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931.
932.
Limitations of data quality and difficulties to assess uncertainty are long since acknowledged problems in LCA. During recent
years a range of tools for improvement of reliability in LCA have been presented, but despite this there is still a lack of
consensus about how these issues should be handled. To give basic understanding of data quality and uncertainty in LCA, key
concepts of data quality and uncertainty in the context of LCA are explained. A comprehensive survey of methods and approaches
for data quality management, sensitivity analysis, and uncertainty analysis published in the LCA literature is presented.
It should serve as a guide to further reading for LCA practitioners interested in improving data quality management and uncertainty
assessment in LCA projects. The suitability of different tools for addressing different types of uncertainty and future needs
in this field is discussed. 相似文献
933.
Andrzej Borychowski Katarzyna Niemirowicz-Szczytt Magdalena Jędraszko 《Acta Physiologiae Plantarum》2002,24(3):257-264
Morphogenetic potential of hypocotyl and cotyledon explants of the three Polish Capsicum annuum L. cultivars (Kujawianka, Passat and Zorza) was studied to develop a reliable plant regeneration protocol. Out of 8 and 15
combinations of growth regulators used in the first and second series respectively, the best medium contained BAP (5 mg·l−1) and IAA (1 mg·l−1). Media containing thidiazuron (TDZ) and IAA proved to be worse than those with BAP and IAA. Additionally, it was indicated
that hypocotyl explants placed upside-down developed more adventious buds. ‘Passat’ was the most responsive variety (approximately
40 % of both types of explants produced buds).
In the second part of experiment the aim was to stimulate shoot induction in the conditions most adapted to Agrobacterium transformation. ‘Bryza’ replaced cv ‘Kujawianka’ and proved to be better than ‘Passat’, previously distinguished as a highly
responsive cultivar. The experiments confirmed a significant effect of the hypocotyl explant length and induction period on
shoot regeneration. Finally, the optimum concentration of carbenicillin and kanamycin was determined. 相似文献
934.
Diurnal changes in the expressionof glutamate dehydrogenase and nitrate reductase are involved in the C/N balance of tobacco source leaves 总被引:1,自引:0,他引:1
C. Masclaux-Daubresse M.-H. Valadier E. Carrayol M. Reisdorf-Cren & B. Hirel 《Plant, cell & environment》2002,25(11):1451-1462
A novel cDNA encoding glutamate dehydrogenase (GDH) from tobacco(Nicotiana tabacum), named gdh1, was characterized.The gdh1 mRNA was detected in roots, stems and source/senescentleaves. In order to investigate diurnal regulation of gdh1 inleaves, the content in gdh1 mRNA was measured every 3 h overa 48 h period and compared to nia and gs2 mRNAlevels, encoding, respectively, nitrate reductase (NR) and chloroplasticglutamine synthetase (GS2). In source leaves, gdh1 mRNA levelsexhibit diurnal fluctuations. A 12 h shift was observedbetween the day–night rhythms of gdh1 and nia expression.Metabolite contents were also measured and a shift in the day–nightfluctuations of both glutamate (GLU) and γ‐aminobutyricacid (GABA) was observed between sink and source leaves, whereasthe diurnal rhythm of α‐ketoglutarate showed no change.A possible role of GDH in the shift of GLU and GABA contents isdiscussed. Leaf disc experiments showed that gdh1 expressionis enhanced in conditions of continuous darkness. This trend isinhibited by sucrose feeding. The opposite was observed for nia expression.An important outcome of this work is the reverse regulation of gdh1 and nia genes.A possible role of sugars and amino acids in the co‐regulation of gdh1 and nia genesis suggested. 相似文献
935.
936.
Teicoplanin, a glycopeptide antibiotic, is composed of five main components, denoted T-A2-1 to T-A2-5. We investigated the use of glycerol as a carbon source affecting the teicoplanin components and its acyl moieties. As a result, we show the change of teicoplanin components, as well as an increase of total teicoplanin yields, caused by the addition of glycerol to the production medium. Analysis of the total cell lipids upon the addition of glycerol also showed a corresponding change in the proportion of teicoplanin, suggesting that glycerol strongly affects a change of teicoplanin branched acyl moieties. 相似文献
937.
