson series of events. Most of the grain regions in the USSR follow this regularity. In the case of simultaneous drought throughout the principal grain zone of the USSR, comprising the European part and the Midland region (West Siberia and Kazakhstan), the sequence of events assumes a nonstationary character. Statistical parameters are developed for the time series of drought years and nondrought years, and are compared with extreme values in grain-yield fluctuations. Over the last 140 years, drought occurred in 76 years in at least one of the three major grain regions of the USSR (European part, West Siberia, Kazakhstan) while 64 years had no drought and corresponding normal or higher yields. A catastrophic drought affecting all three grain regions simultaneously is virtually (95%) certain to occur at least once in 20 years.  相似文献   

8.
苟倩  王成金  程佳佳 《人文地理》2017,32(6):95-103
粮食运输关乎中国民生大计,而港口是其网络中的重要节点。本文以中国港口为研究对象,着眼于1982-2013年,从进出港、进出口等角度,深入考察中国港口在国内外贸易中的职能分工与变化,归纳其空间模式。同时,从粮食生产分布、产需差异、需求结构、政策等方面探讨其格局演变的动力机制。研究发现,中国港口粮食运输能力不断增强,出港格局先是“向环渤海地区集聚”再“轻度分散”,进港格局则从“以北方港口为主”向“较为分散”演化,环渤海港口一直承担着中国粮食的出口职能,粮食进口则由“北进”向“南北同进”模式演变。  相似文献   

9.
A series of 112 waterlogged archaeological wood samples of different provenances, wood species, burial times and states of preservation were analysed with the aim of assessing the validity (in terms of limits and reliability) of procedures conventionally used in the pulp and paper industry, to evaluate the state of preservation of decayed wood. In particular, the extent of any damage wrought on decayed wood tissue by the repetitive cycles that characterize these procedures was evaluated as a function of the degradation of the samples. The results indicated that standard methodologies give reliable measurements regardless of the extent of wood decay. However, it is essential to compare these data with those of non‐decayed wood that has been measured using the same procedures to take account of the errors that are inherent in these methodologies and that affect measurements.  相似文献   

10.
长期以来,关于潮湿环境下土遗址加固保护的适用材料问题一直是困扰我国文物保护和考古界的难点,至今尚没有成熟的规范可以参考。福建昙石山遗址作为我国东南沿海地区典型潮湿环境下的土遗址,近年来在遗址本体加固保护过程中,在加固材料的选取上,按照基础成分的不同分别对四类主要加固剂进行施工试验,通过大量的室内和现场局部试验,证明基本成分为长链烷基、烷氧基硅氧烷小分子和主要成分为含有乙氧基团的聚硅酸乙酯混合物以及主要成分为水玻璃和硅氧烷共聚物的加固剂材料加固效果较好,可用于潮湿环境下昙石山遗址的本体加固保护,这对推进我国潮湿环境下土遗址保护工作的全面发展无疑也是一次有益的尝试和探索。  相似文献   

11.
Abstract

Beetle (Coleoptera) pests of stored products such as the granary weevil may have entered the archaeological record by various routes, including: (1) deliberate dumping, and usually burial, of spoilt grain with the aim of preventing further infestation of grain in storage; (2) the use of infested grain as human and animal food; (3) the incorporation of infested grain and living or dead grain pests into deposits by accident and by reworking. It is suggested that these routes, although outlined specifically for beetle grain pests, can stand as a model for the way other insects and biological remains became incorporated into the archaeological record. It also is suggested that the identification of these different depositional routes depends strongly on taking a multi-proxy (‘indicator group’ or ‘indicator package’) approach to the archaeological and biological record of urban sites.  相似文献   

12.
This paper describes an algorithm for spatial search, which is used in an expert system for site selection. The algorithm, named ProfMat, is able to find the best site in the area of interest even when the number of possible sites is large and many decision criteria are involved. Compared to commonly used search procedures, ProfMat improves the efficiency of spatial search in two ways. First, the best site is identified through an iterative rather than a linear process of selection and evaluation of optional sites. Second, an area is searched by narrowing down the focus to increasingly smaller areas and, thus, sites are evaluated as much as possible groupwise. The ProfMat procedure is illustrated by analyzing the problem of retail site selection. A comparison with alternative search procedures shows that ProfMat considerably reduces the evaluation costs needed to find the best site. The implementation of the algorithm in an expert system shows how ProfMat can be used in combination with specialist's knowledge to solve site-selection problems. The efficiency of the procedure allows considering large sets of optional sites, so that it may improve the quality of the outcome.  相似文献   

13.
The characterization of various samples of white marble from the archaeological site of Tharros (Sardinia) is the starting point for the reexamination of the capabilities of electron spin resonance (ESR) spectroscopy as a tool for identifying the quarries of origin of ancient marble artefacts. Existing methods and data bases are employed for the assignment of our samples, but also reviewed to see if a more extensive use of the technique is feasible. It turns out that ESR spectroscopy, coupled with other available methods, may readily provide valuable information, often yielding the final answer to the problem of marble provenance. However, it is also clear that much work has still to be done to standardize the data collection and analysis procedures and to expand the available data base.  相似文献   

