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991.
Hao Yuan Yi-min Liu Guo-zhu Pan Gang Zhang Jun Zhou Zhan-jun Zhang 《Quantum Information Processing》2014,13(11):2535-2549
A quantum identity authentication scheme based on ping-pong technique without entanglements is proposed. It can verify the legitimate user’s identity and update the initial authentication key for reuse. The security of the proposed scheme is extensively analyzed and accordingly confirmed in the case of general individual attacks. The present scheme owns high efficiency due to the use of single-particle states in a two-way quantum channel. Moreover, the scheme is economical and feasible with present-day technique. 相似文献
992.
Xin Huo Kai Zheng Kemao Ma 《International Journal of Control, Automation and Systems》2014,12(4):733-741
In order to improve flexibility of sliding mode control (SMC) for a class of nonlinear systems, a new control design method is proposed in this paper. The sliding surface is extended to be a generic Lipschitz continuous surface instead of a smooth one, with which different characteristics of sliding motion may be realized. Due to the nonsmoothness of the sliding surface, the control design problem is discussed in the framework of Filippov’s differential inclusion, by analyzing the geometric properties of the nonsmooth surface. Discontinuous control laws are presented based on new contingent cone criteria, which steer all of the trajectories of the closed-loop system to reach the piecewise smooth sliding surface in finite time. 相似文献
993.
Qiang?Chen Gang?LiEmail author Yuan?Nie Shuhuai?Yao Jianlong?ZhaoEmail author 《Microfluidics and nanofluidics》2014,16(1-2):83-90
Reversibly assembled microfluidic devices are dismountable and reusable, which is useful for a number of applications such as micro- and nano-device fabrication, surface functionalization, complex cell patterning, and other biological analysis by means of spatial–temporal pattern. However, reversible microfluidic devices fabricated with current standard procedures can only be used for low-pressure applications. Assembling technology based on glass–PDMS–glass sandwich configuration provides an alternative sealing method for reversible microfluidic devices, which can drastically increase the sealing strength of reversibly adhered devices. The improvement mechanism of sealing properties of microfluidic devices based on the sandwich technique has not been fully characterized, hindering further improvement and broad use of this technique. Here, we characterize, for the first time, the effect of various parameters on the sealing strength of reversible PDMS/glass hybrid microfluidic devices, including contact area, PDMS thickness, assembling mode, and external force. To further improve the reversible sealing of glass–PDMS–glass microfluidic devices, we propose a new scheme which exploits mechanical clamping elements to reinforce the sealing strength of glass–PDMS–glass sandwich structures. Using our scheme, the glass–PDMS–glass microchips can survive a pressure up to 400 kPa, which is comparable to the irreversibly bonded PDMS microdevices. We believe that this bonding method may find use in lab-on-a-chip devices, particularly in active high-pressure-driven microfluidic devices. 相似文献
994.
Shuangling Dong Liancun Zheng Xinxin Zhang Songping Wu Bingyu Shen 《Microfluidics and nanofluidics》2014,16(1-2):131-139
A new expression is proposed to simulate Brownian force based on the experimental measurement results of Brownian motion, which follows white Gaussian noise process. As the time t → 0 and the particle density is equal to the fluid density, the new expression approaches the classical formula of the model used by many researchers. The modified model is validated by theoretical and experimental data. On the other hand, as it origins from the unbalanced force exerted by surrounding fluid molecules, the drag analogy force model is constructed describing the Brownian force, which depends on size-related statistical velocity. Thus, a different expression for the Langevin equation is presented. The present model is applied in simulating flow and heat transfer in a channel utilizing alumina–water nanofluid. Navier–Stokes equations with modified source terms for the continuous flow have been discretized using finite element method. The velocities and temperatures of nanoparticles are determined in the Lagrangian reference frame. The simulation results show that the distribution of nanoparticles inside the channel is obviously unsteady and nonuniform. The fluid velocity and temperature profiles show significant fluctuation feature at low Reynolds numbers (Re). The impact of Brownian motion on the fluid flow is analyzed quantitatively. We have found that for Re < 0.06, the affected intensity increases rapidly. 相似文献
995.
双组分海岛型超细纤维及其染整工艺研究 总被引:1,自引:0,他引:1
采用正交设计对海岛纤维进行了碱减量开纤处理,减量率为25%-35%。在优化条件下:NaOH:15g/L~20g/L;碱减量调节剂:0.1g/L~0.5g/L;耐碱渗透剂;1g/L~5g/L;80℃~85℃;25~30分钟,将海组分COPET除去,获得了0.039dt的超细纤维。此纤维染色时K/S值较高,提升同步性好,三原色临界温度为90℃~120℃,120℃时上染率达到90%、扩散性和迁移性好,获得各项牢度较好的匀染效果。对影响海岛纤维的织物风格、纤维开纤和染色的有关因素进行了讨论。 相似文献
996.
针对电子商务中的商品评论信息过载问题,运用情感计算理论,通过挖掘商品评论信息中的商品特征及相应的情感褒贬态度,为消费者提供一个商品特征粒度上的情感分析结果,从而帮助消费者从庞杂的商品评论中快速获取有效信息。系统首先采集指定商品的评论集并挖掘商品特征,然后结合情感语料库和词汇相似度计算,利用依存关系找到特征-极性词对以及程度副词和否定词。基于以上结果,考虑程度副词的强度,以及程度副词和否定词共现语序不同造成的语义差异,提出了商品评论情感倾向程度的计算方式。最后,进行系统实现并验证算法的有效性。实验结果表明,系统具有良好的应用效果。 相似文献
997.
研究开发了一次烷基化分离法生产高纯度均三甲苯新工艺,并对其进行了技术经济分析评价。生产实践表明,该工艺技术含量高,设备投资少,流程简单,容易操作,产品收率高,质量稳定,是理想的生产工艺。 相似文献
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