ISSN 0253-2778

CN 34-1054/N

2012 Vol. 42, No. 4

Display Method:
An applicable multiple-players quantum market game
SUN Min, LU Dawei, JU Chenyong, QIN Gan, DU Jiangfeng
2012, 42(4): 259-264. doi: 10.3969/j.issn.0253-2778.2012.04.001
The quantum game of the classical Bertrands duopoly model was generalized to N-player case. In a quantized game, the more entanglement is involved, the higher maximal profits it will be. It monotonously increases until the optimal collusive profit, which is restricted, and cannot be achieved in its classical game. With partial information entanglement between two adjacent firms, the generalizing evolutionary N-player Bertrands model not only solved the Bertrand paradox, but also achieved a practical result.
Dynamic monitoring system with double-wire BPM of the macromolecular crystallography beamline 1W2B at BSRF
CHANG Guangcai, GUO Xian, SHI Hong, LI Ming, GAN Quan, LIU Peng
2012, 42(4): 265-269. doi: 10.3969/j.issn.0253-2778.2012.04.002
The stability of the synchrotron radiation (SR) beams position is essential to beam flux, and it will also directly affect the quality of the experiment data. It is therefore necessary to monitor the beam position in real-time during the whole experiment. The double-wire type BPM (beam position monitor) is normally used to scan the beam profile and it can also monitor the beam position in a fixed position. But this kind of monitoring demands a special beam distribution because when the beam greatly deviates from the original position, the double-wire BPM might face the threat of damage. By means of the dynamic real-time tracking mode, 1W2B macromolecular beamline of BSRF (Beijing Synchrotron Radiation Facility) has solved the problems of the routine monitoring mode, such as beam distribution and the damage of the photosensitive wires, thus providing a basis for the study of beam stability.
Response of elastic-plastic plate embedded cracks at different orientation under impact load
LIU Lei, LIU Yadong, ZHANG Yajun, XU Shengli
2012, 42(4): 270-278. doi: 10.3969/j.issn.0253-2778.2012.04.003
Three-dimensional computation was carried out on the dynamic response of metal plate embedded at the different inclined cracks under parallel impact load. To describe the elastic-plastic material, an increase type of constitutive relationship was adopted and governing equation in Lagrangian form was solved by finite element method(FEM). Referring to LS-DYNA commercial code, six types of failure criteria based on stress and strain respectively indicate the fatigued elements which represent the cracks. During the loading, stress waves are generated which propagate inwards the plate and lead to the stress concentration around the crack tips. Meanwhile, new cracks are formed evolving from the crack tips. In contrast to the loading, the vertical cracks propagate perpendicularly and the parallel ones propagate horizontally. But these new cracks are independent of the inclination of the embedded cracks. The stress time history at each point in the plate is approximately related to the distance to the tips and either independent of the crack inclination. Moreover, the distances to the tips and plate frontier, and loading walls mainly affect the local strain time history. This means that the local strain is determined by the time integration of the plate loading. If the load amplitude is below a threshold value, the cracks do not prolong further. Otherwise, it takes a long time to release the strain energy concentrated around the tips, which postpones the appearance of the parallel cracks.
Nonlinear flow characteristics in low-permeability reservoirs with stress sensitive effect
LIU Wenchao, YAO Jun, LI Aifen, SUN Zhixue, HUANG Zhaoqin
2012, 42(4): 279-288. doi: 10.3969/j.issn.0253-2778.2012.04.004
Based on the continuity of the derivative of the nonlinear seepage velocity function in low-permeability reservoirs, the nonlinear kinematic equation in the real number field for the low-permeability reservoirs was deduced. The mathematical formula of the apparent permeability and the apparent pseudo threshold pressure gradient were defined. It was demonstrated that the continuous derivative of the seepage velocity function was consistent with the continuous permeability change. The mathematical model of the nonlinear flow in low-permeability reservoirs with stress sensitive effect under the condition of constant well production rate was constructed. Owing to its strong nonlinearity, efficient Douglas-Jones predictor-corrector finite difference method was adopted to obtain its numerical solution. Moreover, its accuracy was verified by comparison with the numerical solution obtained by the fully implicit finite difference method. Result analysis shows: log-log curves of dimensionless transient wellbore pressure corresponding to the nonlinear kinematic equation and pseudo-linear kinematic equation both have inflexions at the initial period. And the inflexion corresponding to the pseudo-linear one is more obvious; the permeability modulus has a major effect on the second half of these curves; the bigger its value, the sharper the pressure drop; there exists a moving boundary in the nonlinear flow in low-permeability reservoirs; the moving boundary of the pseudo-linear flow moves more slowly than that of the nonlinear flow.
