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101.
用免疫分离法检测稻种上的白叶枯病菌 总被引:2,自引:0,他引:2
免疫分离法是一种新型的、高度灵敏和准确的种菌带菌检验法,它结合了利用专化性抗血清的选择法吸附作用和活细菌可形成菌落的两方面的优点,从种苗材料中分离到目标细菌,用纯菌测试它的回收率为50~70%,最低检出率为50~100个菌/ml,人工喷接种和病田收获的病种带菌率达87%,平均每粒自然病种上的细菌数在100个左右。免疫分离所得菌落经致病性测定,大多数为白叶枯菌。 相似文献
102.
樟子松松针锈病病原菌——鞘锈菌(Coleosporium)的分类历来很乱。传统的分类方法都是依冬孢子形态和冬孢子寄主来进行的。但近年的研究表明1种鞘锈菌的春孢子可以侵染2种或2种以上的冬孢子寄主,所以按冬孢子寄主来划分鞘锈菌的种是不合理的。文中在病害症状观察和春孢子表面形态观察的基础上,首次对樟子松3种不同形态的春孢子的酯酶同工酶进行了分析,从而为鞘锈菌的分子分类学研究奠定了基础。 相似文献
103.
苯丙氨酸解氨酶活性与玉米对纹枯病抗性的关系 总被引:15,自引:0,他引:15
苯丙氨酸解氨酶活性变化在玉米抗、感品种和不同生育期与叶鞘位之间存在差异。在玉米(川单10号)的不同生育期和叶鞘位中,随生育期的发展和叶鞘位的下降,苯丙氨酸解氨酶活性降低。在受纹枯病菌侵染后,抗病品种(R15)的苯丙氨酸解氨酶活性增加的速度和程度明显高于感病品种(K09)。这一结果表明,玉米对纹枯病的阶段抗性变化以及品种抗性与苯丙氨酸解氨酶活性变化相关。 相似文献
104.
Spray mixtures consisting of the plant activator BABA (DL-3-aminobutyric acid) and the protectant fungicide mancozeb were
significantly more effective than BABA or mancozeb alone in controlling late blight (Phytophthora infestans) in potato and tomato and downy mildew (Pseudoperonospora cubensis) in cucumber. A mixture composed of 5 parts BABA and 1 part mancozeb (w/w, a.i.) exhibited a higher synergy factor than the
1+1 or the 1+5 (BABA + mancozeb) mixtures. No synergistic interaction was detected between BABA plus mancozeb in controlling
sporangial or cystospore germination, nor mycelial growth ofP. infestans in vitro. The results showed enhanced effect of mancozeb in BABA-induced plants, suggesting, therefore, that lower dosages of this
fungicide may be sufficient to control late blight or downy mildew under field conditions.
http://www.phytoparasitica.org posting July 15, 2003. 相似文献
105.
Resistance to early blight of tomato with respect to various parameters of disease epidemics 总被引:3,自引:1,他引:2
Koshlendra Kumar?PandeyEmail author Padma Kant?Pandey Gautam?Kalloo Malay Kumar?Banerjee 《Journal of General Plant Pathology》2003,69(6):364-371
Resistance to early blight in the tomato was assessed by examining various parameters of the progress of the disease. Artificial inoculation and the scoring technique were standardized. Test plants were inoculated with 125cfu/ml of a 12-day-old culture of a pathogenic isolate of Alternaria solani. Screening under artificial conditions was more informative than that under natural epidemic conditions. Tomato cultivars CLN-2071-C, CLN-2070-A, BSS-174, and DTH-7 with resistance expressed as slow blighting against four pathogenic isolates of A. solani, were selected for cultivation in disease-prone areas. Disease intensity increased with the age of plants under the same inoculum load. The area under the disease progress curve (AUDPC) was positively correlated with the percentage disease index and negatively with resistance. Calculation of the apparent infection rate (r) was more informative for natural epidemics than for artificial conditions. The sequential apparent infection rate between observation periods was better correlated with disease progress than was the total apparent infection rate between the first and last observations. A double sigmoidal disease progress curve during the same cropping season was characteristic of some varieties when fungal infection took place during the vegetative phase of crop growth. 相似文献
106.
Marco I Cuenca R Pastor J Velarde R Lavin S 《Veterinary clinical pathology / American Society for Veterinary Clinical Pathology》2003,32(4):195-198
Background: Hematology and serum biochemistry values can be useful for evaluating the health of populations of captive and free-living European brown hares ( Lepus europaeus ). However, current information is fragmented and incomplete.
Objective: The objective of this study was to determine normal hematology and serum chemistry values for a population of captive European brown hares and to investigate differences related to sex and age.
Methods: Routine hematology and serum chemistry values were determined for 48 captive European brown hares in Catalonia (northeastern Spain): 21 young (6 males and 15 females) and 27 adult (14 males and 13 females) hares. Blood was obtained by auricular venipuncture while animals were physically restrained. Results were expressed as the mean ± SD, and reference intervals were calculated as the mean ± 2SD.
