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951.
The surface of ZrO2 nanoparticles was modified by styrene coupling grafting method to improve the dispersion and interaction of the nanoparticles with the epoxy coating in which the modified ZrO2 nanoparticles were used as an additive. The grafting performance and microstructure of the nano- ZrO2/epoxy coating were analyzed by Fourier transformation infrared spectroscopy, X-ray diffraction, and scanning electron microscopy. The corrosion behavior of the nano-ZrO2/epoxy coating on mild steel was evaluated in neutral 3.5 wt% NaC1 solution using electrochemical impedance spectroscopy (EIS). Both the coating capacitance and coating resistance fitted by the equivalent circuit from EIS were used to evaluate the protective performance of the coating towards the mild steel. The results show a superior stability and efficient corrosion protection by the modified ZrO2 nanoparticles. The epoxy coating containing 2 wt% modified ZrO2 nanoparticles exhibited the best corrosion performance among all the coating specimens. This research may provide an insight into the protection of mild steel using modified epoxy coatings.  相似文献   
952.
This paper falls into the broad area of economic geography and economics of creativity,and it presents an alternative approach to explain why total factor productivity(TFP)growth is different across China′s regions.It establishes an empirical model to estimate the spatial agglomeration effects of creative industries on regional TFP growth,using China′s provincial panel data during the period of 2003 to 2010.We found that the creative industries agglomeration(CIA)has significant and positive impact on regional TFP growth.The result also implies that the CIA can facilitate regional TFP growth through promoting regional innovation instead of improving regional efficiency.Therefore,we argue that policy makers should take some measures to retain and establish more creative zones.  相似文献   
953.
The industrially important organic compound 1,3-propanediol(1,3-PDO) is mainly used as a building block for the production of various polymers. In the present study, response surface methodology protocol was followed to determine and optimize fermentation conditions for the maximum production of 1,3-PDO using marine-derived Klebsiella pneumoniae HSL4. Four nutritional supplements together with three independent culture conditions were optimized as follows: 29.3 g/L glycerol, 8.0 g/L K 2 HPO 4, 7.6 g/L(NH 4) 2 SO 4, 3.0 g/L KH 2 PO 4, pH 7.1, cultivation at 35°C for 12 h. Under the optimal conditions, a maximum 1,3-PDO concentration of 14.5 g/L, a productivity of 1.21 g/(L·h) and a conversion of glycerol of 0.49 g/g were obtained. In comparison with the control conditions, fermentation under the optimized conditions achieved an increase of 38.8% in 1,3-PDO concentration, 39.0% in productivity and 25.7% in glycerol conversion in flask. This enhancement trend was further confirmed when the fermentation was conducted in a 5-L fermentor. The optimized fermentation conditions could be an important basis for developing lowcost, large-scale methods for industrial production of 1,3-PDO in the future.  相似文献   
954.
SVG作为移动互联时代获得各种丰富图形信息的有效表达方法,已成为LBS中空间信息表达与描述的热点应用之一,但目前的研究大多没有考虑多源数据格式向SVG格式转换后的图像质量评价问题。针对多源空间数据向SVG格式转换方法和转换效果评价技术,本文设计了栅格数据和矢量数据向SVG格式转换的表达方法,分别利用直接载入栅格图像和编程实现矢量数据转换的方法实现了多源空间数据向SVG格式的有效转换;从定性与定量相结合的角度分析了转换前后的图像质量,设计了角点检测评价指标和流程,提出了基于Harris角点检测的SVG转换前后图形几何质量的评价方法。实验证明:SVG格式比较适用于位置服务中对空间数据尤其是矢量数据的表达,经过SVG转换后的图像,无论是栅格数据还是矢量数据都具有较高的图像质量,且栅格数据的转换效果相对略差于矢量数据;验证了一种基于SVG的移动位置空间服务信息表达和组织模式,对普及和强化SVG在位置服务系统中的应用具有一定的推动作用。  相似文献   
955.
In the discipline of geotechnical engineering, fiber optic sensor based distributed monitoring has played an increasingly important role over the past few decades. Compared with conventional sensors, fiber optic sensors have a variety of exclusive advantages, such as smaller size, higher precision, and better corrosion resistance. These innovative monitoring technologies have been successfully applied for performance monitoring of geo-structures and early warning of potential geo- hazards around the world. In order to investigate their ability to monitor slope stability problems, a medium-sized model of soil nailed slope has been constructed in laboratory. The fully distributed Brillouin optical time-domain analysis (BOTDA) sensing technology was employed to measure the horizontal strain distributions inside the model slope. During model construction, a specially designed strain sensing fiber was buried in the soil mass. Afterward, the surcharge loading was applied on the slope crest in stages using hydraulic jacks and a reaction frame. During testing, an NBX-6o5o BOTDA sensing interrogator was used to collect the fiber optic sensing data. The test results have been analyzed in detail, which shows that the fiber optic sensors can capture the progressive deformation and failure pattern of the model slope. The limit equilibrium analyses were also conducted to obtain the factors ofsafety of the slope under different surface loadings. It is found that the characteristic maximum strains can reflect the stability of the model slope and an empirical relationship was obtained, This study verified the effectiveness of the distributed BOTDA sensing technology in performance monitoring of slope.  相似文献   
956.
