We discussed the Dirichlet problem of semilinear elliptic equation (P β,ε):β 2Δu=u p +εu,u>0, in Ω;u=0, on ?Ω, where Ω?R N (N≥4) is smooth and bounded domain, ,β,ε>0. We have proved that there exist ...We discussed the Dirichlet problem of semilinear elliptic equation (P β,ε):β 2Δu=u p +εu,u>0, in Ω;u=0, on ?Ω, where Ω?R N (N≥4) is smooth and bounded domain, ,β,ε>0. We have proved that there exist positiveε 0 andε 1, such that when 0?ε?ε 0,β>√ε 1, (P β,ε) has a single-peaked solutionu β,ε; furthermore, |?u β0|2?0 in the sense of measure as ε→0 and β→0.展开更多
We report a high-peak-power, single-polarized master oscillator power amplification system employing polarization- maintaining Yb-doped rod-type photonic crystal fiber. The MOPA system comprises of a Q-switched microc...We report a high-peak-power, single-polarized master oscillator power amplification system employing polarization- maintaining Yb-doped rod-type photonic crystal fiber. The MOPA system comprises of a Q-switched microchip laser generating ~630ps pulses at 8.6 kHz repetition-rate and two amplification stages employing double cladding fiber and rod-type PCF respectively. The MOPA system obtains narrow spectral bandwidth, single-polarized pulses of 9W maximum output average power, corresponding to peak power of 1.7MW.展开更多
With the rapid development of the installed capacity of clean energy sources such as wind power, hydropower and photovoltaic, significant changes have taken place in the domestic power structure, and deep peak-shaving...With the rapid development of the installed capacity of clean energy sources such as wind power, hydropower and photovoltaic, significant changes have taken place in the domestic power structure, and deep peak-shaving operation of large thermal power units has become the norm. When the depth of the unit reaches a lower load, the once-through boiler changes from dry to wet operation, and the water separated from the boiler steam-water separator directly enters the condenser or is discharged through the blowdown system, resulting in a large amount of discharge and heat loss. As a result, the operating economy of the unit decreased significantly.展开更多
Previous studies revealed the double-peak mode(DPM)in South China precipitation,corresponding to the two stages in the rainy season,i.e.the first rainy stage(FRS)and the second rainy stage(SRS).But observations in rec...Previous studies revealed the double-peak mode(DPM)in South China precipitation,corresponding to the two stages in the rainy season,i.e.the first rainy stage(FRS)and the second rainy stage(SRS).But observations in recent two decades show that the DPM has changed to a single-peak mode(SPM).Both the precipitation amount and the heavy rainfall event frequency enhanced significantly in the gap between the FRS and the SRS in 1991–2010,compared to those in 1961–1990.This change can be linked to the effects of the global warming.During the warmer period,the July sea surface temperature over the western Pacific has greater increases than that over the central and eastern Pacific,especially west of 140°E.It may generate more tropical cyclones(TCs)in the inshore areas and then more typhoon rainfall over South China.On the other hand,the increments of the air temperature over the East Asian continent are greater than those of the SST over the western Pacific under the global warming,which enlarges the land-ocean temperature/pressure contrast and leads to a trend of the earlier onset dates of the Asian summer monsoon(ASM)in recent two decades.Then,the earlier ASM will facilitate the western Pacific subtropical high(WPSH)to retreat earlier from the South China Sea and enhance the convective precipitation in South China between the FRS and the SRS.Also,due to the warmer ocean,the WPSH locates more westward in July,and more moisture will be transported to South China from the southwest side to the WPSTH.All these influences favor a remarkably increasing precipitation in the gap in the warmer period and changes the seasonal cycle from double-peak mode to single-peak mode.展开更多
We study the following Schr?dinger equation with variable exponent−Δu+u=u^(p+∈a)(x),u>0 in R^(N),where∈>0,1<p<N+2/N−2,a(x)∈C^(1)(R^(N))∩L^(∞)(R^(N)),N≥3.Under certain assumptions on a vector field r...We study the following Schr?dinger equation with variable exponent−Δu+u=u^(p+∈a)(x),u>0 in R^(N),where∈>0,1<p<N+2/N−2,a(x)∈C^(1)(R^(N))∩L^(∞)(R^(N)),N≥3.Under certain assumptions on a vector field related to a(x),we use the Lyapunov–Schmidt reduction to show the existence of single peak solutions to the above problem.We also obtain local uniqueness and exact multiplicity results for this problem by the Pohozaev type identity.展开更多
基金the National Natural Science Foundation of ChinaFoundation for Fundamental Sciences of Nanchang UniversityHua-chen Found
文摘We discussed the Dirichlet problem of semilinear elliptic equation (P β,ε):β 2Δu=u p +εu,u>0, in Ω;u=0, on ?Ω, where Ω?R N (N≥4) is smooth and bounded domain, ,β,ε>0. We have proved that there exist positiveε 0 andε 1, such that when 0?ε?ε 0,β>√ε 1, (P β,ε) has a single-peaked solutionu β,ε; furthermore, |?u β0|2?0 in the sense of measure as ε→0 and β→0.
