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61.
The sources of NO during biomass oxidation, and in particular tobacco oxidation, have been disputed. Literature results range from decomposition of nitrate to the oxidation of atmospheric nitrogen. To rectify these discrepancies, this study focuses on the sources of nitric oxide (NO) during the oxidation of tobacco samples. When Burley tobacco was heated in a partially oxidized atmosphere, NO was produced at two distinct temperature ranges, namely 275-375 degrees C (the low-temperature range) and 425-525 degrees C (the high-temperature range). The formation of NO at the low-temperature range with Burley tobacco was found to be unaffected by oxygen, while the formation of NO at the high-temperature range required an oxygen atmosphere. With Bright and Oriental tobacco, NO was produced only within the higher-temperature range. To understand the formation processes and the sources of NO formation within these two temperature ranges, several endogenous nitrogenous tobacco compounds were examined. These were mixed with non-nitrogenous biomass model materials, namely cellulose, pectin, xylan, or lignin, which also occur naturally in tobacco, and the mixtures were heated in a flow tube reactor under a partially oxidative atmosphere. A commercial gas analyzer was used to monitor the formation of NO during heating. Nitrate ion was determined to be the source of NO formation in the range of 275-375 degrees C. This ion was decomposed in a carbonaceous surrounding to produce NO. For NO formation at the higher temperature range, amino acids and proteins were shown to be the sources. The interaction between nitrogenous organic compounds (amino acids and proteins) and pectin first produced a nitrogen-containing char at a temperature below 350 degrees C. Oxidation of this char at the higher temperatures produced NO. 相似文献
62.
Carboxymethyl cellulose (CMC) has been used in medical area by virtue of their high water absorption property, bio-degradability, and biocompatibility. It has been mainly used as forms of gel, powder, and film due to the limitation in processability on textile structures, especially nonwoven. In this study we demonstrated wet-laid nonwoven process for viscose rayon and carboxymethylation to produce CMC nonwoven. The effects of process conditions, such as reaction time and amount of monochloroacetic acid (MCA) in carboxymethylation, were investigated in terms of the degree of substitution (DS), morphological properties and mechanical properties of the CMC nonwoven. Molar ratio of MCA to cellulose and etherification time played important roles in determining characteristics of CMC nonwoven. As DS increased, strength was improved while elongation decreased. Gel blocking behavior of CMC nonwoven with higher DS indicated the applicability of CMC nonwoven as wound dressing and adhesion prevention materials. 相似文献
63.
Im HW Suh BS Lee SU Kozukue N Ohnisi-Kameyama M Levin CE Friedman M 《Journal of agricultural and food chemistry》2008,56(9):3341-3349
Potato plants synthesize phenolic compounds as protection against bruising and injury from bacteria, fungi, viruses, and insects. Because antioxidative phenolic compounds are also reported to participate in enzymatic browning reactions and to exhibit health-promoting effects in humans, a need exists for accurate methods to measure their content in fresh and processed potatoes. To contribute to our knowledge about the levels of phenolic compounds in potatoes, we validated and used high-performance liquid chromatography and liquid chromatography/mass spectrometry to measure levels of chlorogenic acid, a chlorogenic isomer, and caffeic acid in flowers, leaves, stems, and tubers of the potato plant and in home-processed potatoes. The total phenolic acid content of flowers (626 mg/100 g fresh wt) was 21 and 59 times greater than that of leaves and stems, respectively. For all samples, chlorogenic acid and its isomer contributed 96-98% to the total. Total phenolic acid levels (in g/100 g fresh wt) of peels of five potato varieties grown in Korea ranged from 6.5 to 42.1 and of the flesh (pulp) from 0.5 to 16.5, with peel/pulp ratios ranging from 2.6 to 21.1. The total phenolic acid content for 25 American potatoes ranged from 1.0 to 172. The highest amounts were present in red and purple potatoes. Home processing of pulp with various forms of heat induced reductions in the phenolic content. The described methodology should facilitate future studies on the role of potato phenolic compounds in the plant and the diet. 相似文献
64.
The effects of giant embryo brown rice Seonong 17 and Keunnunjami, in comparison with that of ordinary normal brown rice, on the body weight and lipid profile in mice under a high‐fat diet condition were investigated. The animals were fed with experimental diets for eight weeks: normal control, high fat (HF), and high fat supplemented with normal brown rice, Seonong 17 rice, or Keunnunjami rice powder. Their body and fat weights, lipid profiles, lipogenic enzyme activities, and adipokine concentrations were determined. Significant differences between the animal groups were analyzed with Tukey's test (P < 0.05). A marked increase in the body weight and fat, plasma triglyceride and total cholesterol concentrations, and free fatty acid level were found in HF mice relative to the control group. On the other hand, diet supplementation with rice, particularly the giant embryo rice samples, significantly suppressed this high‐fat‐induced body weight gain and hyperlipidemia via regulation of lipogenesis and adipokine production. Both the Seonong 17 and Keunnunjami exhibited greater hypolipidemic and body fat–lowering effects than the normal brown rice. The results demonstrate that these giant embryo mutants may be beneficial as biomaterials for functional foods with antiobesity and hypolipidemic effects. 相似文献
65.
66.
