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91.
Hideki Endo Masataka Yoshida Truong Son Nguyen Yuki Akiba Masahiro Takeda Kohei Kudo 《Anatomia, histologia, embryologia》2019,48(1):3-11
Semiaquatic walking has resulted in the evolution of functional and morphological changes in various hoofed mammals, such as hippopotamus and Brazilian tapir. The biomechanics of skilful walking in wetlands or at the bottom of a waterbody involve the medio‐lateral opening and closing of the feet to effectively support and stabilize the body on soft ground and to reduce the water resistance during recovery stroke, respectively. We demonstrate that the opening and closing of the feet in hippopotamus and Brazilian tapir are mediated by the adduction and abduction of the most medial and lateral phalanges from the CT examination. The axial toes, metacarpals and metatarsals do not contribute to changes in the width and shape of the feet, unlike the medial and lateral toes. We suggest that this semiaquatic walking motion is derived from the original terrestrial mode of locomotion, in contrast to the highly functional swimming motion using webs or fins in morphologically modified feet and tail. From the present data we demonstrate that semiaquatic locomotion evolved due to the acquisition of adductor–abductor mobility in the phalanges of the most medial and lateral digits, as shown in hippopotamus and Brazilian tapir. 相似文献
92.
Thanh Quang Dang‐Nguyen Hiep Thi Nguyen Tamas Somfai David Wells Nguyen Thi Men Nguyen Viet‐Linh Junko Noguchi Hiroyuki Kaneko Kazuhiro Kikuchi Takashi Nagai 《Animal Science Journal》2018,89(6):880-887
We investigated whether high‐quality in vitro matured (IVM) oocytes can be distinguished from poor ones based on the morphological changes after treatment with hyperosmotic medium containing 0.2 mol/L sucrose in pigs. We hypothesize that IVM oocytes maintaining round shape have higher quality than mis‐shapened oocytes following dehydration. Oocyte quality was verified by determining embryonic developmental competence using in vitro fertilization, nuclear transfer and parthenogenetic activation. In all cases, the round oocytes had greater (p < .05) developmental competence than that of mis‐shapened oocytes in terms of blastocyst rate and total cell number in blastocysts obtained after 6 days of in vitro culture. We also confirm that round aged oocytes are higher in quality than mis‐shapened aged oocytes. In an attempt to find out why high‐quality oocytes maintain a round shape whereas poorer oocytes become mis‐shapened following sucrose treatment, we examined the arrangement of actin microfilaments and microtubules. Abnormal organization of these cytoskeletal components was higher (p < .05) in mis‐shapened oocytes compared to round oocytes after 52 hr of IVM. In conclusion, sucrose treatment helps selection of high‐quality oocytes, including aged oocytes, in pigs. Abnormal cytoskeleton arrangements partly explain for low developmental competence of mis‐shapened oocytes. 相似文献
93.
94.
Molecular expression of caprine estrogen receptor gene 1 in reproductive and non‐reproductive tissues 下载免费PDF全文
S Saraswat PK Rout SD Kharche SK Jindal AK Goel 《Reproduction in domestic animals》2016,51(6):1049-1054
During the last decades, physiological effects of oestrogens have been increasingly explored by scientists and biotechnologists. Estrogens exert a wide range of effects on a large variety of cell types. Oestrogen and its receptors are essential for sexual development and reproduction. Estrogen receptor alpha is a nuclear receptor activated by the hormone oestrogen. In male, ERα is encoded by the gene estrogen receptor gene 1 (ESR1), responsible for better fertility. The ESR1 is involved in the reabsorption of luminal fluid during the transit of spermatozoa from the testis to the head of the epididymis which is important for their survival and maturation during epididymal storage. The absence of ESR1 leads to reduced epididymal sperm content, reduced sperm motility and fertilizing ability. Therefore, this is a good startby to study the expression pattern of estrogen receptor 1 gene in high‐fertile (G1) and low‐fertile (G2) bucks of Jamunapari and Barbari breeds identified on the basis of seminal quality traits and fertility trials. RNA was extracted from the tissues by TRIzol method. The identification and expression pattern of caprine ESR1 gene was analysed by real‐time PCR (Roche LC‐480). Our work shows that the relative quantification by RT‐PCR indicates more fold in head of epididymis as compared to spleen of caprine ESR1 gene. Furthermore, the RT‐PCR indicated that fertile bucks of Jamunapari breed have more fold value as compared to Barbari breed in respect of reproductive organ. 相似文献
95.
Martella V Elia G Lucente MS Decaro N Lorusso E Banyai K Blixenkrone-Møller M Lan NT Yamaguchi R Cirone F Carmichael LE Buonavoglia C 《Veterinary microbiology》2007,122(1-2):32-42
CDV is a highly contagious viral pathogen causing a lethal systemic disease in dogs and other carnivores. Several lineages or genotypes of CDV exist that are variously distributed throughout several continents. Legal or uncontrolled trading of animals may modify the epidemiology of CDV, introducing novel strains in CDV-na?ve areas or accounting for the resurgence of CDV in areas where vaccine prophylaxis was effective and successful to control the disease. A hemi-nested PCR system was developed to genotype strains of the major CDV lineages, America-1, Europe, Asia-1, Asia-2 and Arctic. The assay was tested using a collection of 27 laboratory and vaccine strains and of 36 field CDV strains. Distinct lineages could be differentiated by specific primers targeted to the H gene. The method could be useful for molecular epidemiological studies of CDV, providing a tool for large-scale studies, and for the diagnosis of vaccine-related disease. 相似文献
96.
