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271.
许睿  陈方  丁陈君 《生物工程学报》2023,39(5):1867-1882
当前,白色污染造成的消极影响已经扩散到人类社会经济、生态和健康等各个方面,循环生物经济发展进程面临严峻挑战。作为全球最大的塑料生产消费国家,我国在塑料污染的治理问题上肩负着重要责任。在此背景下,本文分析了美国、欧洲、日本与我国塑料降解与回收的相关战略,并对该领域的文献与专利展开计量,从研发趋势、主要研发国家和研发机构等角度了解其技术研发现状,探讨我国塑料降解回收发展面临的机会与挑战,最终提出了政策体系、技术路径、产业发展与公众认知四位一体的未来发展建议。  相似文献   
272.
Action to pursue the circular economy (CE) transition is burgeoning in the government and the private sector. Does this action signal that CE is a distinct field of research with a unique disciplinary identity? This article argues that CE has reached field status, through its own epistemic communities characterized by increasingly shared methodological perspectives and normative ideals, and through institutionalized knowledge development through research journals and authority structures. The recent growth of CE research points toward more contextualized and nuanced operationalizations of the concept, evidence that the field is approaching a threshold state of maturity. Drawing on observations from academic literature and discussions with researchers and experts, we trace the process by which CE has arrived at the status of a field. The article concludes with reflections on research directions.  相似文献   
273.
产业生态学的新思路   总被引:9,自引:0,他引:9  
分析扩展了产业生态学的概念。新扩展的产业生态学概念在产业生态学原有闭路循环原则的基础上 ,扩展出了本土性、经济性和开放性等基本原则。结合芬兰吉瓦斯克拉产业系统进行了实证分析 ,展望了完善的产业生态系统的基本特征。  相似文献   
274.
Aims According to traditional theory, superior competitive ability in plants generally requires relatively large plant body size. Yet even within the most crowded vegetation, most resident species are relatively small; species size distributions are right-skewed at virtually every scale. We examine a potential explanation for this paradox: small species coexist with and outnumber large species because they have greater 'reproductive economy', i.e. they are better equipped—and hence more likely—to produce offspring despite severe size suppression from intense competition.Methods Randomly placed plots within old-field vegetation were surveyed across the growing season. Within each plot, the largest (MAX) and smallest (MIN) reproductive individuals of each resident species were collected for above-ground dry mass measurement. We tested three hypotheses: (i) smaller resident species (with smaller MAX size) have generally smaller reproductive threshold sizes; (ii) smaller resident species have greater 'reproductive economy', i.e. a smaller MIN relative to MAX reproductive plant size; and (iii) MIN size predicts plot occupancy (species abundance within the community) better than MAX size.Important findings The results supported the first and third, but not the second hypothesis. However, we could not reject the hypothesis that smaller species have greater reproductive economy, as it was not possible to record data for the largest potential plant size for each species—since even the largest (MAX) plants collected from our sampled plots were subjected to competition from neighbours under these natural field conditions. Importantly, contrary to conventional competition theory, more successful species (in terms of greater plot occupancy) had smaller minimum not larger (or smaller) maximum reproductive sizes. These results suggest that a small reproductive threshold size, commonly associated with relatively small potential body size, is generally more effective in transmitting genes into future generations when selection from neighbourhood crowding/competition is intense—at least within natural old-field vegetation. Accordingly, we propose a simple conceptual model that represents the basis for a fundamental paradigm shift in the predicted selection effects of crowding/competition on plant body size evolution.  相似文献   
275.
Historically labor has been central to humaninteractions with the environment, yetenvironmentalists pay it scant attention. Indeed, they have been critical of those whoforeground labor in their politics, socialistsin particular. However, environmentalists havefound the nineteenth-century socialist WilliamMorris appealing despite the fact that he wroteextensively on labor. This paper considers theplace of labor in the relationship betweenhumanity and the natural world in the work ofMorris and two of his contemporaries, theeminent scientist Thomas Henry Huxley, and theFabian socialist Herbert George Wells. Isuggest that Morris's conception of labor hasmuch to recommend it to environmentalists whoare also interested in issues of socialjustice.  相似文献   
276.
