Diode pumped monolithic nonplanar ring laser has been developed, yielding single frequency laser and has the advantages of compactness, reliability and high efficiency. Its principles are given in detail and a monolit...Diode pumped monolithic nonplanar ring laser has been developed, yielding single frequency laser and has the advantages of compactness, reliability and high efficiency. Its principles are given in detail and a monolithic nonplanar ring laser is designed. As a result, a laser of hundreds milliwatts cw single frequency output was built up, placed in a magnetic field and pumped by LD. The optical conversion efficiency was more than 15% and the slope efficiency more than 30%. The laser beam had a good quality, with M 2 about 1 2.展开更多
The temperature dependence of some performance of 6H SiC unipolar power devices is analyzed theoretically.By employing the temperature dependent ionization coefficient and mobility of a silicon carbide,the analytica...The temperature dependence of some performance of 6H SiC unipolar power devices is analyzed theoretically.By employing the temperature dependent ionization coefficient and mobility of a silicon carbide,the analytical expressions of the temperature dependent performance,such as breakdown characteristics and on resistance of 6H SiC unipolar power devices are derived in a closed form.The analytical results are compared with the experimental results,with good accordance found in the breakdown characteristics.展开更多
A simple and compact microstrip-fed ultra wideband (UWB) printed monopole antenna with band-notched performance is proposed for wireless universal serial-bus (WUSB). The antenna is composed of a U-shaped line radi...A simple and compact microstrip-fed ultra wideband (UWB) printed monopole antenna with band-notched performance is proposed for wireless universal serial-bus (WUSB). The antenna is composed of a U-shaped line radiator and a small strip bar and is partially grounded, so that the measured impedance bandwidth of the antenna is about 7. 88 GHz covering 3. 12 to 11 GHz with VSWR below 2, and the expected band rejection of 5.06 to 5. 89 GHz is also obtained. The characteristics of the proposed antenna are analyzed, and the geometric parameters for optimal performance are investigated in detail. A relatively stable, quasi-omnidirectional and quasi-symmetrical radiation pattern is also found. The proposed band-notched UWB antenna requires no external filters to avoid interference with other systems, and thus, greatly simplifies the system design of an ultra wideband WUSB communication system.展开更多
The silicon nano-crystalline (nc-Si) film is fabricated on <100> orientation,0.01Ω·cm resistivity,and p-type boron-doped silicon wafer by the anodic etching.The microstructure and the orientation of nc-Si ...The silicon nano-crystalline (nc-Si) film is fabricated on <100> orientation,0.01Ω·cm resistivity,and p-type boron-doped silicon wafer by the anodic etching.The microstructure and the orientation of nc-Si are examined by the scanning electron microscopy,transmission electron microscopy,and X-ray diffraction spectroscopy,respectively.The average size of particle is estimated by Raman spectroscopy.The results show that the particle size of nc-Si film is scattered from 10nm to 20nm,the alignment is compact,the orientation is uniform,the expansion of lattice constant is negligible,and mechanical robustness and stability are good.The correlations between film structure and the experiment parameters such as etching time,HF concentration,and etching current density are discussed.As a potential application,efficient field emission is observed from the nc-Si film,and the turn-on field is about 3V/μm at 0.1μA/cm 2 of current density,which is close to carbon nanotube film's.展开更多
Rotational isomerism effects on the optical spectra of a push-pull nonlinear optical chro-mophore 2-dicyanomethylen-3-cyano-4-f2-[E-(4-N,N-di(2-acetoxyethyl)-amino)-phenylene-(3,4-dibutyl)-thien-5]-E-vinylg-5,5-...Rotational isomerism effects on the optical spectra of a push-pull nonlinear optical chro-mophore 2-dicyanomethylen-3-cyano-4-f2-[E-(4-N,N-di(2-acetoxyethyl)-amino)-phenylene-(3,4-dibutyl)-thien-5]-E-vinylg-5,5-dimethyl-2,5-dihydrofuran (FTC) in a few solvents have been studied using the time-dependent density functional theory in combination with the polarizable continuum model. It is shown that the maximum absorption peaks of the ro-tamers have difference of nearly 30 nm both in vacuum and in solutions. The population of the rotamers changes a lot in different solvents. Based on the geometries optimized by Hartree-Fock method, the Maxwell-Boltzmann averaged absorption has been calculated and the maximum absorption peak is in good agreement with experiment. It indicates that the bond length alternation can have an important effect on the optical spectra.展开更多
