全文获取类型
收费全文 | 482篇 |
免费 | 13篇 |
专业分类
林业 | 51篇 |
农学 | 13篇 |
基础科学 | 1篇 |
33篇 | |
综合类 | 32篇 |
农作物 | 15篇 |
水产渔业 | 102篇 |
畜牧兽医 | 221篇 |
园艺 | 4篇 |
植物保护 | 23篇 |
出版年
2023年 | 1篇 |
2022年 | 9篇 |
2021年 | 18篇 |
2020年 | 11篇 |
2019年 | 10篇 |
2018年 | 12篇 |
2017年 | 12篇 |
2016年 | 13篇 |
2015年 | 14篇 |
2014年 | 15篇 |
2013年 | 28篇 |
2012年 | 35篇 |
2011年 | 25篇 |
2010年 | 23篇 |
2009年 | 18篇 |
2008年 | 25篇 |
2007年 | 26篇 |
2006年 | 36篇 |
2005年 | 27篇 |
2004年 | 18篇 |
2003年 | 19篇 |
2002年 | 14篇 |
2001年 | 23篇 |
2000年 | 17篇 |
1999年 | 11篇 |
1998年 | 6篇 |
1997年 | 1篇 |
1995年 | 1篇 |
1994年 | 2篇 |
1993年 | 1篇 |
1992年 | 7篇 |
1991年 | 3篇 |
1990年 | 2篇 |
1988年 | 3篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1983年 | 2篇 |
1981年 | 2篇 |
1980年 | 1篇 |
1973年 | 1篇 |
1966年 | 1篇 |
排序方式: 共有495条查询结果,搜索用时 15 毫秒
101.
102.
High‐throughput development of SSR marker candidates and their chromosomal assignment in rye (Secale cereale L.) 下载免费PDF全文
Shotgun survey sequences of flow‐sorted individual rye chromosomes were data mined for the presence of simple sequence repeats (SSRs). For 787,850 putative SSR loci, a total of 358,660 PCR primer pairs could be designed and 51,138 nonredundant SSR marker candidates were evaluated by in silico PCR. Of the 51,138 SSR primer candidates, 1,277 were associated with 1,125 rye gene models. A total of 2,112 of the potential SSR markers were randomly selected to represent about equal numbers for each of the rye chromosomes, and 856 SSRs were assigned to individual rye chromosomes experimentally. Potential transferability of rye SSRs to wheat and barley was of low efficiency with 4.3% (2,189) and 0.4% (223) of rye SSRs predicted to be amplified in wheat and barley, respectively. This data set of rye chromosome‐specific SSR markers will be useful for the specific detection of rye chromatin introgressed into wheat as well as for low‐cost genetic and physical mapping in rye without the need for high‐tech equipment. 相似文献
103.
Masaki Okuda Isao Aramaki Takuya Koseki Naoyoshi Inouchi Katsumi Hashizume 《Cereal Chemistry》2006,83(2):143-151
Structural and physicochemical characteristics of endosperm starch from milled rice grains of seven Japanese cultivars used in sake production were examined. Amylose content was 15.2–20.2%, number-average degree of polymerization (DPn) of amylose was 900–1,400, and the ratio of short-to-long chain amylopectin was 2.7–3.5, respectively. The degree of retrogradation of purified starch stored for seven days at 4°C after gelatinization was 20–31%. The degree of retrogradation correlated negatively with the ratio of short-to-long chain amylopectin. The effect of holding time after steaming on enzyme digestibility and starch retrogradation of steamed rice grains was investigated. The longer the holding time after steaming, the greater the extent of retrogradation, and the less the degree of enzymatic digestibility. The decreased rate of enzyme digestibility correlated with amylopectin chain length distribution. Samples with short-chain amylopectin exhibited a slow decrease in enzyme digestibility. It was determined that the structure and retrogradation properties of endosperm starch in Japanese rice cultivars affect the decreasing rate of enzyme digestibility of the steamed, milled rice grains. 相似文献
104.
