Three-dimensional transformation of magnetization direction and magnetic field component at low latitudes based on vertical relationship

The transformation of the magnetization direction and the magnetic fi eld component is one of the important methods in magnetic data processing and transformation,which can be conducted in both wavenumber and spatial domains.The transformation method in the wavenumber domain has simpler processing expression and higher processing effi ciency than in the spatial domain;however,they are unstable at low latitude.In this paper,the conclusion that the sum is 0 of two vertical magnetic fi eld components(magnetization inclinations are also perpendicular)in 2D is used for the 3D transformation of the magnetization direction and the magnetic field component.In addition,the transformation method at low latitudes based on vertical relationship(VMT)is proposed,which is an iterative algorithm that converts the transformation of the magnetization direction and the magnetic field component at the low latitude into the high latitude.This method restrains the instability of transformation of constant and variable magnetization direction and magnetic fi eld components in low latitudes.The accuracy,stability,and practicality are verifi ed from synthetic models and real data.

The relationship between tidal current field and sediment transport in the Huanghai Sea and the Bohai Sea

-Based on a two-dimensional numerical M2 tidal model of the Huanghai and Bohai Seas, sediment transport of particles with different sizes in the computational area is given. It is concluded that tidal currents play an important role in sediment transport and deposition in the Huanghai and Bohai Seas.

Phase-field modeling for anisotropic ductile damage of magnesium alloys at finite deformations

The damage anisotropy of an extruded ZK60 Mg alloy is characterized using tensile tests and scanning electronic microscopy.The accumulation of anisotropic deformations leads to the great differences of the dimple evolution and strains at fracture along different loading directions.To introduce the anisotropic deformation information into the damage constitutive relationship,a thermodynamically consistent phase-field model of ductile damage fully coupled with elastoplastic finite deformations is developed in this study.Using the user-defined constitutive relationship and displacement-temperature coupling element,the finite element simulations are conducted.The results show that:(1)ZK60 Mg alloys presents clear R-value difference in 0°,45°,and 90°tests of intact specimens.The 45°test possesses the greatest R-value(1.50)and the greatest strain at fracture,however,the R-value for 0°is less than 1,indicating the thinning is preferential.(2)The higher ultimate stress leads to a larger average dimension of the dimples,whereas the higher density correlates with a larger elongation ratio at the fracture.The disappearance of the stress-bearing area indicates that the phase-field assumption on stress degradation is completely compatible with the dimple analysis on fractography.(3)The simulation results of the stress-strain relationships and damage paths correlate well with the experimental ductile damage of magnesium alloys at 200◦C.Slight errors are basically attributed to the modeling parameters and finite element iteration algorithm.The proposed model presents fine applicability and reliability for the predictions of plastic deformations,ductile damage,and fracture of anisotropic Mg alloys.

Application of the Levenberg-Marquardt Method in Improving Technology of the Seismic Influence Field

Attenuation relation of seismic intensity is fitted by using 152 complete isoseismic lines from65 earthquakes which were greater than MS4. 0 from 1940 to 2015 in Inner Mongolia and neighboring regions. Meanwhile,based on the difference of land form and geological structure characteristics,the study area is the divided into eastern,western and central.The intensity attenuation relationships are established separately by using the LM( Levenberg-Marquardt) method and elliptic attenuation model. Comparisons are made by using the earthquake affecting field model of North China and computed results. The analytical study shows that the relation obtained represents the features of earthquake damage distribution in the areas well,and has positive meaning to guide loss assessments immediately after a destroyed earthquake.

Bruch's membrane opening-minimum rim width and visual field loss in glaucoma:a broken stick analysis