A monolithic single pole single throw (SPST) switch is developed with GaAs PIN diode technology from IMECAS. A novel small signal model of a GaAs PIN diode is developed for circuit simulation. The switch features an...A monolithic single pole single throw (SPST) switch is developed with GaAs PIN diode technology from IMECAS. A novel small signal model of a GaAs PIN diode is developed for circuit simulation. The switch features an on-state insertion loss of less than 1.6dB and a return loss of greater than 10dB while maintaining an off-state isolation of greater than 23dB from 5.5 to 7. 5GHz. The measured 1dB power gain compression point is about 20dBm.展开更多
In order to analyze the load carrying capacity of prestressed concrete box girders, failure behaviors of in-situ deteriorated continuous prestressed concrete box girders under loading are experimentally observed and a...In order to analyze the load carrying capacity of prestressed concrete box girders, failure behaviors of in-situ deteriorated continuous prestressed concrete box girders under loading are experimentally observed and a finite failure analysis method for predicting behaviors of box girders is developed. A degenerated solid shell element is used to simulate box girders and material nonlinearity is considered. Since pre-stressed concrete box girders usually have a large number of curve prestressed tendons, a type of combined element is presented to simulate the prestressed tendons of box girders, and then the number of elements can be significantly reduced. The analytical results are compared with full-scale failure test results. The comparison shows that the presented method can be effectively applied to the failure analysis of in-situ continuous prestressed concrete box girders, and it also shows that the studied old bridge still has enough load carrying capacity.展开更多
A near-infrared single-photon detection system is established by using pigtailed InGaAs/InP avalanche photodiodes. With a 50GHz digital sampling oscilloscope, the function and process of gated-mode (Geiger-mode) sin...A near-infrared single-photon detection system is established by using pigtailed InGaAs/InP avalanche photodiodes. With a 50GHz digital sampling oscilloscope, the function and process of gated-mode (Geiger-mode) single-photon detection are intuitionally demonstrated for the first time. The performance of the detector as a gated-mode single-photon counter at wavelengths of 1310 and 1550nm is investigated. At the operation temperature of 203K,a quantum efficiency of 52% with a dark count probability per gate of 2.4 × 10 ^-3 ,and a gate pulse repetition rate of 50kHz are obtained at 1550nm. The corresponding parameters are 43%, 8.5 × 10^-3 , and 200kHz at 238K.展开更多
In this paper we discuss the anti-periodic problem for a class of abstractnonlinear second-order evolution equations associated with maximal monotone operators in Hilbertspaces and give some new assumptions on operato...In this paper we discuss the anti-periodic problem for a class of abstractnonlinear second-order evolution equations associated with maximal monotone operators in Hilbertspaces and give some new assumptions on operators. We establish the existence and uniqueness ofanti-periodic solutions, which improve andgeneralize the results that have been obtained. Finally weillustrate the abstract theory by discussing a simple example of an anti-periodic problem fornonlinear partial differential equations.展开更多
A film of mesoporous single-crystal rutile TiO2 rod arrays supported on a transparent conductive glass substrate was synthesized with the assistance of a template layer of closely packed silica nanospheres. This film ...A film of mesoporous single-crystal rutile TiO2 rod arrays supported on a transparent conductive glass substrate was synthesized with the assistance of a template layer of closely packed silica nanospheres. This film was used as a photoanode and showed significant improvement for photoelectrochemical water oxidation compared with a reference film of nonporous single-crystal rutile TiO2rod arrays.展开更多
