全文获取类型
| 收费全文 | 1416篇 |
| 免费 | 54篇 |
| 国内免费 | 2篇 |
专业分类
| 林业 | 124篇 |
| 农学 | 56篇 |
| 基础科学 | 4篇 |
| 236篇 | |
| 综合类 | 61篇 |
| 农作物 | 44篇 |
| 水产渔业 | 214篇 |
| 畜牧兽医 | 619篇 |
| 园艺 | 17篇 |
| 植物保护 | 97篇 |
出版年
| 2023年 | 3篇 |
| 2022年 | 14篇 |
| 2021年 | 53篇 |
| 2020年 | 20篇 |
| 2019年 | 19篇 |
| 2018年 | 30篇 |
| 2017年 | 35篇 |
| 2016年 | 41篇 |
| 2015年 | 71篇 |
| 2014年 | 68篇 |
| 2013年 | 136篇 |
| 2012年 | 102篇 |
| 2011年 | 115篇 |
| 2010年 | 35篇 |
| 2009年 | 64篇 |
| 2008年 | 98篇 |
| 2007年 | 96篇 |
| 2006年 | 89篇 |
| 2005年 | 89篇 |
| 2004年 | 85篇 |
| 2003年 | 76篇 |
| 2002年 | 48篇 |
| 2001年 | 27篇 |
| 2000年 | 18篇 |
| 1999年 | 9篇 |
| 1998年 | 3篇 |
| 1997年 | 3篇 |
| 1996年 | 1篇 |
| 1995年 | 2篇 |
| 1993年 | 2篇 |
| 1992年 | 1篇 |
| 1991年 | 1篇 |
| 1990年 | 1篇 |
| 1986年 | 1篇 |
| 1985年 | 2篇 |
| 1982年 | 1篇 |
| 1980年 | 2篇 |
| 1978年 | 3篇 |
| 1977年 | 3篇 |
| 1974年 | 2篇 |
| 1973年 | 1篇 |
| 1972年 | 1篇 |
| 1971年 | 1篇 |
排序方式： 共有1472条查询结果，搜索用时 15 毫秒
151.
Bannai H Tsujimura K Kondo T Nemoto M Yamanaka T Sugiura T Kato T Maeda K Matsumura T 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2012,74(6):791-795
The immunoglobulin G (IgG) subclass response was investigated in horses with or without pyrexia after natural infection with equine herpesvirus type 1 (EHV-1) in the field. All horses were kept at the training centers of the Japan Racing Association and were immunized with an inactivated EHV-1 vaccine before EHV-1 infection. An IgG subclass response dominated by IgGa and IgGb was induced in horses without pyrexia after EHV-1 infection. In contrast, horses that developed pyrexia showed increased IgGc and IgG (T) subclass production in addition to IgGa and IgGb. Although inactivated EHV-1 vaccines are considered to induce a mainly Th-2-biased response, these results indicated that the responses in horses inoculated with inactivated EHV-1 vaccine were not uniform, and that horses with a Th-1-biased response were likely to be protected from pyrexia. 相似文献
152.
K Nakamura M Yamasaki T Osaki H Ohta N Sasaki K Aoshima T Kimura M Takiguchi 《Journal of the American Animal Hospital Association》2012,48(5):327-330
Bilateral segmental aplasia of the uterine horns with unilateral pyometra and uterine horn torsion were diagnosed in a Pomeranian bitch that presented with chronic abdominal distension and an acute onset of anorexia and lethargy. Because radiographic and ultrasonographic findings revealed the presence of markedly enlarged bilateral uterine horns filled with fluid in the caudal abdomen, a tentative diagnosis of either pyometra or hydrometra with uterine horn torsion was made. Exploratory laparotomy showed bilateral, segmentally distended uterine horns with unilateral uterine horn torsion. Ovariohysterectomy was performed, and bilateral segmental aplasia of the uterine horns with the development of unilateral uterine horn torsion was diagnosed histopathologically. To the authors' knowledge, this is the first report of uterine horn torsion in conjunction with segmental aplasia of the uterine horn in a bitch. 相似文献
153.