文摘We report a high-peak-power, single-polarized master oscillator power amplification system employing polarization- maintaining Yb-doped rod-type photonic crystal fiber. The MOPA system comprises of a Q-switched microchip laser generating ~630ps pulses at 8.6 kHz repetition-rate and two amplification stages employing double cladding fiber and rod-type PCF respectively. The MOPA system obtains narrow spectral bandwidth, single-polarized pulses of 9W maximum output average power, corresponding to peak power of 1.7MW.
文摘With the rapid development of the installed capacity of clean energy sources such as wind power, hydropower and photovoltaic, significant changes have taken place in the domestic power structure, and deep peak-shaving operation of large thermal power units has become the norm. When the depth of the unit reaches a lower load, the once-through boiler changes from dry to wet operation, and the water separated from the boiler steam-water separator directly enters the condenser or is discharged through the blowdown system, resulting in a large amount of discharge and heat loss. As a result, the operating economy of the unit decreased significantly.
基金supported by the National Basic Research Program of China (2012CB417205 and 2013CB430203)the International Cooperation Program of Ministry of Science and Technology of China (2009DFA23010)+1 种基金the Special Research Fund (Meteorology) of Public Welfare Project (GYHY201306033)the National Natural Science Foundation of China (41005037)
文摘Previous studies revealed the double-peak mode(DPM)in South China precipitation,corresponding to the two stages in the rainy season,i.e.the first rainy stage(FRS)and the second rainy stage(SRS).But observations in recent two decades show that the DPM has changed to a single-peak mode(SPM).Both the precipitation amount and the heavy rainfall event frequency enhanced significantly in the gap between the FRS and the SRS in 1991–2010,compared to those in 1961–1990.This change can be linked to the effects of the global warming.During the warmer period,the July sea surface temperature over the western Pacific has greater increases than that over the central and eastern Pacific,especially west of 140°E.It may generate more tropical cyclones(TCs)in the inshore areas and then more typhoon rainfall over South China.On the other hand,the increments of the air temperature over the East Asian continent are greater than those of the SST over the western Pacific under the global warming,which enlarges the land-ocean temperature/pressure contrast and leads to a trend of the earlier onset dates of the Asian summer monsoon(ASM)in recent two decades.Then,the earlier ASM will facilitate the western Pacific subtropical high(WPSH)to retreat earlier from the South China Sea and enhance the convective precipitation in South China between the FRS and the SRS.Also,due to the warmer ocean,the WPSH locates more westward in July,and more moisture will be transported to South China from the southwest side to the WPSTH.All these influences favor a remarkably increasing precipitation in the gap in the warmer period and changes the seasonal cycle from double-peak mode to single-peak mode.
基金National Natural Science Foundation of China(Grant Nos.11971147 and12371111)The second author is partially supported by National Natural Science Foundation of China(Grant No.11831009)+1 种基金the Fundamental Research Funds for the Central Universities(Grant Nos.KJ02072020-0319,CCNU22LJ002)The third author is supported by National Natural Science Foundation of China(Grant No.12201232)。
文摘We study the following Schr?dinger equation with variable exponent−Δu+u=u^(p+∈a)(x),u>0 in R^(N),where∈>0,1<p<N+2/N−2,a(x)∈C^(1)(R^(N))∩L^(∞)(R^(N)),N≥3.Under certain assumptions on a vector field related to a(x),we use the Lyapunov–Schmidt reduction to show the existence of single peak solutions to the above problem.We also obtain local uniqueness and exact multiplicity results for this problem by the Pohozaev type identity.