A kind of compact ultra wideband (UWB) monopole antenna with dual-band notched function is presented.The proposed antenna,using "C" and "L" apertures embedded in the annular ring patch and ground patch,gets two ...A kind of compact ultra wideband (UWB) monopole antenna with dual-band notched function is presented.The proposed antenna,using "C" and "L" apertures embedded in the annular ring patch and ground patch,gets two bandnotched characteristics in WiMAX3.5 GHz and WLAN 5.5 GHz.The size of antenna is 24 mm × 36 mm × 1.6 mm.The simulation results show that waveband range of the antenna is 2.7-10.6 GHz for S11 <-10 dB and the band-notched wavebands are 3.2-3.8 GHz and 5.1-6 GHz.So it has miniaturization,ultra-band and band-notched characteristics.Meanwhile,the radition pattern,directivety and gain are perfect,which meets the practical need.展开更多
Using the generalized uncertainty relation, the new equation of state density is obtained, and then the entropy of black hole with an internal global monopole is discussed. The divergence that appears in black hole en...Using the generalized uncertainty relation, the new equation of state density is obtained, and then the entropy of black hole with an internal global monopole is discussed. The divergence that appears in black hole entropy calculation through original brick-wall model is overcome. The result of the direct proportion between black hole entropy and its event horizon area is drawn and given. The result shows that the black hole entropy must be the entropy of quantum state near the event horizon.展开更多
The mass mortality of pond-reared scattered mirror carp, Cyprinus carpio, caused by Thelohanellus kitauei, occurred at fish farms in Sichuan Province, southwest China. Morphological and molecular analyses were supplem...The mass mortality of pond-reared scattered mirror carp, Cyprinus carpio, caused by Thelohanellus kitauei, occurred at fish farms in Sichuan Province, southwest China. Morphological and molecular analyses were supplemented with histological evaluation of infected tissues to better understand the route of infection and the pathological effects of 1". kitauei on the fish host. The intestine of the diseased host was full of large cysts of the myxosporean. The cysts range from 2 cm to 3.6 cm in diameter. Histopathology indicated that T. kitauei first invaded the submucosa of the host intestine and then moved into the mucosa layers with the development of their spores, finally entering into the enteric cavity of the hosts after the disruption of mucosa layers. The pyriform spores of T. kitauei were surrounded by the transparent spore sheath, measuring 25.98/μm±0.95 μm in body length, 8.72 μm±0.51μm body width, and 7.86 μm±0.26 μm in body thickness. The single polar capsule was pyriform, measuring 14.73 μm±0.92μm in length and 6.82 μm±0.45μm in width, with eight to 10 turns of filament coils winding inside. Phylogenetic analysis based on the 18S small-subunit ribosomal DNA sequences indicated that minimal genetic differences were present between T. kitauei samples from South Korea and from China. Close affinity was found between the genus Thelohanellus and Myxobolus. Additionally, two polar capsule nuclei were found at the anterior end of the single polar capsule in spores of T. kitauei stained with hematoxylin and eosin, which suggested the separation of the genus Thelohanellus from Myxobolus.展开更多
Applying Parikh's quantum tunneling model, we study the quantum tunneling radiation of Reissne- Nordstrom de Sitter black hole with a global monopole. The result shows that the tunneling rates at the event horizon an...Applying Parikh's quantum tunneling model, we study the quantum tunneling radiation of Reissne- Nordstrom de Sitter black hole with a global monopole. The result shows that the tunneling rates at the event horizon and the cosmic horizon are related to Bekenstein-Hawking entropy if we take the energy conservation into consideration, and the true radiate spectrum is not precisely thermal.展开更多
Considering the self-gravitation and energy conservation as well as charge conservation, we extend Medved and Vagenas's quantum tunneling method to the global monopole charged black hole, and give a correction to Haw...Considering the self-gravitation and energy conservation as well as charge conservation, we extend Medved and Vagenas's quantum tunneling method to the global monopole charged black hole, and give a correction to Hawking radiation of a charged particle.展开更多
We present the extended hydrogen atom and monopole-hydrogen atom theory through generalizing the usual hydrogen atom model and with a monopole model respectively, in which Y (sl(2) ) algebras are realized. We derive t...We present the extended hydrogen atom and monopole-hydrogen atom theory through generalizing the usual hydrogen atom model and with a monopole model respectively, in which Y (sl(2) ) algebras are realized. We derive the Hamiltonians of the two models based on the Y(sl(2) ) and the generalized Pauli equation. The energy spectra of the systems are also given in terms of Yangian algebra and quantum mechanics.展开更多
