The quantum dynamics of an exciton dressed by acoustic pnonons in an optically driven quantum dotsemiconductor microcavity at finite temperatures is investigated theoretically by quantum optics methods. It is shown ...The quantum dynamics of an exciton dressed by acoustic pnonons in an optically driven quantum dotsemiconductor microcavity at finite temperatures is investigated theoretically by quantum optics methods. It is shown that the temperature dependence of the vacuum Rabi splitting is 2√2g×exp[ - ∑qλq（Nq＋1/2）],where Nq=1/[exp（ωq/kBT）-1] is the phonon population, g is the single-photon Rabi frequency, and λq corresponds to exciton-phonon coupling.展开更多
Aim In accordance with the positioning control for valve controlled motor electrohydraulic proportional servo systems driving the static load torque, the positioning performance was studied in the presence of the ti...Aim In accordance with the positioning control for valve controlled motor electrohydraulic proportional servo systems driving the static load torque, the positioning performance was studied in the presence of the time? varying deadzone and gain. Methods The large positioning errors caused by the time varying deadzone were significantly reduced by using the dynamic compensation method for the deadzone; and the large overshoot caused by the time varying gain were dramatically reduced by using the three section intelligent control schemes. Results Experimental results demonstrated that the positioning performance of rapid response, high accuracy and smaller or even no overshoot was achieved under a wide variations of load torque. Conclusion The good positioning performance for valve controlled motor servo systems has been achieved in the presence of the time varying deadzone and gain.展开更多
AIM： To examine the clinical characteristics of a subgroup of patients with hepatocellular carcinoma （HCC） and compare them to those with known risk factors. METHODS： We used the HCC database of 306 patients seen ...AIM： To examine the clinical characteristics of a subgroup of patients with hepatocellular carcinoma （HCC） and compare them to those with known risk factors. METHODS： We used the HCC database of 306 patients seen at our institution from January 1, 1995 to December 31, 2001. Of the 306 patients, 63 （20%, group 1） had no known risk factors （hepatitis C virus, hepatitis B virus, alcohol, hemochromatosis or cirrhosis from any cause） and 243 （group 2） had one or more risk factors. RESULTS： The median age was similar in both groups, but there were disproportionate numbers of younger （〈 30 years old）, older （〉 80 years） patients, women （33% vs 18%）, and Caucasians （81% vs 52%） in group 1 as compared to group 2. There were fewer Asians （2% vs 11%） and African Americans （13% vs 27%） in group 1. Abdominal pain （70% vs 37%） was more common while gastrointestinal bleeding （0% vs 11%） and ascites （4% vs17%） were less common in group i compared to group 2. Group 1 had larger tumor burden （median size 9.4 cm vs 5.7 cm） at the time of presentation, but there were no differences in the site （right, left or bilateral lesions）, or number of tumors between the two groups. CONCLUSION： HCC patients without identifiable risk factors have different characteristics and clinical presentation compared to those with known risk factors.Absence of cirrhosis and larger tumor burden may explain the differences in the presenting symptoms.展开更多
Security of the quantum secure direct communication protocol （i.e., the C-S QSDC protocol） recently proposed by Cao and Song [Chin. Phys. Lett. 23 （2006） 290] is analyzed in the case of considerable quantum channe...Security of the quantum secure direct communication protocol （i.e., the C-S QSDC protocol） recently proposed by Cao and Song [Chin. Phys. Lett. 23 （2006） 290] is analyzed in the case of considerable quantum channel noise. The eavesdropping scheme is presented, which reveals that the C-S QSDC protocol is not secure if the quantum bit error rate （QBER） caused by quantum channel noise is higher than 4.17%. Our eavesdropping scheme induces about 4.17% QBER for those check qubits. However, such QBER can be hidden in the counterpart induced by the noisy quantum channel if the eavesdropper Eve replaces the original noisy channel by an ideal one. Furthermore, if the QBER induced by quantum channel noise is lower than 4.17%, then in the eavesdropping scheme Eve still can eavesdrop part of the secret messages by safely attacking a fraction of the transmitted qubits. Finally, an improvement on the C-S QSDC protocol is put forward.展开更多
Aviation heavy-fuel spark ignition(SI)piston engines have been paid more and more attention in the area of small aviation.Aviation heavy-fuel refers to aviation kerosene or light diesel fuel,which is safer to use and ...Aviation heavy-fuel spark ignition(SI)piston engines have been paid more and more attention in the area of small aviation.Aviation heavy-fuel refers to aviation kerosene or light diesel fuel,which is safer to use and store compared to gasoline fuel.And diesel fuel is more suitable for small aviation application on land.In this study,numerical simulation was performed to evaluate the possibility of switching from gasoline direct injection spark ignition(DISI)to diesel DISI combustion.Diesel was injected into the cylinder by original DI system and ignited by spark.In the simulation,computational models were calibrated by test data from a DI engine.Based on the calibrated models,furthermore,the behavior of diesel DISI combustion was investigated.The results indicate that diesel DISI combustion is slower compared to gasoline,and the knock tendency of diesel in SI combustion is higher.For a diesel/air mixture with an equivalence ratio of 0.6 to 1.4,higher combustion pressure and faster burning rate occur when the equivalence ratios are 1.2 and 1.0,but the latter has a higher possibility of knock.In summary,the SI combustion of diesel fuel with a rich mixture can achieve better combustion performance in the engine.展开更多
