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重构震源振幅谱一致性的吸收参数反演方法

石油地球物理勘探 2024年第1期59卷 122-132页

作者：马雄申天赐李国发桂志先李勇根长江大学地球物理与石油资源学院湖北武汉430100 油气资源与勘探技术教育部重点实验室(长江大学) 湖北武汉430100 中国石油大学(北京)地球物理学院北京102249 中国石油勘探开发研究院北京100083

谱比法和质心频移法是两种工业应用较为广泛的品质因子Q反演方法,它们主要依靠地震振幅谱的某个单一属性(对数谱比斜率或者质心频率)对地层吸收参数进行估算和反演,因而反演结果很容易受到地震噪声和波场干涉等因素的影响。为此,提出一... 详细信息

谱比法和质心频移法是两种工业应用较为广泛的品质因子Q反演方法,它们主要依靠地震振幅谱的某个单一属性(对数谱比斜率或者质心频率)对地层吸收参数进行估算和反演,因而反演结果很容易受到地震噪声和波场干涉等因素的影响。为此,提出一种基于重构震源振幅谱一致性的地层吸收参数反演方法。其核心思想是将地震信号沿射线路径向震源位置反向传播,并进行吸收补偿,然后利用地震信号在震源位置重构的振幅谱一致性进行地层吸收参数反演。该方法既不需要已知震源子波,也不需要提取地震信号振幅谱的某个特定属性,具有提高地层吸收参数反演精度的潜力。模型实验表明:相较于谱比法和质心频移法,该方法具有更高的反演精度和更强的抗噪性。M区块应用结果表明:该方法能够为后续的吸收补偿提供高精度的吸收结构模型,有较好的工业应用前景。

关键词：吸收参数反演振幅谱一致性反向传播吸收补偿吸收结构模型

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夏热冬冷地区铁路站房复合通风效果分析

制冷与空调（四川） 2024年第2期38卷 210-216页

作者：卢垚周傲轩于文华沈天赐中国铁建电气化局集团有限公司新型建筑工程公司太原030000 广东迦南通用设备有限公司佛山528200 四川省艾耳能科技有限公司成都610083 西南交通大学机械工程学院成都610031

铁路站房采用自然通风+机械通风+空调的复合通风系统可以提高人员热舒适性,同时降低能耗。采用EnergyPlus软件对夏热冬冷地区铁路站房的自然通风潜力、复合通风切换温度和复合通风策略下的通风效果进行了模拟研究。结果表明:在非供暖季... 详细信息

铁路站房采用自然通风+机械通风+空调的复合通风系统可以提高人员热舒适性,同时降低能耗。采用EnergyPlus软件对夏热冬冷地区铁路站房的自然通风潜力、复合通风切换温度和复合通风策略下的通风效果进行了模拟研究。结果表明:在非供暖季,夏热冬冷地区铁路站房自然通风平均换气量可达60~70m^(3)/s,平均总换气次数可达1.9次/h;复合通风上下切换温度应设置在23℃和15℃;与完全采用机械制冷空调系统相比,自然通风+机械通风+空调的复合通风系统可降低6.5万kW h左右的能耗。

关键词：夏热冬冷地区铁路站房复合通风热舒适性节能分析

定量测量前列腺周围脂肪组织对预测前列腺癌骨转移的临床价值

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中国中西医结合影像学杂志 2024年第1期22卷 90-95页

作者：王洋洋周云烽沈天赐刘月湖北省襄阳市第一人民医院骨科湖北襄阳430079 湖北省襄阳市第一人民医院放射科湖北襄阳430079 湖北省襄阳市第一人民医院手术室湖北襄阳430079

目的:建立新发前列腺癌患者骨转移风险列线图预测模型,探讨前列腺周围脂肪组织(PPAT)与前列腺癌骨转移的关系。方法:纳入160例患者(骨转移组、非骨转移组各80例),在MRI图像上定量测量耻骨联合层面腹部皮下脂肪厚度(NFSP)、耻骨联合至椎... 详细信息

