针对镜频和中频干扰对接收机性能影响的问题,分析了其原因并给出解决方案,设计了跟踪选频滤波器、逆切比雪夫陷波滤波器、5阶巴特沃斯低通滤波器,以及低噪声放大器的三级滤波方式所组成的短波接收机前端滤波放大电路,使短波接收机的中...针对镜频和中频干扰对接收机性能影响的问题,分析了其原因并给出解决方案,设计了跟踪选频滤波器、逆切比雪夫陷波滤波器、5阶巴特沃斯低通滤波器,以及低噪声放大器的三级滤波方式所组成的短波接收机前端滤波放大电路,使短波接收机的中频、镜频抑制比均大于90 d B,接收机的性能得到较大提高。展开更多
Objective To report our experience of retrograde hepatectomy in 244 cases of difficultly resected liver cancer. Methods Large, poor-exposure and inferior vena cava (IVC)-involving liver cancers that were difficult t...Objective To report our experience of retrograde hepatectomy in 244 cases of difficultly resected liver cancer. Methods Large, poor-exposure and inferior vena cava (IVC)-involving liver cancers that were difficult to remove by classical hepatectomy, have been resected successfully by retrograde hepatectomy combined with vascular surgical techniques in 244 patients (group A). Thirty one patients with similar circumstances undergoing classical hepatectomy duing the same period served as controls (group B). Results There were no perioperative mortalities in both groups. The comparison between group A and group B, the estimated intraoperative blood loss was 1290±998 ml versus 2286±1363 ml, post-operative pleural effusions occurred in 26/244 versus 10/31, ascites in 72/244 versus 19/31, moderate to severe jaundice in 14/244 versus 5/31, effusion in the operative area in 17/244 versus 7/31, subphrenic infection in 3/244 versus 1/31, bile leakage in 2/244 versus 1/31, wound infection in 3/244 versus 1/31, respectively. The time until ALT normalizaton in the groups A and B was 13.8±5.1 days and 18.9±8.9 days respectively. The difference between the two groups were statistically significant (P<0.01). Conclusion Retrograde hepatectomy is a safe and effective method for difficultly resected liver cancer. Key words cancer - liver - liver surgery - retrograde展开更多
A M_L3.8 earthquake occurred on February 23,2014 in Rongchang County,which is located at the southern edge of the Sichuan Basin in the border area between Sichuan and Chongqing. This paper presents results of focal me...A M_L3.8 earthquake occurred on February 23,2014 in Rongchang County,which is located at the southern edge of the Sichuan Basin in the border area between Sichuan and Chongqing. This paper presents results of focal mechanism solution of this earthquake using the CAP( cut and paste) method based on broadband seismograms recorded by regional seismic stations. Our results show that the moment magnitude is M_W3. 09 and focal depth is 3km. The hypocenter of this earthquake is located close to a buried fault in the Luoguangshan anticline. Oil prospecting and deep drilling data indicate that this buried fault is a thrust fault,striking SW230°,dipping NW45°,and 1. 7km deep. There are some injection wells within the anticline,and significant injection-induced earthquakes were observed during the periods of injection of waste water into the deep formations through those wells. The best double couple solution of the M_L3.8 earthquake is 247°,48°and 104° for strike,dip and rate,respectively,for one nodal plane( and 46°,44° and 74°for another nodal plane),which is in agreement with the geometry of the buried fault.Therefore,we conclude that the M_L3.8 Rongchang earthquake is possibly the result of faulting along the buried reverse fault induced by water injection under the compressive stress regime in the area.展开更多
This paper concerns the dimension reduction in regression for large data set. The authors introduce a new method based on the sliced inverse regression approach, cMled cluster-based regularized sliced inverse regressi...This paper concerns the dimension reduction in regression for large data set. The authors introduce a new method based on the sliced inverse regression approach, cMled cluster-based regularized sliced inverse regression. The proposed method not only keeps the merit of considering both response and predictors＇ information, but also enhances the capability of handling highly correlated variables. It is justified under certain linearity conditions. An empirical application on a macroeconomic data set shows that the proposed method has outperformed the dynamic factor model and other shrinkage methods.展开更多
Photoactive cocrystal materials have received growing research interest in construction of photofunctional systems owing to the crucial roles in modifying the photo-related properties of molecular solids, based on the...Photoactive cocrystal materials have received growing research interest in construction of photofunctional systems owing to the crucial roles in modifying the photo-related properties of molecular solids, based on the non-bonding interactions between self-assembly units. Herein, we report tunable luminescence and acid-base stimuli-responsive properties of a cocrystal assembled by 4-[2-(4-quinolinyl)vinyl]phenol (qv) and tetrafluoroterephthalic acid (a). The luminescent properties (such as wavelength, quantum yield and fluorescence lifetime) of qv.a changed obviously relative to the pristine qv, due to the proton transfer and the alternation of molecular arrangement within two-component crystalline material. The photoemission intensity of qv.a underwent from weak to strong upon HCl gas fuming, and the corresponding wavelength changed from 517 nm to 597 nm, which can be reversibly transferred after exposed in NH3. Such luminescent switching behavior may provide an effective way to develop new types of photoactive stimuli-responsive materials and optical sensors.展开更多