Dew-water was collected from January 1999 to February 2000 in Yokohama, Japan and analyzed for not only soluble major components but also insoluble or trace components. The pH of dew-water ranged from 5.36 to 6.71 and volume-weighted average pH was 5.81. In dew-water, Si, Al, Fe, Cl, and Na were abundant and they were confirmed to be transported from natural sources, sea and soil dust. The concentrations of Si, Al, Fe, and Ti contained in coarse mode aerosol were several times higher in dew-water than those in rain-water, while the concentrations of V and Pb contained in fine mode aerosol were about the same level to each other. Besides these elements derived from aerosol, the elements derived from gaseous species are also major components in dew-water. The high concentration of weak acid is one of the significant characteristics of dew-water. Bisulfite ion in dew-water is the important species as the precursor of the sulfate ion but it is stable by forming hydroxyalkanesulfonate (HASA). The HASA concentrations were evaluated by using concentrations of total S(IV) and aldehydes and hydroxymethanesulfonate (HMSA) was shown to be the dominant species in S(IV). 相似文献
105.
ABSTRACTExcessive application of animal manure to farmland leads to phosphorus (P) loss into the surrounding water. Manure is incinerated to convert it to P-rich ash as a slow-release P fertilizer. However, the potential P loss and P availability for plants from cattle manure ash (CMA) have not been fully understood. The aims of this study were to determine the P release mechanism from CMA and to propose appropriate application rates that mitigate P loss and increase available P to soil in Fukushima, where the soil is deficient in nutrients after the replacement of cesium-137-contaminated soil with sandy mountain soil. Different P fractions in CMA were sequentially extracted with H2O, 0.5 M NaHCO3, 0.1 M NaOH, and 1 M HCl. Phosphorus contents in different fractions of CMA were in the order of HCl–P > NaHCO3–P > H2O–P > NaOH–P. Water-soluble P release of CMA was also determined by kinetic experiments for 120 h. Results showed that total water-soluble P accounted for a maximum of 2.9% of total P in CMA over 120 h due to recalcitrant P compounds formed through incineration. The Fukushima sandy soil amended with CMA at three application rates, 94, 157, and 314 mg P kg?1 (corresponding to 300, 500, 1000 kg P2O5 ha?1) was incubated for 56 days. Cattle manure compost and KH2PO4 were applied at 157 mg P kg?1 for comparison. Phosphorus release in water and CaCl2 solution from ash-amended soil was significantly lower than those from compost and KH2PO4-amended soil at the same P application rate of 157 mg P kg?1 (p < 0.05). Available P in ash-amended soil, determined by Fe-oxide impregnated strips, was not significantly different from those in compost-amended soil after day 7 and KH2PO4-amended soil on day 56 at the same P application rate. Thus, CMA reduces P losses from soil to the surrounding water while it increases P availability for plants. In comparison of different rates of CMA, P release in water or CaCl2 was significantly greater at 314 mg P kg?1 than at 94 or 157 mg P kg?1, while the percentage of available P to total P was the lowest at the highest application rate (p < 0.05), suggesting that the best application rates were 94 and 157 mg P kg?1 in this experiment. 相似文献
106.
Ferulic and p‐coumaric acids were analyzed in 50 rice (Oryza sativa L.) samples from 32 cultivars harvested in Japan. In brown rice, ferulic and p‐coumaric acid levels ranged from 309 to 607 mg/kg and from 49 to 100 mg/kg, respectively. In 70% polished rice, ferulic and p‐coumaric acid levels ranged from 27 to 103 mg/kg and from 0.4 to 3.5 mg/kg, respectively. Ratios of average phenolic acid levels in the 70% polished rice to the brown rice were 13.9% for ferulic acid and 1.9% for p‐coumaric acid. The ferulic acid level was highly correlated between brown and 70% polished rice (R = 0.815; P < 0.01), but there was no clear correlation for p‐coumaric acid. Phenolic acid levels in the 70% polished rice did not show any clear correlations between the analytical index measurements for sake brewing suitability (weight of 1,000 grains, water absorption, digestibility, crude protein, and potassium content). Phenolic acid levels in the 70% polished rice directly affected levels in the rice koji enzyme digest. The results indicated that phenolic acid levels in sake were affected by the levels in ingredient rice grains, which may then influence the sensory quality of sake. 相似文献
107.
