目的观察瘢痕子宫再次妊娠产妇行椎管内分娩镇痛的安全性和有效性。方法选择2017年5月至2018年4月我院收治的瘢痕子宫再次妊娠同意阴道试产单胎足月头位产妇101例,随机选取分娩镇痛产妇70例为观察组,其中硬膜外分娩镇痛(E组)36例,腰-硬...目的观察瘢痕子宫再次妊娠产妇行椎管内分娩镇痛的安全性和有效性。方法选择2017年5月至2018年4月我院收治的瘢痕子宫再次妊娠同意阴道试产单胎足月头位产妇101例,随机选取分娩镇痛产妇70例为观察组,其中硬膜外分娩镇痛(E组)36例,腰-硬联合分娩镇痛(C组)34例,同期未镇痛产妇31例为对照组(N组)。记录产妇各产程时间、出血量、新生儿1、5 min Apgar评分、阴道分娩、产钳助产、子宫破裂情况,记录镇痛前、给药后5、10、20 min产妇NRS评分和Bromage评分。结果与N组比较,E组和C组第二产程时间明显延长(P<0.05);E组出血量高于N组及C组,但差异无统计学意义。三组第一、第三产程时间、新生儿1、5 min Apgar评分、阴道分娩、产钳助产、子宫破裂发生率差异无统计学意义;镇痛后E组和C组NRS评分均呈下降趋势。与E组比较,C组NRS评分明显降低(P<0.05)。结论瘢痕子宫再次妊娠产妇采用椎管内分娩镇痛安全可行,不降低阴道分娩率,不增加出血量以及产钳助产、子宫破裂发生率。腰-硬联合分娩镇痛较硬膜外分娩镇痛的镇痛效果好。展开更多
Lie group technique for solving differential-difference equations is applied to a new (2+1)-dimensional Toda-like lattice. An infinite dimensional Lie algebra and the corresponding commutation relations are obtained.
A laser coherent detection system of 1550 nm wavelength was presented, and experimen- tal research on detecting micro-Doppler effect in a dynamic target was developed. In the study, the return signal in the time domai...A laser coherent detection system of 1550 nm wavelength was presented, and experimen- tal research on detecting micro-Doppler effect in a dynamic target was developed. In the study, the return signal in the time domain is decomposed into a set of components in different wavelet scales by multi-resolution wavelet analysis, and the components are associated with the vibrational motions in a target. Then micro-Doppler signatures are extracted by applying the reconstruction. During the course of the final data processing frequency analysis and time-frequency analysis are applied to analyze the vibrationM signals and estimate the motion parameters successfully. The experimental results indicate that the system can effectively detect micro-Doppler information in a moving target, and the tiny vibrational signatures also can be acquired effectively by wavelet multi-resolution analy- sis and time-frequency analysis.展开更多
In this letter, using a Baecklund transformation and the new variableseparation approach, we find a new general solution of the (N+1)-dimensional Burgers system. Theform of the universal formula obtained from many (2+...In this letter, using a Baecklund transformation and the new variableseparation approach, we find a new general solution of the (N+1)-dimensional Burgers system. Theform of the universal formula obtained from many (2+1)-dimensional system is extended.展开更多
By using a Baecklund transformation and the multi-linear variable separationapproach, we find a new general solution of a (2+1)-dimensional generalization of the nonlinearSchroedinger system. The new 'universal...By using a Baecklund transformation and the multi-linear variable separationapproach, we find a new general solution of a (2+1)-dimensional generalization of the nonlinearSchroedinger system. The new 'universal' formula is defined, and then, rich coherent structures canbe found by selecting corresponding functions appropriately.展开更多
This paper investigates the frustration induced phenomena at the commensurate-incommensurate crossing point in one-dimensional massive systems. The massive elementary excitation can be described by a dispersion e(k )...This paper investigates the frustration induced phenomena at the commensurate-incommensurate crossing point in one-dimensional massive systems. The massive elementary excitation can be described by a dispersion e(k )=√∑ an cos(nk), with a set of phenomenological coefficients an, which depend on the frustration. From the dispersion,we find that at the commensurate-incommensurate crossing point, both pitch angle and the correlation length have square root singularities, being functions of funstration intensity. The gap in the incommensurate side also comes to be singular while approaching the crossing point. Anomalous magnetization exponent appears at the singular point of the spin gap.展开更多
