全文获取类型
收费全文 | 102篇 |
免费 | 12篇 |
专业分类
林业 | 13篇 |
农学 | 6篇 |
25篇 | |
综合类 | 8篇 |
农作物 | 7篇 |
水产渔业 | 5篇 |
畜牧兽医 | 44篇 |
园艺 | 1篇 |
植物保护 | 5篇 |
出版年
2021年 | 1篇 |
2020年 | 4篇 |
2019年 | 2篇 |
2018年 | 6篇 |
2017年 | 9篇 |
2016年 | 4篇 |
2015年 | 1篇 |
2014年 | 1篇 |
2013年 | 8篇 |
2012年 | 2篇 |
2011年 | 5篇 |
2010年 | 5篇 |
2009年 | 5篇 |
2008年 | 11篇 |
2007年 | 1篇 |
2006年 | 7篇 |
2005年 | 3篇 |
2004年 | 3篇 |
2003年 | 4篇 |
2002年 | 2篇 |
2000年 | 1篇 |
1999年 | 2篇 |
1998年 | 1篇 |
1997年 | 1篇 |
1996年 | 6篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1990年 | 6篇 |
1989年 | 3篇 |
1983年 | 1篇 |
1976年 | 1篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1966年 | 1篇 |
排序方式: 共有114条查询结果,搜索用时 93 毫秒
71.
Vimal Kothiyal Jaideep Seema Bhandari H. S. Ginwal Sachin Gupta 《Wood Science and Technology》2015,49(4):769-793
Feasibility of near-infrared (NIR) spectroscopy for developing multi-species model for plantation timber was explored for estimation of holocellulose in un-extracted milled wood samples. Six commonly planted species of Eucalyptus tereticornis, E. camaldulensis, E. grandis, Leucaena leucocephala, Dalbergia sissoo and Populus deltoides from a wide range of locations and varying age groups were taken for the present study. Few samples of E. hybrid between E. tereticornis and E. camaldulensis were also included in the study to make the model useful for practical application. NIR models were evaluated using partial least squares regression (PLSR-1—full cross-validation, PLSR-2—cross-validation which leaves more than one out) and by dividing the samples into calibration and prediction (test) sets and interchanging them from calibration to prediction sets. The predictive ability of the model was assessed by calculating four ratios of multivariate statistics for individual species model and combined species models. A final combined model for all the species having component range of 76.14–63.03 % and standard deviation of 2.586 % was developed in the spectral range of 7502–4246 cm?1 wave number using 1st derivative plus multiplicative scatter correction using factor of nine by removing samples with outliers found in all the PLSR-2 evaluation steps and in most of the models. The model remained stable even when 30 % of the samples were left out with no outlier detected. 相似文献
72.
Kishor Bhandari Pankaj Sood Pawan K. Mehta Amit Choudhary Chandra S. Prabhakar 《Phytoparasitica》2009,37(4):317-322
A granulosis virus strain infecting Pieris brassicae (PbGV) was isolated from the dry temperate region of northwestern Himalayas as a potential microbial agent for its management.
The effect of different botanicals (having insecticidal action against P. brassicae) on the bioefficacy of PbGV was evaluated under laboratory conditions using leaf disc bioassays on cabbage for improving
the insecticidal performance of the PbGV. The synergistic action of different botanical extracts was evident in terms of reduction
in LC50 values against different botanical extracts. Among different extracts, petroleum-ether extract of neem seed kernel (NSK)
when combined with PbGV resulted in maximum reduction of LC50 value (4.39 × 102 occlusion bodies [OBs] ml−1) followed by methanolic extract (7.38 × 102 OBs ml−1) and aqueous extract (9.36 × 103 OBs ml−1) as compared with PbGV alone (1.85 × 104 OBs ml−1) for 2nd instar larvae of the test insect. These trends were found analogous in cases of 3rd and 4th instars of P. brassicae with different solvent extracts of NSK. The other botanicals evaluated, viz., Eupatorium and Artemesia, also resulted in reduction of LC50 values for 2nd, 3rd and 4th instars as compared with PbGV alone when different extracts were combined with virus for bioassays.