AIM：To determine the Bruch＇s membrane opening-minimum rim width（BMO-MRW） tipping point where corresponding visual field（VF） damages become detectable.METHODS：A total of 85 normal subjects and 83 glaucoma patients（one eye per participant） were recruited for the study.All of the patients had VF examinations and spectral-domain optical coherence tomography to measure the BMO-MRW.Total deviation values for 52 VF points were allocated to the corresponding sector according to the Garway-Heath distribution map.To evaluate the relationship between VF loss and BMOMRW measurements,a ＂broken-stick＂ statistical model was used.The tipping point where the VF values started to sharply decrease as a function of BMO-MRW measurements was estimated and the slopes above and below this tipping point were compared.RESULTS：A 25.9% global BMO-MRW loss from normative value was required for the VF loss to be detectable.Sectorally,substantial BMO-MRW thinning in inferotemporal sector（33.1%） and relatively less BMO-MRW thinning in the superotemporal sector（8.9%） were necessary for the detection of the VF loss.Beyond the tipping point,the slopes were close to zero throughout all of the sectors and the VF loss was unrelated to the BMO-MRW loss.The VF loss was related to the BMO-MRW loss below the tipping point.The difference between the two slopes was statistically significant（P≤0.002）.CONCLUSION：Substantial BMO-MRW loss appears to be necessary for VF loss to be detectable in patients with open angle glaucoma with standard achromatic perimetry.

QSAR Study on Some N-[5-(2-Furanyl)-2-methyl-4-oxo-4H-thieno[2,3-d]pyrimidin-3-yl]-carboxamide and 3-Substituted-5-(2-furanyl)-2-methyl-3H-thieno-[2,3-d]pyrimidin-4-ones Using Three-dimensional Holographic Vector of Atomic Interaction Field

Study on the quantitative structure-activity relationship （QSAR） of 26 compounds, N-[5-（2-furanyl）-2-methyl-4-oxo-4H-thieno[2,3-d]pyrimidin-3-yl]-carboxamide and 3-substituted- 5-（2-furanyl）-2-methyl-3H-thieno[2,3-d]pyrimidin-4-ones, with three-dimensional holographic vector of atomic interaction field （3D-HoVAIF） was carried out. SMR-PLS QSAR models have been created and good correlation coefficients and cross-validated correlation coefficients were obtained. The result shows that the models have good prediction capability and favorable stability and the 3D-HoVAIF is applicable to the molecular structural characterization and biological activity prediction.

Water-cut rising mechanism and optimized water injection technology for deepwater turbidite sandstone oilfield: A case study of AKPO Oilfield in Niger Delta Basin, West Africa

Through the analysis of the reservoir connection relationship and the water-cut rising rules after water breakthrough in the highly volatile oil AKPO oilfield, a new model of water-cut rising was established, and the timing and strategy of water injection were put forward. The water-cut rising shapes of producers after water breakthrough can be divided into three types, and their water-cut rising mechanism is mainly controlled by reservoir connectivity. For the producers which directly connect with injectors in the single-phase sand body of the single-phase channel or lobe with good reservoir connectivity, the water-cut rising curve is "sub-convex". For the producers which connect with injectors through sand bodies developed in multi-phases with good inner sand connectivity but poorer physical property and connectivity at the overlapping parts of sands, the response to water injection is slow and the water-cut rising curve is "sub-concave". For the producers which connect with injectors through multi-phase sand bodies with reservoir physical properties, connectivity in between the former two and characteristics of both direct connection and overlapping connection, the response to water injection is slightly slower and the water-cut rising curve is "sub-S". Based on ratio relationship of oil and water relative permeability, a new model of water cut rising was established. Through the fitting analysis of actual production data, the optimal timing and corresponding technology for water injection after water breakthrough were put forward. Composite channel and lobe reservoirs can adopt water injection strategies concentrating on improving the vertical sweep efficiency and areal sweep efficiency respectively. This technology has worked well in the AKPO oilfield and can guide the development of similar oilfields.

Quantitative Structure Activity Relationship Studies of Benzoxazinone Derivative Antithrombotic Drug Using New Three-dimensional Structure Descriptors

A novel three-dimensional holographic vector of atomic interaction field（3D-HoVAIF） was used to describe the chemical structures of 23 benzoxazinone derivatives as antithrombotic drugs.Here a quantitative structure activity relationship（QSAR） model was built by partial least-squares（PLS） regression.The estimation stability and prediction ability of the model were strictly analyzed by both internal and external validations.The correlation coefficients of established PLS model,leave-one-out（LOO） cross-validation,and predicted values versus experimental ones of external samples were R2=0.899,RCV2=0.854 and Qext2=0.868,respectively.These values indicated that the built PLS model had both favorable estimation stability and good prediction capabilities.Furthermore,the satisfactory results showed that 3D-HoVAIF could preferably express the information related to the biological activity of benzoxazinone derivatives.

