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1.
旋转生物传感器高灵敏检测盐酸克伦特罗方法研究   总被引:5,自引:0,他引:5  
盐酸克伦特罗(clenbuterol hydrochloride, CL),又名双氯醇胺、氨哮素、克喘素,为白色结晶状粉末, 无味略苦,是一种人工合成的β2-肾上腺素受体激动剂。盐酸克伦特罗又称"瘦肉精",被非法用于肉用动物生产。彻底查禁CL 的非法滥用,必须要有高效、灵敏、特异的残留检测方法。本研究着重应用免疫学和生物化学方法,构建了基于量子点标记的ATP合酶分子马达免疫旋转生物传感器 (immuno-rotary biosensor, IRB),结合荧光技术,利用中国科学院生物物理研究所张仲伦老师研发的BPCL弱光检测器实现了对盐酸克伦特罗快速、高灵敏度的检测。  相似文献
2.
Understanding land use changes and their implications for grain production are important for the maintenance of food security. We analyzed changes in quantity and quality of cropland in the Huang-Huai-Hai Plain of China during the last 30 years and the implications for future grain production. Several categories of data were used, including long-term remote sensing images (1990–2005), spatial datasets of soil quality levels (1980s), spatial datasets of irrigation area (2000), data from hydrological stations (1978–2003) and meteorological stations (1950–2007) and statistical datasets of grain production, grain yield, area sown to grain, fertilizer use and effective irrigation area (1978–2008). The results showed that annual grain production losses due to shrinkage of cropland area over the Huang-Huai-Hai Plain were 4.30 and 2.63 million tons during 1990–2000 and 2000–2005, respectively. The greatest decline in cropland area occurred as a result of the expansion of economically developed metropolises or in provinces with large areas of urbanization. Furthermore, more “above average” quality and irrigated cropland was abandoned, i.e. sacrificed to urbanization or other non-agricultural uses, than that obtained by reclamation. Conversion of fertile and irrigated land to non-agricultural uses due to rapid urbanization appears to be a potential threat to the food security of the Huang-Huai-Hai Plain - even the whole of China. Most of the increase of grain production in the Plain can be attributed to increase in yield per hectare, which was due to improvement of crop varieties, a ~400 % increase in fertilizer use and a ~20 % increase in effective irrigation area. Policies to optimize utilization of land resources to ensure the soil fertility of cropland and to maximize nitrogen and water use efficiency are required to sustain current grain production and to achieve further increases.  相似文献
3.
烟碱预防帕金森氏综合症和老年痴呆症的分子机理   总被引:4,自引:1,他引:3  
流行病学统计显示,吸烟者患帕金森氏综合症(PD)和老年痴呆症(AD)的概率远低于不吸烟者,但是其机理还不清楚。我们研究发现:(1)烟碱可以有效清除活性氧自由基,能够抑制多巴胺自氧化,是一个抗氧化剂。(2)烟碱能够有效抑制6-OHDA和MPP^+诱导的线粒体肿胀和细胞色素C(Cyt.C)释放。(3)烟碱可以保护海马神经元抵抗邯淀粉样蛋白诱导细胞的凋亡。(4)烟碱可以防止淀粉样蛋白在转基因AD鼠脑沉淀。(5)烟碱可以络合金属铜防止和减少其在脑中积聚。这对于解释烟碱防治神经退行性疾病AD和PD机理具有重要意义。  相似文献
4.