Takano K Watanabe-Takano H Suetsugu S Kurita S Tsujita K Kimura S Karatsu T Takenawa T Endo T 《Science (New York, N.Y.)》2010,330(6010):1536-1540
Insulin-like growth factor 1 (IGF-1) induces skeletal muscle maturation and enlargement (hypertrophy). These responses require protein synthesis and myofibril formation (myofibrillogenesis). However, the signaling mechanisms of myofibrillogenesis remain obscure. We found that IGF-1-induced phosphatidylinositol 3-kinase-Akt signaling formed a complex of nebulin and N-WASP at the Z bands of myofibrils by interfering with glycogen synthase kinase-3β in mice. Although N-WASP is known to be an activator of the Arp2/3 complex to form branched actin filaments, the nebulin-N-WASP complex caused actin nucleation for unbranched actin filament formation from the Z bands without the Arp2/3 complex. Furthermore, N-WASP was required for IGF-1-induced muscle hypertrophy. These findings present the mechanisms of IGF-1-induced actin filament formation in myofibrillogenesis required for muscle maturation and hypertrophy and a mechanism of actin nucleation. 相似文献
108.
JH Warner ER Margine M Mukai AW Robertson F Giustino AI Kirkland 《Science (New York, N.Y.)》2012,337(6091):209-212
The movement of dislocations in a crystal is the key mechanism for plastic deformation in all materials. Studies of dislocations have focused on three-dimensional materials, and there is little experimental evidence regarding the dynamics of dislocations and their impact at the atomic level on the lattice structure of graphene. We studied the dynamics of dislocation pairs in graphene, recorded with single-atom sensitivity. We examined stepwise dislocation movement along the zig-zag lattice direction mediated either by a single bond rotation or through the loss of two carbon atoms. The strain fields were determined, showing how dislocations deform graphene by elongation and compression of C-C bonds, shear, and lattice rotations. 相似文献
109.
The adduct of the hydroxyl radical with oxygen has been studied theoretically, in connection with atmospheric reactions, but its stability and structure remained an open question. Pure rotational spectra of the HOOO and DOOO radicals have now been observed in a supersonic jet by using a Fourier-transform microwave spectrometer with a pulsed discharge nozzle. The molecular constants extracted from 12 rotational transitions with fine and hyperfine splittings support a trans planar molecular structure, in contrast to the cis planar structure predicted by most ab initio calculations. The bond linking the HO and O2 moieties is fairly long (1.688 angstroms) and comparable to the F-O bond in the isoelectronic FOO radical. 相似文献
110.
Barley can be used as an extender of rice to increase the nutritive value of the end-product. Specific quality barley is required if the processed barley is to resemble cooked white rice in colour and shape. The barley must pearl and split without the production of broken kernels or fines and yet produce desired end use quality. Barley endosperm texture and colour are key to determining these processing characteristics. Testing of Canadian barley types indicated the waxy type was most appropriate for pearling and processing as rice extender. It had a firm endosperm texture that was not steely and yet processed into a white product with few broken grains. Covered barley was of better quality than hull-less, as the former generally had fewer steely kernels as well as firmer endosperm texture. Differences observed between two- and six-rowed type were related to grain size and could be overcome by proper adjustments to processing conditions. Growing conditions affected kernel size and barley protein contents but to a lesser extent than barley type. L* brightness values, Particle Size Index and kernel size were found to be important predictors of barley quality for pearling and as rice extender. 相似文献