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101.
Monitoring and assessment of agricultural land degradation is of vital importance for better land and water management planning and reclamation. It requires setting baseline information and basic analysis at specific time and space. About 33 geo-referenced soil sampling spots were selected in two agricultural production locations in the Kingdom of Bahrain to assess the status and preliminary causes of land degradation. Soil samples were taken from 13 sites in Diraz location while 19 samples were taken from Budayyi location. The samples were taken to 90 cm depth at 30 cm intervals. Standard procedures were followed to determine soil physiochemical properties. In addition, field observations on farm condition, distance from the sea, method of irrigation and irrigation water source were taken. Some of the soil samples were deliberately taken from outside the irrigated basins among trees compared with samples taken from inside the actively growing area for comparison. The results indicated that the salinity level was significantly (P 〈 0.001) higher at the 0-30 cm soil depth compared with 30-60 cm or 60-90 cm depths in both locations. The distance from the sea did not show clear correlation with surface soil salinity in Budayyi area compared with Diraz. Both locations showed significantly higher salinity levels on samples taken outside the actively growing areas compared with those taken from within. The effect is more prominent at the 0-30 cm depth. The observed variability on salinity levels may be attributed to farm management practices and deteriorating quality of ground water. Thus, agricultural land degradation in Bahrain cannot be attributed to ground water deterioration alone. The use of tertiary treated sewage water (TSE) may ease the pressure on ground water, but the pH of the TSE should be carefully monitored and managed with proper studies on leaching requirements to avoid further salinity complications.  相似文献   
102.
Six potato cultivars from North America were grown in two greenhouses under 18-h photoperiods. All plants were started in a greenhouse that was well ventilated and maintained as close as possible to summer ambient temperatures. One month after planting, half the plants of each cultivar were moved to a greenhouse that was kept at 30 C during the night and was allowed to reach 40 C or higher during the day. Plants from each treatment were harvested at monthly intervals for growth analyses. Concurrently, five clones considered to be heat tolerant were subjected to a similar test in a second experiment. In response to high temperatures, plants in both experiments were taller with smaller leaves, lower tuber yields, higher ratios of stem to leaf dry matter, and lower ratios of tuber to leaf and to stem dry matter. Tubers were lower in percent dry matter, maturity was delayed, and cuttings developed fewer tubers. Cultivars differed greatly in the degree to which they were affected by the heat. In the first experiment, Norchip had outstanding heat tolerance. LT-2 was the most tolerant of the clones in the second experiment. For the cooler treatment the best performance in either experiment was from two clones originally selected in the lowland tropics.  相似文献   
103.
Mycosphaerella graminieola (anamorph: Zymoseptoria tritici) is the causal agent of Septoria tritici blotch, the most frequently occurring disease on wheat crops worldwide. A set of 163 monoconidial isolates of this fungus were sampled in 2012 from five geographical locations of Tunisia (Bizerte, B6ja, Kef, Jendouba and Siliana) in order to examine the status of strobilurin resistance of M. graminicola in this country. The resistance was assessed by using PCR-based mismatch mutation assay that determined the cytochrome b substitution G143A responsible for strobilurin resistance. All isolates were found sensitive since they possessed the wild-type allele G143 conferring sensitivity. This study confirms previous reports on the fungus in Tunisia and reveals that the Tunisian population of M. graminicola remains fully sensitive to strobilurin fungicides. An appropriate management of strobilurin applications in Tunisia is thereby recommended to prevent local development and widespread of resistance, as in Europe, where pathogen populations are fully resistant to strobilurins today.  相似文献   
104.
Summary Field trials were done to study the relation of dry matter accumulation, tuberization, and total carbohydrate content in different plant organs with the activities of amylase and invertase in different growth seasons (winter and summer). The activities of both enzymes showed higher levels in winter and were correlated with lower total carbohydrate contents in leaves. However, dry matter production in tubers was higher in winter. It is suggested that higher hydrolytic activity might therefore be needed in winter for the mobilization of the stored carbohydrates in the leaves for transport to the physiological sink. In the conditions of earlier tuberisation and more dry matter production, higher activities of amylase and invertase were found. Chlormequat treatments led to higher amylase activity in leaves correlated with earlier tuberisation and higher tuber yield, thouth invertase activity was not affected or rather slightly decreased.