Design of a compact planar inverted-F antenna
HU Chaobin, ZHU Qi
2012, 42(4): 289-295. doi: 10.3969/j.issn.0253-2778.2012.04.005
Considering the disadvantage of the traditional planar inverted-F antenna (PIFA), a miniaturization PIFA applied in the wireless local area network (WLAN) wireless router was proposed. The dimension of the antenna and PCB, the antennas placement on the PCB and parameters of the plastic shell were investigated to improve the performance. Due to the small size and simple feed structure, the proposed antenna can be feasibly integrated on the PCB. The measured results show that a bandwidth between 235 GHz and 25 GHz with return loss less than -10 dB can be achieved. Meanwhile, the radiation beam width of this antenna is much wider than that of the traditional PIFA. The nearly isotropic radiation patterns guarantee the reception of signals in all directions.
Anonymous identity-based encryption scheme without random oracles
REN Yanli, GU Dawu, WANG Shuozhong, ZHANG Xinpeng
2012, 42(4): 296-301. doi: 10.3969/j.issn.0253-2778.2012.04.006
The anonymous identity-based encryption (IBE) schemes are currently only selective-ID secure without random oracles or provably secure under a complex assumption. An anonymous IBE scheme based on decisional bilinear Diffie-Hellman (BDH) assumption in a group of composite order was proposed, which is ANON-IND-ID-CPA secure without random oracles and only needs two bilinear pairing computations. This scheme is more secure and efficient than the existing ones.
Functional evolution of Eukaryote DNA ligase Ⅲ
JIN Chunyan, SHENG Zizhang, HUANG Jingfei
2012, 42(4): 302-310. doi: 10.3969/j.issn.0253-2778.2012.04.007
Previous studies revealed that DNA ligase Ⅲ was restricted to vertebrates and functioned in nucleus DNA repair and mitochondria DNA replication and repair. Although recent researches have reported that DNA ligase Ⅲ is also found in non-vertebrates, little attention has been devoted to the distribution and functional evolution of DNA ligase Ⅲ. To probe the functional evolution of DNA ligase Ⅲ, database searches, mitochondrial localization signal prediction (MLS) and functional conservation analysis were performed. The results show that, DNA ligase Ⅲ can be observed in amoebozoa, metazoa and choanoflagellates, but the whole protein or some domains are lost in some species including fungi. The MLS prediction analysis suggests that, the DNA ligase Ⅲ in many species can not function in mitochondria, and is consequently less likely to play a role for DNA ligase Ⅲ in mitochondria. The conservation analyses of functional site demonstrate that nucleus DNA repair is an ancient and conserved function of DNA ligase Ⅲ.
The role of CXCR7 on the proliferation, adhesion and invasion of HeLa cells
SUN Wei, CAI Shaoxi, YAN Xiaoqing, CHEN Sijia, SONG Zhen, YE Qunfang
2012, 42(4): 311-317. doi: 10.3969/j.issn.0253-2778.2012.04.008
Stromal cell-derived factor 1 (SDF-1) is a principal regulator of tumor invasion and metastasis. SDF-1 had been considered to mediate biological process through its unique receptor CXC chemokine receptor 4 (CXCR4) for many years.Recent studies reported that SDF-1 was also a ligand of a novel chemokine receptor-CXC chemokine receptor 7(CXCR7). It was confirmed that CXCR7 plays an important role in invasion and metastasis of several types of tumor induced by SDF-1.However, its role in cervical cancer is still unclear. In the present study, the expressions of CXCR4 and CXCR7 on HeLa cells were detected by Western blotting and the effects of CXCR4 and CXCR7 on cell behaviors were tested by blocking with their antagonists, respectively. Cell proliferation, cell invasion and cell adhesion were evaluated by MTT, Transwell assay, adhesion assay, respectively. Results reveal that both CXCR4 and CXCR7 are expressed on HeLa cells. The proliferation, invasion and adhesion of HeLa cells induced by SDF-1 are inhibited by CXCR4 blockage or CXCR7 blockage. These results suggest that CXCR7 can mediate proliferation, invasion and adhesion of HeLa cells induced by SDF-1, which indicates that CXCR7 is a potential target for cervical cancer therapy.