For the detection and tracking of dim point targets with SNR 〈 2 dB, the combined SPRT and FSS method is given to accomplish detection in whicb likelihood testing are carried out twice to prune constantly. Firstly, t...For the detection and tracking of dim point targets with SNR 〈 2 dB, the combined SPRT and FSS method is given to accomplish detection in whicb likelihood testing are carried out twice to prune constantly. Firstly, the SPRT is developed aiming at the heuristic segments formed by correlation analysis. In order to avoid missing detection the threshold is chosen much lower. Secondly, by adding samples and choosing the one most similar to the heuristic segment to make state estimation FSS is implemented. This time we choose a higher threshold. Moreover in preprocessing the compound kernel estimation is designed to depress varying background clutter. Multiple experimental sequences validate that the method is more suitable for the dim targets detection and tracking compared with the scheme choosing the higher intensity pixel in tracking. It not only has perfect detection performance but also can greatly enhance tracking performance.展开更多
Proximal point algorithms （PPA） are attractive methods for solving monotone variational inequalities （MVI）. Since solving the sub-problem exactly in each iteration is costly or sometimes impossible, various approx...Proximal point algorithms （PPA） are attractive methods for solving monotone variational inequalities （MVI）. Since solving the sub-problem exactly in each iteration is costly or sometimes impossible, various approximate versions ofPPA （APPA） are developed for practical applications. In this paper, we compare two APPA methods, both of which can be viewed as prediction-correction methods. The only difference is that they use different search directions in the correction-step. By extending the general forward-backward splitting methods, we obtain Algorithm Ⅰ; in the same way, Algorithm Ⅱ is proposed by spreading the general extra-gradient methods. Our analysis explains theoretically why Algorithm Ⅱ usually outperforms Algorithm Ⅰ. For computation practice, we consider a class of MVI with a special structure, and choose the extending Algorithm Ⅱ to implement, which is inspired by the idea of Gauss-Seidel iteration method making full use of information about the latest iteration. And in particular, self-adaptive techniques are adopted to adjust relevant parameters for faster convergence. Finally, some numerical experiments are reported on the separated MVI. Numerical results showed that the extending Algorithm II is feasible and easy to implement with relatively low computation load.展开更多
Researchers in several disciplines and fields agree that the image establishing has both perceptual and affecfive evaluations. The paper comparatively analyzes the image of landscapes in ancient water towns held by 16...Researchers in several disciplines and fields agree that the image establishing has both perceptual and affecfive evaluations. The paper comparatively analyzes the image of landscapes in ancient water towns held by 1619 tourists after the investigations of Zbouzhuang and Tongli of Jiangsu Province. Based on the elements of the image of urban landscapes, the perceptual/cognitive image of tourist landscapes in water towns is developed including path, node, landmark, important courtyard, district and edge. Particularly the important courtyard plays the great role on the perceptive image of tourists, however, the perceptual/cognitive images of the district and the edge are obviously weak. Meanwhile, the finding showed that the affective images of tourist landscapes in Zhonzhuang differ with those of Tongli by the method of paired comparison. The main reason is that the affective images are influenced by the impressive scenery spots. Furthermore, the commercialization of streets and pollution of rivers are easy to be functioned negatively.展开更多
The morphogenetic processes of Uronemella filificum (Kahl, 1931) Song and Wilbert ①, were studied using protargol method. The stomatogenesis of U. filificum can be summarized as follows: membranelles 1-2, paroral mem...The morphogenetic processes of Uronemella filificum (Kahl, 1931) Song and Wilbert ①, were studied using protargol method. The stomatogenesis of U. filificum can be summarized as follows: membranelles 1-2, paroral membrane and scutica of the opisthe originate from the parental paroral membrane, while membranelle 3 in the opisthe develops from the parental scutica. The paroral membrane of the proter developes from the parental paroral membrane. The stomatogenetic sequences are similar to the previous descriptions for other related taxa. The phylogenetic position of Uronematidae is discussed in the light of morphogenetic data obtained.展开更多
文摘The quantum dynamics of an exciton dressed by acoustic pnonons in an optically driven quantum dotsemiconductor microcavity at finite temperatures is investigated theoretically by quantum optics methods. It is shown that the temperature dependence of the vacuum Rabi splitting is 2√2g×exp[ - ∑qλq（Nq＋1/2）],where Nq=1/[exp（ωq/kBT）-1] is the phonon population, g is the single-photon Rabi frequency, and λq corresponds to exciton-phonon coupling.