Results: RBC count, PCV, concentrations of hemoglobin, total protein, albumin, gamma globulin, urea nitrogen, and creatinine, and alanine aminotransferase activity were significantly higher in adults than in young hares, and alkaline phosphatase activity and total bilirubin concentration were lower. Sex differences were not observed.
Conclusions: Hematology and serum chemistry results obtained in this study are considered representative for healthy captive European brown hares. A single reference interval can be used for values from male and female hares, however, age-specific intervals are needed for some analytes. 相似文献
Objective: The objective of this study was to determine normal hematology and serum chemistry values for a population of captive European brown hares and to investigate differences related to sex and age.
Methods: Routine hematology and serum chemistry values were determined for 48 captive European brown hares in Catalonia (northeastern Spain): 21 young (6 males and 15 females) and 27 adult (14 males and 13 females) hares. Blood was obtained by auricular venipuncture while animals were physically restrained. Results were expressed as the mean ± SD, and reference intervals were calculated as the mean ± 2SD.
Results: RBC count, PCV, concentrations of hemoglobin, total protein, albumin, gamma globulin, urea nitrogen, and creatinine, and alanine aminotransferase activity were significantly higher in adults than in young hares, and alkaline phosphatase activity and total bilirubin concentration were lower. Sex differences were not observed.
Conclusions: Hematology and serum chemistry results obtained in this study are considered representative for healthy captive European brown hares. A single reference interval can be used for values from male and female hares, however, age-specific intervals are needed for some analytes. 相似文献
107.
J.?LichtenzveigEmail author P.?Winter S.?Abbo D.?Shtienberg W.?J.?Kaiser G.?Kahl 《Phytoparasitica》2002,30(5):467-472
A genetic map was developed for the ascomyceteDidymella rabiei (Kovachevski) v. Arx (anamorph:Ascochyta rabiei Pass. Labr.), the causal agent of Ascochyta blight in chickpea (Cicer arietinum L.). The map was generated with 77 F1 progeny derived from crossing an isolate from the U.S.A. and an isolate from Syria. A total of 232 DAF (DNA Amplification
Fingerprinting) primers and 37 STMS (Sequence-Tagged Microsatellite Site) primer pairs were tested for polymorphism between
the parental isolates; 50 markers were mapped, 36 DAFs and 14 STMSs. These markers cover 261.4cM in ten linkage groups. Nineteen
markers remained unlinked. Significant deviation from the expected 1:1 segregation ratios was observed for only two markers
(Prob. of χ2<0.05). The implications of our results on ploidy level of the asexual spores are discussed.
http://www.phytoparasitica.org posting Sept. 5, 2002. 相似文献
108.
109.
Reclassification of an isolate of Guignardia citricarpa from New Zealand as Guignardia mangiferae by sequence analysis 总被引:3,自引:0,他引:3
Citrus black spot was recorded as present in New Zealand in international databases on the basis of one isolate (ICMP 8336) identified by morphological features as Guignardia citricarpa . This isolate was from a soft rot, not a typical symptom of citrus black spot, on a Seminole tangerine fruit grown in the northern region of New Zealand. Sequence analysis of the internal transcribed spacer (ITS) region (ITS1, 5·8S and ITS2) showed that this isolate was 99% identical to the ITS region of G. mangiferae , a closely related saprotroph. Despite climatic conditions being suitable for this disease, citrus black spot symptoms have never been seen on citrus fruits grown in New Zealand. Thus the absence of symptoms on citrus in New Zealand is probably because G. citricarpa is not present. On the basis of these results, the record of citrus black spot occurring in New Zealand should be re-examined. 相似文献
110.
Cavity spot is a major disease of carrots, causing cavities on the surface of the root. Available commercial varieties show a range of susceptibility but no significant resistance. Seed progeny from 46 tissue culture-derived carrot ( Daucus carota ) somaclones were screened for viability, then 19 selected somaclone families were sown under glasshouse conditions, along with commercial cultivars (Bertan, Nandor, Bolero and Vita Longa) as controls. Mature roots were exposed to Pythium violae in a cavity spot bioassay to determine their response as measured by disease incidence and severity. Some somaclones formed fewer lesions than the least susceptible control cultivar, Vita Longa. Seven somaclonal families that showed a range of susceptibility were sown under field conditions and the assessment was repeated. Although there was little relationship between glasshouse and field-trial results, under field conditions one of the somaclones had a mean incidence of disease, as estimated by transformed data, of 1·9 compared with 37·9 for the most susceptible somaclone and 3·5 for Bolero, the most resistant commercial cultivar. The results indicated that significant genetic variation in susceptibility to cavity spot disease was present in the somaclones. 相似文献