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1.
《Scientia Horticulturae》2005,106(3):341-352
Peppers (Capsicum spp.) were grown for phytochemical analyses at three different locations including a greenhouse at College Station and field plots at Uvalde and Weslaco, Texas. Cultivar effects were significant at each location for all compounds. The best sources of β-carotene were mature greenhouse-grown fruit of Fidel (23.7 μg/g) and C 127 (22.3 μg/g). Mature greenhouse fruit of Tropic Bell (10.1 μg/g) and PI 357509 (9.2 μg/g) had high lutein, but Uvalde field-grown mature fruit of these lines were low in this compound, (1.4 and 0.5 μg/g, respectively). MJ 201 fruit had the highest zeaxanthin levels (10 μg/g) at both College Station and Uvalde. The best sources of quercetin over all locations were the yellow wax types, Banana Supreme (186 μg/g), PI 357509 (86 μg/g) and Rio Grande Gold (26 μg/g). Fidel (37 μg/g) and Banana Supreme (21.5 μg/g) were the best sources of luteolin. Immature fruit generally contained lower levels of lutein and xeaxanthin than mature, colored fruit. These differences were not always statistically significant. Greenhouse-grown peppers at College Station contained more carotenoids than the field-grown peppers in Uvalde and Weslaco, but there were no significant differences among locations for flavonoid concentrations. Several good candidate parents were identified for the breeding program to develop novel pepper varieties with increased health benefits. Families of these varieties are currently being examined to assess the impact of specific environmental factors and identify genes involved in regulating synthesis of these beneficial phytochemicals. 相似文献
2.
The vapours of allyl-isothiocyanate (AITC) were evaluated in in vitro and in vivo trials against Botrytis cinerea, a severe pathogen of strawberries. In in vitro trials AITC activity was assayed on conidial germination and mycelial growth of the fungus. The mycelium appeared less sensitive to AITC than conidia (EC50 values of 1.35 mg L−1 and 0.62 mg L−1, respectively). In addition, AITC had a fungistatic effect against the pathogen, since the values of EC50, for both parameters, increased by around 30% after AITC removal. In in vivo trials, ‘Tecla’ and ‘Monterey’ strawberries (spring-bearing and day-neutral cultivars, respectively) obtained from organic production and naturally infected by B. Cinerea, were exposed for 4 h in an atmosphere enriched by pure AITC or derived from defatted seed meals of Brassica carinata (0.1 mg L−1, in a 0.1 m3 treatment cabinet). After 2 days at 0 °C and another 3–4 days at 20 °C, the fruit were evaluated for grey mould infections. The AITC treatment reduced the decay caused by the pathogen by over 47.4% up to 91.5%, significantly different from the untreated fruit. No significant differences were found between synthetic and glucosinolate-derived AITC. Residue analysis performed on fruit at the end of storage (7 d after treatment) showed values lower than 1 mg kg−1. Total phenolic content and antioxidant capacity estimated in treated and untreated strawberries showed no significant difference between control and AITC treated fruit. Our results show it is possible to reduce the incidence of postharvest grey mould on strawberries with a treatment of AITC (0.1 mg L−1) for 4 h, opening a potential application of biofumigation in the postharvest control of B. cinerea in strawberry. 相似文献
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5.
《Soil Technology》1993,6(2):137-144
Much of work relating plant temperature to plant water stress has been done in arid regions. In 1989–1990, investigations were carried out verifying the validity of the Scheduler Plant Stress Monitor made by the Standard Oil Engineering Materials Company of the United States, in irrigation timing, under Hungary's changeable weather conditions.Three different water treatments were used:
- 1.⊎ natural rainfall only (control),
- 2.⊎ lysimeter study, where the water supply is in accordance with the water demand of plants,
- 3.⊎ irrigation according to the instructions of the Scheduler.
6.
