全文获取类型
收费全文 | 118篇 |
免费 | 6篇 |
国内免费 | 13篇 |
专业分类
137篇 |
出版年
2024年 | 1篇 |
2023年 | 4篇 |
2022年 | 6篇 |
2021年 | 3篇 |
2020年 | 8篇 |
2019年 | 8篇 |
2018年 | 9篇 |
2017年 | 7篇 |
2016年 | 4篇 |
2015年 | 2篇 |
2014年 | 1篇 |
2013年 | 13篇 |
2012年 | 8篇 |
2011年 | 8篇 |
2010年 | 2篇 |
2009年 | 9篇 |
2008年 | 6篇 |
2007年 | 5篇 |
2006年 | 9篇 |
2005年 | 1篇 |
2004年 | 5篇 |
2003年 | 2篇 |
2002年 | 4篇 |
2001年 | 4篇 |
2000年 | 2篇 |
1996年 | 3篇 |
1994年 | 1篇 |
1992年 | 1篇 |
1991年 | 1篇 |
排序方式: 共有137条查询结果,搜索用时 7 毫秒
31.
Ananta Kumar Giri 《Dialectical Anthropology》2006,30(3-4):227-271
Modern social research, as we know it now, emerged as a part of rise of modern social sciences in the context of transition
to modernity. As an enterprise of modernity social research reflected some of the foundational assumptions of modernity. For
example, the project of sociology was closely tied to the project of nation-state, embodying in its epistemology methodological
nationalism. Social research also proceeded within the bounded logic of disciplines. But all these assumptions of modernity
as well as their social manifestations have been subjected to fundamental criticisms and interrogations in the last decades.
Both anti-systematic socio-cultural movements and critical discursive movements and new movements of ideas have challenged
the modernist paradigms of pathology and normality as well as distinction between ontology and epistemology. In the background
of critiques of modernity, social movements and processes of transformations the present essay submits some proposals for
a creative and critical social research. It explores ways of moving beyond mere denunciations and critiques and embodying
transformational theories and methods which would facilitate creative and critical research. The essay also calls for a new
vocation of social research by pleading for a simultaneous engagement in activism and creative understanding, fieldwork and
philosophical reflections, ontological self-cultivation and epistemic labour of learning.
Ananta Kumar Giri originally from Madras Institute of Development Studies, Chennai, India is currently a Alexander von Humboldt
Fellow at Institute of Sociology, Albert Ludwig Univesitat, Freiburg, Germany. The present essay builds upon author’s introduction
to his recently edited volume, Creative Social Research: Rethinking Theories and Methods (Lanham, MD, USA: Lexington Books, 2004 & New Delhi. Sage, 2004. This has benefited from presentations in many different
places, most recently at the Ernest Gellenr seminar series in Prague and Institute of Sociology, Freiburg, and my grateful
to thanks are due to participants in all these places of dialogues, particularly to Professors Chitta Ranjan Das , Peter Skalnik
and Hermann Shwengel. 相似文献
32.
磷酰基的参与作用导致N-磷酰氨基酸和二肽自身活化,在无活化试剂的情况下能成肽和肽链延长。14种磷酸小肽或游离肽被分离并经各谱图证实,该研究对蛋白质前生物合成的探讨提供了重要线索。 相似文献
33.
The development and implementation of an effective national biosafety system is important for several key reasons: to ensure safe access to products of modern biotechnology, to build public confidence, to encourage the growth of domestic modern biotechnology, and to comply with international standards and agreements. There is no single best approach in the development and implementation of a national biosafety system and each country is faced with unique challenges. Slovenia is a small country and a new EU Member State. However, it has developed and implemented an efficient national biosafety system. The key elements of this system are administrative procedure, risk assessment, enforcement, and public participation and information. 相似文献
34.