碱回收白泥精制填料碳酸钙的生产实践   总被引:3,自引:3,他引:0  
王桂林 《中华纸业》2008,29(2):55-60
对某纸业集团碱回收白泥精制碳酸钙工程项目及运行情况作了系统介绍。在分析了草浆碱回收白泥特征的基础上,提出了白泥精制填料碳酸钙系统的设计中需要解决的一些问题,并设计了苛化系统的优化流程及白泥碳酸钙填料的精制流程。通过ATM-HO1型绿液提纯剂的使用,晶型控制剂的使用优化了苛化工艺,保证了绿液的提纯和白泥碳酸钙的粒度。白泥的高强分散与匀整处理在白泥匀整机中进行,控制好匀整工艺可得到平均粒度在4~7μm、表面带阳离子电荷的超细活性碳酸钙填料产品。生产的白泥碳酸钙填料经加填试验结果表明:可以提高纸的松厚度、不透明度并可以减少填料用量,加填后纸页裂断长、耐折度、表面强度等指标明显提高。白泥碳酸钙填料的缺点是对AKD施胶有一定的负面影响。  相似文献
5.
The bacterial strain F6 was isolated from a biological aerated filter that is used for purifying recirculating water in a marine aquaculture system and was identified as Marinobacter sp. based on the analysis of its 16S rRNA gene sequence. Strain F6 showed efficient aerobic denitrifying ability. One hundred percent of nitrates and 73.10% of nitrites were removed, and the total nitrogen (TN) removal rates reached 50.08% and 33.03% under a high nitrate and nitrite concentration in the medium, respectively. N(2)O and (15)N(2), as revealed by GC-MS and GC-IRMS, were the products of aerobic denitrification. Factors affecting the growth and aerobic denitrifying performance of strain F6 were investigated. The results showed that the optimum aerobic denitrification conditions for strain F6 were the presence of sodium succinate as a carbon source, a C/N ratio of 15, salinity ranging from 32-35?g/L of NaCl, incubation temperature of 30°C, an initial pH of 7.5, and rotation speed of 150?rpm [dissolved oxygen (DO) 6.75?mg/L]. In addition, strain F6 was confirmed to be a heterotrophic nitrifier through its NO(2)(-) generation and 25.96% TN removal when NH(4)(+) was used as the sole N source. Therefore, strain F6, the first reported member of genus Marinobacter with aerobic heterotrophic nitrifying-denitrifying ability, is an excellent candidate for facilitating simultaneous nitrification and denitrification (SND) in industry and aquaculture wastewater.  相似文献
6.
转几丁质酶-葡聚糖酶双价基因水稻稻米毒理试验   总被引:3,自引:0,他引:3  
通过小鼠急性毒性试验、小鼠致突变试验、大鼠90d毒性试验,对转几丁质酶-葡聚糖酶双价基因水稻稻米的毒理进行了初步的评价。转基因大米粉MTD≥37.5g/kg灌胃给予小鼠,连续观察7d,动物全部存活,表现正常,未见中毒反应。致突变灌胃给予小鼠,未发现对小鼠骨髓细胞微核和精子畸形发生率有不良影响。转基因大米粉分别以15、7.5g/kg/d,90d灌胃大鼠,其行为活动、外观体征、饮食、粪便、体重,结果均无异常,5项血液学检查和13项生化指标检测及尸体解剖观察、脏器系数、脏器病理学检查,结果均属正常,与空白对照无显著差异。转基因大米粉结果提示携带几丁质酶基因、葡聚糖酶基因、NPT-II标记基因等外源DNA的转基因大米无明显的毒性和致畸作用。  相似文献
7.
Mercury distribution and deposition in glacier snow over western China   总被引:2,自引:0,他引:2  
Western China is home to the largest aggregate of glaciers outside the polar regions, yet little is known about how the glaciers in this area affect the transport and cycling of mercury (Hg) regionally and globally. From 2005 to 2010, extensive glacier snow sampling campaigns were carried out in 14 snowpits from 9 glaciers over western China, and the vertical distribution profiles of Hg were obtained. The Total Hg (THg) concentrations in the glacier snow ranged from <1 to 43.6 ng L(-1), and exhibited clear seasonal variations with lower values in summer than in winter. Spatially, higher THg concentrations were typically observed in glacier snows from the northern region where atmospheric particulate loading is comparably high. Glacier snowpit Hg was largely dependent on particulate matters and was associated with particulate Hg, which is less prone to postdepositional changes, thus providing a valuable record of atmospheric Hg deposition. Estimated atmospheric Hg depositional fluxes ranged from 0.74 to 7.89 μg m(-2) yr(-1), agreeing very well with the global natural values, but are one to two orders of magnitude lower than that of the neighboring East Asia. Elevated Hg concentrations were observed in refrozen ice layers in several snowpits subjected to intense melt, indicating that Hg can be potentially released to meltwater.  相似文献
8.