Zusammenfassung Feldversuche wurden mit der Sorte Alpha unternommen, um den Zusammenhang zwischen Trockensubstanzbildung, Knollenbildung und gesamtem Kohlenhydratgehalt in verschiedenen Pflanzenorganen mit den Wirkungen von Amylase und Invertase in verschiedenen Anbauperioden in Aegypten (Winter, Anbau im Oktober; Sommer, Anbau im M?rz) zu untersuchen. Die Wirkungen beider Enzyme zeigten im Winter einen h?heren Grad, wie aus den in den Abb. 1, 2 und 3 dargestellten Kontrollwerten hervorgeht, und dieser war mit einem im allgemeinen etwas tieferen Kohlenhydratgehalt in den Bl?ttern korreliert (vgl. Abb. 4 und 5). Die Trockensubstanzproduktion in den Knollen war im Winter h?her (Abb. 6 und 7). Es wird angenommen, dass eine h?here hydiolytische T?tigkeit im Winter zur Mobilisierung der gelagerten Kohlenhydrate in den Bl?ttern für den Transport zum physiologischen sink ben?tigt wird-Unter den Bedingungen für frühere Knollenbildung und h?here Trockensubstanzproduktion wurde eine gr?ssere Aktivit?t von Amylase und Invertase gefunden. Behandlungen mit Chlormequat (500, 1000 oder 2000 g Aktivsubstanz pro Hektar) 7 Wochen nach dem Auspflanzen führte zu früherer Knollenbildung und, bei den zwei niedrigeren Dosierungen, zu h?heren Ertr?gen (Abb. 6 und 7). Diese dürften mit der gr?sseren Aktivit?t der Amylase in den Bl?ttern (Abb. 1 und 3) korreliert sein; das Fehlen den Ertragszunahme bei der st?rksten Dosierung is vielleicht auf zeitweilige Blattnekrosen zurück zuführen. Die Aktivit?t der Invertase war vergleichsweise wenig beeinflusst durch die Behandlung.

Résumé Des essais en champ ont été effectués sur la variété Alpha pour étudier la relation de l'accumulation de matière sèche, de la tubérisation et de la teneur en hydrates de carbone totale dans les différents organes de la plante, avec les activity tés de l'amylase et de l'invertase au cours des différentes saisons de croissance en Egypte (hiver, plantation en octobre; été, plantation en mars) Les deux enzymes atteignent des niveaux d'activité plus élevés en hiver, comme le révèle l'examen des valeurs illustrées dans les figures 1, 2 et 3, et le phénomène est en liaison avec une teneur en hydrates de carbone généralement quelque peu plus basse dans les feuilles (comparer les fig. 4 et 5). La production de matière sèche dans les tubercules est plus haute en hiver (fig. 6 et 7). L'hypothèse est émise que l'activité hydrolitique plus élevée peut par conséquence être due en hiver à la mobilisation des hydrates de carbone des feuilles pour leur transport vers le sink physiologique. Dans des conditions de tubérisation plus précoce et d'une production plus abondante de matière sèche, on trouve des activités plus élevées de l'amylase et de l'invertase. Des traitements au chlormequat (500, 1000 ou 2000 g de substance active par ha) 7 semaines après la plantation provoquent une tubérisation plus précoce et, avec deux doses les moins élevées, des productions plus élevées (fig. 6 et 7). Ces faits pourraient être en corrélation avec des activités plus élevées de l'amylase dans les feuilles (fig. 1 et 5), le manque d'accroissement de la production avec la dose la plus élevée étant peut-être d? à une nécrose temporaire de la feuille. L'activité de l'invertase est comparativement plus influencée par le traitement.
  相似文献   
105.
Purslane (Portulaca oleracea), grown under greenhouse conditions, was harvested at three growth stages and analyzed for total solids, total protein, ash, soluble carbohydrate, and fructose/fructane in whole plants, leaves, stems, and roots. Significant increases were observed in total solids and protein during plant maturation. Leaves had the highest amount of protein in the third growth stage (44.25g/100g dry matter). Roots showed a decline in protein level as the plant aged. Soluble carbohydrate was significantly higher in growth states 1 and 3. Significant variation among growth stages was found with regard to total phosphorous, calcium, potassium, iron, managanese, and copper. Total phosphorus (P) content in leaves was significantly higher than P found in stems and roots. Iron (Fe) content varied significantly among growth stages, and roots and leaves had the highest Fe content (121.47 and 33.21 mg, respectively). Significant accumulation of managanese (Mn) was found in different growth stages. Leaves and roots had significantly higher Mn content than stems.  相似文献   
106.