Objective To compare the therapeutic effects and safety of monopolar and bipolar radiofrequency(RF) ablation used during cardiac surgery to treat atrial fibrillation.Methods We retrospectively studied a total of 81 pa...Objective To compare the therapeutic effects and safety of monopolar and bipolar radiofrequency(RF) ablation used during cardiac surgery to treat atrial fibrillation.Methods We retrospectively studied a total of 81 patients with chronic atrial fibrillation who underwent open cardiac surgery with concomitant RF ablation between January 2007 and March 2011.Fifty-eight patients received bipolar RF ablation and 23 received monopolar RF ablation,respectively.The sinus rhythm restoration rate,the procedural duration,the frequency of severe perioperative complications,and mortality were compared between the two groups.Results The sinus rhythm restoration rate did not differ significantly between the two groups after follow-up of 15.1 ± 12.6 months(P=0.199).The frequencies of severe perioperative complications and mortality were also similar in the two groups.The total procedural time using bipolar RF ablation was significantly shorter than that using monopolar ablation(19.7±4.6 minutes vs.28.1±8.5 minutes,P< 0.001).Conclusions Both monopolar and bipolar RF ablation are safe and effective in treating chronic atrial fibrillation patients during open cardiac surgery,but bipolar RF ablation is more convenient in practice.展开更多
基金Fundfor Research on Doctoral Programs in Institutions of Higher Learning
文摘Diode pumped monolithic nonplanar ring laser has been developed, yielding single frequency laser and has the advantages of compactness, reliability and high efficiency. Its principles are given in detail and a monolithic nonplanar ring laser is designed. As a result, a laser of hundreds milliwatts cw single frequency output was built up, placed in a magnetic field and pumped by LD. The optical conversion efficiency was more than 15% and the slope efficiency more than 30%. The laser beam had a good quality, with M 2 about 1 2.
文摘The temperature dependence of some performance of 6H SiC unipolar power devices is analyzed theoretically.By employing the temperature dependent ionization coefficient and mobility of a silicon carbide,the analytical expressions of the temperature dependent performance,such as breakdown characteristics and on resistance of 6H SiC unipolar power devices are derived in a closed form.The analytical results are compared with the experimental results,with good accordance found in the breakdown characteristics.
文摘A simple and compact microstrip-fed ultra wideband (UWB) printed monopole antenna with band-notched performance is proposed for wireless universal serial-bus (WUSB). The antenna is composed of a U-shaped line radiator and a small strip bar and is partially grounded, so that the measured impedance bandwidth of the antenna is about 7. 88 GHz covering 3. 12 to 11 GHz with VSWR below 2, and the expected band rejection of 5.06 to 5. 89 GHz is also obtained. The characteristics of the proposed antenna are analyzed, and the geometric parameters for optimal performance are investigated in detail. A relatively stable, quasi-omnidirectional and quasi-symmetrical radiation pattern is also found. The proposed band-notched UWB antenna requires no external filters to avoid interference with other systems, and thus, greatly simplifies the system design of an ultra wideband WUSB communication system.
文摘The silicon nano-crystalline (nc-Si) film is fabricated on <100> orientation,0.01Ω·cm resistivity,and p-type boron-doped silicon wafer by the anodic etching.The microstructure and the orientation of nc-Si are examined by the scanning electron microscopy,transmission electron microscopy,and X-ray diffraction spectroscopy,respectively.The average size of particle is estimated by Raman spectroscopy.The results show that the particle size of nc-Si film is scattered from 10nm to 20nm,the alignment is compact,the orientation is uniform,the expansion of lattice constant is negligible,and mechanical robustness and stability are good.The correlations between film structure and the experiment parameters such as etching time,HF concentration,and etching current density are discussed.As a potential application,efficient field emission is observed from the nc-Si film,and the turn-on field is about 3V/μm at 0.1μA/cm 2 of current density,which is close to carbon nanotube film's.
基金ACKNOWLEDGMENTS This work was supported by Young Scientists Fund of the National Natural Science Foundation of China (No.10904085).
