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991.
X-ray diffraction, compositional analysis, and 29Si and 27Al MAS NMR spectroscopy of Al-substituted tobermorite-type C-S-H made by precipitation from solution provide significant new insight into the structural mechanisms of Al-substitution in this important and complicated phase. Al occurs in 4-, 5-, and 6-coordination (Al[4], Al[5], and Al[6]) and plays multiple structural roles. Al[4] occurs on the bridging tetrahedra of the drierkette Al-silicate chains, and Al[5] and Al[6] occur in the interlayer and perhaps on particle surfaces. Al does not enter either the central Ca-O sheet or the pairing tetrahedra of the tobermorite-type layers. Al[4] occurs on three types of bridging sites, Q3 sites that bridge across the interlayer; Q2 sites that are charge balanced by interlayer Ca+2, Na+, or H+; and Q2 sites that are most likely charge balanced by interlayer or surface Al[5] and Al[6] through Al[4]-O-Al[5,6] linkages. Although the data presented here are for relatively well-crystallized tobermorite-type C-S-H with C/S ratios ≤ 1.2, comparable spectral features for hydrated white cement pastes in previously published papers[30], [31] and [32] [M.D. Andersen, H.J. Jakobsen, J. Skibsted, Incorporation of aluminum in the calcium silicate hydrate (C-S-H) of hydrated Portland cements: a high-field 27Al and 29Si MAS NMR investigation Inorg. Chem. 42 (2003) 2280-2287; M.D. Andersen, H.J. Jakobsen, J. Skibsted, Characterization of white Portland cement hydration and the C-S-H structure in the presence of sodium aliminate by 27Al and 29Si MAS NMR spectroscopy, Cem. Concr. Res. 43 (2004) 857-868; M.D. Andersen, H. J. Jakobsen, J. Skibsted, A new aluminum-hydrate phase in hydrated Portland cements characterized by 27Al and 29Si MAS NMR spectroscopy, Cem. Concr. Res., submitted for publication.] indicate the presence of similar structural environments in the C-S-H of such pastes, and by implication OPC pastes.  相似文献   
992.
In this paper, two multi-party quantum private comparison (MQPC) protocols are proposed in distributed mode and traveling mode, respectively. Compared with the first MQPC protocol, which pays attention to compare between arbitrary two participants, our protocols focus on the comparison of equality for \(n\) participants with a more reasonable assumption of the third party. Through executing our protocols once, it is easy to get if \(n\) participants’ secrets are same or not. In addition, our protocols are proved to be secure against the attacks from both outside attackers and dishonest participants.  相似文献   
993.
Graft copolymerization of acrylic acid (AA) onto polyphenylene sulfide (PPS) nonwoven initiated by low temperature plasma was studied. The effects of various conditions on graft reaction and the grafting rate were investigated. SEM images showed that PPS nonwoven was grafted, and the graft copolymerization only occurred on the surface of PPS. It may be due to the chain transference going with the graft copolymerization. It was found that with the increasing of plasma power, treatment time, space between electrodes, monomer concentration, and temperature of graft polymerization, the grafting rate increased at first, went to the top, and then decreased. The PPS nonwoven surface graft reaction could be optimized by the following processing conditions: 120 s of plasma treatment time, 50 W of plasma power, 1.5 cm of space between electrodes, 30% (w/w) of monomer concentration, and 50°C of temperature of graft polymerization. Measurement of XPS showed that the peak of C1s of graft polyacrylic acid was existed, and the peak area increased with the increase of the grafting rate. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 5884–5889, 2006  相似文献   
994.
α—呋喃丙酸酯香料的合成研究   总被引:2,自引:0,他引:2  
以糠醛为原料 ,通过三步反应合成了α-呋喃丙酸甲酯、乙酯、正丙酯、异丙酯、正丁酯、正戊酯等六种呋喃丙酸酯香料。此外 ,通过正交实验对呋喃丙酸甲酯的合成条件进行了优化。  相似文献   
995.
Deutsch–Jozsa algorithm has been implemented via quantum adiabatic evolutions by Das et al. (Phys Rev A 65:062310, 2002) and Wei et al. (Phys Lett A 354:271, 2006). In the latter literature, the authors have shown a modified version of the adiabatic evolution which can improve the performance of the algorithm of S. Das et al’s to constant time. In this paper, we also improve the algorithm of S. Das et al’s in a constant time but by using a different construction of adiabatic evolution, i.e., adding ancillary qubits. The algorithm in this paper provides an alternative option to potential users.  相似文献   
996.
