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81.
从产业经济角度,包括医药工业总产值、医药工业销售收入、医药工业盈利水平、医药流通行业销售规模、医药商业效益水平、 相似文献
82.
83.
ABSTRACT Even faced with overwhelming evidence that tobacco threatens human health, along with economic developments undermining their status as independent producers, North Carolina tobacco farmers view tobacco production in ways congruent with a moral economy. A shift from independent to contract production of tobacco and the dismantling of government price supports have challenged this moral economy, converting tobacco producers into a quasi–working class dependent on tobacco companies while leading to fewer tobacco farms and an increase in the average tobacco farm's size. These changes signal a shift away from a moral economy of tobacco, although moral-economic dimensions remain. Producers today emphasize different moral dimensions of economic behavior, such as producing quality human beings, than during earlier eras, when moral-economic actors pressed for state intervention in economic crises. Moral-economic principles are not restricted to either non-Western or historical peoples but, rather, influence economic production and ideology in advanced capitalist settings today. 相似文献
84.
M. J. S. Hodge 《Journal of the history of biology》2009,42(3):399-416
When socio-economic contexts are sought for Darwin’s science, it is customary to turn to the Industrial Revolution. However,
important issues about the long run of England’s capitalisms can only be recognised by taking a wider view than Industrial
Revolution historiographies tend to engage. The role of land and finance capitalisms in the development of the empire is one
such issue. If we historians of Darwin’s science allow ourselves a distinction between land and finance capitalisms on the
one hand and industrial capitalism on the other; and if we ask with which side of this divide were Darwin and his theory of
branching descent by natural selection aligned, then reflection on leading features of that theory, including its Malthusian
elements, suggests that the answer is often and largely, though not exclusively: on the land side. The case of Wallace, socialist
opponent of land capitalism, may not be as anomalous for this suggestion as one might at first think. Social and economic
historians have reached no settled consensuses on the long-run of England’s capitalisms. We historians of Darwin’s science
would do well to import some of these unsettled states of discussion into our own work over the years to come. 相似文献
85.
Integrating dark and light bio-hydrogen production strategies: towards the hydrogen economy 总被引:1,自引:0,他引:1
Mark D. Redwood Marion Paterson-Beedle Lynne E. Macaskie 《Reviews in Environmental Science and Biotechnology》2009,8(2):149-185
Biological methods of hydrogen production are preferable to chemical methods because of the possibility to use sunlight, CO2 and organic wastes as substrates for environmentally benign conversions, under moderate conditions. By combining different
microorganisms with different capabilities, the individual strengths of each may be exploited and their weaknesses overcome.
Mechanisms of bio-hydrogen production are described and strategies for their integration are discussed. Dual systems can be
divided broadly into wholly light-driven systems (with microalgae/cyanobacteria as the 1st stage) and partially light-driven
systems (with a dark, fermentative initial reaction). Review and evaluation of published data suggests that the latter type
of system holds greater promise for industrial application. This is because the calculated land area required for a wholly
light-driven dual system would be too large for either centralised (macro-) or decentralised (micro-) energy generation. The
potential contribution to the hydrogen economy of partially light-driven dual systems is overviewed alongside that of other
bio-fuels such as bio-methane and bio-ethanol. 相似文献
86.
