ON SOME ROTATIONALLY SYMMETRIC GRADIENT PSEUDO-KHLER-RICCI SOLITONS

In this paper, we explicitly construct some rotationally symmetric gradient pseudo- Kahler-Ricci solitons which depend on some parameters, on some line bundles and other bundles over projective spaces. We also discuss the ＂phase change＂ phenomenon caused by the variation of parameters.

Solving Load Flow Problems of Power System by Explicit Pseudo-Transient Continuation (E-ψtc) Method

This paper is a further study of two papers [1] and [2], which were related to Ill-Conditioned Load Flow Problems and were published by IEEE Trans. PAS. The authors of this paper have some different opinions, for example, the 11-bus system is not an ill-conditioned system. In addition, a new approach to solve Load Flow Problems, E-ψtc, is introduced. It is an explicit method;solving linear equations is not needed. It can handle very tough and very large systems. The advantage of this method has been fully proved by two examples. The authors give this new method a detailed description of how to use it to solve Load Flow Problems and successfully apply it to the 43-bus and the 11-bus systems. The authors also propose a strategy to test the reliability, and by solving gradient equations, this new method can answer if the solution exists or not.

伪单调变分不等式解集与拟非扩张映射不动点集公共元的强收敛定理

在Hilbert空间中提出一种新的关于求解伪单调变分不等式问题的Tseng外梯度算法。在适当条件下,证明由此算法生成的迭代序列强收敛于伪单调变分不等式问题的解集与拟非扩张映射不动点集的公共元,并用数值实验说明所提算法的有效性。

基于自适应组合窗函数的SPWVD算法及应用研究

针对平滑伪Wigller-Ville分布(Smoothing Pseudo-Winger-Ville distribution,SPWVD)在处理不同信号时,需要采用对应的平滑窗参数才能达到最优时频分布的问题,提出了一种基于自适应组合窗函数的SPWVD算法。该算法将Rényi熵作为时频评价指标,以组合窗函数的窗长和系数作为参数库,提出将随机梯度下降和扰动随机梯度下降分别用于窗长和系数的选取,提升计算速度分别为遍历法的20倍和9倍,最终得到信号的最优时频图。将上述的改进方法应用于碳纤维复合材料的缺陷检测中,结果表明,自适应组合窗函数的SPWVD可以有效地对不同信号选取最优的窗函数参数,对比固定窗函数的SPWVD,自适应组合窗函数的SPWVD具有更好的时频聚集效果,更加完备地对信号进行了表征,并对缺陷进行了定量分析,具备缺陷检测的良好应用前景。

基于自适应闭环反馈的高空车臂架避障控制研究

针对改进梯度投影法在混合式高空作业车应用中出现的速度、轨迹不连续以及避障过程中末端速度突变等问题,提出了一种基于自适应闭环反馈的高空车臂架避障控制算法。对改进梯度投影法进行优化,实现了存在伸缩臂的高空车臂架与末端的速度、轨迹连续的运动控制。采用伪距离描述臂架与障碍物的接近程度,对传统避障速度算法进行优化,并提出一种自适应闭环反馈方法,将反馈权重与伪距离相关联,使反馈权重自适应变化。所提算法在保证末端轨迹精度的同时大大改善了臂架关节在避障过程中的速度突变。仿真及半物理实验结果表明,相较于传统方法,所提方法速度变幅大大减小且轨迹更加平滑,实现了多障碍物避障与同一障碍物多次避障。

利用伪Margenau-Hill分布提取地震波能量衰减梯度

地震波在聚集了石油、天然气的储层中传播时存在能量的剧烈衰减,且频率越高能量衰减越快,所以通过地震波高频端能量衰减梯度可以灵敏地检测地层中是否存在烃类流体。通过传统的傅里叶变换求取地震波能量衰减梯度面临诸多问题,而伪Margenau-Hill(PMH)分布作为科恩类时频分布的一种则具有许多优良的特性:真边缘性、弱支撑性、好的时频聚集性等。为此,该文将PMH分布的时频分析方法引入到了地震波吸收衰减分析技术中,利用地震波高频端能量与其对应频率的拟线性关系来计算各时刻的地震波能量衰减梯度。实际资料应用表明,利用PMH分布来求取地震波能量衰减梯度在储层预测中具有重要意义。

关于C^(1-0)泛函的极小极大原理的一个注记

用非光滑分析的思想,对C^(1-0)泛函进行了分析,得到了关于C^(1-0)泛函的几个极小极大定理。

Effect of Heat Treatment on Gradient Microstructure and Tensile Property of Laser Powder Bed Fusion Fabricated 15-5 Precipitation Hardening Stainless Steel

