全文获取类型
收费全文 | 569篇 |
免费 | 14篇 |
国内免费 | 2篇 |
专业分类
林业 | 50篇 |
农学 | 16篇 |
42篇 | |
综合类 | 39篇 |
农作物 | 21篇 |
水产渔业 | 59篇 |
畜牧兽医 | 321篇 |
园艺 | 4篇 |
植物保护 | 33篇 |
出版年
2022年 | 7篇 |
2021年 | 7篇 |
2020年 | 6篇 |
2019年 | 8篇 |
2018年 | 6篇 |
2017年 | 10篇 |
2016年 | 9篇 |
2015年 | 12篇 |
2014年 | 11篇 |
2013年 | 21篇 |
2012年 | 28篇 |
2011年 | 27篇 |
2010年 | 22篇 |
2009年 | 17篇 |
2008年 | 36篇 |
2007年 | 45篇 |
2006年 | 31篇 |
2005年 | 29篇 |
2004年 | 19篇 |
2003年 | 22篇 |
2002年 | 19篇 |
2001年 | 11篇 |
2000年 | 16篇 |
1999年 | 5篇 |
1998年 | 12篇 |
1997年 | 3篇 |
1994年 | 2篇 |
1992年 | 12篇 |
1991年 | 9篇 |
1990年 | 10篇 |
1989年 | 14篇 |
1988年 | 7篇 |
1987年 | 13篇 |
1986年 | 9篇 |
1985年 | 7篇 |
1984年 | 6篇 |
1983年 | 2篇 |
1982年 | 3篇 |
1981年 | 4篇 |
1980年 | 4篇 |
1979年 | 8篇 |
1978年 | 5篇 |
1977年 | 3篇 |
1976年 | 3篇 |
1975年 | 2篇 |
1973年 | 4篇 |
1972年 | 2篇 |
1971年 | 3篇 |
1970年 | 2篇 |
1967年 | 2篇 |
排序方式: 共有585条查询结果,搜索用时 15 毫秒
91.
Sakiko Orui Sakaguchi Shigeru Shimamura Yuichi Shimizu Gen Ogawa Yuichiro Yamada Keiko Shimizu Hiroaki Kasai Hiroshi Kitazato Yoshihiro Fujiwara Katsunori Fujikura Kiyotaka Takishita 《Fisheries Science》2017,83(1):47-56
To identify the stomach contents of marine organisms, morphological observations are commonly conducted. However, the results obtained by this traditional method are frequently biased, as it is difficult to detect partially digested, soft-bodied organisms. To resolve this, recent studies have used DNA-based (DNA barcoding) analyses to examine the diet breadth of marine organisms. Here, we compared the prey richness of juvenile fishes using morphological observations and DNA-based analyses, with a focus on juvenile chum salmon Oncorhynchus keta. A higher number of prey taxa were successfully identified using DNA-based analyses than morphological observations. However, we also noticed several shortcomings of the DNA-based analyses, as reported in other diet-analysis studies that used molecular techniques. For example, the degree of digestion among prey taxa might have resulted in differential sensitivity to DNA detection. Additionally, several prey taxa could not be precisely identified, as the sequence data for some of the targeted organismal groups are unavailable in public gene databases. Remarkably, it is also possible that DNA-based analyses detected secondary prey, and therefore, the richness of prey taxa was likely overestimated. Thus, dietary analyses of juvenile fishes need to be carefully conducted, considering the respective advantages and disadvantages of DNA-based and morphological techniques. 相似文献
92.
Masato Kobayashi Tomohito Shimizu Koichi Okuzawa Kiyoshi Soyano Kenzo Yoseda 《Fisheries Science》2010,76(5):777-784
To determine the sexual maturity of fourteen male wild-caught hawksbill turtles [straight carapace length (SCL) range 63–79 cm]
held in captivity, we investigated their hormone levels in blood and morphological characteristics. Male turtles were divided
into two groups: five individuals showing mating behavior (group A) and nine individuals not showing mating behavior (group B).
Then, seasonal changes of plasma testosterone of both groups were studied. We also tried to determine male maturity based
on tail elongation (TE) index, i.e., the ratio of tail length (TL) to SCL. Plasma testosterone level of group A gradually
increased during premating and then sharply declined to low levels between mating and postmating seasons. In contrast, that
of group B remained low during the experimental periods. The distinct seasonal changes of plasma testosterone levels of groups A
and B correlated with their maturity. Furthermore, males were clearly divided into mature and immature based on TE values
>0.35 and <0.33, respectively, corresponding to results based on plasma testosterone levels. Our results indicate that TE
can be used more conveniently and accurately to determine maturity of male hawksbill turtles in captivity. 相似文献
93.