Quantitative structure-activity relationship of 2-alkyl-4-(biphenylylmethoxy) pyridine derivatives with AT1 receptor antagonistic activity

The quantitative structure-activity relationship(QSAR) of 2-alkyl-4-(biphenylylmethoxy) pyridine derivatives was studied.Three different alignment methods were used to get the models of the comparative molecular field analysis(CoMFA),the comparative molecular similarity indices analysis(CoMSIA),and the hologram quantitative structure?activity relationship(HQSAR).The statistical results from the established models show believable predictivity based on the cross-validated value(q2>0.5) and the non-validated value(r2>0.9),The analysis on contour maps of CoMFA and CoMSIA models suggests that hydrophobic and hydrogen-bond acceptor fields are important factors that affect the AT1 antagonistic activity of 2-alkyl-4-(biphenylylmethoxy) pyridine derivatives besides the steric and electrostatic fields,The structural modification information from different atom contributions in the HQSAR model is in agreement with that in the 3D-QSAR models.

基于双磁场的管道非体积损伤检测研究

管道应力集中区的应力量化对管道寿命评估及安全预防具有重要作用。弱磁检测技术是一种有效的应力集中检测方法,但是管道的硬点也会产生类似的缺陷信号对应力量化分析产生干扰。本文建立了管道非体积损伤的磁信号检测解析模型,分析了硬点及应力对管材磁特性参数的影响,对硬点及应力集中区在不同励磁强度下的信号特征进行了研究,提出利用强弱励磁的双磁场应力检测方法用以排除硬点对应力弱磁信号的干扰,对理论研究进行了试验验证。研究结果表明:弱励磁下,磁化强度随应力及硬度增大而减弱。磁化强度的衰减梯度随应力增大而增大,随硬度增大而减小;强磁激励下,磁化强度随硬度增大呈近线性减小趋势且不受应力变化影响。引入信号特征磁敏系数表征不同励磁强度下非体积缺陷的检测能力,10 kA/m励磁下,随着应力增大,磁信号的切向磁敏系数从1.54增强到25.87,随着硬度的增大,磁信号的切向磁敏系数从7.46增强到33.87,应力及硬点均有较好的识别能力;30 kA/m励磁下,随着应力增大,磁信号的切向磁敏系数从0.07增强到0.54,随着硬度的增大,磁信号的切向磁敏系数从0.49增大到4,硬点仍有较好的识别能力,应力识别能力低,因此利用强弱磁双场检测方法可以排除硬点对应力检测的干扰。

岩浆通道成矿核心内涵“两深一浅一通道”及其找矿意义

岩浆通道成矿模型的建立深刻改变了岩浆铜镍硫化物矿床成因研究的范式,成为该领域的研究前沿,而且已经成功地应用于找矿勘查中。该模型揭示了硫化物熔离与聚集成矿在空间上的不一致性以及成矿与相关玄武岩铂族元素强烈亏损的成因联系,很好地解释了为什么很多含矿岩体围岩贫硫化物的现象。笔者将该模型的核心内涵概括为“两深一浅一通道”,“两深”指成矿物质来源于地幔、硫化物熔离发生在深部,“一浅”指硫化物的聚集成矿主要发生在较浅的岩浆房,“一通道”指较稳定的岩浆通道更有利于成大矿。结合对典型矿床和成矿带的分析,笔者提出侵位较浅的、规模相对较大的岩体,其成矿潜力好于深部的岩浆通道相。因此,认为地表矿化并不是唯一可靠的、甚至不能作为最重要的找矿标志,要提高找矿效率(特别是隐伏矿床),首先要全面分析成矿带岩浆通道系统在不同区域的埋藏、剥蚀和暴露状况,目标岩体地质产状及其与围岩时代差异等宏观地质要素,查明深部通道相与浅部岩体空间分布和形成深度的差异,在此基础上,判断浅部岩体的位置、合理部署重点勘查区域、选择有效的勘查技术、定位目标岩体,进行钻探验证。