Merim Bilali? Kieran Smallbone Peter McLeod Fernand Gobet 《Proceedings. Biological sciences / The Royal Society》2009,276(1659):1161-1165
A popular explanation for the small number of women at the top level of intellectually demanding activities from chess to science appeals to biological differences in the intellectual abilities of men and women. An alternative explanation is that the extreme values in a large sample are likely to be greater than those in a small one. Although the performance of the 100 best German male chess players is better than that of the 100 best German women, we show that 96 per cent of the observed difference would be expected given the much greater number of men who play chess. There is little left for biological or cultural explanations to account for. In science, where there are many more male than female participants, this statistical sampling explanation, rather than differences in intellectual ability, may also be the main reason why women are under-represented at the top end. 相似文献
35.
Jacqueline L. Stroud Iain Dummett Simon J. Kemp Craig J. Sturrock 《The Annals of applied biology》2023,182(1):92-100
The conversion from conventional tillage to no-tillage soil management practices is generally associated with an improvement in aggregate stability and anecic earthworm populations. We worked with UK farmers who measured Lumbricus terrestris midden area (%) and earthworm numbers associated with middens compared to the general soil. They found that middens covered up to 42% of the soil surface. Middened soil (i.e., soil underlying the middens) was associated with significantly more earthworms than the general soil (i.e., non-middened soil) in agreement with research from scientific field trials. We compared the biophysical properties of middened soil to general soil across an experimental field trial recently converted to no-tillage soil management practices. We measured water-stable aggregation, soil porosity at scales relevant to water storage and gas diffusion and invertebrate feeding activity. Middened areas covered up to 13% of the field trial and were associated with significantly improved aggregate stability and porosity compared to the general soil. Our findings highlight the importance of considering middens when surveying soil quality and health in arable systems. 相似文献
36.
37.
Melissa M. Murphy H. Richard Johnston Michael E. Zwick 《Journal of biomolecular techniques》2021,32(2):74
Across the United States, the number of staff scientists (master’s- or doctoral-level professionals working in nonfaculty roles) has grown by 35% since 2010, and they play an increasingly important role in research efforts. However, few targeted resources are available, which potentially limits the effectiveness of this group. Launched in 2016, the staff scientist path at Emory has tripled in size over 4 y to 138 staff. The present case study evaluated the perceptions of staff scientists related to onboarding experiences and professional development needs, including those needs arising from coronavirus disease 2019 (COVID-19) impacts in the workplace. A survey of Emory staff scientists was conducted from May to June 2019 as part of a program evaluation initiative to assess perceptions of onboarding and professional development opportunities. Interviews with a subset of scientists informed the survey development and identified COVID-19–related impacts on daily work. Results indicated the need for targeted orientation resources specific to staff scientists, accurate and timely information and resources to support scientists’ supervisors, and professional development for scientists in leadership and management-related skills. Remote work associated with COVID-19 accentuated the need for managerial skills, including team development in digital work environments. Findings from this case study can inform policies and practices at Emory and other institutions that employ a similar staff scientist model. 相似文献
38.
Gizaw S Getachew T Tibbo M Haile A Dessie T 《Animal : an international journal of animal bioscience》2011,5(7):995-1001
Designing breeding schemes suitable for smallholder livestock production systems in developing regions has hitherto been a challenge. The suggested schemes either do not address farmers' breeding goals (centralized station-based nucleus schemes) or yield slow genetic progress (village-based schemes). A new breeding scheme that integrates the merits of previously suggested schemes has been designed for Menz sheep improvement in Ethiopia. It involves selection based on breeding values in nucleus flocks to produce elite rams, a one-time only provision of improved rams to villagers and a follow-up village-based selection to sustain genetic progress in village flocks. Here, we assessed whether conventional selection of breeding rams based on breeding values for production traits, which is the practice in station-based nucleus flocks, meets farmers' breeding objectives. We also elicited determinants of farmers' ram choice. Low but significant correlations were found between rankings of rams based on farmers' selection criteria, estimated breeding values (EBV) and body weight (BW). Appearance traits (such as color and horn) and meat production traits (BW and linear size traits) significantly determined farmers' breeding ram choice. The results imply that conventional selection criteria based solely on EBV for production traits do not address farmers' trait preferences fully, but only partially. Thus, a two-stage selection procedure involving selection on breeding values in nucleus centers followed by farmers' selection among top- ranking candidate rams is recommended. This approach accommodates farmers' preferences and speeds up genetic progress in village-based selection. The Menz sheep scheme could be applied elsewhere with similar situations to transform conventional station-based nucleus breeding activities into participatory breeding programs. 相似文献
39.
