Fast forward modeling of gravity anomalies for two-dimensional bodies of arbitrary shape and density distribution

A fast and high precision spatial domain algorithm is presented for forward modeling of two-dimensional(2D)body gravity anomalies of arbitrary shape and density distribution.The new algorithm takes advantage of the convolution properties of the expression for 2D gravity anomalies,uses a rectangular cell as a grid subdivision unit,and then 2D bodies with irregular cross-sections are approximated by a combination of 2D bodies with a rectangular cross section.The closed-form expression is used to calculate the gravitational anomalies of the combination of 2D bodies with a rectangular cross section.To improve computing effi ciency,the new algorithm uses a fast algorithm for the implementation of the Toeplitz matrix and vector multiplication.The synthetic 2D models with rectangular and circular cross-sections and constant and variable densities are designed to evaluate the computational accuracy and speed of the new algorithm.The experiment results show that the computation costs less than 6 s for a grid subdivision with 10000×10000 elements.Compared to the traditional forward modeling methods,the proposed method significantly improved computational effi ciency while guaranteeing computational accuracy.

AN EXPLORATION TO THE MODELLING OF TWO-DIMENSIONAL COMPLEX TURBULENT SHEAR FLOWS

The regions with shear stress and mean velocity gradient of opposite sign often exist in complex turbulent shear flows.In these cases,the eddy viscosity hypothesis breaks down.Hinze regards the,departure from eddy viscosity hypothesis as a result from transportation of mean momentum over distance by the large structures and arrives at a shear stress expression including the second order derivatives of the mean velocity.However,his expression greatly overestimates the shear stress.This implies that the flow particles are unlikely to have enough memory of the mean momentum over distance.By assuming the departure from eddy viscosity hypothesis as a result from transportation of the shear stress contained in smaller eddies over distance by the large structures,the present author has arrived at a new shear stress expression.The shear stress estimated so far is in good agreement with the experiments.

Safe roof thickness and span of stope under complex filling body

Longhole caving method was used to mine gently inclined thick orebody step by step in a test stope of tin mine under complex filling body. The problem that the complex filling body around the stope affects the stability of roof thickness, chamber and spacer pillar in actual mining was investigated; meanwhile, the formed goaf during mining is so vulnerable that surrounding rock collapses early. Based on this point, elasticity mechanics and limit span theory were used to study separately the roof thickness and the span limit of goaf formed in mining, and then a reasonable roof thickness of 8 m and goaf span of 14 m are proposed. In addition, the stability of roof thickness, chamber and spacer pillar were investigated and analyzed by using numerical analysis method; meanwhile, the field monitoring on the displacement of caving chamber was conducted. The results show that the maximum compressive stress of surrounding rock is 20 MPa, and the maximum tensile stress is 1.2 MPa, which is less than the ultimate tensile strength of 2.4 MPa. Moreover, plastic zone has little influence on stope stability. In addition, the displacement of 11 mm is also smaller. The displacement monitoring results are consistent with the numerical results. Thus, the roof thickness and span of goaf proposed are safe.

Analysis of characteristic features in ultrasound diagnosis of fetal limb body wall complex during 11-13+6 weeks

BACKGROUND Limb body wall complex(LBWC)is a fatal malformation characterized by major defects in the fetal abdominal or thoracic wall,visceral herniation,significant scoliosis or spina bifida,limb deformities,craniofacial deformities,and umbilical cord abnormalities(short or absent umbilical cord).Early diagnosis of this condition is of great clinical significance for clinical intervention and pregnancy decision-making.With the rapid development of fetal ultrasound medicine,early pregnancy(11-13+6 wk)standardized prenatal ultrasound examinations have been widely promoted and applied.AIM To explore the value of prenatal ultrasound in the diagnosis of fetal LBWC syndrome during early pregnancy.METHODS The ultrasonographic data and follow-up results of 18 cases of fetal LBWC diagnosed by prenatal ultrasound during early pregnancy(11-13+6 wk)were retrospectively analyzed,and their ultrasonographic characteristics were analyzed.RESULTS Among the 18 fetuses with limb wall abnormalities,there were spinal dysplasia(18/18,100%),varying degrees of thoracoschisis and gastroschisis(18/18,100%),limb dysplasia in 6 cases(6/18,33%),craniocerebral malformations in 4 cases(4/18,22%),thickening of the transparent layer of the neck in 5 cases(5/18,28%),and umbilical cord abnormalities in 18 cases(18/18,100%),single umbilical artery in 5 cases.CONCLUSION Prenatal ultrasound in early pregnancy can detect LBWC as early as possible,and correct prenatal evaluation provides important guidance value for pregnancy decision-making and early intervention.