The ground-state and thermodynamic properties of quantum mixed-spin chains of1/2-1/2-1-1and 3/2-3/2-1-1are investigated by a quantum Monte Carlo simulation with the loop-cluster algorithm. For 1/2-1/2-1-1 chain, we fi...The ground-state and thermodynamic properties of quantum mixed-spin chains of1/2-1/2-1-1and 3/2-3/2-1-1are investigated by a quantum Monte Carlo simulation with the loop-cluster algorithm. For 1/2-1/2-1-1 chain, we find it has two phases separated by an energy-gap vanishing point in the ground-state. For 3/2-3/2-1-1 chain, the numerical results show two energy-gap vanishing points isolated by different phases in its ground-state. Our calculations indicate that all these ground state phases can be understood by means of valence-bond-solid picture, and the thermodynamic behavior at finite temperatures is continuous as a function of parameterα=J2/J1.展开更多
The multi-linear variable separation approach method is very useful to solve (2+1)-dimensional integrable systems. In this letter, we extend this method to solve (1+1)-dimensional Boiti system, (2+1)-dimensional Burge...The multi-linear variable separation approach method is very useful to solve (2+1)-dimensional integrable systems. In this letter, we extend this method to solve (1+1)-dimensional Boiti system, (2+1)-dimensional Burgers system, (2+1)-dimensional breaking soliton system, and (2+1)-dimensional Maccari system. Some new exact solutions are obtained and the universal formula obtained from many (2+1)-dimensional systems is extended or modified.展开更多
The variable separation approach method is very useful to solving (2+ 1 )-dimensional integrable systems. But the (1+1)-dimensional and (3+ 1 )-dimensional nonlinear systems are considered very little. In this letter,...The variable separation approach method is very useful to solving (2+ 1 )-dimensional integrable systems. But the (1+1)-dimensional and (3+ 1 )-dimensional nonlinear systems are considered very little. In this letter, we extend this method to (1+1) dimensions by taking the Redekopp system as a simple example and (3+1)-dimensional Burgers system. The exact solutions are much general because they include some arbitrary functions and the form of the (3+ 1 )-dimensional universal formula obtained from many (2+ 1 )-dimensional systems is extended.展开更多
A new approach for noninvasively tracing brain white matter fiber tracts is presented using diffusion tensor magnetic resonance imaging (DT-MRI) data. This technique is based on successive anisotropic diffusion simula...A new approach for noninvasively tracing brain white matter fiber tracts is presented using diffusion tensor magnetic resonance imaging (DT-MRI) data. This technique is based on successive anisotropic diffusion simulations over the human brain, which are utilized to construct three dimensional diffusion fronts. The fiber pathways are determined by evaluating the distance and orientation from fronts to their corresponding diffusion seeds. Real DT-MRI data are used to demonstrate the tracking scheme. It is shown that several major white matter fiber pathways can be reproduced noninvasively, with the tract branching being allowed. Since the diffusion simulation,which is a truly physical phenomenon reflecting the underlying architecture of cerebral tissues, makes full use of the entire diffusion tensor data, the proposed approach is expected to enhance robustness and reliability of the DT-MRI based fiber tracking techniques in white matter fiber reconstruction.展开更多
文摘目的观察瘢痕子宫再次妊娠产妇行椎管内分娩镇痛的安全性和有效性。方法选择2017年5月至2018年4月我院收治的瘢痕子宫再次妊娠同意阴道试产单胎足月头位产妇101例,随机选取分娩镇痛产妇70例为观察组,其中硬膜外分娩镇痛(E组)36例,腰-硬联合分娩镇痛(C组)34例,同期未镇痛产妇31例为对照组(N组)。记录产妇各产程时间、出血量、新生儿1、5 min Apgar评分、阴道分娩、产钳助产、子宫破裂情况,记录镇痛前、给药后5、10、20 min产妇NRS评分和Bromage评分。结果与N组比较,E组和C组第二产程时间明显延长(P<0.05);E组出血量高于N组及C组,但差异无统计学意义。三组第一、第三产程时间、新生儿1、5 min Apgar评分、阴道分娩、产钳助产、子宫破裂发生率差异无统计学意义;镇痛后E组和C组NRS评分均呈下降趋势。与E组比较,C组NRS评分明显降低(P<0.05)。结论瘢痕子宫再次妊娠产妇采用椎管内分娩镇痛安全可行,不降低阴道分娩率,不增加出血量以及产钳助产、子宫破裂发生率。腰-硬联合分娩镇痛较硬膜外分娩镇痛的镇痛效果好。
文摘Lie group technique for solving differential-difference equations is applied to a new (2+1)-dimensional Toda-like lattice. An infinite dimensional Lie algebra and the corresponding commutation relations are obtained.