Kebebew Assefa Seyfu Ketema Hailu Tefera Henry T. Nguyen Abraham Blum Mulu Ayele Guihua Bai Belay Simane Tiruneh Kefyalew 《Euphytica》1999,106(1):87-97
Three hundred twenty germplasm lines of the major Ethiopian cereal, tef, [ Eragrostis tef (Zucc.) Trotter], were evaluated
for 20 morphological, phenological and agronomic characters in two-replicated randomized complete blocks at Debre Zeit and
Melkassa Agricultural Research Centers in Ethiopia during the 1995 main season. The objectives were to assess the diversity
of the lines, and to estimate the broad sense heritability (H) and genetic advance (GA) of the various characters. The mean
squares of genotypes were highly significant (p ≤ 0.001) for all the traits. The phenotypic and genotypic coefficients of
variation ranged in that order from about 6–40% and 3–23% for days to maturity and grain yield/plant, and days to maturity
and number of spikelets/main shoot panicle, respectively. The cluster analysis grouped the genotypes into 14 major complexes
consisting of one to 183 lines. Of the 19 principal components involved in explaining the entire variation among the genotypes
the first five which had eigenvalues of more than one explained about 73.8%. The first principal component which accounted
for about 34% of the total variance was due chiefly to plant height, culm and panicle length, diameters of the two basal culm
internodes, main shoot panicle mass and grain yield, number of main shoot panicle branches and spikelets, and days to panicle
emergence and maturity. Estimates of H varied from about 22% for length of the lowest main shoot stem internode to 74% for
number of main shoot panicle branches. Values of GA (expected from selection of the superior 5% of the lines and expressed
relative to the means) ranged from about 3% for days to maturity to 36% for number of spikelets/main shoot panicle. Overall,
the study indicated the existence of trait diversity in tef germplasm and this can be exploited in the genetic improvement
of the crop through hybridization and selection.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
97.
Heat tolerance in spring wheat. I. Estimating cellular thermotolerance and its heritability 总被引:1,自引:0,他引:1
High temperature is a major environmental stress factor limiting wheat (Triticum aestivum L.) productivity. Improvement of
heat tolerance in wheat is an important breeding objective. Genetic variation in cellular thermotolerance among 56 spring
wheat cultivars was evaluated at the seedling stage of growth by cell membrane thermostability (CMS) and triphenyl tetrazolium
chloride (TTC) assays. A subset of eight lines was also evaluated at the flowering stage using the same assays. With both
assays Average thermotolerance tended to decrease from the seedling to the flowering stages. However, thermotolerance was
well correlated between growth stages among the eight cultivars for both CMS (r = 0.92; p = 0.004) and TTC (r = 0.84; p =
0.050). The correlation between TTC and CMS among the eight cultivars tested at the seedling and the flowering growth stages
was significant (r = 0.74; p = 0.031 and r = 0.75; p = 0.029, respectively). The same correlation was less strong, though
still significant (r = 0.32; p = 0.014) across 56 cultivars at the seedling stage. In a study of the cross V747 (tolerant)/Barkaee
(susceptible), broad sense heritability was estimated at 89% for TTC. Most of the genetic variance was additive. CMS in seedlings
of 16 cultivars was positively and significantly (p ≤ 0.05) correlated with yields of these cultivars in each of four hot
environments in Mexico, Sudan, India, and Brazil. The same correlations for TTC were positive but nonsignificant.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
98.
A partial skeleton of a primitive bird, Rahona ostromi, gen. et sp. nov., has been discovered from the Late Cretaceous of Madagascar. This specimen, although exhibiting avian features such as a reversed hallux and ulnar papillae, retains characteristics that indicate a theropod ancestry, including a pubic foot and hyposphene-hypantra vertebral articulations. Rahona has a robust, hyperextendible second digit on the hind foot that terminates in a sicklelike claw, a unique characteristic of the theropod groups Troodontidae and Dromaeosauridae. A phylogenetic analysis places Rahona with Archaeopteryx, making Rahona one of the most primitive birds yet discovered. 相似文献
99.
Blood Polymorphism in West African Breeds of Sheep 总被引:1,自引:0,他引:1
This paper reports the blood groups and blood protein distribution in West African sheep breeds. About 100 animals of the Djallonke, Fulani and Touabire breeds were sampled for blood polymorphism analysis. Their blood groups were typed by haemolytic and agglutination reactions, and their blood proteins by starch gel electrophoresis. Almost all the loci analysed showed variability in the three breeds, with the Touabire and Fulani being closer to each other than to the Djallonke. 相似文献
100.