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991.
Dorafshan S Kalbassi MR Pourkazemi M Amiri BM Karimi SS 《Fish physiology and biochemistry》2008,34(3):195-200
The aim of this study was a comparison of key haematological features of diploid (2n) and triploid (3n) Caspian salmon (Salmo trutta caspius). Morphometric indices of erythrocytes were determined on blood smears by light microscopy. Triploidy significantly (P < 0.001) increased all morphometric indices measured in the erythrocytes including cell size, cell surface area, and cell
volume. The increase in cell size was larger for the major (27%) axis than for the minor (22%) axis, thus making erythrocytes
of 3n Caspian salmon more ellipsoidal. The estimated increase in erythrocyte nuclear volume (87%) was bigger than the theoretical
expected 50% increase. Haematological indices were measured manually by hemocytometry. Triploids had lower numbers of red
blood cells (RBC: 1,120,000 cells/mL in 2n vs. 700,000 cells/mL in 3n; P < 0.001) but they were larger in size (mean erythrocytic volume [MEV]: 363.1 nm3 in 2n vs. 483.3 nm3 in 3n; P < 0.001). The decrease in RBC number was not compensated by the increase in MEV and, thus, triploidy affected the haematocrit
(Hct: 38.8% in 2n vs. 33.06% in 3n; P < 0.05). Total blood hemoglobin concentration was lower in triploid fish (Hb: 9.9 g/dL in 2n vs. 8.9 g/dL in 3n; P < 0.05). In contrast, mean erythrocytic hemoglobin (MEH: 95 μg in 2n vs. 133.2 μg in 3n; P < 0.001) was higher for 3n Caspian salmon as a result of their larger erythrocytes, although MEH concentration (MEHC: 0.26 g/dL
in 2n vs. 0.27 g/dL in 3n) did not significantly differ (P > 0.05). White blood cell (WBC) counts (lymphocytes and neutrophiles) were measured and WBC/RBC ratios were calculated. There
were no significant differences in WBC (15,710 cells/mL in 2n vs. 12,683 cells/mL in 3n; P > 0.05), lymphocytes, and neutrophils as %WBC as well as WBC/RBC ratios between two ploidy levels (P > 0.05). Triploid Caspian salmon showed higher erythrocyte abnormalities such as ‘twisted’, ‘tailed’, and ‘anucleated’ cells
as well as high portions of immature RBC in blood smears in comparison with diploids (P < 0.001). 相似文献
992.
Wataru Doi Than Than Lwin Masashi Yokota Carlos Augusto Strüssmann Seiichi Watanabe 《Fisheries Science》2007,73(2):331-340
ABSTRACT: Sexual maturity, morphological sexual dimorphism, and reproduction of the goneplacid crab Carcinoplax vestita were investigated in Tokyo Bay, Japan, from November 2002 to October 2003. The puberty molt in males was evidenced by changes in the relative size of the chelipeds and merus of the walking legs, and was estimated to occur at a size range of 13.20–18.85 mm carapace length. Post-pubertal females were identified by the relative size of the abdomen and puberty was estimated to occur at a size range of 12.81–15.46 mm carapace length. Sexual dimorphism in C. vestita was observed in all features that showed secondary sexual characteristics. Monthly changes of gonad index in males, and of seminal receptacle index and occurrence of sperm plugs in females were synchronized, and indicated that mating was intense in spring. Ovaries began developing in March. Ovigerous females were found in all months except December, but were clearly more abundant between August and October. Fecundity ranged from 7800 to 57 000 mature oocytes per female per batch and was highly correlated with body size. The results suggest that some females may spawn more than one batch per year. 相似文献
993.
Noriyuki Takai Noriyuki Hirose Takuya Osawa Kazuyuki Hagiwara Takahito Kojima Yuji Okazaki Tomohiro Kuwae Toru Taniuchi Kiyoshi Yoshihara 《Fisheries Science》2007,73(3):593-608
ABSTRACT: It is important to clarify trophic dynamics in marine ecosystems for management of the fishing ground. Organic carbon sources and trophic position of pelagic fishes in the coastal waters of the south-eastern Izu Peninsula, Japan, were examined on the basis of carbon and nitrogen stable isotope distributions. The δ13 C of the fishes was mostly distributed from −19 to −16‰ for nektonic fishes (13 species of adults and immatures) and planktonic fishes (10 species of larvae and juveniles), close to the δ13 C values of particulate organic matter and planktonic decapods. These δ13 C signatures for the inhabitants of the water column were in contrast with the high δ13 C values (mainly −16 to −13‰) for demersal fishes of Scorpaeniformes and benthic polychaetes collected in the surf zone. These results indicate that nektonic and planktonic fishes depend on phytoplankton for carbon supply. The δ15 N signatures suggest that the trophic position ranged 3.1–4.5 for the nektonic fishes and 2.9–3.7 for the planktonic fishes, premised on trophic level 3 for larval Japanese anchovy Engraulis japonicus . Thus, planktivorous fishes should be mainly assigned to trophic levels 3 and 4 in this area. 相似文献
994.
The ability to discriminate local stocks of Japanese anchovy Engraulis japonicus was assessed based on data from four elements (K, Na, P, and Sr) using an electron probe micro analyzer (EPMA) and data from
three elements (Ba, Mn, and Sr) using inductively coupled plasma mass spectrometry (ICP-MS) from the otoliths of 40 anchovy
(23.6–47.0 mm body length). Anchovy were caught at three sites (Aki-nada, Hiuchi-nada, and Osaka Bay) in the Seto Inland Sea,
and one site (Kuroshio extension) in the Pacific Ocean in 2002. In order to discriminate different spawning grounds, EPMA
data from the core portion (from core to 30 μm in the core-posterior axis) were used. Results showed that it was difficult
to discriminate between the Seto Inland Sea and the Pacific anchovy by EPMA data. Conversely, it was possible to discriminate
between the Seto Inland Sea and the Pacific anchovy by ICP-MS data from bulk otoliths. Our results showed that Mn contents
of otoliths using ICP-MS discriminate between spawning grounds most, and Ba and Sr discriminate less. The difference in elemental
compositions in anchovy otoliths between the Seto Inland Sea and the Pacific Ocean might be reflected by cumulative experienced
elemental composition of ambient sea water during life history between the Seto Inland Sea and the Pacific anchovy. 相似文献
995.