Volume Difference Inequalities for the Polars of Mixed Complex Projection Bodies

In this paper, based on the notion of mixed complex projection and generalized the recent works of other authors, we obtain some volume difference inequalities containing Brunn-Minkowski type inequality, Minkowski type inequality and Aleksandrov-Fenchel inequality for the polars of mixed complex projection bodies.

A NEW TWO-DIMENSIONAL "MAN-WCV" MATHEMATICAL MODEL OF THE HUMAN THERMOREGULATION

In the paper a new two-dimensional 'man-WCV'(water cooling vest) mathematical model is developed. This model is of practical use: it can predict transient temperature responses and body temperature distribution for a person in a nonuniform hot environment, doing various jobs and dressed in different clothes. In addition, the results calculated from the model can be used to optimize the distribution of the tube-net lined on the WCV and to evaluate an individual thermal conditioning system with cooling water. The results obtained from the model agree well with the author's experimental data.

Application of cerebral-myocardial perfusion combined with lower body circulatory arrest in pediatric complex aortic arch surgery

Background Adjunct RCP to DHCA ensures some extent uninterrupted cerebral perfusion and that promotes one-stage repair of complex aortic arch anomaly.One-stage repair may induce longer myocardial ischemic time.So there evolved cerebral-myocardial perfusion to reduce myocardial ischemic time.Methods We reviewed 78 patients from January 2010 to July 2017 in our center.

Numerical Study of Effects of Complex Topography on Surface-Piercing Wave-Body Interactions

In this paper, wave-body interactions under the effects of complex topography are investigated numerically by a two-phase incompressible Reynolds-Averaged Navier-Stokes(RANS) solver in OpenFOAM. A submerged bottom-standing structure is distributed below the floating body, and the effects of the water depth and top width of the submerged structure on wave-body interactions are studied. The results show that the submerged structure can affect wave loads and roll motion. The vertical force can be amplified on the fixed body when the water depth of the submerged structure is smaller than half of the water depth of the body. The top width significantly affects the vertical force when the top width is smaller than the incident wave length and larger than the body width. For the free-rolling body, roll amplitude can be increased when the ratio of the incident wave length to the water depth of the submerged structure is large enough. On the resonance condition, roll amplitude is slightly reduced by the submerged structure. The effects of the top width on roll amplitude are remarkable when special conditions are fulfilled.

过表达带电多泡体蛋白2B基因抑制肾透明细胞癌细胞的增殖

目的肾透明细胞癌中带电多泡体蛋白2B(CHMP2B)的表达水平与临床病理特征及预后的关系,探究CHMP2B在肾透明细胞癌发生发展中的潜在作用机制。方法从TCGA数据库下载并整理肾透明细胞癌的RNAseq数据并提取FPKM格式的数据,比较肿瘤样本与癌旁样本CHMP2B的表达差异,根据其表达中位值分为高、低表达组,分析CHMP2B表达水平与临床病理特征的相关性,采用Kaplan-Meier模型进行生存分析,COX风险回归模型用于临床预后因素分析;使用ESTIMATE算法分析CHMP2B与免疫和基质细胞浸润及肿瘤纯度的关系;使用Limma包对CHMP2B筛选共表达基因,并进一步行GSVA富集分析。使用ESTIMATE算法和Timer数据库分析CHMP2B表达与免疫浸润的相关性;使用cBioPortal数据库分析CHMP2B的基因突变对肾透明细胞癌免疫治疗的影响;从HPA数据库获取CHMP2B蛋白质在肾透明细胞癌组织和正常组织的免疫组化表达情况;通过收集健康与肾癌患者外周血标本评价CHMP2B作为临床标志物的可能。通过细胞实验验证CHMP2B对肾癌细胞增殖与迁移的影响。结果与癌旁组织相比较,CHMP2B在肾透明细胞癌组织中低表达,使其过表达会抑制肿瘤细胞增殖(P<0.01),其表达水平与年龄、性别、是否淋巴结转移以及分期等具有相关性(P<0.05)。生存分析结果显示CHMP2B低表达肾透明细胞癌患者生存预后更差(P<0.05),富集差异分析及共表达基因富集发现CHMP2B在肾透明细胞癌中主要涉及病毒出芽、坏死性凋亡、内吞作用等,并涉及免疫调节过程。结论CHMP2B在肾透明细胞癌组织中低表达,可有效影响肿瘤进展和肿瘤免疫过程,是一种有前途的预后分子标志物及治疗靶点。