Anne C. Lang Werner Härdtle Helge Bruelheide Christian Geißler Karin Nadrowski Andreas Schuldt Mingjian Yu Goddert von Oheimb 《Forest Ecology and Management》2010
Trees are able to respond to their local biotic and abiotic environment with morphological adjustments which improve resource acquisition and, thus, growth. In forests, light is broadly recognised as one of the major factors determining growth, and morphological responses comprise changes in crown architecture and stem stature. On sloping terrain, the interplay of phototropism and gravitropism may further affect morphological growth characteristics. However, different tree species are expected to show species-specific responses. In this study, we analysed three growth characteristics of tree individuals belonging to four species of two functional groups (evergreen: Schima superba, Castanopsis eyrei, deciduous: Quercus serrata var. brevipetiolata, Castanea henryi) in a species-rich Chinese subtropical forest. Crown projection area, relative crown displacement and stem inclination were related to biotic (local species richness, functional richness, competition, stand age) and abiotic (slope aspect and inclination, soil depth) variables in the local neighbourhood of the tree individuals. We hypothesised that (i) there are species-specific differences in the morphological response of crown architecture and stem stature and (ii) that crown size and asymmetry as well as stem inclination are influenced by both, biotic and abiotic factors. In contrast to our expectations we were unable to reveal any species-specific differences in any of the three growth characteristics. The results of mixed effects models showed that crown area was mainly affected by the target tree's dbh and biotic variables related to neighbours (competition, functional diversity), whereas stem inclination was mainly influenced by slope. Relative crown displacement was influenced by both, biotic and abiotic variables. We conclude that growth responses resulting in crown displacement and stem inclination seem to be an important mechanism to ameliorate foraging for light in our study area, but that these responses appear to be species-independent. The interplay of stem inclination and crown displacement allows for a plastic response of tree individuals in biotically and abiotically heterogeneous environments. Our results indicate that forest management in this region should focus on functionally diverse stands which are promoting crown area positively resulting in increased growth rates of individual trees. 相似文献
7.
The effects of Phomopsis longanae Chi infection on browning development and disease incidence in relation to energy status in pericarp of harvested longan fruit were investigated. Longan fruit were inoculated for 5 min with P. longanae at 104 spores mL−1, while fruit dipped in sterile deionized water were used as control. These fruits were stored at (28 ± 1) °C and 90% relative humidity for up to five days. The results showed that the browning index, disease incidence, cellular membrane permeability and AMP content increased but the contents of ATP and ADP, and energy charge decreased in pericarp of longan fruit infected by P. longanae. It was suggested that P. longanae infection caused energy deficiency in longan fruit, possibly resulting in accelerated senescence and decreased resistance to pathogen, and thus promoted browning development and disease occurrence. 相似文献
8.
This study aimed to investigate the effect of chitin on the antagonistic activity of Rhodosporidium paludigenum against Penicillium expansum, the cause of blue mold in apple fruit, and the possible mechanisms involved. Our results showed that biocontrol efficacy and population growth of R. paludigenum were greatly enhanced when it was harvested from nutrient yeast dextrose with added chitin (NYCB) medium compared with that harvested from nutrient yeast dextrose (NYDB) medium. The ability of R. paludigenum produced in NYCB to induce resistance to blue mold in apple fruit was significantly enhanced. The enhanced disease control efficacy was correlated with higher levels of polyphenoloxidase (PPO) and superoxide dismutase (SOD) activities in apple fruit treated with R. paludigenum. Moreover, the SOD and catalase (CAT) activities of R. paludigenum were stimulated by cultivating in NYCB, while malondialdehyde (MDA) accumulation in the yeast cells was suppressed. These results indicated that adding chitin to normal media might be an effective method to improve the antagonistic activity of R. paludigenum and the active oxygen metabolism of R. paludigenum might be closely related to the biocontrol activity of the yeast. 相似文献
9.
作为农村体制改革创新的村级集体经济股份合作制,是一种农民凭借其集体成员身份参与收入分配的制度安排。结合对改革试点杭州市江干区的调研,运用双重差分模型分析该区23村社2003—2011年的相关社会经济数据,得出村级集体经济股份合作制在实施当年及之后的3年内,促进农民增收的正向作用显著,但在随后年份中增收效果逐年降低且影响作用在统计上均不显著,表明村级集体经济股份合作制的持续增收效应不明显。其原因可能是村级集体经济股份合作社与农民之间缺乏公平合理的利益分配机制,应在确保促进公共利益增长的同时,重视利益分配机制的公平合理性以切实增加农民收入。 相似文献
10.
Zhijun Tong Zemao Yang Xuejun Chen Fangchan Jiao Xuying Li Xingfu Wu Yulong Gao Bingguang Xiao Weiren Wu 《Plant Breeding》2012,131(5):674-680