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921.
XingLan Zhang 《科学通报(英文版)》2009,54(12):2018-2021
Based on public key, a quantum identity authenticated (QIA) system is proposed without quantum entanglement. The public key acts as the authentication key of a user. Following the idea of the classical public key infrastructure (PKI), a trusted center of authentication (CA) is involved. The user selects a public key randomly and CA generates a private key for the user according to his public key. When it is necessary to perform QIA, the user sends a sequence of single photons encoded with its private key and a message to CA. According to the corresponding secret key kept by CA, CA performs the unitary operations on the single photon sequence. At last, the receiver can judge whether the user is an impersonator. 相似文献
922.
The Wiener index of a connected graph (molecule graph) G is the sum of the distances between all pairs of vertices of G. In this paper, simple exact formula are established for the expected value of Wiener index in random cyclooctane chain. Moreover, we obtain the average value of the Wiener indices with respect to the set of all cyclooctane chains with n octagons. 相似文献
923.
This paper proposes a distributed dynamic k-medoid clustering algorithm for wireless sensor networks (WSNs), DDKCAWSN. Different from node-clustering algorithms and
protocols for WSNs, the algorithm focuses on clustering data in the network. By sending the sink clustered data instead of
practical ones, the algorithm can greatly reduce the size and the time of data communication, and further save the energy
of the nodes in the network and prolong the system lifetime. Moreover, the algorithm improves the accuracy of the clustered
data dynamically by updating the clusters periodically such as each day. Simulation results demonstrate the effectiveness
of our approach for different metrics.
Biography: WANG Leichun (1974–), male, Ph.D. candidate, research direction: wireless communication. 相似文献
924.
It has been found that high-order deformation (e.g.β6) can have important effects on the structures of superheavy nuclei. In the present work, we investigate octupole deformation effects on superheavy nuclei with an improved potential-energy-surface (PES) calculation by including reflection-asymmetric deformations in a space of (β2 ,β3 ,β4 , β5). The calculations give various deformations including highly deformed (β2 ≈ 0.4) and superdeformed (β2 ≈ 0.7) shapes. The octupole-deformation degree of freedom mainly affects the fission barrier beyond the second minimum of PES. 相似文献
925.
ZeHong Zou Ying He Lin Ruan BaoQing Sun HuiFang Chen De Chen ShiMing Liu XiaoGuang Yang AiLin Tao 《科学通报(英文版)》2012,57(15):1824-1832
The potential of genetically modified organisms(GMOs) to increase allergenicity or predispositions to allergies has attracted much attention.An approach that will properly and holistically evaluate the allergenicity of GMOs is yet to be found.Here,85 transgenes that have been reported in both international and domestic studies during recent years are summarized case by case;49 of the transformed genes were from plant sources and 36 were from animal sources.EVALLERTM,a web server for the in silico assessment of potential protein allergenicity,was used to evaluate the potential of the transgenic proteins as allergens.The biomedical journals listed in Highwire(http://highwire.stanford.edu/) were searched and reviewed to decipher whether any of the transformed genes were linked to allergenicity or human health.The EVALLER analysis identified 5 allergenic genes,whilst our literature review found 11 genes that were either related to allergic cases or to clinical adverse events;all 16 of these genes have been used in GMOs.The analysis pathway that we have developed can help guide the selection of genes to be used in genetic modification.The pathway also provides a paradigm for allergenicity analysis of transgene candidates. 相似文献
926.
Benzimidazolium-based receptors 1-3 were designed and synthesized. On the basis of fluorescence, UV-Vis, and 1H NMR spectroscopic studies, and X-ray single crystal structure analysis, it was confirmed that the receptor 1 displays strong (C-H)+···X, N-H···X hydrogen bonds and charge-charge interactions with anions. More importantly, these investigations demonstrated that the charged (C-H)+ benzimidazolium and urea moieties play a synergistic role in anion recognition. 相似文献
927.
High-speed all-optical logic circuits have attracted much attention because of their important roles in signal processing in next-generation optical networks.The digital encoder is widely used in binary calculation,multiplexing,demultiplexing,address recognition and data encryption.A priority encoder allows the existence of multiple valid inputs simultaneously,identifies the priority of the request signals and encodes the priority.We propose and experimentally demonstrate an all-optical 4-bit priority encoder for return-to-zero signals at 40 Gbit/s based on cross-gain modulation in semiconductor optical amplifiers.Detuning fil-ters after semiconductor optical amplifiers are employed to improve the output performance.Correct logic bit sequences and clear open eye patterns with extinction ratios exceeding 10 dB are achieved. 相似文献
928.
LI YiPing HE LangChong 《科学通报(英文版)》2007,52(7):922-928
A model of vascular endothelial cell membrane chromatography was established by using an ECV304 cell membrane stationary phase (ECV304 CMSP) prepared by immobilizing the ECV304 cell membrane onto the surface of silica carrier. The surface and chromatographic characteristics of ECV304 CMSP were studied. The active component from Caulophyllum robustum was screened by using the model of vascular endothelial cell membrane chromatography. The interaction between the active component and membrane receptor was determined by using a replace experiments. The effect of the active component was tested by using tube formation of ECV304 cell. The results indicated that the model of ECV304 cell membrane chromatograph (ECV304 CMC) can stimulate the interaction between drug and receptor in vitro and the retention characteristics of taspine as active component was similar to that of model molecule in the model of ECV304 CMC. And therefore, taspine acted on VEGFR2 and inhibited the tube formation of ECV304 cell induced by VEGF. This model can be used to screen definite active component as a screening model. 相似文献
929.
Variations in equilibrium line altitude of the Qiyi Glacier,Qilian Mountains,over the past 50 years 总被引:6,自引:0,他引:6
Based on observations of the equilibrium line altitude (ELA) of the Qiyi Glacier in the Qilian Mountain, we established a
statistical model between ELA and its major influencing factors, warm season air temperature (air temperature averages for
September, July and August) and cold season precipitation (total precipitation in the period January through March). Warm
season air temperature was the leading climatic factor influencing ELA variations. The glacier ELA ascends (descends) 172
m when warm season air temperature increases (decreases) by 1°C, and ascends (descends) 62 m when cold season precipitation
decreases (increases) by 10%. In the period 1958–2008, the glacier ELA showed a general increasing trend, ascending 230 m
and reaching its highest altitude in 2006 at 5131 m a.s.l., close to the glacier summit. If future climate is similar to that
in the period 2001–2008, the Qiyi Glacier will not stabilize until it retreats by 2.08 km. 相似文献
930.
The probability density function of irradiance fluctuations in a turbulent atmosphere remains an open topic of research.It is generally considered that the speckle field has an elliptical-Gaussian speckle distribution,but because of its complexity there is still no exact analytical solution.By introducing the concept of random fluctuation intensity and using an equiprobability density ellipse,exact models of the random fluctuation intensity and its phase are proposed.Through theoretical analysis and numerical simulation,it is concluded that the random fluctuation intensity and its corresponding phase are independent only under the circular-Gaussian approximation. 相似文献