安徽池州的铜山岩体是长江中下游地区沿江岩浆岩主带中的含矿岩体之一,其形成年龄及岩石成因尚存在争议。该岩体主要由石英闪长玢岩、石英二长斑岩和花岗闪长岩组成,与铜金矿化关系密切。对铜山矽卡岩型铜(金)矿床的花岗闪长岩开展了锆石U-Pb定年和Hf同位素地球化学研究。岩石地球化学及同位素年代学研究结果表明:花岗闪长岩侵入年龄为(146.3±3.2)Ma,形成于早白垩世;锆石εHf(t)值平均为-5.23,说明铜山侵入岩具有壳幔混合的岩浆岩源区性质;锆石的二阶段Hf模式年龄分布在1 184.51~1 422.72Ma之间,说明岩浆源区与皖南地区出露的中元古代基底有密切关系。构造判别图解显示,铜山岩体属火山弧花岗岩,与长江中下游铜金矿床含矿岩体形成于同一构造背景下,据此推测铜山地区大地构造背景形成于与古太平洋板块俯冲密切相关的大陆边缘岩浆弧环境。  相似文献   
957.
青海德尔尼铜(钴)矿床矿石矿物特征及其地质意义   总被引:1,自引:0,他引:1  
青海德尔尼铜(钴)矿床赋存于东昆仑阿尼玛卿蛇绿岩套中部,岩石类型主要有蛇纹石化的方辉橄榄岩、纯橄榄岩和二辉橄榄岩,矿石类型主要为块状、条带状含铜黄铁矿矿石,矿床成因存在多种认识。通过野外详细观察、室内显微镜下矿石矿物特征鉴定以及电子探针分析,确定德尔尼铜(钴)矿床的矿石矿物主要为黄铁矿,其次为磁铁矿、磁黄铁矿、黄铜矿、闪锌矿和方铅矿等,矿石结构以半自形粒状结构为主;钴元素在早期黄铁矿中比较富集,晚期黄铁矿中较贫,w(Co)/w(Ni)值指示黄铁矿与巴西Sossego铁氧化物-铜-金矿一致;早期黄铁矿、黄铜矿、闪锌矿的微量元素质量比值指示矿床成矿温度为200℃~300℃,属于中温环境,进一步证明了该矿床不是岩浆型矿床,属于海底喷流-沉积成因。矿床成矿过程可划分为4个阶段:海底喷流-沉积阶段、构造变形阶段、热液阶段和表生氧化阶段,其中前两个阶段为铜、钴、锌的主要成矿期。  相似文献   
958.
为探究溶藻弧菌(Vibrio alginolyticus)ZJ03株Ⅲ型分泌系统(Type III secretion system,T3SS)注射装置蛋白VscO作为疫苗候选抗原的可能性,根据GeneBank上登陆的溶藻弧菌VscO序列(NO.KJ179947),设计1对带酶切位点的特异性引物,PCR扩增vscO基因,序列分析结果显示,该基因全长462 bp,理论分子质量为18.430ku。将vscO基因定向插入原核表达载体pET-28a(+),构建重组表达质粒pET-vscO。用异丙基-β-D-硫代半乳糖苷(IPTG)诱导后,可在大肠杆菌(Escherichia coli)BL21(DE3)中表达分子质量约为22 ku的VscO融合蛋白,且该蛋白主要以包涵体形式存在。VscO蛋白表达和纯化的最优条件为:0.1 mmol/L IPTG、37℃条件下诱导4 h,咪唑洗脱浓度为400 mmol/L。用纯化后的融合蛋白免疫SPF级小鼠,获得高效多克隆抗体。Western-blotting结果表明,鼠抗VscO血清既能与重组VscO蛋白发生反应,也能与分离自溶藻弧菌约22 ku的天然蛋白发生反应,提示T3SS注射装置蛋白VscO可能是溶藻弧菌的重要保护性抗原之一。  相似文献   
959.
采用直接甲酯化、乙醚抽提、正己烷提取等3种方法对微拟球藻进行前处理,用索氏法提取油脂,经气相色谱分析,对比前处理方法对微拟球藻油脂提取率及脂肪酸组分的影响。结果表明:乙醚提取藻粉油脂的提取率(微藻的油脂质量分数)为12.70%,正己烷提取藻粉油脂的提取率为11.00%,乙醚提取油脂的提取率大于正己烷的提取率;直接甲酯化后测得微拟球藻脂肪酸中多不饱和脂肪酸(Polyunsaturated Fatty Acids,PUFAs)质量分数为20.04%,多不饱和脂肪酸中二十碳五烯酸(Eicosapentaenoic Acid,EPA)含量最丰富,占总脂肪酸13.0%;经过乙醚和正己烷提取后的油脂,脂肪酸组成更加简单,PUFAs含量明显增加,乙醚提取油脂EPA含量是直接甲脂化法的2.3倍,正己烷提取所得油脂EPA含量是直接甲脂化法的2.08倍。  相似文献   
960.
介绍总体最小二乘的奇异值分解法(SVD)和混合总体最小二乘法(LS-TLS),基于间接平差原理推导一种总体最小二乘迭代解法,可以用来解决系数矩阵含常数列的总体最小二乘平差问题。最后分别对系数矩阵不含常数列和系数矩阵含常数列的算例进行验证,得到的结果与采用奇异值分解法和混合总体最小二乘法计算的结果相同,表明算法的有效性。  相似文献   
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