996.
P. Joseph John 《Fish physiology and biochemistry》2007,33(1):15-20
Indiscriminate use of pesticides has elevated the risk of contamination of environment and aquatic habitat. Considering the
above fact, the present study has been under taken to investigate the alteration of some blood parameters of freshwater teleost
Mystus vittatus after chronic exposure to sublethal concentrations of Metasystox (4 ppm.) and Sevin (7 ppm.) individually. The main alterations
observed in certain haematological parameters were clotting time (CT), erythrocyte sedimentation rate (ESR), haemoglobin percentage
(Hb%), red blood corpuscles (RBCs), white blood corpuscles (WBCs), pack cell volume (PCV), mean corpuscular volume (MCV),
mean corpuscular haemoglobin (MCH) and mean corpuscular haemoglobin concentration (MCHC). Alterations in organic constituents
of blood, such as glucose, blood urea, total plasma protein and cholesterol, and in inorganic constituents, such as calcium,
iron, magnesium, and phosphorus, were also studied. Alteration of enzymes such as glucose-6-phosphatase (G-6-pase), fructose-1-6-diphosphatase
(F-1-6-dipase),
serum glutamic oxaloacetic transaminase (SGOT) and serum glutamic pyruvic transaminase (SGPT) were also studied, so that the
changes in the blood biochemistry due to the pesticidal stress could be understood. Results indicated that CT, WBCs, MCH,
MCHC, glucose, blood urea, cholesterol, magnesium and SGOT were increased, whereas other parameters were found to be decreased
in both cases. Possible reasons for the above elevation are discussed in the light of available literature. 相似文献
997.
Growth and ontogeny of digestive function were studied in pikeperch (Sander lucioperca) larvae weaned on artificial food at different ages. Three weaning treatments initiated respectively on day 9 (W9), day 15
(W15) or day 21 (W21) post-hatching (p.h.) were compared with a control group, fed Artemia nauplii from first feeding until the end of the rearing trial on day 36 p.h. The digestive enzyme activities and the ontogeny
of digestive structures were investigated using enzymatic assays and histological methods. Growth of pikeperch larvae was
significantly affected by precocious weaning. Pancreatic (trypsin and amylase) and intestinal (leucine-alanine peptidase,
leucine aminopeptidase N and alkaline phosphatase) enzyme activities were detected from hatching onwards, increased at the
moment of first feeding and then decreased. Pepsin secretion occurred at day 29 p. h. only, concurrently with the stomach
development and differentiation of gastric glands. In the early weaning group (W9) the maturation process of intestinal enterocytes
seems to be impaired and/or delayed and several signs of malnutrition were recorded. Except for alkaline phosphatase activity,
no differences in enzyme activities and development of digestive structures were observed among the control, W21, and W15
groups. Moreover, at the end of the experiment, no differences in proteolytic activities were observed among larvae from the
different treatments, indicating that, in surviving individuals, the digestive structures were properly developed and the
larvae had acquired an adult mode of digestion. Based on the artificial diet used, our results suggested that pikeperch larvae
can be weaned from day 15 p.h. without significant adverse effect on digestive capacities (except for alkaline phosphatase)
or development of digestive tract, while earlier weaning impaired the onset of the maturation processes of the digestive system,
both in terms of morphological structures and enzymatic activities. 相似文献
998.
The attracting effect of paralytic shell poison (PSP) on eight toxic snail species (Polinices didyma, Natica lineata, N. vitellus, Zeuxis sufflatus, Niotha clathrata, Oliva miniacea, O. mustelina, O. hirasei) and two non-toxic species (Pomacea canaliculata, Satsuma bairdi) was investigated. Eight toxic species were reported to contain tetrodotoxin, and three out of these contained minor PSP.
The minimum lethal dose of PSP in most toxic gastropods was estimated to be more than 150 MU PSP/20 g body weight, but in
non-toxic gastropods was less than 15 MU PSP/20 g body weight. After the attracting test, all toxic gastropods showed significant
positive linear relationship (Y=3.716X+0.363, r=0.8427) between comparative attracting variation and the toxicity reported. The relationship between PSP resistance ability
and the toxicity also had a positive correlation (Y=0.91X+210.090, r=0.6803). However, the non-toxic species showed a negative response. This indicates that PSP is an attractant for toxic snails. 相似文献
999.
To determine how stock abundance fluctuations of walleye pollock Theragra chalcogramma are related to variations in reproductive characteristics, the length at 50% maturity of the fish sampled off the Pacific
coast of northern Japan from 1990 to 1999 was examined. In both sexes, the fish density increased, and the body length of
age-3-5 fish decreased, but the condition factor and the age at 50% maturity showed no clear trend during this period. Male
length at 50% maturity decreased, while value for females showed no clear trend. In both sexes, significant negative correlations
were found between density index (combined age-3-5) and each body length at age-3-5. Significant positive correlations were
seen between each body length at age-3-5 and length at 50% maturity in males. Positive correlation between body length at
age-5 and length at 50% maturity was significant in females from 1990 to 1999, except for the samples in 1998. We suggest
that the fish density might affect the length at maturity in males and possibly also in females. 相似文献
1000.