马占相思的日光合作用和日碳固定总量研究 (英文)   总被引:9,自引:0,他引:9       下载免费PDF全文
 马占相思(Acacia mangium)是一种具有较高经济价值和生态效益的热带速生树种。为了研究其光合作用对一天内光强、温度等环境因子变化的响应,揭示其迅速生长的生理生态机制,在叶片水平上测量了马占相思在24 h内的净光合速率(Pn)、蒸腾速率、气孔导度(Gs)、胞间CO2浓度(Ci)、每日固定碳的总量、夜间消耗碳的总量以及日间光合系统Ⅱ光化学效率(Fv/Fm)的变化。结果显示:其净光合速率在正午降低了14.5%;其较高的蒸腾速率和气孔导度有助于保持叶片日间较高的碳固定速率;光合系统Ⅱ对于高光强和高温有较强的忍受度;每日固定碳的总量为502 mmol CO2·m-2,夜间碳的损失为54 mmol CO2·m-2。研究结果在一定程度上揭示了马占相思在热带高光强和高温条件下迅速生长的生理机制。  相似文献   
277.
Concepts of development are inevitably loaded with value judgements concerning what constitutes ‘proper’ social and economic organisation. Focusing on the cultural politics of development on Siquijor, an island in the Central Visayas region of the Philippines, this paper explores these often tacit ideals. It considers one of the key idioms Siquijodnon use in explaining how development is brought about—cooperation—and some of its locally perceived opposites—‘crab mentality’, politicking and corruption—which contain powerful moral critiques of self and society. On Siquijor, local discourses of development have it that widespread poverty in the Philippines demonstrates a failing of Filipinos to live up to supposedly universal norms of ethical socio‐economic conduct. However, I argue that attention to local norms of moral economy reveal the ambivalence underlying these notions of development, particularly in relation to the roles of individualism and reciprocity in socio‐economic organisation.  相似文献   
278.
This study compares U.S. and Japanese consumers’ perceptions of remanufactured auto parts. Remanufactured parts have a long history and enjoy continuing success in the U.S. domestic aftermarket. In contrast, although Japan's domestic aftermarket is growing, it remains comparatively underdeveloped. This research examines whether customers’ perceptions of remanufactured products explain their lower acceptance in Japan. Our Internet survey of 440 U.S. and 300 Japanese respondents examined their knowledge of remanufactured auto parts, perceptions of their benefits and risks, and price consciousness. The results reveal that Japanese consumers know less about remanufactured products, perceiving them as entailing lower benefits and greater risk, especially concerning quality, and are less price conscious. Drawing on its results, this study suggests measures to promote markets for remanufactured auto parts in Japan and in economies in which such markets are in an early stage of development.  相似文献   
279.
循环经济建设的生态误区、整合途径和潜势产业辨析   总被引:11,自引:1,他引:10  
王如松 《应用生态学报》2005,16(12):2439-2446
运用复合生态系统方法剖析了我国发展循环经济在规划、建设和管理上的各种右的和左的偏差,分析了认识上的个误区,提出了观念转型、体制改革和功能重组的循环经济建设大3R原则,探讨了产业转型的横向耦合、纵向闭合、功能导向、结构柔化、区域耦合、社会整合、能力组合、增加就业和人性化生产等9类生态整合途径,展望了当前循环经济建设中诸如化肥农药工业向农田生态系统保育业转型等10类复合型潜势生态产业.  相似文献   
280.
The life expectancy, at the age of 75 years, is nowadays 11 years for men and 13.5 for women, and is still increasing. Two aspects are here discussed; (i) the role of independent elderly people bringing to the younger generations financial support, experience, rules of social behaviour and memory, and (ii) the specific needs of solidarity that society and family have to provide to dependent elderly people. Adequate management of these problems is certainly a challenge for our culture.  相似文献   
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