首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   8篇
  免费   1篇
  国内免费   1篇
林业   1篇
  3篇
综合类   1篇
农作物   1篇
水产渔业   2篇
畜牧兽医   1篇
植物保护   1篇
  2023年   1篇
  2016年   1篇
  2014年   1篇
  2013年   1篇
  2010年   1篇
  2007年   1篇
  2006年   1篇
  2005年   1篇
  2001年   2篇
排序方式: 共有10条查询结果,搜索用时 78 毫秒
1
1.
The daggertooth pike conger, Muraenesox cinereus (Forsskål), has become an important fish resource in the western Seto Inland Sea, Japan, since the 1990s. However, introducing sustainable fisheries resource management for this species is difficult in this region because stock assessments have not been performed, and official fisheries statistics for this stock were discontinued after 2007. This study used existing limited data sets to compile the first report for fisheries resource management for this M. cinereus stock. Yield‐per‐recruit analyses showed that increasing fishing pressure above current levels would provide only a minimal increase in expected catch levels. Hence, the current harvest level is considered to represent the upper limit of fishing pressure. Age composition in a given year could potentially be used to forecast landing abundance for the following 2 years. This study provides a basis for establishing effective fisheries resource management strategies for M. cinereus.  相似文献   
2.
Sakamoto  K.  Terauchi  Y.  Ishitani  O.  Kamide  M.  Wang  Q. 《Water, air, and soil pollution》2001,130(1-4):253-258
In China, the large amount of sulfur dioxide and dust discharged from the combustion of low-grade raw coal causes severe air pollution and acid rain. Therefore, the need to control the emission of such pollutants is urgent. It is well known that wet coal-cleaning technology is used to prepare clean coal from low-grade raw coal containing large amounts of sulfur and ash. However, this technology is not used in areas where water is scarce or severely polluted, because of the high cost of treating the wastewater. In an attempt to overcome this limitation, we studied an integrated technology, which combines dry coal-cleaning and bio-briquetting technologies, to prepare clean coal from low-grade raw coal. In the dry coal-cleaning method, refined coal was separated from ash and other minerals containing inorganic sulfur as pyrite by means of the differences in their electrostatic character. Most of the sulfur left in the refined coal was organic sulfur. The residual ash was fixed in combustion ashes of bio-briquettes made from coal, biomass, and slaked lime (Ca/S mole ratio =2) under pressure. By combining these two technologies, we were able to decrease the emission of sulfur dioxide and ash by 70≈90% compared to the combustion of raw coal.  相似文献   
3.
The aim of the current study was to examine the effects of clenbuterol injection into newly hatched chicks on both the abdominal fat pad tissue weight and the skeletal muscle weight during subsequent growth. Twenty‐seven 1‐day‐old chicks were divided into two groups, receiving either a single intraperitoneal (i.p.) injection of clenbuterol (0.1 mg/kg body weight) or phosphate‐buffered saline (PBS). Body weight gain, feed intake and feed conversion ratio were not affected by clenbuterol injection during the 5‐week experimental period, while the abdominal fat pad tissue weight of the clenbuterol‐injected chicks was lower than that of the control chicks at 5 weeks post‐injection. Plasma non‐esterified fatty acid concentrations were significantly increased in the clenbuterol‐injected chicks, while plasma triacylglycerol concentrations did not differ. Additionally, the enzymatic activity of fatty acid synthase was lower in the liver of the clenbuterol‐injected chicks. Conversely, the skeletal muscle weights were not affected by clenbuterol injection. These results suggest that a single clenbuterol injection into 1‐day‐old chicks decreases the abdominal fat pad tissue weight, but may not affect skeletal muscle weights during growth. © 2015 Japanese Society of Animal Science  相似文献   
4.
In order to obtain information on dry deposition of SO2 onto loess in China, the effects of water vapor and NO2 on SO2 deposition-oxidation processes were investigated in laboratory measurements. The deposition velocities of SO2 onto loess particles were 2.34–7.33 cm s?1, were high in comparison with the other studies. Deposition of SO2 onto the particles was decreased with exposed time and amounts of SO2, but was influenced by adsorption of water vapor onto the particles. On the other hand, oxidation of SO2 physically8 adsorbed was promoted by the coexistence of water vapor and NO2. So, it was indicated that it was possible for water vapor and NO2 in the atmosphere to play an important role in dry deposition for the deposition-oxidation interaction between SO2 and loess particles.  相似文献   
5.