A GC×GC-ToFMS Investigation of the Unresolved Complex Mixture and Associated Biomarkers in Biodegraded Petroleum

Heavy biodegraded crude oils have larger numbers of coeluting compounds than nonbiodegraded oils, and they are typically not resolved with conventional gas chromatography（GC）. This unresolved complex mixture（UCM） has been investigated using comprehensive two-dimensional gas chromatography–time-of-flight mass spectrometry（GC×GC-To FMS） within a set of biodegraded petroleums derived from distinct sedimentary basins, including northwestern Sichuan（Neoproterozoic, marine）, Tarim（Early Paleozoic, marine）, Bohai Bay（Eocene, saline/brackish） and Pearl River Mouth（Eocene, freshwater）. In general, the hydrocarbons that constitute the UCM in petroleum saturate fractions can be classified into three catalogues based on the distributions of resolved compounds on two dimensional chromatograms. Group 1 is composed mainly of normal and branched alkanes, isoprenoid alkanes and monocyclic alkanes; Group 2 comprises primarily terpanes ranging from two to five rings, and Group 3 is dominated by monoaromatic hydrocarbons such as tetralins and monoaromatic steranes. In addition, the UCM is source dependent and varies between oil populations. i.e., the UCM of petroleum derived from Precambrian and Early Paleozoic marine, Eocene saline/brackish and freshwater source rocks is specifically rich in higher homologues of A-norsteranes, series of 1,1,3-trimethyl-2-alkylcyclohexanes（carotenoid-derived alkanes）, and tetralin and indane compounds, respectively.

Thinking in three's: Changing surgical patient safety practices in the complex modern operating room

The three surgical patient safety events, wrong site surgery, retained surgical items (RSI) and surgical fires are rare occurrences and thus their effects on the complex modern operating room (OR) are difficult to study. The likelihood of occurrence and the magnitude of risk for each of these surgical safety events are undefined. Many providers may never have a personal experience with one of these events and training and education on these topics are sparse. These circumstances lead to faulty thinking that a provider won't ever have an event or if one does occur the provider will intuitively know what to do. Surgeons are not preoccupied with failure and tend to usually consider good outcomes, which leads them to ignore or diminish the importance of implementing and following simple safety practices. These circumstances contribute to the persistent low level occurrence of these three events and to the difficulty in generating sufficient interest to resource solutions. Individual facilities rarely have the time or talent to understand these events and develop lasting solutions. More often than not, even the most well meaning internal review results in a new line to a policy and some rigorous enforcement mandate. This approach routinely fails and is another reason why these problems are so persistent. Vigilance actions alone havebeen unsuccessful so hospitals now have to take a systematic approach to implementing safer processes and providing the resources for surgeons and other stake-holders to optimize the OR environment. This article discusses standardized processes of care for mitigation of injury or outright prevention of wrong site surgery, RSI and surgical fires in an action-oriented framework illustrating the strategic elements important in each event and focusing on the responsibilities for each of the three major OR agents-anesthesiologists, surgeons and nurses. A Surgical Patient Safety Checklist is discussed that incorporates the necessary elements to bring these team members together and influence the emergence of a safer OR.

Quantum theory-based physical model of the human body in TCM

In the study,a quantum resonant cavity model based on wave-particle duality was proposed for the explanation of the dynamic processes of essence,vigor,and spirit in the human body in traditional Chinese medicine(TCM).It is assumed that there is a macro human order parameter(wave function),and its dynamics are governed by a macro potential field reflecting influences from heaven,earth,and society,and satisfy the generalized Schrodinger equation.This proposed model was applied in the study to interpret basic concepts of human body in TCM,with an aim to unfold the TCM development in the future.

