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1.
With the increasing popularity and use of medicinal herbs, their global demand has gained momentum. Developing countries, including China, India and South East Asian (SEA) countries, are the centres of origin and major global suppliers for most of these traditionally used medicinal herbs. One of the factors affecting the quality of these herbs is the contamination of heavy metals, mycotoxins, pesticide residues, polycyclic aromatic hydrocarbons (PAHs) and fumigants. These contaminants can accumulate during the cultivation, storage and processing of herbs and may have adverse effects on consumer health. There have been various reports regarding the presence of these contaminants in medicinal herbs. This review discusses the important contaminants of medicinal herbs, the frequency and magnitude of their occurrences, the potential causes of contamination and their regulatory limits in medicinal herbs. The major challenge in the international trade of medicinal herbs is the lack of common guidelines, regulatory measures and monitoring body to strictly enforce their regulation.  相似文献   
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Summary Traditionally, the adaptive value of mammalian white fat stores is considered in relation to longterm needs such as providing protection against the vagaries of winter or signalling the reproductive system when energy reserves are sufficient to risk pregnancy. As shown here, the fat stores of young house mice could not serve such needs. Despite prolonged acclimation and excess nesting material, food deprivation at 10°C significantly lowered the fat stores of peripubertal female house mice in only 12 h, and would exhaust them in 30 h. Even close to thermoneutrality (24°C) the calculated time to exhaustion was only 70 h. The fat stores of a young house mouse are obviously too meager to offer any meaningful protection over a winter of several months duration, or even over a 5–6-week cycle of pregnancy and lactation. Furthermore, in a wild habitat where food availability and ambient temperature can vary rapidly and greatly, such fat stores would be too labile to effectively coordinate puberty with somatic development.  相似文献   
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Freshwater ecosystem service is essential to human’s survival and development. Many studies have documented the spatial differences in the supply and demand of ecosystem services and proposed the concept of ecosystem services flows. However, few studies characterize freshwater ecosystem service flow quantitatively. Therefore, our paper aims to quantify the effects of freshwater ecosystem service flow on downstream areas. We developed a freshwater ecosystem service flow model and applied it in the Beijing–Tianjin–Hebei (BTH) region, China, for the year of 2000, 2005, and 2010. We assessed the regional water security with an improved freshwater security index by integrating freshwater service provision, consumption and flow; and found that most areas of the BTH region (69.2%) were affected by upstream freshwater flows. The areas achieving water security in the region also expanded to 66.9%, 66.1%, and 71.3%, which were 6.4%, 6.8% and 5.7% increments compared to no-flow situation, in 2000, 2005 and 2010, respectively. Setting quota for human water consumption is suggested to further improve water security. These results highlight the need to fully understand the connections between distant freshwater ecosystem service provision and local freshwater ecosystem service consumption. This approach may also help managers to choose more sustainable strategies for critical freshwater resource management across different regions.  相似文献   
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Biogenic amines (BAs) are a class of harmful compounds often be found in high protein foods, especially naturally fermented foods. BAs derive from free amino acid decarboxylation through microbial activities and can cause toxic effects (headache, heart palpitations, vomiting) on humans, depending on individual sensitivity. Indigenous amine-degrading strains or strains producing amine-degrading enzymes (ADEs) have drawn great attention since they play an important role in affecting BA accumulation, and enzymes/genes involved in the biosynthetic mechanisms. They also help maintain the sensory quality of the final products. Besides, due to ADEs’ harmless catalytic products, they can be further utilized in fermented foods and beverages to reduce BAs. This review describes in detail the mechanisms of BAs formation, as well as the diversity of ADEs able to degrade BAs in a model or real food systems. A deeper knowledge of this issue is crucial because ADEs’ activities are often associated with strains rather than species or genera. Moreover, this information can help to improve the selection and characterization of strains for further applications as starters or bioprotective cultures, to obtain high-quality foods with reduced BAs contents.  相似文献   
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The production of maize, a major staple food crop in sub-Saharan Africa is being constrained by the parasitic weed Striga hermonthica. The fungus Fusarium oxysporum f. sp. strigae (Foxy 2) that causes fusarium wilt of Striga in Ghana, West Africa, is being considered for biological control of the weed in Western Kenya. The present study investigated the efficacy of F. oxysporum f. sp. strigae (Foxy 2) for S. hermonthica management in Western Kenya. Research was conducted in post-entry quarantine (PEQ) facilities at Alupe, Busia, Homabay, Kibos and Siaya field stations for two seasons. Each PEQ was a split-plot, with 4 main blocks each having 6 treatment subplots. The treatments included seeds of two S. hermonthica-susceptible maize varieties, either coated with Foxy 2 using gum Arabic, gum Arabic alone, or left untreated. Data was collected over seven sampling periods on S. hermonthica population per plant, percentage of those that were wilting, and the severity of wilting. Maize plant growth parameters assessed included duration to 50% anthesis and 50% silking, plant height, number of leaves, stover and cob weights, and maize yield per hectare. Statistical analysis was done using SAS 9.1 software. Data on S. hermonthica population were analyzed by χ2-test using Proc Genmod (Poisson); while the other parameters were analyzed by Proc Mixed using study location, season and blocks as random effects, and the sampling periods as repeated effects. All the assessed parameters were similar between plants grown from seeds inoculated with F. oxysporum f. sp. strigae (Foxy 2), those coated with gum Arabic, and the ones without any coating. These parameters were also not different between the maize varieties. There are varying reasons for the disparities between results on F. oxysporum f. sp. strigae (Foxy 2) obtained in this Kenyan study, and those from researches outside this country. In conclusion, F. oxysporum f. sp. strigae strain Foxy 2 is predominantly safe on maize growth, but its efficacy in controlling S. hermonthica was not evident on the tested Kenyan soils.  相似文献   