14.
The development of agriculture is closely associated with the domestication of wheat, one of the earliest crop species. During domestication key genes underlying traits important to Neolithic agriculture were targeted by selection. One gene believed to be such a domestication gene is NAM-B1, affecting both nutritional quality and yield but with opposite effects. A null mutation, first arisen in emmer wheat, decreases the nutritional quality but delays maturity and increases grain size; previously the ancestral allele was believed lost during the domestication of durum and bread wheat by indirect selection for larger grain. By genotyping 63 historical seed samples originating from the 1862 International Exhibition in London, we found that the ancestral allele was present in two spelt wheat and two bread wheat cultivars widely cultivated at the time. This suggests that fixation of the mutated allele of NAM-B1 in bread wheat, if at all, occurred during modern crop improvement rather than during domestication. We also discuss the value of using archaeological and historical plant material to further the understanding of the development of agriculture.  相似文献   

15.
Abstract

This paper aims at assessing the influence of the design procedure followed in designing the columns of a reinforced concrete (R/C) building on the performance of the columns, aa well as of the structure as a whole, when subjected to seismic loading; to identify potential weaknesses in currently adopted procedures; and to present a new procedure which is based on currently-available, powerful analytical tools, and results in increased reliability with regard to seismic loading. Two case studies are presented, involving multistorey reinforced concrete buildings with frame and dual structural systems subjected to various appropriately-scaled input accelerograms. The results obtained indicate that capacity design of columns results in adequate safety margins against failure, even when the adopted overstrength factors are quite low, but hinging in columns is not avoided unless very high overstrength factors are used. The suggested novel technique of capacity design led to very satisfactory seismic performance, and offers the possibility of cost reduction by achieving an appropriate balance between provided flexural strength and corresponding confinement.  相似文献   

16.
This paper compares three methods commonly used to extract fossil phytoliths from sediments. A basic procedure using heavy liquid flotation and oxidation is compared with two other procedures across a range of sediment types commonly encountered in archaeological studies. The three procedures are: (1) a heavy liquid flotation method (HLF); (2) a burning method (POW); and (3) another heavy liquid flotation method (HLFPol) similar to HLF, but adapted to allow the extraction of pollen and spores as well as phytoliths, within a single process. Comparisons of the resulting output using these three techniques for phytolith extraction show that different methods can produce different results, and therefore basic techniques should be modified according to the characteristics of the sediments for which they are used. While all the techniques showed similarities in assemblage results, there were problems associated with disaggregation and effective separation of light and heavy fractions, in particular with the POW procedure. The evidence suggests that morphotype selection occurred both within the physical sorting process and in the process of inverting slides to shed excess residue; in both cases it is difficult to suggest a solution to the problem. The results show clearly that the advantages gained by using the POW procedure are largely outweighed by the problems encountered with its use, and because of possible size/shape selection, it is not recommended for general extraction procedures. The heavy liquid flotation procedures, on the other hand, are shown to produce more concentrated residues with higher levels of clarity and less potential than the POW procedure for sample bias. The use of a non-toxic heavy liquid, sodium polytungstate, now allows the process to be used in relative safety. It is recommended that analysts use heavy liquid flotation procedures with chemical treatments specific to sediment requirements.  相似文献   

17.
My main purpose in writing this paper is to build a coherent set of questions, emphasizing their archaeological visibility, in order to devise a series of archaeological test procedures for the evaluation of some current chronological and behavioral inferences. Archaeological sites result from a combination of a vast number of processes, which can be partitioned into natural agencies and human behaviorally induced phenomena. After a short review of the ecological context of the Perichadian plain and its implications for late prehistoric human settlement in that specific area, an analysis of formation processes is carried out. The use of field observations and actualistic researches carried out elsewhere in the African continent allows the selection of various criteria, useful for the evaluation of the kinds of information pertaining to cultural transformations, which can be gathered from the mound of Mdaga, a site excavated from 1960 to 1968. Some of these selected criteria are then compared to other sites of the same area.  相似文献   

18.
赵明  甄江红 《人文地理》2000,15(5):68-71
内蒙古地处中纬度内陆地区,生态环境脆弱,干旱和半干旱面积占自治区总面积的80%以上。长期以来,形成的观念是内蒙古地广人稀、资源丰富,尤其是"文革"期间,在牧民不吃亏心粮口号的驱使下,将大向积林草地辟为粮田,导致草场的退化和土地的沙化。本文分析内蒙古人口发展和粮食生产的历史和现状,揭示在PRED系统中,人口增长与粮食生产面临的主要问题,结合内蒙古"九五"计划和2010年远景目标的要求,提出控制人口数量,提高粮食单产水平,实行退耕还草还林、降低耕地总量,保持人均粮食产量的动态平衡。  相似文献   

19.
This paper introduces GIS-based statistical methods for the study of settlement patterning in an archaeological context. The main aspect is an improvement over suboptimal stepwise statistical model selection procedures, with the introduction of a Deletion/Substitution/Addition (DSA) algorithm, a systematic model selection algorithm that provides an optimal model choice. The paper also introduces the combined use of Receiving Operator Characteristic (ROC) curves, and variable ranking as key tools aimed at an understanding of settlement patterning causation. An illustrative case study is provided whereby both a purely environmental and a mixed environmental/historical model (based on settlement hierarchy considerations) are investigated.  相似文献   

20.
殷都安阳兴衰的地理因素探析   总被引:1,自引:0,他引:1  
周书灿 《人文地理》2006,21(5):70-73,60
殷都安阳的兴起和发展与安阳一带相对优越的自然环境和农业、交通、人口、历史文化基础等地理因素有着较为密切的关系。商晚期以后,安阳的衰落与安阳一带的自然环境趋于恶化,政治中心转移,经济衰退及军事防守方面的缺陷和漕运不便等地理因素有关。  相似文献   

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