During baking, bread dough undergoes an expansion followed by a slight contraction at the end of baking. The contraction during baking has been evidenced by some authors. However, there is a limited amount of literature about the contraction of the crumb during the chilling phase and also during the freezing phase in the case of freezing. A study has been carried out to better understand the impact of the baking degree on the contraction of the crumb during chilling after baking and during freezing. The volume of the samples has been evaluated with a laser volumeter. Breads (70 g dough) were baked until reaching 75 °C, 85 °C, 95 °C, 98 °C and then 98 °C for 10 min. Results showed that a longer baking resulted in a lower contraction of the bread. The volume change was between 25% and 2.5% for baking at 75 °C—0 min dwell and 98 °C—10 min dwell, respectively. The contraction was compared to the contraction of degassed bread crumb samples, which was more important. SEM pictures showed that the degree of baking also corresponded to a very different structure of the crumb. For the longer baking, the starch granules were fully gelatinized and no ghosts of starch granules were visible. The magnitude of the contraction was thus associated with the degree of baking and with the degree of starch granule destructuration.  相似文献   
107.
108.
A marine furanoterpenoid derivative, 10-acetylirciformonin B (10AB), was found to inhibit the proliferation of leukemia, hepatoma, and colon cancer cell lines, with selective and significant potency against leukemia cells. It induced DNA damage and apoptosis in leukemia HL 60 cells. To fully understand the mechanism behind the 10AB apoptotic induction against HL 60 cells, we extended our previous findings and further explored the precise molecular targets of 10AB. We found that the use of 10AB increased apoptosis by 8.9%–87.6% and caused disruption of mitochondrial membrane potential (MMP) by 15.2%–95.2% in a dose-dependent manner, as demonstrated by annexin-V/PI and JC-1 staining assays, respectively. Moreover, our findings indicated that the pretreatment of HL 60 cells with N-acetyl-l-cysteine (NAC), a reactive oxygen species (ROS) scavenger, diminished MMP disruption and apoptosis induced by 10AB, suggesting that ROS overproduction plays a crucial rule in the cytotoxic activity of 10AB. The results of a cell-free system assay indicated that 10AB could act as a topoisomerase catalytic inhibitor through the inhibition of topoisomerase IIα. On the protein level, the expression of the anti-apoptotic proteins Bcl-xL and Bcl-2, caspase inhibitors XIAP and survivin, as well as hexokinase II were inhibited by the use of 10AB. On the other hand, the expression of the pro-apoptotic protein Bax was increased after 10AB treatment. Taken together, our results suggest that 10AB-induced apoptosis is mediated through the overproduction of ROS and the disruption of mitochondrial metabolism.  相似文献   
109.
Recently natural antioxidants have gained increased interest because natural food ingredients are safer than synthetic ones. Antioxidant activities and protective effects of sesame cake extract (SCE) in stabilizing sunflower oil (SFO) and soybean oil (SBO) were tested. Since different antioxidant compounds have different mechanisms of action, 2,2-azinobis (3-ethylbenzthiazoline sulfonate) (ABTS) radical scavenging activity, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging capacity, and β-carotene/linoleic acid test system were used to assess the antioxidant efficacy of SCE. Total phenolic, flavonoid and flavonol contents in SCE were 1.94 (mg gallic acid equivalent (GAE) g−1 dry weight (DW)), 0.88 (mg quercetain equivalent (QE) g−1 DW), and 0.40 (mg QE g−1 DW), respectively. Protective effects of SCE in stabilizing SFO and SBO were tested, compared to synthetic antioxidants, by measuring their peroxide values (PV), conjugated dienes (CD), conjugated trienes (CT) and p-anisidine value during accelerated storage. Results indicated that SCE exhibited stronger antioxidant activity in SFO and SBO than butylated hydroxytoluene (BHT) and butylated hydroxyanisole (BHA), while its antioxidant activity was less than that of tert-butyl hydroquinone (TBHQ).  相似文献   
110.
Polypyrrole (PPy) film was prepared via in-situ chemical polymerization of pyrrole monomer on the surface of red-clay-brick (RCB) substrate. The deposited PPy film was characterized and used as an adsorbent for removal of benzene polycarboxylic acids from aqueous solutions. The effects of solution pH, contact time, initial concentration, and temperature on the adsorption process were systematically investigated to find the optimum operating conditions. Adsorption kinetic data were best fitted by pseudo-second order kinetic model. The adsorption equilibrium data were most represented by the Freundlich isotherm model. The maximum adsorption amounts of Trimellitic, Hemimellitic, and Pyromellitic acids were 189.27, 177.26, and 203.31 mg/g, respectively. The thermodynamic studies indicate that the adsorption was an endothermic and spontaneous process. Also, the PPy-RCB film was successfully regenerated using sodium hydroxide solution. The regenerated PPy-RCB can be reused for more than four successive cycles with a low reduction in adsorption efficiency.  相似文献   
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