Holistic medicine: A new medical system based on body constitution and functional status

At present,modern medicine is a scientific system in the following sense:it uses observation of static states and analysis of single factors to determine the relationship between structure and function in the human body in states of health and disease.Physiology and pathology are based on observation from multiple perspectives and at multiple levels.The study of human body constitution and overall functional status is relatively unexplored territory in the field of modern medicine.This article discusses the possible confluences between traditional Chinese medicine (Chinese medicine) and the methods and concepts of complexity science.It also reveals that Chinese medicine,unlike biomedicine (Western medicine),uses a method of modeling to study the human body,and law and control methods from the perspective of functional state and viewpoint.To derive from there,in time of complexity science concept becoming the mainstream scientific idea of today,by adopting its methodsand techniques,and introduce Chinese medicine theoretical model,methods and experience,to develop a holistic medicine that can reveal human body constitution and functional state.It will be the main direction for the development of the 21st century modern medicine.

Spanning Pre-disks in a Compression Body

A properly embedded essential planar surface P（not a disk） in a compression body V is called a spanning pre-disk with respect to J, if one boundary component of P is lying in ?;V and all other boundary components of P are lying in?;V and coplanar with J. In this paper, we show that the number of boundary components of spanning pre-disks in a compression body is unbounded. But the number of a maximal collection of spanning pre-disks is bounded.

Study on Development Law of Complex Fluvial Reservoir under Water

The Bozhong oilfield (Hereinafter referred to as BZ oilfield) is a typical representative of complex fluvial reservoirs in the Bohai Sea, located in the southern Bohai Sea, with an average porosity of 30.3% and an average permeability of 643 × 10-3 μm2, belonging to medium high porosity and permeability reservoir, the reservoir has good connectivity, and the average underground crude oil viscosity is 5 mPa·s. There are many plane fault blocks, and the longitudinal oil well section is long, so the oil-water relationship is very complex. With the further development of the oilfield, the vertical and horizontal oil-water movement law, residual oil distribution and potential are unclear, resulting in rapid bottom water coning, unbalanced injection and production in the oilfield, and increasingly prominent contradictions among layers, planes and layers in the oilfield. Through numerical simulation analysis and comparison of displacement law and recovery degree under different influence conditions, this paper studies the development effect of actual sand body under different influence conditions such as different well types, different development methods and well layout positions, and takes appropriate development methods for the oilfield, which is of great significance to improve the development effect of the oilfield.

贵东复式岩体中东部晚期花岗质小岩体的SHRIMP锆石U-Pb年龄及其地质意义

贵东复式岩体由多期次、多类型的岩体组成,且东部盛产铀矿床,因此精确厘定该复式岩体的时代及其时序,查明复式岩体东部与中西部岩浆活动的差异性及其与铀成矿的关系,不仅有利于深入研究区域岩浆活动,而且有利于深刻认识铀的成矿规律。现有研究认为,以龟尾山断裂带为界,贵东复式岩体中西部岩基属燕山早期、东部岩基属印支早期,东部广泛发育的燕山期中基性脉岩与铀成矿关系密切。但对复式岩体中东部呈岩枝、岩株广泛出露的晚期花岗质小岩体的成岩地质时代及其分布规律尚存在争议,也有待进一步查明花岗质小岩体与铀矿床的时空关系。文章选择贵东复式岩体中东部晚期花岗质小岩体为研究对象,采用SHRIMP锆石U-Pb法厘定其成岩时代,并分析它们的时空分布及其与铀成矿的关系。测试结果显示,贵东复式岩体中东部晚期花岗质小岩体普遍存在高铀锆石,这可能是对同一岩体不同学者所获得的^(206)Pb/^(238)U加权平均年龄差别较大的主要原因。剔除高铀锆石的年龄数据,龟尾山断裂带以西的隘子、司前、陈洞岩体锆石^(206)Pb/^(238)U加权平均年龄分别为163.0±1.6 Ma、163.1±1.6 Ma、160.7±1.9 Ma,属燕山早期岩浆活动的产物;而以东的帽峰、分水坳、龟尾山岩体锆石^(206)Pb/^(238)U加权平均年龄分别为230.0±2.7 Ma、225.9±2.9 Ma和232.6±3.1 Ma,属印支期岩浆活动的产物。所以,龟尾山断裂以西和以东晚期花岗质小岩体的时代不同。且龟尾山断裂带以东的印支期花岗质小岩体空间上与铀矿化、尤其是与燕山早期的绢英岩化型等中高温热液铀矿化关系密切,是主要的储矿围岩;结合元素地球化学研究结果,该区产出的印支期花岗质小岩体也可为铀成矿提供铀源。