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Oecophylla ants are sold at high prices on several commercial markets as a human delicacy, as pet food or as traditional medicine. Currently markets are supplied by ants collected from the wild; however, an increasing interest in ant farming exists as all harvest is easily sold and as ant farming can be combined with the use of the ants in biological control programmes in tropical plantations where pest insects are converted into ant biomass. To assess the cost‐benefits of ant farming based on artificial feeding, food consumption and food conversion efficiency (ECI) of Oecophylla smaragdina (Fabricius) was tested under laboratory conditions. Of the two types of food offered, the ants ingested 76% pure sucrose and 24% insect prey (dry weights) leading to ECI’s of 29% and 39% including brood only or brood plus imago gain, respectively. Based on Thai sugar and protein food costs and ant brood selling prices these efficiencies led to rates of return from 1.52 to 4.56, respectively, if: (i) protein is supplied from commercial products; or (ii) alternatively supplied from free sources such as insects and kitchen waste. These results suggest that Oecophylla ant farming may become highly profitable and deserves further research.  相似文献   
8.
How to assort with the relationship between the urban construction and the maintenance of ecological security is a hot issue during the process of urbanization. The purpose of this study is to identify the key ecological land maintaining ecological security and to put forward some measures for environmental management. Based on the GIS technology, from the view of water security, biodiversity conservation, disaster protection, natural recreation security, and human disturbance, an integrated index is put forward to evaluate the ecological importance of regional space. Then, a GIS-based approach for evaluating ecological importance was created, with Xingguo county of China as a case study. The results show that the area of core eco-space in the study area accounts for 30% of the total area. These areas mainly consist of the core areas of regional river systems, wetlands, nature reserves, forest parks, and scenic spots and the endangered and protected zone of geological hazards. According to the spatial characteristics of ecological importance for different regions, this study proposes some zoning regulations and measures for environmental management.  相似文献   
9.
Ghrelin administration directly into hypothalamic nuclei, including the arcuate nucleus (ArcN) and the paraventricular nucleus (PVN), alters the expression of stress-related behaviors. In the present study we investigated the effect of feeding status on the ability of ghrelin to induce stress and anxiogenesis. Adult male Sprague Dawley rats were implanted with guide cannula targeting either the ArcN or PVN. In the first experiment we confirmed that ArcN and PVN ghrelin treatment produced anxiety-like behavior as measured using the elevated plus maze (EPM) paradigm. Ghrelin was administered during the early dark cycle. Immediately after microinjections rats were placed in the EPM for 5 min. Both ArcN and PVN treatment reduced open arm exploration. The effect was attenuated by pretreatment with the ghrelin 1a receptor antagonist [d-Lys3]-GHRP-6. In a separate group of animals ghrelin was injected into either nucleus and rats were returned to their home cages for 60 min with free access to food. An additional group of rats was returned to home cages with no food access. After 60 min with or without food access all rats were tested in the EPM. Results indicated that food consumption just prior to EPM testing reversed the avoidance of the open arms of the EPM. In contrast, rats injected with ghrelin, placed in their home cage for 60 min without food, and subsequently tested in the EPM, exhibited an increased avoidance of the open arms, consistent with stress activation. Overall, our findings demonstrate that ghrelin 1a receptor blockade and feeding status appear to impact the ability of ArcN and PVN ghrelin to elicit stress and anxiety-like behaviors.  相似文献   
10.
Phytoestrogens are polyphenolic secondary plant metabolites that have structural and functional similarities to 17β-oestradiol and have been associated with a protective effect against hormone-related cancers. Most foods in the UK only contain small amounts of phytoestrogens (median content 21 μg/100 g) and the highest content is found in soya and soya-containing foods. The highest phytoestrogen content in commonly consumed foods is found in breads (average content 450 μg/100 g), the main source of isoflavones in the UK diet. The phytoestrogen consumption in cases and controls was considerably lower than in Asian countries. No significant associations between phytoestrogen intake and breast cancer risk in a nested case-control study in EPIC Norfolk were found. Conversely, colorectal cancer risk was inversely associated with enterolignan intake in women but not in men. Prostate cancer risk was positively associated with enterolignan intake, however this association became non-significant when adjusting for dairy intake, suggesting that enterolignans can act as a surrogate marker for dairy or calcium intake.  相似文献   
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