产教集体行动困境与融合:基于组织场域的结构性分析

产教融合是产业发展的内在规律和现代职业教育高质量发展的必然要求,已成为国家层面的重大战略举措。然而,在实践过程中,产教集体行动困境似乎成为“天然的常态”,这是产教组织场域参与主体、关系系统和制度环境等结构性要素共同作用的结果。破解困境之策在于:主体层面,要正视利益诉求,价值共创共享,提供产教集体行动的持续性动力;关系系统层面,要创新组织形态,提升结构化程度,稳固产教集体行动的共生性空间;制度环境层面,要完备制度性要素,刚柔相济,形成产教集体行动的约束性力量。

国有企业推进关键核心技术突破对协同创新网络竞合关系的治理机制——基于“华龙一号”核电技术案例研究

国有企业是科技创新的主力军,在“卡脖子”关键核心技术突破中如何对创新网络多主体竞合关系进行有效治理是推进科技创新的关键。选取中核工程作为案例研究对象,基于竞合关系与利益相关者视角探究国有企业作为核心企业对创新网络竞合关系的治理机制。研究发现:①国有企业对协同创新网络主体存在行政要素驱动、技术要素驱动和利益要素驱动3类竞合关系;②针对不同类型竞合关系,分别采取行政协调、柔性治理与规范合作3种细分机制,促进创新网络主体良性合作,同时对价值创造与分配中存在的竞合关系进行有效治理。研究结论有助于丰富国有企业情境下的关键核心技术突破研究,为国有企业管理协同创新网络主体提供参考。

我国本科职业教育治理的批判性思考:场域理论的视角

基于场域理论的视角,分析我国本科层次职业教育各场域及其组织间的互动情境,以此探寻不同场域与组织间的关系。立足科层管理、育人定位、职业技能和社会空间四个主要关系场域,思考如何突破科层权力失衡、育人资本缺失、职业惯习固化、社会资源协同不足等困局,进而结合组织与场域理论的适切性,分析路径过程为“入场准备”“中场适应”“出场联动”三个阶段。为应对关系场域形成的困局,提出应从以下三个场域阶段进行治理路径探究:首先是入场的环境建构,考虑权力与文化资本的完善;其次是控场的惯习重塑,重在加深职业行动能力;最后是出场的社会资本联动,关注治理的社会化发展,以期丰富我国本科职业教育治理思路,促进治理多样化发展。

基于CoMFA方法对氟喹啉-4-酮衍生物的分子建模与设计

基于比较分子力场分析法(CoMFA),建立了16个已知活性的氟喹啉-4-酮衍生物抗肝癌活性(K_(S))的三维定量构效关系(3D-QSAR)模型,并研究该类结构与生物活性之间的关系.CoMFA模型的交叉验证系数(Q^(2))为0.338,拟合验证系数(R^(2))是0.987.此3D-QSAR模型的预测值与实验值基本一致,表明该模型具有显著的统计学可靠性和预测能力.该模型中立体场、静电场贡献率依次为41.9%、58.1%.根据3D-QSAR模型分析结果进行分子设计并完成活性预测,预测结果印证了分析的合理性,为该系列化合物的结构优化提供了合理建议.

水下非接触爆炸下冲击波载荷与速度场等效关系研究

对于平板在水下非接触爆炸下的结构响应问题,学界目前常采用仿真和试验手段开展研究。但目前的仿真手段主要采用任意拉格朗日欧拉(arbitrary Lagrange-Euler, ALE)方法进行,计算效率低且在中远场计算中难以得到真实的结果,而试验手段成本较高。基于能流密度公式和TAYLOR板理论对平板水下非接触爆炸冲击波载荷与速度场等效关系展开研究,提出了冲击波载荷和等效初速度场的等效换算方法,建立了平板初速度场与水下爆炸参数的等效关系并开展试验验证。结果表明,基于能流密度的冲击波等效初速度场具有更好的计算精度和效率,这一方法可作为研究平板或者简单板架在水下爆炸冲击波作用下结构响应的一个重要的等效计算方法。