Yuki Midorikawa Tomohito Shimizu Tetsuya Sanda Katsuyuki Hamasaki Shigeki Dan Mohammad Tamrin Bin Mohamad Lal Goshi Kato Motohiko Sano 《Journal of fish diseases》2020,43(5):541-549
Mass mortality due to necrosis signs occurred in hatchery-reared zoea stage larvae of the mud crab Scylla serrata in Okinawa, Japan, and a causative bacterium was isolated. In this study, we identified and characterized the bacterium by genome analysis, biochemical properties and pathogenicity. The bacterium was a Gram-negative, non-motile, long rod, forming yellow colonies on a marine agar plate. It grew at 20–33°C (not at 37°C) and degraded chitin and gelatin. Phylogenetic analysis of the 16S rRNA gene sequence identified the bacterium as Aquimarina hainanensis. Genome sequence data obtained from Illumina MiSeq generated 29 contigs with 3.56 Mbp in total length and a G + C content of 32.5%. The predicted 16 chitinase genes, as putative virulence factors, had certain homologies with those of genus Aquimarina. Experimental infection with the bacterium conducted on larvae of four crustacean species, brine shrimp Artemia franciscana, freshwater shrimp Caridina multidentata, swimming crab Portunus trituberculatus and mud crab S. serrata, revealed that this bacterium was highly virulent to these species. The present study suggests that the bacterium caused mass mortality in mud crab seed production was A. hainanensis and can be widely pathogenic to crustaceans. 相似文献
94.
95.
K. Yamanokuchi M. Tagami E. Nishimatsu Y. Shimizu Y. Hirose K. Komatsu K. Misumi 《Equine veterinary journal》2009,41(1):41-46
Reasons for performing study: Measurement of cartilage oligomeric matrix protein (COMP) in serum has potential for diagnosis of equine osteoarthritis (OA), but clinical use is currently limited by the lack of specificity of an inhibition ELISA as well as by baseline increases due to exercise. Improved methods for ELISA with increased antigen specificity and sensitivity are therefore required for reliable measurement. Hypothesis: Measurement of the serum level of COMP by sandwich ELISA allows identification of horses with OA. Methods: New monoclonal antibodies (mAbs) were elicited against equine cartilage COMP, their epitopes were determined and a sandwich ELISA was developed. The concentrations of COMP in synovial fluid (SF; n = 100) and sera (n = 100) from OA cases were measured by sandwich ELISA as well as by inhibition ELISA and compared with concentrations in normal joints (n = 95) and horses (n = 50). Results: Immunoblots of enzymatically cleaved COMP showed that the new mAbs recognised different epitopes located on a 20 kDa fragment between K63 and K238 of the EGF‐like repeats. Inhibition ELISA with any mAb detected significantly increased levels of COMP in OA SF compared with normal SF, whereas no significant difference was detected between serum levels of COMP in OA and normal horses. Conversely, sandwich ELISA with the combination of unlabelled 2A11 × biotinylated 11F10 mAbs detected a significant increase in COMP levels in both serum and SF from OA cases compared with levels in normal animals. Conclusions and potential relevance: Measurement of serum COMP with sandwich ELISA may be useful in identifying horses with OA. 相似文献
96.
R Tanaka M Shimizu K Hoshi A Soda Y Saida K Takashima Y Yamane 《Australian veterinary journal》2009,87(3):88-93
Objective To assess the efficacy of an open patch-graft technique under cardiopulmonary bypass (CPB) in small dogs.
Design and methods A retrospective analysis of 10 dogs with pulmonic stenosis. Records between 1992 and 2002 were reviewed. The effect of surgical correction was evaluated and perioperative parameters were compared between survivors and non-survivors.
Results The postoperative pulmonary pressure gradient was reduced in all seven surviving patients. Mean ± SE was 21.5 ± 7.4 mmHg (range 3.0–54.2 mmHg) and 6/7 dogs were < 40 mmHg at 3 months postoperatively. Comparing the data between those patients that survived and those that did not, the preoperative pressure gradient (P = 0.04) and volume of the Glucose-Insulin-Kalium solution used (P = 0.001) were significantly higher in those that did not survive.
Conclusion Open patch-grafting can be performed in small-breed dogs and decreased the pulmonary pressure gradient in survivors at 3 months postoperatively. However, this technique is more invasive than balloon valvuloplasty and should be used cautiously in severely stenosed patients. 相似文献
Design and methods A retrospective analysis of 10 dogs with pulmonic stenosis. Records between 1992 and 2002 were reviewed. The effect of surgical correction was evaluated and perioperative parameters were compared between survivors and non-survivors.
Results The postoperative pulmonary pressure gradient was reduced in all seven surviving patients. Mean ± SE was 21.5 ± 7.4 mmHg (range 3.0–54.2 mmHg) and 6/7 dogs were < 40 mmHg at 3 months postoperatively. Comparing the data between those patients that survived and those that did not, the preoperative pressure gradient (P = 0.04) and volume of the Glucose-Insulin-Kalium solution used (P = 0.001) were significantly higher in those that did not survive.
Conclusion Open patch-grafting can be performed in small-breed dogs and decreased the pulmonary pressure gradient in survivors at 3 months postoperatively. However, this technique is more invasive than balloon valvuloplasty and should be used cautiously in severely stenosed patients. 相似文献
97.
