基于3D扫描雷达实测数据的海上风电场尾流特性研究

为有效优化实际业务中海上风电场的机组排布方案设计，降低尾流电量损失，在江苏某海上实际运行风电场采用3D扫描雷达进行实地尾流观测实验，分析独立尾流、半尾流和全尾流三种工况下机组的尾流长度、尾流宽度及尾流深度等尾流特性。研究表明，独立尾流工况下机组尾流下游方向11D～12D（D为叶轮直径）距离处风速变化趋平，尾流影响减弱，机组尾流影响长度在11D左右；近尾流区内，全尾流工况机组的风速衰减较独立尾流和半尾流工况机组明显增大，远尾流区三种工况变化趋势一致，尾流宽度均在3D左右，呈“双高斯”或“凹型”分布特征。二者的差异性主要与相邻机组间距的不同相关。三种尾流工况下，近尾流区的尾流深度明显较远尾流区大，尾流速度亏损明显

a key escrow scheme for restoring invalid escrow agency

提出一种新的密钥托管方案,可以在某一托管代理不可信时,由其它托管代理和KEC联合恢复该托管代理的密钥碎片,保证系统正常工作.本方案利用数字签名,防止对RSA的选择密文攻击

Optimal design of minitype permanent magnet motor based on hybrid algorithm of chaos and PSO

在电机的设计中,常常需要通过优化设计得到合理的电机结构尺寸和参数.电机的设计问题实质上是一种带约束的复杂的非线性连续函数优化问题.要得到一个满意的优化结果不仅要求算法具有较高的精度,而且要有快的收敛速度.提出一种新的混合算法对永磁电机的尺寸和整体结构进行优化设计.将混沌算法和粒子群算法相结合,以微型永磁电机为例,对槽形等多个变量进行优化,结果证明了算法的有效性和快速性,适合于同类问题求解

High efficiency multi-jet electrospraying of nano particles with assisted gas

研究了一种带辅助气体的新型纳米颗粒多射流高效雾化喷射技术。开发了带有辅助气流的多喷嘴静电雾化喷头,引导辅助气体均匀分布于各喷嘴四周形成稳定鞘层气流,从而对带电雾化射流产生拉伸与约束作用,而形成的鞘层气流降低了表面电荷密度,克服了带电喷嘴间的电场干扰,实现了多雾化射流的稳定、持续喷射。研究了静电雾化多射流的喷射、沉积行为,分析了辅助气体供气压强对射流喷射临界启动电压和纳米颗粒均匀性的影响规律。实验结果显示:辅助鞘层气流降低了射流喷射临界启动电压和雾化颗粒直径,提升了雾化纳米颗粒的均匀性。辅助气体供气压强从0kPA增加到50kPA时,雾化多射流喷射临界启动电压从4.9kV降低至2.8kV,纳米颗粒平均直径从845.267nM下降至528.06nM。结果表明:鞘层气流的引入为纳米颗粒的多射流、快速喷射提供了一种有效的技术手段,有助于推动静电雾化技术的应用发展。A novel multi-jet electrospray with assisted gas was explored to eject nano particles in a high efficiency.The electrospray spinneret with multi nozzles was designed to guide the assisted gas to form the uniform sheath gas around each nozzle and to provide the excess stretching and restriction forces on the charged electrospray jets.The obtained sheath gas decreases the surface charge density of charged electrospray jets and the interferences among charged jets and makes stable multi electrospray jets for continuously ejection for a long time.The ejection and deposition behaviors of multi electrospray jets were investigated and the effects of sheath gas on the threshold voltage of multi electrospray jet ejection and the uniformity of nano particles were analyzed.The experiments show that the sheath gas is beneficial to the decrease of threshold voltages of multi electrospray jets and the diameters of electrospray nano particles and to the increase of the uniformity of nano particles.When the supply pressure of assisted gas increases from 0kPa to 50 kPa,the threshold voltage of multielectrospray jet ejection decreases from 4.9kV to 2.8kV and the average diameter of nano particles decreases from 845.267 nm to 528.06 nm.It concludes that introducing the assisted gas into electrospray spinneret provides a good way to rapidly fabricate the nano particles through multi-jet electrospray.This work would promote the application research of electrospray technology.国家自然科学基金资助项目(No.51305373); 福建省科技计划重大项目(No.2012H6022); 福建省自然科学基金资助项目(No.2013J05083

尉犁蛭石微波膨胀试验研究

对新疆尉犁蛭石样品采用微波加热法和900℃电加热法制备膨胀蛭石,并对制备的膨胀蛭石样品进行SEM、XRD分析。结果表明:微波法制备的膨胀蛭石层与层之间分离彻底,层间孔隙多,平均膨胀度大于电加热膨胀蛭石的;蛭石层间距变化小;蛭石层间铁离子没有发生氧化反应,膨胀后颜色为银灰色,蛭石不发脆。对蛭石样品用不同功率相同时间、相同功率不同时间微波加热后发现:微波加热时间为50s、功率为400W时蛭石的膨胀度最大