This work investigated the gradient microstructure evolution and tensile property of LPBF fabricated 15-5 precipitation hardening stainless steel in post-process direct ageing(DA)and solution treating&ageing(STA).The varied microstructures for austenite and small-sized oxide inclusions at different sample heights in the as-built(AB)condition was generally preserved after DA treatment.However,austenite was almost disappeared,and oxide particle grew significantly after the STA treatment.As a result,the tensile property differences in sample top and bottom for AB and DA conditions did not occur in the STA samples.For the influence of post-process heat treatment,the STA condition had the highest yield strength due to the highest volume fraction of nano-sized Cu precipitates.However,the DA specimen had the highest ultimate tensile strength and elongation owing to the considerable amount of austenite phase and associated transformation induced plasticity effect.

P-SV波AVO响应特征分析

本文首先回顾了P-P波AVO响应特征及其分类,随后从P-SV波反射系数及振幅特征、归一化的P-SV波反射系数及截距-梯度特征、地层参数变化趋势与AVO类型的关系等方面系统地阐述了P-SV波AVO响应特征。文中选用(Castagna、Hilterman给出的四种AVO类型的岩性参数,利用佐普里兹方程计算了P-SV波反射系数,得出以下认识:⑴对于不同类型气层,P-SV波AVO响应特征比较复杂,利用单一的反射系数曲线和振幅特征无法同时区分四类AVO类型,表明P-SV波AVO响应对储层流体成分并不敏感;②通过引入伪转换波阻抗的概念,归一化反射系数曲线呈现单调性,同时放大了弱AVO异常。对于Ⅰ、Ⅱ、Ⅲ类AVO类型的气层,无论储层含水还是含气,垂直入射时归一化反射系数随入射角单调递增;对于Ⅳ类AVO类型的气层,储层流体的性质不影响反射系数的变化趋势,反射系数都为正值且随入射角单调递减;③Ⅰ、Ⅱ类气层具有负截距和正梯度,Ⅲ类气层的截距和梯度都接近于零,Ⅳ类气层具有正截距和负梯度。文中利用P-SV波AVO截距-梯度理论对不同AVO类型和Castagna给出的25种含(油)气砂岩模型进行了截距-梯度分析,进一步验证了P-SV波AVO响应特征及其对不同气层的分辨能力。本文的研究对AVO正演模拟、储层流体替换、多波AVO分析和参数反演都具有重要意义。

Experimental study of temperature gradient in track slab under outdoor conditions in Chengdu area

Temperature is one of the important loads for designing slab track. The characteristic of slab track tem- perature varies greatly with different regional climates. In this work, a bi-block slab track model was built under outdoor conditions in Chengdu area; the statistical characteristic of temperature gradient in track slab and the relationship between temperature gradient and surface air temperature were tested and analyzed. The results show that the track slab temperature gradient will vary periodically according to the surface air temperature, and show a clear nonlinearity along the height direction. The temperature gradient distribution is extremely uneven： the temperature gradient in the top part of the track slab is larger than that in the bottom part; the most frequently occurring temperature gradient of the track slab is around -3.5 ℃/m and more than 75 % locates in the level -10 to 10 ℃/m; concrete with a relatively good heat exchange condition with the surrounding air has a narrower band distribution. In addition, the frequency distribution histogram should exclude the time zone from 00：00 to 06：00 because there is almost no traffic in this period. The amplitude of track slab temperature variation is obviously lower than that of the air temperature variation, and the former is approximately linear with the latter.

CSAMT阻抗梯度法之初探--以新疆和什托洛盖盆地为例

沉积盆地中由于各岩层电阻率差异小,传统的CSAMT方法解译仅依靠电阻率资料对层位进行划分,具有多解性,探测精度难以满足要求。根据电磁波与地震波的相似性,以电磁法的拟地震波解释法理论为基础,结合CSAMT方法特点,初步研究了一维层状介质的阻抗梯度法在资料解释中的可行性。结合在新疆和什托洛盖盆地的一条实测剖面成果与多个钻孔资料的对比分析,该方法在盆地的地层结构和构造的划分中具有指示作用,与传统方法的解释效果对比,其对低阻区域分层效果明显,使CSAMT资料解释提高了测量精度。