The studies suggest that the PbGV in combination with botanical pesticides could be more useful as a bio-pesticide against
cabbage butterfly (P. brassicae) in IPM programs. 相似文献
73.
Anjula Pandey Rakesh Singh J. Radhamani D. C. Bhandari 《Genetic Resources and Crop Evolution》2010,57(6):929-936
Ziziphus nummularia (Burm. f.) Wight et Arn. is a multipurpose wild economic species well adapted to dry and hot climates of north-western plains,
central India and dry regions of peninsular India. This species is reported here for its potential value in drier regions
of India and may be considered for future plant genetic resource programmes. 相似文献
74.
K. C. Bhatt Anjula Pandey O. P. Dhariwal N. S. Panwar D. C. Bhandari 《Genetic Resources and Crop Evolution》2009,56(5):729-733
Crotalaria tetragona Roxb. ex Andr., locally known as “Tum-thang” was collected from Mizoram state of north-eastern hill region of India during
2008. Its flowers were being sold by the tribal communities in local markets. The buds and flowers are cooked as vegetables
and used in garnishing of local food preparations especially in non-vegetarian recipes. This species is reported here as little
known Edible type in Indian region and may be considered as a multi-purpose species with potential. Edible uses of some of
the Crotalaria species in different regions of world have also been included in the present communication. 相似文献
75.
V. K. Vikas M. Sivasamy J. Kumar P. Jayaprakash Sundeep Kumar R. Parimalan Arun Kumar Kalyani Srinivasan J. Radhamani Sherry Rachel Jacob Mamata Yadav Jyotisna Rani I. S. Bisht D. C. Bhandari Sunil Archak M. Dutta R. K. Tyagi K. C. Bansal 《Genetic Resources and Crop Evolution》2014,61(4):861-874
Resistance to stem rust and leaf rust in five D genome species of wheat viz., 267 accessions of Aegilops tauschii Coss., 39 of Ae. cylindrica Host, 17 of Ae. ventricosa Tausch, 4 of Ae. crassa Boiss. and 8 of Ae. juvenalis (Thell.) Eig were evaluated at adult plant stage. Two hundred and thirty nine (90 %) accessions of Ae. tauschii, 30 (77 %) of Ae. cylindrica, 16 (94 %) of Ae. ventricosa, 3 (75 %) of Ae. crassa Boiss. and 5 (62.5 %) of Ae. juvenalis were resistant to stem rust pathotypes prevalent in South India at Wellington under field condition. Invariably, all the accessions of the five species were resistant to leaf rust pathotypes. Quantitative measurement of disease using area under the disease progress curve revealed the slow progress of disease in the resistant accessions compared to susceptible check (Agra Local). Since all the five species have D genome, it could be concluded that the genes present in D genome might play a vital role in leaf rust resistance, but in case of stem rust resistance wide range of differential response was noticed. Among the species evaluated, Ae. tauschii was exploited to a larger extent, followed by Ae. ventricosa and Ae. cylindrica for leaf and stem rust resistance because of the homology of D genome with hexaploid bread wheat. While, Ae. crassa and Ae. juvenalis could not be utilized so far, possibly due to partial homology which makes the transfer of traits difficult. So, these species have considerable potential as a source of rust resistance and may enhance the existing gene pool of resistance to stem and leaf rusts. 相似文献
76.
Farming communities in traditional agroecosystems have been playing an important role in conserving agricultural diversity.
They are not only the custodians but also managers of the crop diversity and maintain the dynamic processes of crop evolution
and adaptation, the key elements of sustainable agricultural productions. The Himalayan highlands are important centres of
crop plant diversity due to high ecological heterogeneity and high local socio-cultural integrations. The crop genetic diversity
of Kumaon Himalaya in Uttarachal State of India has been documented in the present study. Existing crop genetic diversity
at inter- and intra-species level was assessed and factors for changes in crop compositions and farming systems during the
recent past were studied. Farmer management of rice landrace populations were studied in greater detail. Various benefit enhancing
options for farmers from local crop diversity were scrutinized based on farmer perceptions and priorities for efficient management
of local crop diversity on-farm and its sustainable utilization for agricultural production. 相似文献
77.