复杂地质体三维数值模型构建研究

对于复杂地质体三维数值模型构建困难的问题,基于AutoCAD、SURPAC、ANSYS、FLAC^(3D)等软件进行了建模。首先利用工程地形地质图,在AutoCAD中进行地形等高线处理,以获得地表等高线;其次,利用钻孔柱状图等原始资料通过SURPAC构建钻孔模型,生成不同岩层数字地面模型(DTM),同时利用地表等高线生成地表DTM;再次,建立有规律的钻孔网格点模型,利用钻孔与DTM相交获得相交网格点坐标,在ANSYS中导入网格点坐标,建立有限元网格模型;最后通过接口程序将其导入FLAC^(3D),建立了三维数值模型。以山西朔州某煤矿为工程实例,利用该方法构建三维数值模型,并对其进行了煤层开采后地表位移数值模拟,为复杂地质体三维数值模型的构建提供了借鉴。

复合酶制剂对哺乳期驴驹生长发育及营养物质消化代谢的影响

试验旨在探究复合酶制剂对驴驹生长发育、营养物质消化代谢的影响,为哺乳驴驹早期胃肠道机能、肠道健康及营养需要量的研究提供参考依据。选择出生日期与体重[(45.22±7.32)kg]相近,健康的2月龄哺乳母驴驹10头。随机分为对照组与试验组,每组各5头。在相同的饲养管理条件下,驴驹自由哺乳,自由采食玉米秸秆和苜蓿,补喂精料补充料。试验组驴驹在对照组驴驹饲喂的基础上补喂复合酶制剂(木聚糖酶15000 U/g,β-甘露聚糖酶400 U/g,β-葡聚糖酶10000 U/g,纤维素酶2000 U/g,蛋白酶1000 U/g,淀粉酶300000 U/g),补喂量为6.5 mg/(kg BW·d),进行为期60 d的补饲及营养物质消化代谢试验。结果显示:驴驹的体重、体尺无显著性变化,试验组驴驹体斜长和管围总增长较对照组分别提高了26.02%和2.17%(P>0.05);试验组驴驹干物质、有机物、酸性洗涤纤维、钙、磷和能量的采食量分别比对照组提高了2.99%、3.14%、6.67%、2.07%、1.11%和2.81%(P>0.05);试验组驴驹摄入能、粪能、沉积能、摄入氮、粪氮、沉积氮、氮代谢率、摄入钙、粪钙、沉积钙、钙代谢率、摄入磷、沉积磷和磷代谢率分别比对照组提高了2.81%、13.03%、4.46%、1.65%、10.09%、21.49%、19.54%、2.07%、3.47%、4.59%、2.32%、1.11%、39.06%和40.77%,尿能、尿氮、尿钙、粪磷和尿磷分别比对照组降低了78.10%、20.19%、33.33%、4.35%和9.81%,无显著性差异(P>0.05)。综上所述,在本研究条件下,给驴驹补喂酶制剂促进了驴驹体斜长和管围的增长,营养物质的采食量和代谢率有升高的趋势,但均未达到显著的效果。

复杂地形下轮腿复合机动平台动态运动控制

复杂地形环境下质心参考轨迹的动态精确跟踪是保障轮腿复合机动平台稳定执行各项任务的关键。为提升平台的地形适应能力与位姿跟踪能力,提出一种动态运动控制策略。综合地形因素,建立包含车轮动力学的单刚体动力学模型,并通过近似简化将系统动力学模型转化为状态空间方程的标准形式。考虑车轮与腿部耦合运动,提出一种基于前馈力矩与反馈力矩的混合运动控制方法。通过二次规划算法求解最优地面反作用力,利用雅克比矩阵将作用力映射至关节以获取前馈力矩。为避免由环境引起的外部扰动造成系统无法在较短时间内完成优化计算,引入关节力矩反馈控制及时修正位姿跟踪误差,使系统能够快速准确地响应外部扰动,有效提高系统的鲁棒性和稳定性。仿真结果表明,新方法可有效提升平台在复杂地形下位姿动态跟踪精度,保障平台平稳运行,为复杂地形下轮腿复合机动平台的工程应用提供有力支撑。