新型可再生工业用油脂的代谢工程 总被引:2,自引:0,他引:2
植物种子油是一种可再生资源,亦用作生物燃油和化学工业原料. 一些野生植物能高水平合成积累羟化、环氧化和共轭脂肪酸等具有重要工业应用价值的特异脂肪酸.催化这些特异脂肪酸合成的酶主要是类脂肪酸去胞和酶2(类FAD2). 由特异脂肪酸合成到三酰基甘油脂 (TAG) 形成还需要酰基转移酶 (如DGAT) 的参与. 在油料作物种子中表达类FAD2酶及其相关基因(如DGAT),已培育出了能合成积累一定含量特异脂肪酸的工程油料品系,为基于农作物生产高附加值工业用油脂开辟了新途径. 本文论述了参与特异脂肪酸生物合成途径的关键酶基因、油料作物代谢工程策略,以及应用工程油料作物大规模生产重要工业用脂肪酸的研究进展、存在问题和应用前景等. 相似文献
938.
A laboratory-scale hybrid-denitrification filter (HDF) was designed by combining a plant material digester and a denitrification filter into a single unit for the removal of nitrate and phosphorus from glasshouse hydroponic wastewater. The carbon to nitrate (C:N) ratio for efficient operation of the HDF was calculated to be 1.93:1 and the COD/BOD5 ratio was 1.2:1. When the HDF was continuously operated with the plant material replaced every 2 days and 100% internal recirculation of the effluent, a high level of nitrate removal (320–5 mg N/L, >95% removal) combined with a low effluent sBOD5 concentration (<5 mg/L) was consistently achieved. Moreover, phosphate concentrations in the effluent were maintained below 7.5 mg P/L (>81% reduction). This study demonstrates the potential to combine a digester and a denitrification filter in a single unit to efficiently remove nitrate and phosphate from hydroponic wastewater in a single unit. 相似文献
939.
Indra Sandal Ajay Kumar Amita Bhattacharya Madhu Sharma Adarsh Shanker Paramvir Singh Ahuja 《Plant Growth Regulation》2005,47(2-3):121-127
Adventitious shoot regeneration via callus phase from in vitro leaf explants is reported for the first time in tea. Callus was obtained on Murashige and Skoog medium supplemented with
varied concentrations of 2,4-dichlorophenoxyacetic acid (2,4-D) (2.5, 5.0, 7.5 and 10.0 mg/l). Rhizogenesis was observed at
all concentrations of 2,4-D. Adventitious shoot buds developed indirectly on leaf explants after prolonged culture for 16 weeks
on medium supplemented with 10.0 mg/l 2,4-D. GC analysis of the medium and the tissues at different stages of development
showed that specific levels of 2,4-D in the tissue were responsible for morphogenesis. Shoot buds developed on rhizogenic
calli, only when 2,4-D declined to undetectable or negligible concentrations in the tissue probably due to detoxification
and metabolism. Alternatively, shoot buds could also be evoked when rhizogenic calli were transferred to medium supplemented
with low concentration of 2,4-D (1.5 mg/l). The adventitious nature of the shoots was confirmed through histological studies. 相似文献
940.
The carbon bonus of organic nitrogen enhances nitrogen use efficiency of plants 总被引:2,自引:0,他引:2
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Oskar Franklin Camila Aguetoni Cambui Linda Gruffman Sari Palmroth Ram Oren Torgny Näsholm 《Plant, cell & environment》2017,40(1):25-35
The importance of organic nitrogen (N) for plant nutrition and productivity is increasingly being recognized. Here we show that it is not only the availability in the soil that matters, but also the effects on plant growth. The chemical form of N taken up, whether inorganic (such as nitrate) or organic (such as amino acids), may significantly influence plant shoot and root growth, and nitrogen use efficiency (NUE). We analysed these effects by synthesizing results from multiple laboratory experiments on small seedlings (Arabidopsis, poplar, pine and spruce) based on a tractable plant growth model. A key point is that the carbon cost of assimilating organic N into proteins is lower than that of inorganic N, mainly because of its carbon content. This carbon bonus makes it more beneficial for plants to take up organic than inorganic N, even when its availability to the roots is much lower – up to 70% lower for Arabidopsis seedlings. At equal growth rate, root:shoot ratio was up to three times higher and nitrogen productivity up to 20% higher for organic than inorganic N, which both are factors that may contribute to higher NUE in crop production. 相似文献