目的:建立新发前列腺癌患者骨转移风险列线图预测模型,探讨前列腺周围脂肪组织(PPAT)与前列腺癌骨转移的关系。方法:纳入160例患者(骨转移组、非骨转移组各80例),在MRI图像上定量测量耻骨联合层面腹部皮下脂肪厚度(NFSP)、耻骨联合至椎体前缘的最短直线距离(FNPF)、耻骨联合层面后背部皮下脂肪厚度(BSF)、耻骨联合至前皮下最大距离(PSSF)、耻骨联合至前列腺的最大垂直距离(MDSP)、耻骨联合上缘切线至椎体前缘的距离(PSPF)、前列腺面积(PA)、前列腺周围脂肪面积(PPFA),分析其与前列腺癌骨转移的相关性,筛选特征属性。采用分层随机抽样的方法将160例患者按照7∶3的比例分为训练集和测试集,建立脂肪定量测量回归预测模型,并测试集进行验证。结果:MDSP、PSPF、FNPF、PPFA/PA是前列腺癌骨转移的独立危险因素(均P<0.05)。测试MDSP、PSPF、FNPF、PPFA/PA及包含上述4种特征的联合模型的诊断效能,在训练集AUC分别为0.90、0.78、0.72、0.80、0.92,在测试集AUC为0.87、0.86、0.68、0.79、0.98。结论:基于脂肪定量测量的列线图可很好地预测前列腺癌患者的骨转移风险。

关键词：前列腺肿瘤骨转移内脏脂肪列线图

基于GIS的土地储备综合管理平台设计与实现

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测绘与空间地理信息 2022年第7期45卷 154-156,160页

作者：沈天赐新疆维吾尔自治区第一测绘院新疆昌吉831100

随着城市化的快速推进,土地资源已成为城市资源的重要组成部分之一。但是,由于土地储备管理精细化和信息化程度较低,造成土地规划、征收、出让等各环节效率低,严重影响土地供应的需求。本文借助GIS、云计算等先进技术,探讨了土地储备全... 详细信息

随着城市化的快速推进,土地资源已成为城市资源的重要组成部分之一。但是,由于土地储备管理精细化和信息化程度较低,造成土地规划、征收、出让等各环节效率低,严重影响土地供应的需求。本文借助GIS、云计算等先进技术,探讨了土地储备全周期管理流程,构建了土地储备数据库,搭建了土地储备综合管理平台,实现了土地储备“一张图”展示、各类项目管理、资金管理以及档案管理等功能,有效地提高了土地储备管理水平。

关键词： GIS 土地储备综合管理平台建设

Transient Characteristics and Accommodative Current Limiting Strategy for Bidirectional Interlinking Converters in Hybrid AC/DC Microgrids

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CSEE Journal of Power and Energy Systems 2024年第4期10卷 1575-1588页

作者： Xia shen Zhikang Shuai Wen Huang Chao shen Yang shen Z.John shen College of Electrical and Information Engineering Hunan UniversityChangsha 410082China Department of Electrical and Computer Engineering Illinois Institute of TechnologyChicagoIL 60616 USA

Bidirectional interlinking converter(BIC)is the core equipment in a hybrid AC/DC microgrid connected between AC and DC ***,the variety of control modes and flexible bidirectional power flow complicate the influence of AC faults on BIC itself and on DC sub-grid,which potentially threaten both converter safety and system *** study first investigates AC fault influence on the BIC and DC bus voltage under different BIC control modes and different pre-fault operation states,by developing a mathematical model and equivalent sequence ***,based on the analysis results,a general accommodative current limiting strategy is proposed for BIC without limitations to specific mode or operation *** amplitude is predicted and constrained according to the critical requirements to protect the BIC and relieving the AC fault influence on the DC bus *** with conventional methods,potential current limit failure and distortions under asymmetric faults can also be ***,experiments verify feasibility of the proposed method.

关键词： Bidirectional interlinking converter current limiting fault characteristic hybrid AC/DC microgrid variation/oscillation of DC bus voltage

Rational Solutions of First Order Algebraic Ordinary Differential Equations

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Journal of Systems Science & Complexity 2024年第2期37卷 567-580页

作者： FENG Shuang shen Liyong School of Physical and Mathematical Sciences Nanjing Tech UniversityNanjing 211816China School of Mathematical Sciences University of Chinese Academy of SciencesBeijing 100049China

Let f(t,y,y')=∑ _(i=0)^(n )a_(i)(t,y)y'^(i)=0 be an irreducible first order ordinary differential equation with polynomial *** in 1998 proved that there exists a constant C such that every rational solution of f(t,y,y')=0 is of degree not greater than *** show that this degree bound C depends not only on the degrees of f in t,y,y' but also on the coefficients of f viewed as the polynomial in t,y,y'.In this paper,the authors show that if f satisfies deg(f,y)0,then the degree bound C only depends on the degrees of f in t,y,y',and furthermore we present an explicit expression for C in terms of the degrees of f in t,y,y'.