Research on mechanisms of pyrolysis of wheat straw
LI Xiaomin, LI Yongping, DENG Quanwei, LIN Qizhao
2012, 42(4): 318-324. doi: 10.3969/j.issn.0253-2778.2012.04.009
A thermogravimetric experiment was performed to investigate the mass loss of wheat straw in inertial ambience of nitrogen. The results show that, in the process of mass loss, there exist three stages: preheat drying, pyrolysis and thermal decomposition of inorganic components, accompanying mild carbonization in the third stage. At the same time, the characteristic parameters, such as onset temperature, final temperature and peak temperature, increase along with the increase of heating rate. Furthermore, the dual extrapolation method was utilized to obtain appropriate kinetic mechanisms to model the pyrolysis of wheat straw. It was concluded that the mechanisms of pyrolysis for wheat straw follow second-order reaction. In addition, the parameters of chemical kinetics, such as activation energy and frequency factor, were obtained as well. The preliminary comparisons between the model and the experimental data validate the reliability of the kinetic mechanisms as a whole. Finally, the causes of the discrepancy were analyzed.
Effect of fuel air equivalence ratio on the flameless combustion of liquid hydrocarbon
CUI Yunjing, YE Taohong, LIN Qizhao
2012, 42(4): 325-334. doi: 10.3969/j.issn.0253-2778.2012.04.010
A laboratory scale model combustor was designed based on flameless combustion of liquid spray in a microturbine atmosphere. The effects of fuel (0# diesel)/air equivalence ratio Φ on the flow field, combustion regime, range of flameless mode, temperature and pollution emissions of the model combustor were studied mainly through experiments and supplementally numerical computation. The results indicate that there is an obvious ring vortex in the flow field, which provides a basis of fluid dynamics for the recirculation of high-temperature exhaust gases. The mixture of species around the fuel nozzle is significant to the conversion of the combustion regime. The operation range of the flameless mode in the model combustor is 025≤Φ≤050, and in which the combustion temperature is homogeneous. The average chamber temperature Tavg and pollutant emissions are impacted by Φ and the thermal input. At the same thermal input conditions, Tavg increases and the emissions of CO and NOx drop with increasing Φ in the experimental range. At the same Φ condition, Tavg drops and the emissions of CO and NOx increase with the decrease in thermal input. The lower the thermal input, the faster the growth in CO emission amount, while NOx is affected much less. It can be concluded from the analysis that appropriate preheating of combustion air is an effective way to enhance the lean combustion stability with low chamber heat density and expand lean flammability.
Study on thermal storage performance of solar KANG and thermal comfort for sleeping environments
JIANG Qingyang, HE Wei, JI Jie, WEI Wei
2012, 42(4): 335-344. doi: 10.3969/j.issn.0253-2778.2012.04.011
According to the traditional fire KANG characteristics, a solar heating system named solar KANG was proposed and a theoretical study of solar KANG system was presented. Experiments of the solar KANG system were conducted and experimental tests were performed. The theoretical results are in good agreement with the experiment results. Based on the validated model and real time meteorological data of Hefei, thermal comfort in sleeping environments and indoor thermal environments were studied when the solar KANG system was in operation in winter. Results show that indoor air temperature varies between 8 ℃ to 15 ℃ when outdoor temperature is about 0 ℃ and KANG surface temperature is no more than 35 ℃. After stopping heating at 21 oclock at night, sleeping environments can be kept at the comfortable range of 28.5 ℃ to 34 ℃ with thermal energy stored in KANG releasing gradually. Solar contribution rate is about 345%.