This paper is concerned with limit cycles which bifurcate from a period annulus of a quadratic reversible Lotka-Volterra system with sextic orbits.The authors apply the property of an extended complete Chebyshev syste...This paper is concerned with limit cycles which bifurcate from a period annulus of a quadratic reversible Lotka-Volterra system with sextic orbits.The authors apply the property of an extended complete Chebyshev system and prove that the cyclicity of the period annulus under quadratic perturbations is equal to two.展开更多
An organic compound exhibiting simultaneously reversible switch between its emission colors and luminescence mechanisms,possessing high contrast from deep blue normal fluorescence(NF) to yellow thermally activated del...An organic compound exhibiting simultaneously reversible switch between its emission colors and luminescence mechanisms,possessing high contrast from deep blue normal fluorescence(NF) to yellow thermally activated delayed fluorescence(TADF),is reported. Based on these two complementary colors, white-light emission combining NF and TADF from a single compound can be achieved in various states. Experimental results and density functional theory calculations indicate that the controllable conformational distribution under thermal and mechanical activation is the mechanism responsible for the reversible switching behavior.展开更多
Background:Few studies have compared the surgical outcomes of different surgical procedures currently used to treat refractory colonic slow-transit constipation(STC),despite the increase in the number of cases.This st...Background:Few studies have compared the surgical outcomes of different surgical procedures currently used to treat refractory colonic slow-transit constipation(STC),despite the increase in the number of cases.This study aimed to analyse the long-termsurgical outcomes of subtotal colectomy with antiperistaltic caecorectal anastomosis(SC-ACRA)vs total colectomy with ileorectal anastomosis(TC-IRA)for severe STC.Methods:Between January 2005 and January 2015,we retrospectively collected clinical data of 55 patients who underwent TC-IRA(n=35)or SC-ACRA(n=20)for severe STC at our institution.The post-operative functional outcomes between the two groups were compared.Results:There were no significant differences in age(P=0.655),sex(P=0.234),period of constipation(P=0.105)and defecation frequency(P=0.698)between the TC-IRA and SC-ACRA groups.During a median follow-up period of 72 months(range,12–120 months),there were no significant differences between the TC-IRA and SC-ACRA groups regarding the median number of bowel movements per day[3(1/6–7)vs 3(1/6–5),P=0.578],Cleveland Clinic Florida Constipation Score[2(0–20)vs 2(0–19),P=0.454],Cleveland Clinic Incontinence Score[0(0–5)vs 0(0–2),P=0.333]and Gastrointestinal Quality of Life Index[122(81–132)vs 120(80–132),P=0.661].Moreover,there was no significant difference in the incidence of postoperative complications between the two groups(37.1%vs 25.0%,P=0.285).Conclusions:Our findings indicate that both TC-IRA and SC-ACRA are effective treatments for severe STC,with similar long-termoutcomes.展开更多
We have studied the reversal of magnetisation in Ising ferromagnet by the field having gradient along a particular direction. We employed the Monte Carlo simulation with Metropolis single spin nip algorithm. The avera...We have studied the reversal of magnetisation in Ising ferromagnet by the field having gradient along a particular direction. We employed the Monte Carlo simulation with Metropolis single spin nip algorithm. The average lifetime of the metastable state was observed to increase with the magnitude of the gradient of applied field. In the high gradient regime, the system was observed to show two distinct region of up and down spins. The interface or the domain wall was observed to move as one increases the gradient. The displacement of the mean position of the interface was observed to increase with the gradient as hyperbolic tangent function. The roughness of the interface was observed to decay exponentially as the gradient increases. The number of spin flip per site was observed to show a discontinuity in the vicinity of the domain wall. The amount of the discontinuity was found to diverge with the system size as a power law fashion with an exponent 5/3.展开更多