尉犁蛭石微波膨胀试验研究

对新疆尉犁蛭石样品采用微波加热法和900℃电加热法制备膨胀蛭石,并对制备的膨胀蛭石样品进行SEM、XRD分析。结果表明:微波法制备的膨胀蛭石层与层之间分离彻底,层间孔隙多,平均膨胀度大于电加热膨胀蛭石的;蛭石层间距变化小;蛭石层间铁离子没有发生氧化反应,膨胀后颜色为银灰色,蛭石不发脆。对蛭石样品用不同功率相同时间、相同功率不同时间微波加热后发现:微波加热时间为50s、功率为400W时蛭石的膨胀度最大

高速转子用非接触式迷宫密封的密封性能影响因素研究

为了提高高速齿轮箱密封装置的密封性能，对常用于石油、化工等领域中的高速齿轮传动装置的非接触式迷宫密封进行了分析。通过建立（Computational fluid dynamics，CFD）数值计算模型，分析了该密封装置的密封齿数量、密封压差、油气混合物浓度、甩油环位置等因素对各密封腔回油口回油量及漏油口泄漏量的影响。研究对高速齿轮箱用非接触式迷宫密封的设计具有指导意义

基于组合优化策略在毕赤酵母中高效表达 杜邦嗜热菌脂肪酶High-efficient expression of Thermomyces dupontii lipase in Pichia pastoris based on combinatorial optimization strategy

杜邦嗜热菌脂肪酶(LIP1)是一种在洗涤行业、生物柴油制备、油脂改性等领域具有良好应用潜力的碱性脂肪酶，然而其天然产量极低，难以满足产业化需求。采用组合优化策略筛选出高效表达LIP1的毕赤酵母重组菌株。首先，构建毕赤酵母密码子偏好性优化的LIP1基因，通过高浓度G418抗性平板和BMMY-罗丹明B定性平板筛选出脂肪酶活性较高的重组菌株；其次，利用信号肽优化和分子伴侣共表达优化筛选得到一株高效表达的重组毕赤酵母菌株GS115/pPIC9K-Mss-SSA4-LIP1，采用碱滴定法测定其酶活,采用比色法测定其底物特异性。结果表明，经组合优化策略筛选出的菌株在摇瓶和5 L发酵罐中发酵最高分泌酶活分别达到1 136 U/mL和12 150 U/mL。底物特异性结果显示重组脂肪酶LIP1最适底物为C8链长的对硝基苯酚酯。综上所述，基于组合优化策略实现了LIP1在毕赤酵母中的高效表达，为未来LIP1的产业化奠定基础。 Thermomyces dupontii lipase (LIP1) is an alkaline lipase, which posses good application potential in washing industry, biodiesel preparation, oil modification, etc. However, the natural productivity of LIP1 is extremely too low to meet the requirements of industrial application. A combinatorial optimization strategy was applied for the screening of Pichia pastoris strain highly expressing LIP1. Firstly, a Pichia pastoris prefered codon optimized LIP1 gene was constructed, and the recombinant strain with higher LIP1 gene copy numbers was screened through high-concentration G418 plates and BMMY-rhodamine B qualitative plates. Moreover, through signal peptides optimization and chaperone co-expression optimization, a high-productivity recombinant Pichia postoris strain GS115/pPIC9K-Mss-SSA4-LIP1 was obtained.The enzyme activity was determined by alkali titration,and the substrate specificity was determined by colorimetric assay. The results showed that the highest secretive activity of the strain after combinatorial optimization strategy could reach1 136 U/mL in flask fermentation and 12 150 U/mL in 5 L fermenter, The substrate specificity result showed that the most suitable substrate for Pichia pastoris recombinanted LIP1 was p-nitrophenol ester with eight carbons.In conclusion, the high-efficient expression of LIP1 in Pichia pastoris can be realized based on the combinatorial optimization strategy, which will lay the foundation for the future industrialization of LIP1

JUNO Sensitivity on Proton Decay p→νˉK+p\to \bar\nu K^+ Searches

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this paper, the potential on searching for proton decay in $p\to \bar\nu K^+$ mode with JUNO is investigated.The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits to suppress the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via $p\to \bar\nu K^+$ is 36.9% with a background level of 0.2 events after 10 years of data taking. The estimated sensitivity based on 200 kton-years exposure is $9.6 \times 10^{33}$ years, competitive with the current best limits on the proton lifetime in this channel