文摘Aim In accordance with the positioning control for valve controlled motor electrohydraulic proportional servo systems driving the static load torque, the positioning performance was studied in the presence of the time? varying deadzone and gain. Methods The large positioning errors caused by the time varying deadzone were significantly reduced by using the dynamic compensation method for the deadzone; and the large overshoot caused by the time varying gain were dramatically reduced by using the three section intelligent control schemes. Results Experimental results demonstrated that the positioning performance of rapid response, high accuracy and smaller or even no overshoot was achieved under a wide variations of load torque. Conclusion The good positioning performance for valve controlled motor servo systems has been achieved in the presence of the time varying deadzone and gain.
文摘AIM： To examine the clinical characteristics of a subgroup of patients with hepatocellular carcinoma （HCC） and compare them to those with known risk factors. METHODS： We used the HCC database of 306 patients seen at our institution from January 1, 1995 to December 31, 2001. Of the 306 patients, 63 （20%, group 1） had no known risk factors （hepatitis C virus, hepatitis B virus, alcohol, hemochromatosis or cirrhosis from any cause） and 243 （group 2） had one or more risk factors. RESULTS： The median age was similar in both groups, but there were disproportionate numbers of younger （〈 30 years old）, older （〉 80 years） patients, women （33% vs 18%）, and Caucasians （81% vs 52%） in group 1 as compared to group 2. There were fewer Asians （2% vs 11%） and African Americans （13% vs 27%） in group 1. Abdominal pain （70% vs 37%） was more common while gastrointestinal bleeding （0% vs 11%） and ascites （4% vs17%） were less common in group i compared to group 2. Group 1 had larger tumor burden （median size 9.4 cm vs 5.7 cm） at the time of presentation, but there were no differences in the site （right, left or bilateral lesions）, or number of tumors between the two groups. CONCLUSION： HCC patients without identifiable risk factors have different characteristics and clinical presentation compared to those with known risk factors.Absence of cirrhosis and larger tumor burden may explain the differences in the presenting symptoms.
基金The project supported by the Program for New Century Excellent Talents at the University of China under Grant No.NCET-06-0554the National Natural Science Foundation of China under Grant No.60677001+3 种基金the Science Technology Fund of Anhui Province for Outstanding Youth under Grant No.06042087the Key Fund of the Ministry of Education of China under Grant No.206063the Natural Science Foundation of Guangdong Province under Grant Nos.06300345 and 7007806Natural Science Foundation of Hubei Province under Grant No.2006ABA354
文摘Security of the quantum secure direct communication protocol （i.e., the C-S QSDC protocol） recently proposed by Cao and Song [Chin. Phys. Lett. 23 （2006） 290] is analyzed in the case of considerable quantum channel noise. The eavesdropping scheme is presented, which reveals that the C-S QSDC protocol is not secure if the quantum bit error rate （QBER） caused by quantum channel noise is higher than 4.17%. Our eavesdropping scheme induces about 4.17% QBER for those check qubits. However, such QBER can be hidden in the counterpart induced by the noisy quantum channel if the eavesdropper Eve replaces the original noisy channel by an ideal one. Furthermore, if the QBER induced by quantum channel noise is lower than 4.17%, then in the eavesdropping scheme Eve still can eavesdrop part of the secret messages by safely attacking a fraction of the transmitted qubits. Finally, an improvement on the C-S QSDC protocol is put forward.