文摘A laser coherent detection system of 1550 nm wavelength was presented, and experimen- tal research on detecting micro-Doppler effect in a dynamic target was developed. In the study, the return signal in the time domain is decomposed into a set of components in different wavelet scales by multi-resolution wavelet analysis, and the components are associated with the vibrational motions in a target. Then micro-Doppler signatures are extracted by applying the reconstruction. During the course of the final data processing frequency analysis and time-frequency analysis are applied to analyze the vibrationM signals and estimate the motion parameters successfully. The experimental results indicate that the system can effectively detect micro-Doppler information in a moving target, and the tiny vibrational signatures also can be acquired effectively by wavelet multi-resolution analy- sis and time-frequency analysis.
文摘In this letter, using a Baecklund transformation and the new variableseparation approach, we find a new general solution of the (N+1)-dimensional Burgers system. Theform of the universal formula obtained from many (2+1)-dimensional system is extended.
文摘By using a Baecklund transformation and the multi-linear variable separationapproach, we find a new general solution of a (2+1)-dimensional generalization of the nonlinearSchroedinger system. The new 'universal' formula is defined, and then, rich coherent structures canbe found by selecting corresponding functions appropriately.
基金国家自然科学基金，the Science Research Foundation of the Education Bureau of Anhui Province of China
文摘This paper investigates the frustration induced phenomena at the commensurate-incommensurate crossing point in one-dimensional massive systems. The massive elementary excitation can be described by a dispersion e(k )=√∑ an cos(nk), with a set of phenomenological coefficients an, which depend on the frustration. From the dispersion,we find that at the commensurate-incommensurate crossing point, both pitch angle and the correlation length have square root singularities, being functions of funstration intensity. The gap in the incommensurate side also comes to be singular while approaching the crossing point. Anomalous magnetization exponent appears at the singular point of the spin gap.
文摘The ground-state and thermodynamic properties of quantum mixed-spin chains of1/2-1/2-1-1and 3/2-3/2-1-1are investigated by a quantum Monte Carlo simulation with the loop-cluster algorithm. For 1/2-1/2-1-1 chain, we find it has two phases separated by an energy-gap vanishing point in the ground-state. For 3/2-3/2-1-1 chain, the numerical results show two energy-gap vanishing points isolated by different phases in its ground-state. Our calculations indicate that all these ground state phases can be understood by means of valence-bond-solid picture, and the thermodynamic behavior at finite temperatures is continuous as a function of parameterα=J2/J1.
文摘The multi-linear variable separation approach method is very useful to solve (2+1)-dimensional integrable systems. In this letter, we extend this method to solve (1+1)-dimensional Boiti system, (2+1)-dimensional Burgers system, (2+1)-dimensional breaking soliton system, and (2+1)-dimensional Maccari system. Some new exact solutions are obtained and the universal formula obtained from many (2+1)-dimensional systems is extended or modified.
文摘The variable separation approach method is very useful to solving (2+ 1 )-dimensional integrable systems. But the (1+1)-dimensional and (3+ 1 )-dimensional nonlinear systems are considered very little. In this letter, we extend this method to (1+1) dimensions by taking the Redekopp system as a simple example and (3+1)-dimensional Burgers system. The exact solutions are much general because they include some arbitrary functions and the form of the (3+ 1 )-dimensional universal formula obtained from many (2+ 1 )-dimensional systems is extended.
文摘A new approach for noninvasively tracing brain white matter fiber tracts is presented using diffusion tensor magnetic resonance imaging (DT-MRI) data. This technique is based on successive anisotropic diffusion simulations over the human brain, which are utilized to construct three dimensional diffusion fronts. The fiber pathways are determined by evaluating the distance and orientation from fronts to their corresponding diffusion seeds. Real DT-MRI data are used to demonstrate the tracking scheme. It is shown that several major white matter fiber pathways can be reproduced noninvasively, with the tract branching being allowed. Since the diffusion simulation,which is a truly physical phenomenon reflecting the underlying architecture of cerebral tissues, makes full use of the entire diffusion tensor data, the proposed approach is expected to enhance robustness and reliability of the DT-MRI based fiber tracking techniques in white matter fiber reconstruction.