文摘Rotational isomerism effects on the optical spectra of a push-pull nonlinear optical chro-mophore 2-dicyanomethylen-3-cyano-4-f2-[E-(4-N,N-di(2-acetoxyethyl)-amino)-phenylene-(3,4-dibutyl)-thien-5]-E-vinylg-5,5-dimethyl-2,5-dihydrofuran (FTC) in a few solvents have been studied using the time-dependent density functional theory in combination with the polarizable continuum model. It is shown that the maximum absorption peaks of the ro-tamers have difference of nearly 30 nm both in vacuum and in solutions. The population of the rotamers changes a lot in different solvents. Based on the geometries optimized by Hartree-Fock method, the Maxwell-Boltzmann averaged absorption has been calculated and the maximum absorption peak is in good agreement with experiment. It indicates that the bond length alternation can have an important effect on the optical spectra.
文摘A monolithic single pole single throw (SPST) switch is developed with GaAs PIN diode technology from IMECAS. A novel small signal model of a GaAs PIN diode is developed for circuit simulation. The switch features an on-state insertion loss of less than 1.6dB and a return loss of greater than 10dB while maintaining an off-state isolation of greater than 23dB from 5.5 to 7. 5GHz. The measured 1dB power gain compression point is about 20dBm.
基金Post-Doctoral Innovative Projects of Shandong Province(No.200703072)the National Natural Science Foundation of China(No.50574053)
文摘In order to analyze the load carrying capacity of prestressed concrete box girders, failure behaviors of in-situ deteriorated continuous prestressed concrete box girders under loading are experimentally observed and a finite failure analysis method for predicting behaviors of box girders is developed. A degenerated solid shell element is used to simulate box girders and material nonlinearity is considered. Since pre-stressed concrete box girders usually have a large number of curve prestressed tendons, a type of combined element is presented to simulate the prestressed tendons of box girders, and then the number of elements can be significantly reduced. The analytical results are compared with full-scale failure test results. The comparison shows that the presented method can be effectively applied to the failure analysis of in-situ continuous prestressed concrete box girders, and it also shows that the studied old bridge still has enough load carrying capacity.
文摘A near-infrared single-photon detection system is established by using pigtailed InGaAs/InP avalanche photodiodes. With a 50GHz digital sampling oscilloscope, the function and process of gated-mode (Geiger-mode) single-photon detection are intuitionally demonstrated for the first time. The performance of the detector as a gated-mode single-photon counter at wavelengths of 1310 and 1550nm is investigated. At the operation temperature of 203K,a quantum efficiency of 52% with a dark count probability per gate of 2.4 × 10 ^-3 ,and a gate pulse repetition rate of 50kHz are obtained at 1550nm. The corresponding parameters are 43%, 8.5 × 10^-3 , and 200kHz at 238K.
文摘In this paper we discuss the anti-periodic problem for a class of abstractnonlinear second-order evolution equations associated with maximal monotone operators in Hilbertspaces and give some new assumptions on operators. We establish the existence and uniqueness ofanti-periodic solutions, which improve andgeneralize the results that have been obtained. Finally weillustrate the abstract theory by discussing a simple example of an anti-periodic problem fornonlinear partial differential equations.
基金supported by the National Basic Research Program of China(2014CB239401)the National Natural Science Foundation of China(51402306+4 种基金5142221021090343)the Deanship of Scientific Research(50-130-35-HiC i)King Abdulaziz UniversitySaudi Arabia~~
文摘A film of mesoporous single-crystal rutile TiO2 rod arrays supported on a transparent conductive glass substrate was synthesized with the assistance of a template layer of closely packed silica nanospheres. This film was used as a photoanode and showed significant improvement for photoelectrochemical water oxidation compared with a reference film of nonporous single-crystal rutile TiO2rod arrays.
文摘A kind of compact ultra wideband (UWB) monopole antenna with dual-band notched function is presented.The proposed antenna,using "C" and "L" apertures embedded in the annular ring patch and ground patch,gets two bandnotched characteristics in WiMAX3.5 GHz and WLAN 5.5 GHz.The size of antenna is 24 mm × 36 mm × 1.6 mm.The simulation results show that waveband range of the antenna is 2.7-10.6 GHz for S11 <-10 dB and the band-notched wavebands are 3.2-3.8 GHz and 5.1-6 GHz.So it has miniaturization,ultra-band and band-notched characteristics.Meanwhile,the radition pattern,directivety and gain are perfect,which meets the practical need.