Giok Ling Ooi 《Journal of Industrial Ecology》2007,11(2):31-42
In investigating the relationship between urbanization and sustainability in cities of developing countries, many researchers have looked to rising incomes as a driver for environmental improvement. This article challenges the transition and evolutionary models of urban environmental development that suggest that as cities grow in per capita income, their local environmental problems will diminish. The transition model is outcomes-based, and a competing model based on greater attention to participation in setting sustainability goals and assessing the progress toward those goals is presented.
Consensus on appropriate sustainability indicators is a key element, albeit a challenging one, in the task of pursuing urban sustainability. This is due to the contested nature of the concept of sustainability and also the fact that much of the work done on sustainability has been conducted among countries or on a national scale. A brief review of health, urban transport, air quality, and sewerage indicators suggests that cities do not necessarily see more progress as the per capita income increases. Low-income cities in Southeast Asia that are performing well are likely to see a deterioration in standards with rapid economic and population growth. 相似文献
Consensus on appropriate sustainability indicators is a key element, albeit a challenging one, in the task of pursuing urban sustainability. This is due to the contested nature of the concept of sustainability and also the fact that much of the work done on sustainability has been conducted among countries or on a national scale. A brief review of health, urban transport, air quality, and sewerage indicators suggests that cities do not necessarily see more progress as the per capita income increases. Low-income cities in Southeast Asia that are performing well are likely to see a deterioration in standards with rapid economic and population growth. 相似文献
40.
Langqiu Chen Shen-De Shi Yong-Qing Liu Qing-Jiao Gao Xing Yi Kai-Ke Liu Hao Liu 《Carbohydrate research》2011,346(10):1250
A novel 1,2-cis stereoselective synthesis of protected α-d-Gal-(1→2)-d-Glc fragments was developed. Methyl 2-O-acetyl-3-O-allyl-4,6-O-benzylidene-α-d-galactopyranosyl-(1→2)-3-O-benzoyl-4,6-O-benzylidene-α-d-glucopyranoside (13), methyl 2-O-acetyl-3-O-allyl-4,6-O-benzylidene-α-d-galactopyranosyl-(1→2)-3,4,6-tri-O-benzoyl-α-d-glucopyranoside (15), methyl 2-O-acetyl-3-O-allyl-4,6-O-benzylidene-α-d-galactopyranosyl-(1→2)-3-O-benzoyl-4,6-O-benzylidene-β-d-glucopyranoside (17), and methyl 2-O-acetyl-3-O-allyl-4,6-O-benzylidene-α-d-galactopyranosyl-(1→2)-3,4,6-tri-O-benzoyl-β-d-glucopyranoside (19) were favorably obtained by coupling a new donor, isopropyl 2-O-acetyl-3-O-allyl-4,6-O-benzylidene-1-thio-β-d-galactopyranoside (2), with acceptors, methyl 3-O-benzoyl-4,6-O-benzylidene-α-d-glucopyranoside (4), methyl 3,4,6-tri-O-benzoyl-α-d-glucopyranoside (5), methyl 3-O-benzoyl-4,6-O-benzylidene-β-d-glucopyranoside (8), and methyl 3,4,6-tri-O-benzoyl-β-d-glucopyranoside (12), respectively. By virtue of the concerted 1,2-cis α-directing action induced by the 3-O-allyl and 4,6-O-benzylidene groups in donor 2 with a C-2 acetyl group capable of neighboring-group participation, the couplings were achieved with a high degree of α selectivity. In particular, higher α/β stereoselective galactosylation (5.0:1.0) was noted in the case of the coupling of donor 2 with acceptor 12 having a β-CH3 at C-1 and benzoyl groups at C-4 and C-6. 相似文献