Hideo Ishii Junko Tanoue Michiyo Oshima Wen-Hsin Chung Kumiko Nishimura Junichiro Yamaguchi Fumihiro Nemoto Kazuhiro So Toshitaka Iwama Hideaki Yoshimatsu Motoshige Shimizu Toru Kozawa 《Journal of General Plant Pathology》2008,74(6):409-416
Fungicide resistance in plant pathogens is often caused by a single point mutation in a gene encoding fungicide target proteins.
Such is the case for resistance to MBI-D (inhibitors of scytalone dehydratase in melanin biosynthesis) fungicides in rice
blast fungus (Magnaporthe oryzae), which is caused by a mutation in the scytalone dehydratase gene that results in a replacement of valine with methionine
at codon 75 of the fungicide target protein. PCR-Luminex, a novel system developed for high-throughput analysis of single
nucleotide polymorphisms (SNPs) was successfully introduced to diagnose MBI-D resistance using specific oligonucleotide probes
coupled with fluorescent beads. The PCR-Luminex system was further tested for its potential in identifying species causing
Fusarium head blight on wheat. Four major pathogens, Fusarium graminearum (=F. asiaticum), F. culmorum, F. avenaceum, and Microdochium nivale, known to cause the disease, were tested, and the species were identified using the PCR-Luminex method. So far, this report
is the first on the application of the DNA-based PCR-Luminex system in the area of crop protection and/or agricultural sciences. 相似文献
98.
Kohei Osaki Shozo Fujiyama Akiko Nakayama Yoshiaki Shimizu Shin-ichi Ito Shuhei Tanaka 《Journal of General Plant Pathology》2008,74(4):281-288
The relation between diversity of pathogenicity on clubroot-resistant (CR) cultivars of Chinese cabbage (Brassica rapa subsp. pekinensis) bred in Japan and DNA polymorphisms in 17 populations of Plasmodiophora brassicae from cruciferous plants was examined by inoculation tests and random amplified polymorphic DNA (RAPD) analysis using 18 arbitrary
primers. Four pathotypes (A–D) were identified after inoculation of six CR cultivars of Chinese cabbage in the 17 populations
from cruciferous crops. A relatively high level of genetic diversity was also detected among these populations in the RAPD
analysis. Although the four pathotypes could not be clearly differentiated using the RAPD data, most populations of three
pathotypes had a consistent location on the dendrogram. All pathotype B (virulent on five cultivars except Utage 70) and D
(avirulent on all cultivars) populations, which were common in incompatible interactions with cv. Utage 70, were located in
a single subcluster. All five pathotype C populations (virulent only on cv. Utage 70) except for one population grouped in
another single subcluster. Because four pathotype A populations (virulent on all six cultivars, races 4 and 9) fell in different
subclusters, the populations may be genetically polyphyletic. Populations from cruciferous weed Cardamine flexuosa differed remarkably from those from cruciferous crops in pathogenicity on common cultivars of Chinese cabbage and turnip
and C. flexuosa, but they grouped in a single cluster with all race 9 populations from crops. Race 9 populations from crops may thus be closely
related to populations from the weed rather than to races 1 and 4 from crops. 相似文献
99.
Doppo Matsubara Yoshiaki Wakashima Yasushi Fujisawa Hidemaru Shimizu Akihisa Kitamori Koichiro Ishikawa 《Journal of Wood Science》2018,64(2):112-118
To investigate the effects of tightening speed on the torque coefficient in lag screw timber joints with steel side plates, tightening tests were conducted on main timber members made from Cryptomeria japonica, Chamaecyparis obtusa and Pseudotsuga menziesii, under four tightening speed conditions (1, 4, 10, and 20 rpm). Major stick-slip behavior was observed in C. obtusa based on the relationship of tightening angle with clamp force, tightening torque, and thread torque at tightening speeds of 1 and 4 rpm. In addition, tightening speed’s effects on the torque coefficient (K) varied depending on the wood species of the main member. In P. menziesii, K was not affected by the tightening speed: the ratio of torque expended on tightening was 25% on average, and the ratio of torque expended on bearing surface friction was higher than the ratio of torque expended on thread friction. 相似文献
100.
Direct observation and quantification of CO₂ binding within an amine-functionalized nanoporous solid
Vaidhyanathan R Iremonger SS Shimizu GK Boyd PG Alavi S Woo TK 《Science (New York, N.Y.)》2010,330(6004):650-653
Understanding the molecular details of CO(2)-sorbent interactions is critical for the design of better carbon-capture systems. Here we report crystallographic resolution of CO(2) molecules and their binding domains in a metal-organic framework functionalized with amine groups. Accompanying computational studies that modeled the gas sorption isotherms, high heat of adsorption, and CO(2) lattice positions showed high agreement on all three fronts. The modeling apportioned specific binding interactions for each CO(2) molecule, including substantial cooperative binding effects among the guest molecules. The validation of the capacity of such simulations to accurately model molecular-scale binding bodes well for the theory-aided development of amine-based CO(2) sorbents. The analysis shows that the combination of appropriate pore size, strongly interacting amine functional groups, and the cooperative binding of CO(2) guest molecules is responsible for the low-pressure binding and large uptake of CO(2) in this sorbent material. 相似文献