Hirai A Nakama A Chiba T Kai A 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2012,74(2):175-180
Coxiella burnetii is the causative agent of Q fever, and the main route of infection in humans is inhalation of contaminated aerosols. Although oral transmission by contaminated raw milk or dairy products is also a possible route of human infection, there have been few studies investigating the presence of C. burnetii in dairy products. We developed a new method of extracting DNA from cheese and detecting C. burnetii DNA in cheese samples with a nested PCR assay. The limit of detection was 6.0 × 10(2) C. burnetii particles per gram. We subsequently used this method to examine the presence of C. burnetii in cheese at commercial markets in Tokyo from June 2005 to December 2008. Twenty-eight of 147 cheese samples were found to be positive for C. burnetii DNA. However, when we assessed the viability of C. burnetii by inoculating mice with DNA-positive samples, all of the samples were found to be negative. Thus, the viability of C. burnetii appears to have been lost in these cheese samples. 相似文献
154.
Hashino M Kim S Tachibana M Shimizu T Watarai M 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2012,74(8):1075-1077
The mechanisms of abortion and sterility induced by bacterial infection are largely unknown. In the present study, we found that Brucella abortus, a causative agent of brucellosis and facultative intracellular pathogen, caused sterility in pregnant mice. We have recently established a mouse model for abortion induced by B. abortus infection and high rates of abortion are observed for bacterial infection on day 4.5 of gestation, but not for other days. Infected newborn (first generation) mice showed poor growth compared with uninfected newborn mice and bacterial replication in the spleen of the former was observed over a long period. When infected first generation female mice were mated to infected first generation male mice, the number of fetuses was significantly less than that in uninfected first generation mice. These infected second generation mice also showed poor growth. These results suggest that vertical transmission of B. abostus causes sterility in pregnant mice and our mouse model would be useful for the investigating of brucellosis. 相似文献
155.
Yamanaka T Bannai H Nemoto M Tsujimura K Kondo T Muranaka M Hobo S Minamijima YH Yamada M Matsumura T 《Veterinary journal (London, England : 1997)》2012,193(2):358-362
Equine influenza A virus (EIV) of the H3N8 subtype is an important pathogen causing acute respiratory disease in horses. Peramivir is a selective inhibitor of the influenza virus neuraminidase (NA). The characteristics of peramivir are not only its capacity for parenteral administration, but also its strong affinity for NA and slow off-rate from the NA-peramivir complex, suggesting that it could lead to a prolonged inhibitory effect and thus allow a lower dosing frequency. The aims of this study were to evaluate the inhibitory efficacy of peramivir against the NA activities of EIV in vitro and the treatment efficacy of a single intravenous dose of peramivir in horses experimentally infected with EIV. Peramivir inhibited the activities of NA from the seven contemporary EIV strains in vitro, with 50% inhibitory concentrations ranging from 0.10 to 0.20nmol/L. Horses treated with a single IV dose of peramivir (3000mg/600mL/animal, 7.8-9.3mg/kg of bodyweight) showed significantly milder clinical signs (pyrexia, nasal discharge and cough) with a shorter duration than control horses injected with normal saline. Moreover, the mean duration of virus shedding for the horses treated with peramivir was significantly shorter than for the control horses. These findings suggested that a single IV administration of peramivir had good potential for the treatment of equine influenza, and may help to limit the spread of the disease in the horse population. 相似文献
156.
Shinji Hiyama Toshie Sugiyama Seiji Kusuhara Takashi Uchida 《Journal of veterinary science (Suw?n-si, Korea)》2012,13(3):223-227
The temporal expression of estrogen receptor (ER)-α and ER-β mRNA was examined in male Japanese quails. Femurs of quails receiving 17β-estradiol underwent RTPCR and histochemical analysis 1 to 15 days after treatment. Untreated quails were used as controls (day 0). Between days 0 and 5, cells lining the bone endosteal surface differentiated into osteoblasts, which in turn formed medullary bone. Expression of ER-α was already observed on day 0 and increased slightly during bone formation whereas ER-β was hardly detected throughout this process. After osteoclasts appeared on the medullary bone surface, this type of bone disappeared from the bone marrow cavity (days 7~15). ER-α expression simultaneously decreased slightly and ER-β levels remained very low. These results suggest that estrogen activity mediated by ER-α not only affects medullary bone formation but also bone resorption. 相似文献
157.