A class of thermoelectric materials has been synthesized with a thermoelectric figure of merit ZT (where T is temperature and Z is a function of thermopower, electrical resistivity, and thermal conductivity) near 1 at 800 kelvin. Although these materials have not been optimized, this value is comparable to the best ZT values obtained for any previously studied thermoelectric material. Calculations indicate that the optimized material should have ZT values of 1.4. These ternary semiconductors have the general formula RM4X12 (where R is lanthanum, cerium, praseodymium, neodymium, or europium; M is iron, ruthenium, or osmium; and X is phosphorus, arsenic, or antimony) and represent a new approach to creating improved thermoelectric materials. Several alloys in the composition range CeFe4-xCoxSb12 or LaFe4-xCoxSb12 (0 < x < 4) have large values of ZT. 相似文献
78.
In this study, a dot‐enzyme‐linked immunosorbent assay (Dot‐ELISA) was evaluated in comparison with a complement fixation test (CFT) for the detection of Campylobacter antibodies in sheep sera. Acid glycine extracts (AGE) of both Campylobacter fetus ssp. fetus and Campylobacter jejuni strains that had been isolated from the gall‐bladder of slaughtered sheep was used as antigen in both tests. A total of 153 sheep sera from aborted (74) and slaughtered (79) sheep were examined by both Dot‐ELISA and CFT. Twenty‐two sera showed anti‐complementary activity were not suitable for CFT. Of the 22 sera showing anti‐complementary activity, two sera were found to be positive in Dot‐ELISA. Eighty‐eight (67.2%) of the remaining 131 sera were negative by both Dot‐ELISA and CFT using AGE of both Campylobacter strains whereas 43 sera (32.8%) gave different reaction patterns in Dot‐ELISA and CFT with the extracts of both Campylobacter strains. Twelve sera were positive by both tests using AGE of C. fetus ssp. fetus but CFT failed to detect antibodies in nine of these sera when AGE of C. jejuni was used. Twelve sera were positive by both tests only when AGE of C. fetus ssp. fetus was used. Eleven sera were positive only by CFT. Seven of these reacted only with the AGE of C. fetus ssp. fetus and four sera were positive by using AGE of both Campylobacter strains. The remaining eight sera were found to be positive only by dot‐immunobinding assay either with the AGE of both Campylobacter strains or with the AGE of one of the Campylobacter strains. It is concluded that Dot‐ELISA using AGE from C. fetus ssp. fetus could be employed for the detection of Campylobacter antibodies in sheep sera and the additional use of AGE from C. jejuni as antigen appeared not to be profitable for this purpose. 相似文献
79.
Summary Two hundred genotypes of Coriandrum sativum L. exhibited genetic variation for plant height, primary and effective branches, days to flowering and maturity, umbels and umbellets per plant, grains per umbellet, thousand seed weight, straw yield and grain yield per plant and harvest index. Heritability estimates were high for days to flowering, thousand seed weight and days to maturity; moderate for plant height, straw yield, umbels per plant, umbellets per plant and number of primary branches; and low for harvest index, effective branches, grain yield per plant and grains per umbellet. Phenotypic correlations of grain yield per plant were highly significant and positive with umbellets per plant, umbels per plant, number of effective branches, straw yield per plant, number of primary branches, plant height, number of grains per umbellet and harvest index. Maximum direct contribution to grain yield per plant was made by umbellets per plant, followed by straw yield per plant, umbels per plant and grains per umbellet. Umbellets per plant made sizeable indirect effect via straw yield per plant. Straw yield per plant made sizeable indirect contribution via umbellets per plant. 相似文献
80.
The ratios of fluxes of heavy cosmic-ray nuclei [(30 = Z = 40)/(20 < Z = 28), where Z is the atomic number], based on studies of meteorites and lunar samples, show little variation with time, distance in the solar system (1 to 3 astronomical units), or kinetic energy (30 to 2000 megaelectron volts per nucleon). Samples exposed for time intervals of 10(3) to 10(8) years show that the variations in the flux of 30 = Z = 40 nuclei relative to that of the iron group nuclei (20 < Z = 28) have remained within the range of (1.3 +/- 0.6) x 10(-3) during the last billions of years, thus indicating a remarkable similarity in the elemental composition of sources responsible for these nuclei in the cosmic radiation. 相似文献