本研究的主要目的是通过当地的加固方法和胶合杆来防止脆断并提高钉连接(如螺栓连接)的强度。对利用竹胶合板加强钉连接的方法进行了拉力试验,以确认其效果。根据试验结果探讨了当地的不同加固构件和尺寸对接合的机械性能的影响。经加固,接合的性能得到了改进。根据胶合杆的试验结果,探讨了螺栓和胶合杆之间的距离对机械性能的影响。另外,开发出3-D非线性有限元模型,以模拟经当地特殊加固方法和胶合杆加强的钉接合的结构性能,并得到良好的适宜的相关性。  相似文献   
6.
Glutaminyl-transfer RNA (Gln-tRNA(Gln)) in archaea is synthesized in a pretranslational amidation of misacylated Glu-tRNA(Gln) by the heterodimeric Glu-tRNA(Gln) amidotransferase GatDE. Here we report the crystal structure of the Methanothermobacter thermautotrophicus GatDE complexed to tRNA(Gln) at 3.15 angstroms resolution. Biochemical analysis of GatDE and of tRNA(Gln) mutants characterized the catalytic centers for the enzyme's three reactions (glutaminase, kinase, and amidotransferase activity). A 40 angstrom-long channel for ammonia transport connects the active sites in GatD and GatE. tRNA(Gln) recognition by indirect readout based on shape complementarity of the D loop suggests an early anticodon-independent RNA-based mechanism for adding glutamine to the genetic code.  相似文献   
7.
8.
Age determination and growth using otolith rings in Muraenesox cinereus was re-examined in the western Seto Inland Sea, Japan. Previous study in this area indicated that new rings were formed annually from March to May, and then from September to October once individuals had achieved four or five rings. In this study, monthly changes in marginal growth rate indicated that the first ring was formed before November in the year following hatching, and from then on another ring was formed annually in July or August. The birth month was determined to be August based on a peak in monthly change in the gonad somatic index. Estimated von Bertalanffy growth functions were L = 806.6{1 ? exp[? 0.33(t + 0.06)]} and L = 1264.0{1 ? exp[? 0.19(t + 0.15)]} for males and females, respectively. Lengths after 3 years of age in this study were 100 mm longer than those in a previous study for both sexes.  相似文献   
9.
In the low fertility acid soils of the Orinoquian savannas of Colombia, Urochloa humidicola cv. Tully or Humidicola is one of the most widely planted tropical forage grasses for improving livestock productivity. Low nutritional quality of this grass limits sustainable livestock production in this region. In this study, we conducted a phenotypic evaluation under field and greenhouse conditions of one of the first hybrid populations of U. humidicola generated from the forage breeding program of CIAT. Our objective was to identify a set of new hybrids of U. humidicola that combine improved productivity and nutritional quality plus the biological nitrification inhibition (BNI) trait/ability to reduce nitrogen (N) losses via leaching and nitrous oxide (N2O) emissions. To this end, we tested 118 hybrids (planted in pots) in the greenhouse for over 6 months and measured potential nitrification rates (NR) using soil microcosm incubation. NR values observed ranged from 0.27 to 5.75 mg N-NO3 kg soil−1 day−1. Later, 12 hybrids with different levels of NR were selected and field-tested in the Orinoquia region over a 4 years period (2013–2017) for dry matter production, nutrition quality (crude protein, in vitro digestibility and fibres content) and NR in each year. In the rainy season of 2018, two hybrids with superior agronomic performance and contrasting field level NR (Uh08/1149 and 0450) were subjected to analysis of soil-borne N2O emissions after fertilization during 13 days. The NR values recorded were not directly correlated with the forage quality parameters evaluated, however, the two grasses with the lowest NR values were among those with the highest biomass production, crude protein content, and N uptake. The grass hybrid Uh08/1149 and the germplasm accession CIAT 16888 were found as materials with superior forage value, with production of 14.1 and 14.6 tons dry matter ha−1 year−1 (up to 8% higher than the cv. Tully), crude protein of 11.5 and 9.1% per cut (up to 20% higher than the cv. Tully), and N uptake of 31.6 and 25.7 kg N ha−1 cut−1 (up to 30% higher than the cv. Tully). Additionally, these two grasses are likely to exhibit high-BNI ability, with potential to improve N use efficiency in managed pastures.  相似文献   
10.
不同豆浆浓度和浆液深度对腐竹生产的影响   总被引:12,自引:2,他引:10  
通过水浴加热方法研究了豆浆浓度和浆液深度对腐竹产率和成膜速度的影响。结果表明:在豆浆浓度小于5.5%时,腐竹的产率和成膜速度随着豆浆浓度的增加而增加,当豆浆浓度大于5.5%时,腐竹的产率和成膜速度反而随着豆浆浓度增加而降低,同时腐竹的品质也有所下降。控制豆浆浓度为5.5%,腐竹的产率随浆液深度的增加而增大,成膜速度随浆液深度增加而减小,浆液深度在5 cm左右时,腐竹的品质较好。  相似文献   
1
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号