米糠肽对D-半乳糖致衰小鼠线粒体损伤的影响   总被引:2,自引:1,他引:1  
利用D-半乳糖(D-gal)致衰小鼠模型,探讨了米糠肽对小鼠心、脑线粒体锰超氧化物歧化酶(Mn-SOD)活性、丙二醛(MDA)含量以及总抗氧化能力(T-AOC)和Ca2+泵、Na+泵活性的影响,并以透射电镜观察了该肽对小鼠肝细胞及线粒体超微结构的影响。结果显示,与衰老组相比,高剂量米糠肽(500 mg/kg)可明显降低小鼠心、脑线粒体MDA含量(P<0.01),显著提高T-AOC(P<0.01)、Mn-SOD活性(P<0.01)以及Ca2+泵、Na+泵活性,优于中、低剂量(200、100 mg/kg);透射电镜下可见衰老组肝线粒体肿胀明显,膜模糊不清,有空泡形成,而米糠肽各组线粒体损伤程度有所减轻。说明米糠肽对D-gal致衰小鼠线粒体损伤起到良好的保护作用,可能具有延缓衰老的效果。  相似文献
9.
Organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), and brominated flame retardants (BFRs) were investigated in captive giant and red panda tissues from China. The total concentrations of OCPs, PCBs, and polybrominated diphenyl ethers (PBDEs) in tissues ranged from 16.3 to 888 ng/g lipid weight (lw), 24.8 to 854 ng/g lw, and 16.4 to 2158 ng/g lw, respectively. p,p'-DDE and beta-HCH were major OCP contaminants. PCBs 99, 118, 153/132, 170, 180, and 209 were the major contributing congeners determined. Among PBDEs, congener BDE-209 was the most frequent and abundant, followed by BDE-206, BDE-208, BDE-207, BDE-203, BDE-47, and BDE-153. Decabromodiphenyl ethane (DeBDethane) was detected in 87 and 71% of the giant and red panda samples with concentrations up to 863 ng/g lw, respectively. The remarkable levels and dominance of BDE-209 and DeBDethane may relate to significant production, usage, or disposal of BFRs in China. The positive significant correlation between concentrations of PBDEs and PCBs in captive pandas may suggest that the exposure routes of PBDEs and PCBs to panda are similar. To our knowledge, this is the first report of the occurrence of DeBDethane in captive wildlife samples. Therefore, further studies are warranted to better understand DeBDethane production, transport, uptake, and toxicological effect.  相似文献
10.
The arsenic (As) hyperaccumulators, Pteris vittata and Pteris cretica and an As-tolerant plant Boehmeria nivea, were selected to compare the toxicity, uptake, and transportation of inorganic arsenate (As(V)) and its methylated counterpart dimethylarsinic acid (DMA). The XANES method was used to elucidate the effect of As species transformation on As toxicity and accumulation characteristics. Significantly higher toxicity and lower accumulation of DMAthan inorganic As(V) was shown in the As hyperaccumulators and the As-tolerant plant. Reduction of As(V) was commonly found in the plants. Arsenic complexation with thiols, which have less mobility in plants and usually occur in As-tolerant plants, was also found in rhizoids of P. cretica. Plants with greater ability to form As-thiolate have lower ability for upward transport of As. Demethylation of DMA occurred in the three plants. The DMA component decreased from the rhizoids to the fronds in both hyperaccumulators, while this tendency is reverse in B. nivea.  相似文献
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