断控缝洞型油藏注采井间油水界面预测方法

断控缝洞型碳酸盐岩油藏受大型克拉通内走滑断裂控制和改造,其纵向多发育为断裂复合储层体(裂缝-溶洞体),该储集体既是油气运移通道,又是储层空间,其空间及配置关系复杂.为实现注水开发过程中油水界面和见水规律的准确分类及预测,并提供后续开发方案和对策指导,以单一溶洞下的油水界面运移特征为基础,利用物质平衡方程建立一种新的断控缝洞型油藏多溶洞连通下的油水运移数学模型,基于稳态逐步替换法形成了注采井间动态油水界面实时追踪预测方法.与常规数值模拟方法相比,该模型构建简易,计算效率高,综合考虑了油水密度差异和井-裂缝-溶洞间的复杂纵向配置关系,能够较为准确预测生产井的见水规律、各溶洞油水界面运移位置及剩余油分布等各项开发指标.研究结果表明,多缝洞开发单元受生产制度和缝-洞储层参数影响,油井生产期将出现3个阶段(纯油、油水同产和纯水期);合理的采油速度与注水量可有效保持地层压力,兼顾采出程度和裂缝应力敏感效应;裂缝传导率越高,储层能量恢复越快,油水界面上升也变快;随着注采井间溶洞体积及裂缝传导率差异增大,油水同产期将变长.最后,对比Eclipse数值模拟器与本研究模型计算结果,分析溶洞体物性参数(渗透率和孔隙度)对油水界面运移速度的影响.鉴于目前断控缝洞型油藏地质构造及裂缝-溶洞体配置关系的多样性,开展多井生产动态与模型预测结果的实时拟合工作是目前油水界面评价与追踪的有效方法.本研究模型为断控缝洞型油藏见水预警、注采参数优化及剩余油挖潜对策制定提供了基础理论与方法.

基于模糊光照处理的田间鲜烟成熟度图像智能判别方法研究

自然环境下田间烟叶受光照影响导致采收机械对烟叶成熟度的判别率较低,为解决此问题,提出一种基于模糊光照处理的田间烟叶成熟度判别模型。首先,使用卷积神经网络分割模型提取感兴趣烟叶区域;其次,构建烟叶区域的分段模型用以建立光照与烟叶颜色信息间的模糊非线性关系,消除光照的影响;然后,统计不同成熟度颜色先验知识,根据先验知识建立自然环境下黄色、绿色模糊关系推理烟叶区域像素点颜色属性并计算黄色面积;最后,构建黄色面积与鲜烟叶成熟度之间的隶属度概率关系,计算烟叶成熟度。使用本研究方法对四川地区云烟87中、上部叶和中川208中、上部叶田间鲜烟叶进行处理,分别获得82.0%、77.0%、75.0%和71%的成熟度分类准确率,普遍优于ELM、SVM和BP神经网络。试验结果表明,提出的田间烟叶成熟度判别方法能够有效克服光照的影响,准确判定不同田间环境烟叶的成熟度,为烟叶智能采集装备视觉系统提供理论基础。

最近对寻址的专利实体关系抽取方法

针对专利领域没有公开数据集的问题,标注一个中文专利实体关系抽取数据集PERD(patent entity relation dataset)。为完成实体关系抽取任务,提出最近对寻址的实体关系抽取模型NPAM(nearest pair addressing entity relationship extraction model),实体位置信息获取方法的改进、注意力机制建模矩阵和实体抽取方法的创新,使该模型在PERD上F1值达到72.74%,相比模型PRGC提升12.64个百分点。实验结果验证了该模型的有效性。

基于视场相关局部参数优化的复杂物像映射光学设计方法

成像光学系统的观测场景愈发复杂,为了实现物方到像方复杂的投影映射,传统的光学设计方法需优化控制不同视场的像高,该方法采样追迹计算量大。文中提出采用视场相关的局部参数作为优化控制目标,由局部焦距和局部F数实现复杂物像映射关系和分辨率的调控,并达到同步优化提升相对照度的效果。采用该方法分别成功设计了中央-20°~20°视场f-tanθ等线投影,边缘±20°~±60°视场f-θ等距投影,以及中央-16°~16°视场角分辨率相同、边缘±28°~±60°视场角分辨率相同且中央视场角分辨率为边缘视场角分辨率1.5倍/0.667倍的三款120°视场广角镜头。基于视场相关局部参数优化的光学设计方法展现了灵活的物像映射调控能力,对于光学系统在复杂类型观测场景中的应用具有非常重要的价值。