基金Project(2018JJ2041)supported by the Science and Technology Project in Hunan Province,ChinaProject(szjj2019-008)supported by the Open Research Subject of Key Laboratory of Fluid and Power Machinery,Ministry of Education,China。
文摘Aviation heavy-fuel spark ignition(SI)piston engines have been paid more and more attention in the area of small aviation.Aviation heavy-fuel refers to aviation kerosene or light diesel fuel,which is safer to use and store compared to gasoline fuel.And diesel fuel is more suitable for small aviation application on land.In this study,numerical simulation was performed to evaluate the possibility of switching from gasoline direct injection spark ignition(DISI)to diesel DISI combustion.Diesel was injected into the cylinder by original DI system and ignited by spark.In the simulation,computational models were calibrated by test data from a DI engine.Based on the calibrated models,furthermore,the behavior of diesel DISI combustion was investigated.The results indicate that diesel DISI combustion is slower compared to gasoline,and the knock tendency of diesel in SI combustion is higher.For a diesel/air mixture with an equivalence ratio of 0.6 to 1.4,higher combustion pressure and faster burning rate occur when the equivalence ratios are 1.2 and 1.0,but the latter has a higher possibility of knock.In summary,the SI combustion of diesel fuel with a rich mixture can achieve better combustion performance in the engine.
文摘For the detection and tracking of dim point targets with SNR 〈 2 dB, the combined SPRT and FSS method is given to accomplish detection in whicb likelihood testing are carried out twice to prune constantly. Firstly, the SPRT is developed aiming at the heuristic segments formed by correlation analysis. In order to avoid missing detection the threshold is chosen much lower. Secondly, by adding samples and choosing the one most similar to the heuristic segment to make state estimation FSS is implemented. This time we choose a higher threshold. Moreover in preprocessing the compound kernel estimation is designed to depress varying background clutter. Multiple experimental sequences validate that the method is more suitable for the dim targets detection and tracking compared with the scheme choosing the higher intensity pixel in tracking. It not only has perfect detection performance but also can greatly enhance tracking performance.
基金Project (No. 1027054) supported by the National Natural Science Foundation of China
文摘Proximal point algorithms （PPA） are attractive methods for solving monotone variational inequalities （MVI）. Since solving the sub-problem exactly in each iteration is costly or sometimes impossible, various approximate versions ofPPA （APPA） are developed for practical applications. In this paper, we compare two APPA methods, both of which can be viewed as prediction-correction methods. The only difference is that they use different search directions in the correction-step. By extending the general forward-backward splitting methods, we obtain Algorithm Ⅰ; in the same way, Algorithm Ⅱ is proposed by spreading the general extra-gradient methods. Our analysis explains theoretically why Algorithm Ⅱ usually outperforms Algorithm Ⅰ. For computation practice, we consider a class of MVI with a special structure, and choose the extending Algorithm Ⅱ to implement, which is inspired by the idea of Gauss-Seidel iteration method making full use of information about the latest iteration. And in particular, self-adaptive techniques are adopted to adjust relevant parameters for faster convergence. Finally, some numerical experiments are reported on the separated MVI. Numerical results showed that the extending Algorithm II is feasible and easy to implement with relatively low computation load.
基金Under the auspices of the National Natural Science Foundation of China (No. 40371030), Research Project of Ministry of Construction (No. 20031018)
文摘Researchers in several disciplines and fields agree that the image establishing has both perceptual and affecfive evaluations. The paper comparatively analyzes the image of landscapes in ancient water towns held by 1619 tourists after the investigations of Zbouzhuang and Tongli of Jiangsu Province. Based on the elements of the image of urban landscapes, the perceptual/cognitive image of tourist landscapes in water towns is developed including path, node, landmark, important courtyard, district and edge. Particularly the important courtyard plays the great role on the perceptive image of tourists, however, the perceptual/cognitive images of the district and the edge are obviously weak. Meanwhile, the finding showed that the affective images of tourist landscapes in Zhonzhuang differ with those of Tongli by the method of paired comparison. The main reason is that the affective images are influenced by the impressive scenery spots. Furthermore, the commercialization of streets and pollution of rivers are easy to be functioned negatively.
基金This work was supported by the Natural Science F oundation of China(Project number:30170114)the Cheung Kong Scholars Program.
文摘The morphogenetic processes of Uronemella filificum (Kahl, 1931) Song and Wilbert ①, were studied using protargol method. The stomatogenesis of U. filificum can be summarized as follows: membranelles 1-2, paroral membrane and scutica of the opisthe originate from the parental paroral membrane, while membranelle 3 in the opisthe develops from the parental scutica. The paroral membrane of the proter developes from the parental paroral membrane. The stomatogenetic sequences are similar to the previous descriptions for other related taxa. The phylogenetic position of Uronematidae is discussed in the light of morphogenetic data obtained.