Jin Sook Kim Hyun Jeong Jeon Kyung Min Lee Jung Nam Im Ji Ho Youk 《Fibers and Polymers》2010,11(2):153-157
Polyacrylonitrile (PAN) nanoparticles were successfully prepared by dispersion polymerization of acrylonitrile (AN) in water
using 10 and 20 wt% of the poly(ethylene oxide)-b-PAN macromolecular RAFT (PEO-b-PAN macro-RAFT) agent (M
n=5,600 g/mol, PDI=1.15). The degrees of polymerization of the PEO and PAN blocks were 113 and 16, respectively. The PAN nanoparticles
had a crumpled spherical appearance and their sizes ranged from 50–80 nm. The degree of crystallinity of the PAN particles
was 23 %. The M
n
values of the PAN nanoparticles prepared with 10 and 20 wt% of the PEO-b-PAN macro-RAFT agent were 33,900 and 25,800 g/mol, respectively. The existence of the PEO block on the surface of the PAN
nanoparticles was confirmed by 1H NMR spectroscopy and XPS. 相似文献
67.
Yu CH Yhee JY Kim JH Im KS Kim NH Kwon SY Hur TY Sur JH 《Canadian journal of veterinary research》2012,76(1):62-68
This retrospective study was done to characterize the levels of vascular endothelial growth factor (VEGF) and hypoxia inducible factor 1 (HIF-1α) in dog brains with neo-vascularization in the cerebral cortex of frontal, temporal, and parietal lobe by using immunohistochemistry (IHC) and Western blot. In neo-vascularized (NV) brains, we analyzed the number and area of blood vessels and the expression of VEGF and HIF-1α. The IHC results showed that the number and area of blood vessels, as assessed by immunolabeling for von Willebrand factor, was higher in the NV brain than in the control brain. The Western blot results showed that the level of VEGF was increased, predominantly in NV brain of the cerebral cortex relative to the clinically normal cerebral cortex, whereas the expression of HIF-1α in NV brains was not different from the control brains. Our study showed that dilatation of vessels and development of new vessels in the cerebral cortex were observed in cases of canine CNS disease and found increased expression of VEGF in canine brains with neo-vascularization. 相似文献
68.
Kim HJ Choi SH Son DS Cho SR Choe CY Kim YK Han MH Ryu IS Kim IC Kim IH Im KS Nagai T 《The Journal of reproduction and development》2006,52(5):633-638
This study was conducted to evaluate the effects of exposing porcine ovaries to 30-33 C during transportation for 4 h and subsequently room temperature (25 C) for 6 h of storage on in vitro maturation (IVM) and subsequent parthenogenetic development of oocytes collected from the ovaries. After IVM, oocytes having a tight oopalsm membrane and no signs of degeneration were exposed to Dulbecco's phosphate-buffered saline (DPBS) with 7% ethanol (v/v) for 7 min to induce parthenogenetic activation. Moreover, we also determined whether exposure of the collected oocytes to room temperature for 1, 2 and 4 h in DPBS or porcine follicular fluid (pFF) affected parthenogenetic development. When porcine ovaries were stored after transportation, oocytes collected from the stored ovaries showed a significantly higher rate of degeneration after 65 h of IVM (58.4%) and a significantly lower rate of cleavage after parthenogenetic activation (40.1%) than oocytes collected from ovaries immediately after transportation (38.9% and 47.4%, respectively). However, there was no significant difference in developmental rates to the morula and blastocyst stages between these two groups (14.4% and 14.3%, respectively). The duration of preservation, 1, 2, and 4 h, of oocytes in DPBS did not affect parthenogenetic development. In contrast, when preserved for 4 h in pFF, the developmental rates of the oocytes were significantly decreased. This suggested that some factor(s) in follicular fluid affects the developmental rate of oocytes with the passage of time in ambient conditions. These results suggest that even after 6 h storage of ovaries, oocytes having normal morphology after IVM have the same rate of parthenogenetic development as oocytes collected from ovaries just after 4 h of transportation, except for a lower cleavage rate, and that exposure of oocytes to room temperature for 4 h in DPBS does not affect their parthenogenetic developmental competence. 相似文献
69.
A study was made of measures to revitalize mountain ginseng cultivation in the eastern mountainous area of Muju, Jinan and Jangsu municipalities of North Jeolla province, South Korea. The targeted area is typical forested land and is utilized for the cultivation of ginseng. Access to seeds and seedlings for mountain ginseng cultivation is relatively easy in North Jeolla province, and the species is cultivated widely (on 63 % of the area of the province and by 74 % of farmers). This study investigated the current state of mountain ginseng cultivation and business management, including production costs and subsidy, sales and distribution system, and other business management concerns. A survey was conducted on 86 mountain ginseng-cultivating farming households living in the targeted area in 2013. It is concluded that to achieve greater production an aggressive government policy promoting the renting out of suitable sites for mountain ginseng cultivation in national and public production forestland to individual farms and farming cooperatives is necessary. Further research on increasing the survival rate of cultivated mountain ginseng (CMG) until harvesting and preventing damage by wild animals is also deemed necessary. More effective use of related municipal budget subsidy needs to be supported selectively to the enterprising farmers who aggressively pursue mountain ginseng cultivation and business management. Opening CMG retail stores to realize sustainable income growth and developing various processed products will increase farm income. The government needs to introduce policies to sustain consumer trust in CMG through initiatives such as establishing a CMG quality management system for growers, distributing government-approved seeds, and implementing a government-based CMG purchase system. 相似文献
70.