In this paper, we first uncover a fact that a partial adiabatic quantum search with \(O(\sqrt{N/M})\) time complexity is in fact optimal, in which \(N\) is the total number of elements in an unstructured database, and \(M\) ( \(M\ge 1\) ) of them are the marked ones(one) \((N\gg M)\) . We then discuss how to implement a partial adiabatic search algorithm on the quantum circuit model. From the implementing procedure on the circuit model, we can find out that the approximating steps needed are always in the same order of the time complexity of the adiabatic algorithm.  相似文献   
997.
In this paper, we present a QKA protocol with the block transmission of EPR pairs. There are several advantages in this protocol. First, this protocol can guarantee both the fairness and security of the shared key. Second, this protocol has a high qubit efficiency since there is no need to consume any quantum state except the ones used for establishing the shared key and detecting eavesdropping. In addition, this protocol uses EPR pairs as the quantum information carriers and further utilizes single-particle measurements as the main operations. Therefore, it is more feasible than the protocols that need to perform Bell measurements. Especially, we also introduce a method for sharing EPR pairs between two participants over collective-dephasing channel and collective-rotation channel, respectively. This method is meaningful since sharing EPR pairs between two participants is an important work in many quantum cryptographic protocols, especially in the protocols over non-ideal channels. By utilizing this method, the QKA protocols, which are based on EPR pairs, can be immune to these kinds of collective noise.  相似文献   
998.
Jakobi et al. for the first time proposed a novel and practical quantum private query (QPQ) protocol based on SARG04 (Scarani et al. in Phys Rev Lett 92:057901, 2004) quantum key distribution protocol (Jakobi et al. in Phys Rev A 83:022301, 2011). Gao et al. generalized Jakobi et al’s protocol and proposed a flexible QPQ protocol (Gao et al. in Opt Exp 20(16):17411–17420, 2012). When $\theta <\pi /4$ , Gao et al’s protocol exhibits better database security than Jakobi et al’s protocol, but has a higher probability with which Bob can correctly guess the address of Alice’s query. In this paper, we propose a flexible B92-based QPQ protocol. Although SARG04 protocol is a modification of B92 protocol and can be seen as a generalization of B92 protocol, our protocol shows different advantages from Gao et al’s protocol. It can simultaneously obtain better database security and a lower probability with which Bob can correctly guess the address of Alice’s query when $\theta <\pi /4$ . By introducing entanglement, the proposed QPQ protocol is robust against channel-loss attack, which also implies lower classical communication complexity. Similar to Gao et al’s protocol, it is flexible, practical, and robust against quantum memory attack.  相似文献   
999.
The formation of three-dimensional (3D) multicellular cell spheroids such as microspheres and embryoid bodies has recently gained much attention as a useful cell culture technique, but few studies have investigated the suitability of glass for spheroids formation and culture. In this work, we present a novel three-dimensional microfluidic device made of poly(dimethylsiloxane) (PDMS) and glass for the easy and rapid synthesis and culture of tumor spheroid. The cell culture unit is composed of an array of microwells on the bottom of a glass plate, bigger microwells and elastomeric microchannels on the top of a PDMS plate. Cell suspension can be easily introduced into the cell culture unit and exchange with the external liquid environment by the microfluidic channels. A single tumor spheroid can be formed and cultured in each glass cell culture chamber, the surface of which was modified with poly(vinyl alcohol) to render it to be resistant to cell adhesion. As the cell culture medium could be replaced, spheroids of the human breast cancer (MCF-7) cells were cultured on the chip for 3 days, reaching the diameters of about 150 μm. Furthermore, the MCF-7 cells were successfully cultured on the chip in 2D and 3D culture modes. Results have shown that glass is well suitable for multicellular tumor spheroids culture. The established platform provides a convenient and rapid method for tumor spheroid culture, which is also adaptable for anticancer drug screening and fundamental biomedical research in cell biology.  相似文献   
1000.
Deterministic optimization has been successfully applied to a range of design problems involving foam-filled thin-walled structures, and to some extent gained significant confidence for the applications of such structures in automotive, aerospace, transportation and defense industries. However, the conventional deterministic design could become less meaningful or even unacceptable when considering the perturbations of design variables and noises of system parameters. To overcome this drawback, a robust design methodology is presented in this paper to address the effects of parametric uncertainties of foam-filled thin-walled structure on design optimization, in which different sigma criteria are adopted to measure the variations. The Kriging modeling technique is used to construct the corresponding surrogate models of mean and standard deviation for different crashworthiness criteria. A sequential sampling approach is introduced to improve the fitness accuracy of these surrogate models. Finally, a gradient-based sequential quadratic program (SQP) method is employed from 20 different initial points to obtain a quasi-global robust optimum solution. The optimal solutions were verified by using the Monte Carlo simulation. The results show that the presented robust optimization method is fairly effective and efficient, the crashworthiness and robustness of the foam-filled thin-walled structure can be improved significantly.  相似文献   
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