多目标A-N广义凸规划的Mond-Weir型对偶

本文利用锥次微分及Ａ－Ｎ广义伪凸概念。

Radial Permeability Measurements for Shale Using Variable Pressure Gradients

Shale gas is becoming an important component of the global energy supply, with permeability a critical controlling factor for long-term gas production. Obvious deviation may exist between helium permeability determined using small pressure gradient(SPG) methods and methane permeability obtained under actual field production with variable pressure gradients(VPG). In order to more accurately evaluate the matrix permeability of shale, a VPG method using real gas(rather than He) is established to render permeability measurements that are more representative of reservoir conditions and hence response. Dynamic methane production experiments were performed to measure permeability using the annular space in the shale cores. For each production stage, boundary pressure is maintained at a constant and the gas production with time is measured on the basis of volume change history in the measuring pump. A mathematical model explicitly accommodating gas desorption uses pseudo-pressure and pseudo-time to accommodate the effects of variations in pressuredependent PVT parameters. Analytical and semi-analytical solutions to the model are obtained and discussed. These provide a convenient approach to estimate radial permeability in the core by nonlinear fitting to match the semi-analytical solution with the recorded gas production data. Results indicate that the radial permeability of the shale determined using methane is in the range of 1×10-6– 1×10-5 mD and decreases with a decrease in average pore pressure. This is contrary to the observed change in permeability estimated using helium. Bedding geometry has a significant influence on shale permeability with permeability in parallel bedding orientation larger than that in perpendicular bedding orientation. The superiority of the VPG method is confirmed by comparing permeability test results obtained from both VPG and SPG methods. Although several assumptions are used, the results obtained from the VPG method with reservoir gas are much closer to reality and may be directly used for actual gas production evaluation and prediction, through accommodating realistic pressure dependent impacts.

Study on Antimicrobial and Antiviral Activities of Lysozyme From Marine Strain S-12-86 In Vitro

In this study, the in vitro antimicrobial and antiviral activities of the lysozyme from marine strain S-12-86 （LS） were investigated, The antimicrobial activity of LS was tested by minimum inhibition concentration （MIC） and minimum bactericidal concentration （MBC） method. The inhibiting effects of LS on pseudo rabies virus （PRV） in swine kidney cells （PK-15 ceils） were judged by cytopathogenic effect test （CPE）, The results showed LS had a broad antimicrobial spectrum against several standard strains including gram-positive bacteria, gram-negative bacteria, fungi, etc, The MIC of LS was 0.25-4.00 mg mL^-1 and its MBC was 0.25-8.00 mg mL^-1, respectively, Observation under the transmission electron microscope revealed that the cell wall of Candida albicans was distorted seriously, and the cytoplasm with many cavities was asymmetrical after being hydrolyzed by LS, The median cytotoxicity concentration （TC50） of LS was 100.0 μg mL^-1, the median effective concentration （EC50） was 0.46 μg mL^-1, and the selectivity index （TI = TC50/EC50） was 217. LS could inhibit PRV in PK-15 cells when it was added to cell culture medium at 0, 2, 4, 6, and 8 h after PK-15 cells had been infected by PRV. From the results, we concluded that LS had broad antimicrobial spectrum and good inhibiting effects on PRV,

基于PID参数整定的无模型自适应控制器参数整定方法

本文针对一阶线性时不变(FOLTI)系统,将常用的比例–积分–微分(PID)控制器参数整定方法推广到无模型自适应控制(MFAC)参数整定中,利用PID控制参数整定方法整定直接型MFAC方案的伪梯度初值,以期改变MFAC控制律初始参数的试凑式选取,提升MFAC应用的方便性和可接受性.通过仿真,验证了所提伪梯度初值整定方法的有效性,并对比了FOLTI系统的系统参数和系统结构发生变化后,应用MFAC与PID控制的性能差异.

基于伪距离的混凝土泵车臂架避障运动控制研究

针对混凝土泵车臂架末端避障和臂架关节限制问题,提出一种基于伪距离的泵车臂架避障方法。运用超二次曲面函数表示空间障碍物,采用伪距离作为臂架与空间障碍物的接近程度指标。基于最小伪距离判别指标,对泵车臂架赋予一个避障速度,并对传统梯度投影算法进行改进,在避免关节运动超过关节极限位置的情况下实现泵车臂架的安全避障,同时保证避障过程的平稳性和臂架末端的轨迹精度。仿真及半物理实验验证了该算法在混凝土泵车臂架避障过程中的有效性,且能完成空间多障碍物避障。