文摘Objective To report our experience of retrograde hepatectomy in 244 cases of difficultly resected liver cancer. Methods Large, poor-exposure and inferior vena cava (IVC)-involving liver cancers that were difficult to remove by classical hepatectomy, have been resected successfully by retrograde hepatectomy combined with vascular surgical techniques in 244 patients (group A). Thirty one patients with similar circumstances undergoing classical hepatectomy duing the same period served as controls (group B). Results There were no perioperative mortalities in both groups. The comparison between group A and group B, the estimated intraoperative blood loss was 1290±998 ml versus 2286±1363 ml, post-operative pleural effusions occurred in 26/244 versus 10/31, ascites in 72/244 versus 19/31, moderate to severe jaundice in 14/244 versus 5/31, effusion in the operative area in 17/244 versus 7/31, subphrenic infection in 3/244 versus 1/31, bile leakage in 2/244 versus 1/31, wound infection in 3/244 versus 1/31, respectively. The time until ALT normalizaton in the groups A and B was 13.8±5.1 days and 18.9±8.9 days respectively. The difference between the two groups were statistically significant (P<0.01). Conclusion Retrograde hepatectomy is a safe and effective method for difficultly resected liver cancer. Key words cancer - liver - liver surgery - retrograde
基金funded jointly by the Scitech R&D Program of Chongqing Municipality(cstc2014yykfA00002(cstc2014yykfA0234),cstc2014jccxA0028 and cstc2013ggB0011)the Spark Program of Earthquake Sciences of CEA(Grant No.XH14042)
文摘A M_L3.8 earthquake occurred on February 23,2014 in Rongchang County,which is located at the southern edge of the Sichuan Basin in the border area between Sichuan and Chongqing. This paper presents results of focal mechanism solution of this earthquake using the CAP( cut and paste) method based on broadband seismograms recorded by regional seismic stations. Our results show that the moment magnitude is M_W3. 09 and focal depth is 3km. The hypocenter of this earthquake is located close to a buried fault in the Luoguangshan anticline. Oil prospecting and deep drilling data indicate that this buried fault is a thrust fault,striking SW230°,dipping NW45°,and 1. 7km deep. There are some injection wells within the anticline,and significant injection-induced earthquakes were observed during the periods of injection of waste water into the deep formations through those wells. The best double couple solution of the M_L3.8 earthquake is 247°,48°and 104° for strike,dip and rate,respectively,for one nodal plane( and 46°,44° and 74°for another nodal plane),which is in agreement with the geometry of the buried fault.Therefore,we conclude that the M_L3.8 Rongchang earthquake is possibly the result of faulting along the buried reverse fault induced by water injection under the compressive stress regime in the area.
基金supported by the National Science Foundation of China under Grant No.71101030the Program for Innovative Research Team in UIBE under Grant No.CXTD4-01
文摘This paper concerns the dimension reduction in regression for large data set. The authors introduce a new method based on the sliced inverse regression approach, cMled cluster-based regularized sliced inverse regression. The proposed method not only keeps the merit of considering both response and predictors＇ information, but also enhances the capability of handling highly correlated variables. It is justified under certain linearity conditions. An empirical application on a macroeconomic data set shows that the proposed method has outperformed the dynamic factor model and other shrinkage methods.
基金supported by the National Natural Science Foundation of China (21301016, 21473013)the National Basic Research Program of China (2014CB932103)+2 种基金Beijing Municipal Natural Science Foundation (2152016)the Fundamental Research Funds for the Central UniversitiesAnalytical and Measurements Fund of Beijing Normal University
文摘Photoactive cocrystal materials have received growing research interest in construction of photofunctional systems owing to the crucial roles in modifying the photo-related properties of molecular solids, based on the non-bonding interactions between self-assembly units. Herein, we report tunable luminescence and acid-base stimuli-responsive properties of a cocrystal assembled by 4-[2-(4-quinolinyl)vinyl]phenol (qv) and tetrafluoroterephthalic acid (a). The luminescent properties (such as wavelength, quantum yield and fluorescence lifetime) of qv.a changed obviously relative to the pristine qv, due to the proton transfer and the alternation of molecular arrangement within two-component crystalline material. The photoemission intensity of qv.a underwent from weak to strong upon HCl gas fuming, and the corresponding wavelength changed from 517 nm to 597 nm, which can be reversibly transferred after exposed in NH3. Such luminescent switching behavior may provide an effective way to develop new types of photoactive stimuli-responsive materials and optical sensors.