《Animal : an international journal of animal bioscience》2020,14(2):399-408
The use of compost bedded pack systems (CBS) has increased over the past 5 years in tropical countries, and studies associating production traits with economical outcomes of this system are warranted. Our objectives were to evaluate productive traits, economic outcomes and the risks of losses of dairy farms that switched from a drylot system (DLS) to a CBS and to compare these with similar farms that did not change their system. We collected data from 18 farms over 36 consecutive months (August 2014 to July 2017). All farms started the study as DLS, and six farms switched to CBS in the second year. The other 12 farms kept their DLS during the 36 months of evaluation. Annual technical and economic indexes per farm were collected and calculated. Additionally, a risk analysis was performed based on a 10-year historical series of milk prices. The results were analysed using a regression model including year and herd as categorical variables (fixed), system and herd size as quantitative variables (fixed), and system × herd as a random variable. Furthermore, a non-metric multidimensional scaling plot was used to evaluate producers’ profiles in each year. Milk fat, milk total solids, and somatic cell count did not change when farms switched from DLS to CBS, and averaged 3.80%, 12.04%, and 256 500 cells/ml, respectively. However, milk protein (%) decreased in CBS farms. The majority of milk production variables were not affected. Nevertheless, farms that switched to CBS increased milk production per cow by 13.3% compared with DLS farms. Total operation costs (296 076.83 $/year) were not affected by the system, and neither were the costs of concentrates, roughage, labour or medicines. Net margin per litre (0.09 $/l), operating profit (14.95%), assets per litre (398.68 $/l per day) and return on assets (10.27%) did not change when farms switched from DLS to CBS. Net margin ($/l and $/cow) and asset turnover rate increased in CBS farms. Risk analysis indicated that the risk was reduced by 38% in CBS farms. Furthermore, our analysis showed that producers who switched to CBS had similar technical and economic indexes in the first year before switching their system. In conclusion, this study demonstrates that CBS systems might be promising for producers in tropical countries who are looking for a more productive and less risky system. We did not observe improvements in animal health as previously reported in the literature. 相似文献
87.
Lagidium viscacia inhabits where water and food availability is low. We hypothesize that this rodent should minimize metabolic rate and water loss in order to cope with such extreme environments. We observed that Lagidium viscacia has (1) a comparatively lower basal metabolic rate (67%) and thermal conductance (78%) of predicted; (2) a higher pulmocutaneous evaporation rate which is 36% (mesic) and 63% (xeric); and (3) energetic cost of maintaining the water balance similar to that expected for rodents from xeric environments (2.8 cal/g h). In summary, Lagidium viscacia has physiological traits that favour energy and water economy to cope with such extreme habitats. 相似文献
88.
Berenice FarfÁn Alejandro Casas Guillermo Ibarra-ManrÍquez Edgar PÉrez-NegrÓn 《Economic botany》2007,61(2):173-191
This is the first report on Mazahua knowledge and classification of plants and mushrooms and the roles of these resources
in the local economy in the Monarch Butterfly Biosphere Reserve, Mexico. A total of 213 useful plant species and 31 species
of edible mushrooms were recorded. Fruits ofPrunus serotina, Rubus liebmanii, andCrataegus mexicana were the main wild fruit gathered by people (7.47, 4.40, and 1.82 tons of fruits per year, respectively), whereas their availability
in the territory of the village was approximately 302.6, 6.0, and 34.188 tons.Brassica campestris, Rorippa nasturtium-aquaticum, Chenopodium berlandieri, and Amaranthus hybridus were the principal non-cultivated greens consumed by people (4.3, 0.5, 0.7, and 0.9 tons per year, while 23.6, 3.78, traces,
and 46.0 tons, respectively, were available). Extraction of medicinal plants is low but gathering ofTernstroemia spp. flowers endangers local populations of these plants. All households of the village used fuelwood (1,767.2 tons per year),
mainly of pine and oak species. Strategies for sustainable use of these resources are discussed 相似文献
89.
利用灰色系统理论与时间序列分析,提出了带灰色项的时间序列模型,对这类模型进行了分析,给出了建模与预报方法,并将其应用于我国农业产值问题的预报与研究之中,模型的正确性得到了检验. 相似文献
90.
通过生态意义下区域竞争力的研究,提出了经济自由空间的概念.在进行模型静态和动态的分析后,得出科技的进步对区域潜在竞争力具有决定性作用的结论.在实证研究方面,运用因子分析的方法,根据生态水平、人均国内生产总值和生态科技进步等13个指标,对全国31个省(自治区、直辖市)的生态经济水平以及区域竞争力进行了排名.结果发现,由于经济发展水平和自然生态环境等原因,在生态意义下我国各个区域的区域竞争力也成空间上的东、中、西分布格局.在上述理论和实证探讨的基础上,还分别就生态条件下区域发展的公平和效率以及生态条件下有关不发达地区的区域政策进行了探讨.认为生态条件下,如果政策制定不得当,不发达地区会处于更加不平等的地位,所以政策制定者应该重新认识传统的区域理论和区域政策. 相似文献