基金Youth Scientific Foundation of Sichuan Education Department,国家自然科学基金
文摘Using the generalized uncertainty relation, the new equation of state density is obtained, and then the entropy of black hole with an internal global monopole is discussed. The divergence that appears in black hole entropy calculation through original brick-wall model is overcome. The result of the direct proportion between black hole entropy and its event horizon area is drawn and given. The result shows that the black hole entropy must be the entropy of quantum state near the event horizon.
基金Supported by the earmarked fund for China Agriculture Research System(No.CARS-46-08)the National Science Foundation for Young Scientists of China(No.31301863)the Major Scientific and Technological Innovation Project of Hubei Province(No.2015ABA045)
文摘The mass mortality of pond-reared scattered mirror carp, Cyprinus carpio, caused by Thelohanellus kitauei, occurred at fish farms in Sichuan Province, southwest China. Morphological and molecular analyses were supplemented with histological evaluation of infected tissues to better understand the route of infection and the pathological effects of 1". kitauei on the fish host. The intestine of the diseased host was full of large cysts of the myxosporean. The cysts range from 2 cm to 3.6 cm in diameter. Histopathology indicated that T. kitauei first invaded the submucosa of the host intestine and then moved into the mucosa layers with the development of their spores, finally entering into the enteric cavity of the hosts after the disruption of mucosa layers. The pyriform spores of T. kitauei were surrounded by the transparent spore sheath, measuring 25.98/μm±0.95 μm in body length, 8.72 μm±0.51μm body width, and 7.86 μm±0.26 μm in body thickness. The single polar capsule was pyriform, measuring 14.73 μm±0.92μm in length and 6.82 μm±0.45μm in width, with eight to 10 turns of filament coils winding inside. Phylogenetic analysis based on the 18S small-subunit ribosomal DNA sequences indicated that minimal genetic differences were present between T. kitauei samples from South Korea and from China. Close affinity was found between the genus Thelohanellus and Myxobolus. Additionally, two polar capsule nuclei were found at the anterior end of the single polar capsule in spores of T. kitauei stained with hematoxylin and eosin, which suggested the separation of the genus Thelohanellus from Myxobolus.
基金The project supported by National Natural Science Foundation of China under Grant No. 10347008
文摘Applying Parikh's quantum tunneling model, we study the quantum tunneling radiation of Reissne- Nordstrom de Sitter black hole with a global monopole. The result shows that the tunneling rates at the event horizon and the cosmic horizon are related to Bekenstein-Hawking entropy if we take the energy conservation into consideration, and the true radiate spectrum is not precisely thermal.
基金supported by National Science Foundation of China under Grant No. 10773008Sichuan Province Foundation for Fundamental Research under Grand No. 05JY029-092
文摘Considering the self-gravitation and energy conservation as well as charge conservation, we extend Medved and Vagenas's quantum tunneling method to the global monopole charged black hole, and give a correction to Hawking radiation of a charged particle.
文摘We present the extended hydrogen atom and monopole-hydrogen atom theory through generalizing the usual hydrogen atom model and with a monopole model respectively, in which Y (sl(2) ) algebras are realized. We derive the Hamiltonians of the two models based on the Y(sl(2) ) and the generalized Pauli equation. The energy spectra of the systems are also given in terms of Yangian algebra and quantum mechanics.
文摘Objective To compare the therapeutic effects and safety of monopolar and bipolar radiofrequency(RF) ablation used during cardiac surgery to treat atrial fibrillation.Methods We retrospectively studied a total of 81 patients with chronic atrial fibrillation who underwent open cardiac surgery with concomitant RF ablation between January 2007 and March 2011.Fifty-eight patients received bipolar RF ablation and 23 received monopolar RF ablation,respectively.The sinus rhythm restoration rate,the procedural duration,the frequency of severe perioperative complications,and mortality were compared between the two groups.Results The sinus rhythm restoration rate did not differ significantly between the two groups after follow-up of 15.1 ± 12.6 months(P=0.199).The frequencies of severe perioperative complications and mortality were also similar in the two groups.The total procedural time using bipolar RF ablation was significantly shorter than that using monopolar ablation(19.7±4.6 minutes vs.28.1±8.5 minutes,P< 0.001).Conclusions Both monopolar and bipolar RF ablation are safe and effective in treating chronic atrial fibrillation patients during open cardiac surgery,but bipolar RF ablation is more convenient in practice.