基金Project supported by the National Natural Science Foundation of China(Nos.11226152,11201086)the Science and Technology Foundation of Guizhou Province(No.[2012]2167)+1 种基金the Foundation for Distinguished Young Talents in Higher Education of Guangdong(No.2012LYM_0087)the Talent Project Foundation of Guizhou University(No.201104)
文摘This paper is concerned with limit cycles which bifurcate from a period annulus of a quadratic reversible Lotka-Volterra system with sextic orbits.The authors apply the property of an extended complete Chebyshev system and prove that the cyclicity of the period annulus under quadratic perturbations is equal to two.
基金supported by the National Key R&D Program of China (2016YFB0401004)the National Natural Science Foundation of China (51625301, 51573059, 91233116)+1 种基金the National Basic Research Program of China (2015CB655003)Guangdong Provincial Department of Science and Technology (2016B090906003, 2016TX03C175)
文摘An organic compound exhibiting simultaneously reversible switch between its emission colors and luminescence mechanisms,possessing high contrast from deep blue normal fluorescence(NF) to yellow thermally activated delayed fluorescence(TADF),is reported. Based on these two complementary colors, white-light emission combining NF and TADF from a single compound can be achieved in various states. Experimental results and density functional theory calculations indicate that the controllable conformational distribution under thermal and mechanical activation is the mechanism responsible for the reversible switching behavior.
基金funded by grants from the National Natural Science Foundation of China[No.81570492 to C.Q.J.]the National Natural Science Foundation of China[No.81500505 to W.C.L.]the Natural Science Foundation of Hubei Province[No.2015CFB636 to W.C.L.].
文摘Background:Few studies have compared the surgical outcomes of different surgical procedures currently used to treat refractory colonic slow-transit constipation(STC),despite the increase in the number of cases.This study aimed to analyse the long-termsurgical outcomes of subtotal colectomy with antiperistaltic caecorectal anastomosis(SC-ACRA)vs total colectomy with ileorectal anastomosis(TC-IRA)for severe STC.Methods:Between January 2005 and January 2015,we retrospectively collected clinical data of 55 patients who underwent TC-IRA(n=35)or SC-ACRA(n=20)for severe STC at our institution.The post-operative functional outcomes between the two groups were compared.Results:There were no significant differences in age(P=0.655),sex(P=0.234),period of constipation(P=0.105)and defecation frequency(P=0.698)between the TC-IRA and SC-ACRA groups.During a median follow-up period of 72 months(range,12–120 months),there were no significant differences between the TC-IRA and SC-ACRA groups regarding the median number of bowel movements per day[3(1/6–7)vs 3(1/6–5),P=0.578],Cleveland Clinic Florida Constipation Score[2(0–20)vs 2(0–19),P=0.454],Cleveland Clinic Incontinence Score[0(0–5)vs 0(0–2),P=0.333]and Gastrointestinal Quality of Life Index[122(81–132)vs 120(80–132),P=0.661].Moreover,there was no significant difference in the incidence of postoperative complications between the two groups(37.1%vs 25.0%,P=0.285).Conclusions:Our findings indicate that both TC-IRA and SC-ACRA are effective treatments for severe STC,with similar long-termoutcomes.
文摘We have studied the reversal of magnetisation in Ising ferromagnet by the field having gradient along a particular direction. We employed the Monte Carlo simulation with Metropolis single spin nip algorithm. The average lifetime of the metastable state was observed to increase with the magnitude of the gradient of applied field. In the high gradient regime, the system was observed to show two distinct region of up and down spins. The interface or the domain wall was observed to move as one increases the gradient. The displacement of the mean position of the interface was observed to increase with the gradient as hyperbolic tangent function. The roughness of the interface was observed to decay exponentially as the gradient increases. The number of spin flip per site was observed to show a discontinuity in the vicinity of the domain wall. The amount of the discontinuity was found to diverge with the system size as a power law fashion with an exponent 5/3.