Protein-spatiotemporal partition releasing gradient porous scaffolds and anti-inflammatory and antioxidant regulation remodel tissue engineered anisotropic meniscus

Meniscus is a wedge-shaped fibrocartilaginous tissue,playing important roles in maintaining joint stability and function.Meniscus injuries are difficult to heal and frequently progress into structural breakdown,which then leads to osteoarthritis.Regeneration of heterogeneous tissue engineering meniscus(TEM)continues to be a scientific and translational challenge.The morphology,tissue architecture,mechanical strength,and functional applications of the cultivated TEMs have not been able to meet clinical needs,which may due to the negligent attention on the importance of microenvironment in vitro and in vivo.Herein,we combined the 3D(three-dimensional)-printed gradient porous scaffolds,spatiotemporal partition release of growth factors,and anti-inflammatory and anti-oxidant microenvironment regulation of Ac2-26 peptide to prepare a versatile meniscus composite scaffold with heterogeneous bionic structures,excellent biomechanical properties and anti-inflammatory and anti-oxidant effects.By observing the results of cell activity and differentiation,and biomechanics under anti-inflammatory and anti-oxidant microenvironments in vitro,we explored the effects of anti-inflammatory and anti-oxidant microenvironments on construction of regional and functional heterogeneous TEM via the growth process regulation,with a view to cultivating a high-quality of TEM from bench to bedside.

Proton transport controlled at surface layer of CeO_(2) by gradient-doping with a built-in-field effect

Ceramic fuel cells hold an important position for the sustainable energy future using renewable energy sources with high efficiency.The design and synthesis of active materials,interface engineering and having capability of low operating temperature is considered as an important factor to further increase the power output and stability of ceramic fuel cell devices.A novel methodology has vital importance to develop new functionalities of existing materials by introducing new different effects.The built-in electric field(BIEF) is one of the most recently used approaches to improve charge transfer and ionic conductivity of solid oxide materials.Herein,we demonstrate gradient doping strategy in CeO_(2)-δstructure to produce BIEF effect and to modulate the proton transport effectively at the surface layer rather than bulk structure.The inclusions of La and Sr metal ions at the surface and Co-metal ions into bulk-layer of CeO_(2)form the gradiently doped structure.The gradient doping into CeO_(2)highly improves the proton transport properties through the surface layer by modifying the energy levels.Moreover,unbalanced charge distribution due to gradient doping produces built-in electric-field to provide extra driving force for protons transport through surface layer.The acquired gradiently doped fluorite structure exhibits remarkable proton conductivity of>0.2 S/cm,as a result ceramic fuel cell shows power output of>1000 mW/cm2while operating at 500℃.This unique work highlights the critical role of gradiently doped electrolyte in electrochemical conversion energy devices and offers new understanding and practices for sustainable energy future.

低渗透油藏拟启动压力梯度

对大庆外围和长庆西峰油区低渗透油藏岩心进行了恒速压汞、核磁共振和渗流实验,从不同角度研究了低渗透储集层拟启动压力梯度形成原因及影响因素。由于储集层中固液作用形成的边界层的存在,且低渗透油藏喉道非常微细,因而低渗透油藏流体流动需要克服启动压力梯度。在低压力下,参与渗流的喉道少,岩心断面上的渗流截面小,随着驱动压力增加,参与渗流的喉道数量增加,岩心断面上的渗流截面增大。储集层的孔隙结构特征、可动流体饱和度对拟启动压力梯度有显著的影响,主流喉道半径及可动流体饱和度越大,拟启动压力梯度越小。拟启动压力梯度是储集层渗流非线性程度和渗流能力的表征参数,是孔隙结构、固液作用的综合体现。

基于紧格式线性化的无模型动态矩阵控制

针对常规无模型自适应控制(MFAC)算法只利用了受控系统I/O数据的零阶信息,许多系统内部信息没有充分利用的缺陷,提出了一种基于紧格式线性化的无模型动态矩阵控制方法。该方法利用紧格式线性化方法把非线性系统转化为一组由伪梯度向量描述的线性系统,将动态矩阵控制算法的预测模型和该伪梯度向量相结合,推导出无模型动态矩阵控制的动态模型。在此基础上,利用滚动优化和反馈校正等策略,推导出了无模型动态矩阵控制律的解析式。由于该方法中引入了受控系统I/O数据所带的系统内部信息,极大地提高了预测模型的精确性,增强了系统的鲁棒性,从而有效改善了控制器的控制性能。仿真结果表明该算法具有一定的结构自适应性、良好的伺服性和较强的鲁棒性。