Khin Thawda Win Ryoko Nonaka Koki Toyota Takashi Motobayashi Masaaki Hosomi 《Biology and Fertility of Soils》2010,46(6):589-595
A lysimeter experiment was carried out to evaluate the effects of the NH3 volatilization mitigation by adding anaerobically digested cattle slurry (ADCS) alone, with wood vinegar (WV) or with a higher
level of floodwater (HFW), on emissions of CH4 and N2O from a paddy soil planted with fodder rice. We have carried out the following treatments: (1) chemical fertilizer, (2) ADCS,
(3) ADCS + WV, and (4) ADCS + HFW; the height of floodwater was 10 cm in the latter treatment, and it was 3 to 4 cm in the
other treatments just before fertilizer applications. Nitrogen fertilizer rate added to soil in each treatment was 30 g NH4+–N m−2 (split in one basal and two top-dressing additions). Ammonia volatilization in the ADCS treatment was 2.7 g NH3–N m−2 throughout the growing season, and it was significantly reduced by 79% and 55% in the ADCS + WV and ADCS + HFW treatments,
respectively. The total amount of CH4 emitted in the ADCS treatment in the growing season was not significantly enhanced by the mitigation of NH3 volatilization either by adding wood vinegar or by increasing the height of the floodwater. Negligible N2O emissions were observed in all treatments during the growing period. 相似文献
158.
Bivalves serve as an important aquaculture product, as they are the source of essential fatty acids, such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), in our diet. However, their cultivation in the wild can be affected by fouling organisms that, in turn, affect their EPA and DHA content. The effects of fouling organisms on the EPA and DHA contents of cultivated bivalves have not been well documented. We examined the effects of fouling organisms on the EPA and DHA contents and condition index of cultured oysters, Crassostrea gigas, in an aquaculture system. We sampled two-year-old oysters from five sites in Shizugawa Bay, Japan, in August 2014. Most of the fouling organisms were sponges, macroalgae, and Mytilus galloprovincialis. A significant negative relationship existed between the DHA content in C. gigas and the presence of sponges and macroalgae. A lower C. gigas EPA content corresponded to a higher M. galloprovincialis fouling mass and a lower C. gigas condition index. This can be explained by dietary competition between C. gigas and M. galloprovincialis for diatoms, which were the main producer of EPA in our study sites. Our findings indicate that fouling organisms likely reduce the EPA and DHA content in cultivated oysters. Therefore, our results suggest that the current efforts to remove fouling organisms from oyster clusters is an effective strategy to enhance the content of EPA and DHA in oysters. 相似文献
159.
Hiroshi Fukayama Takashi Kobara Keita Shiomi Ryutaro Morita Daisuke Sasayama Tomoko Hatanaka 《Plant Production Science》2013,16(2):296-300
ABSTRACT
Overexpression of Rubisco small subunit (RbcS) of C4 plant, sorghum (sorghum bicolor) was shown to enhance the catalytic turnover rate (k cat) of Rubisco in rice (Oryza sativa). In this study, the effects of other Rubisco small subunits of C4 plants, Napier grass (Pennisetum purpureum) and guinea grass (Megathyrsus maximus) on kinetic properties of Rubisco in rice were studied. The expression levels of Napier grass RbcS (NgRbcS) and guinea grass RbcS (GgRbcS) proteins accounted for 41% and 45% of total RbcS, respectively in homozygous overexpression lines. The k cat and K m for CO2 (Kc) of Rubisco were increased in all transgenic lines. Interestingly, the k cat was markedly higher in NgRbcS homozygous line, whereas K c was notably higher in GgRbcS homozygous line. Although its effects depend on species, these results suggest that the introduction of C4 RbcS are effective approaches to alter the catalytic properties of Rubisco in rice. 相似文献
160.
Takashi Otoda Keiji Sakamoto Muneto Hirobe Jamsran Undarmaa Ken Yoshikawa 《Journal of Forest Research》2013,18(1):82-92
We investigated the effects of disturbances on the dynamics of white birch-dominated forests at the southern boundary of the Mongolian forest-steppe. Dendroecological techniques were used to assess regeneration patterns and recent mortality trends in three stands with no evidence of recent anthropogenic disturbance (undisturbed) and four stands with evidence of cutting or fire (disturbed). In the undisturbed stands, only one distinct stem establishment was observed in the period between 1910 and 1950, and no establishment has been observed since then. In the disturbed stands, however, high establishment mainly by sprouting was observed in the period between 1960 and 1980. Percentages of standing dead stems were higher in the undisturbed stands than in the disturbed stands. Mean ages at death in the undisturbed stands were ≥70 years old. The high mortality was likely induced by the death of smaller stems due to light competition, whereas the mortality of larger stems was likely the result of tree senescence. In summary, the undisturbed stands seem to be in danger of decline due to a lack of regeneration during the last half of the previous century and recent high mortality rates of older stems, while the disturbed stands may be maintained for the next several decades by the younger cohort established between 1960 and 1980. White birch-dominated forests at the southern boundary of Mongolian forest-steppe have probably relied on relatively short disturbance intervals in the past because of the disturbance-dependent regeneration trait and relatively short longevity of Betula species. 相似文献