关键词： Degree bound first order AODE height rational solution

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Large reversible magnetocaloric effect in antiferromagnetic Er_(3)Si_(2)C_(2) compound

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Journal of Rare Earths 2024年第8期42卷 1555-1559,I0005页

作者： Hao Sun Lu Tian Xinqiang Gao Zhaojun Mo Jun shen Baogen shen School of Rare Earths University of Science and Technology of ChinaHefei230026China Ganjiang Innovation Academy Chinese Academy of SciencesGanzhou34100China Department of Energy and Power Engineering School of Mechanical EngineeringBeijing Institute of TechnologyBeijing00081China

The magnetic properties,magnetic phase transition and magnetocaloric effects(MCE) of Er_(3)Si_(2)C_(2) compound were investigated based on theoretical calculations and experimental *** on the first principles calculations,the antiferromagnetic(AFM) ground state type in Er_(3)Si_(2)C_(2) compound was predicted and its electronic structure was *** experimental results show that Ei_(3)Si_(2)C_(2) compound is an AFM compound with the Neel temperature(I_N) of 7 K and undergoes a field-induced firstorder magnetic phase transition from AFM to ferromagnetic(FM) under magnetic fields exceeding 0.6 T at 2 *** magnetic transition process of Er_(3)Si_(2)C_(2) compound was investigated and *** values of the maximum magnetic entropy change(-ΔS_(M)^(max)) and the refrigeration capacity(RC) are 17 J/(kg·K)and 193 J/kg under changing magnetic fields of 0-5 T,*** a potential cryogenic magnetic refrigerant,the Er_(3)Si_(2)C_(2) compound also provides an interesting research medium to study the magnetic phase transition process.

关键词： Magnetic materials Magnetocaloric Metamagnetic transitions Magnetic phase transition Rare earths

Identifying the enhancement mechanism of Al/MoO_(3) reactive multilayered films on the ignition ability of semiconductor bridge using a one-dimensional gas-solid two-phase flow model

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Defence Technology（防务技术） 2024年第3期33卷 168-179页

作者： Jianbing Xu Yuxuan Zhou Yun shen Yueting Wang Yinghua Ye Ruiqi shen School of Chemistry and Chemical Engineering Nanjing University of Science and TechnologyNanjing 210094China Micro-Nano Energetic Devices Key Laboratory of MIIT Nanjing 210094China Institute of Space Propulsion Nanjing University of Science and TechnologyNanjing 210094China

Energetic Semiconductor bridge(ESCB)based on reactive multilayered films(RMFs)has a promising application in the miniature and intelligence of initiator and pyrotechnics *** the ignition enhancement mechanism of RMFs on semiconductor bridge(SCB)during the ignition process is crucial for the engineering and practical application of advanced initiator and pyrotechnics *** this study,a one-dimensional(1D)gas-solid two-phase flow ignition model was established to study the ignition process of ESCB to charge particles based on the reactivity of Al/MoO_(3) *** order to fully consider the coupled exothermic between the RMFs and the SCB plasma during the ignition process,the heat release of chemical reaction in RMFs was used as an internal heat source in this *** is found that the exothermal reaction in RMFs improved the ignition performance of *** the process of plasma rapid condensation with heat release,the product of RMFs enhanced the heat transfer process between the gas phase and the solid charge particle,which accelerated the expansion of hot plasma,and heated the solid charge particle as well as gas phase region with low *** addition,it made up for pressure loss in the gas *** the plasma dissipation process,the exothermal chemical reaction in RMFs acted as the main heating source to heat the charge particle,making the surface temperature of the charge particle,gas pressure,and gas temperature rise *** result may yield significant advantages in providing a universal ignition model for miniaturized ignition devices.

关键词： Ignition enhancement mechanism 1D gas-solid two-phase flow Al/MoO_(3)reactive multilayered films Semiconductor bridge Miniaturized ignition device

Model-free method for LQ mean-field social control problems with one-dimensional state space

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Control Theory and Technology 2024年第3期22卷 479-486页

作者： Zhenhui Xu Tielong shen School of Engineering Tokyo Institute of TechnologyTokyo 152-8550Japan Department of Engineering and Applied Sciences Sophia UniversityTokyo 102-8554Japan

This paper presents a novel model-free method to solve linear quadratic(LQ)mean-field control problems with one-dimensional state space and multiplicative *** focus is on the infinite horizon LQ setting,where the conditions for solution either stabilization or optimization can be formulated as two algebraic Riccati equations(AREs).The proposed approach leverages the integral reinforcement learning technique to iteratively solve the drift-coefficient-dependent stochastic ARE(SARE)and other indefinite ARE,without requiring knowledge of the system dynamics.A numerical example is given to demonstrate the effectiveness of the proposed algorithm.

关键词： Mean-field control Social optima Infinite horizon Reinforcement learning