Method for determining the position of landslide slip-surface with a typical inclinometric curves

In the actual monitoring of deep hole displacement,the identification of slip surfaces is primarily based on abrupt changes observed in the inclinometric curve.In conventional identification methods,inclinometric curves exhibiting indications of sliding can be categorized into three types:B-type,D-type,and r-type.The position of the slip surface is typically determined by identifying the depth corresponding to the point of maximum displacement mutation.However,this method is sensitive to the interval of measurement points and the observation scale of the coordinate axes and suffers from unclear sliding surfaces and uncertain values.Based on the variation characteristics of these diagonal curves,we classified the landslide into three components:the sliding body,the sliding interval,and the immobile body.Moreover,three different generalization models were established to analyze the relationships between the curve form and the slip surface location based on different physical indicators such as displacement rate,relative displacement,and acceleration.The results show that the displacement rate curves of an r-type slope exhibit a clustering feature in the sliding interval,and by solving for the depth of discrete points within the step phase,it is possible to determine the location of the slip surface.On the other hand,D-type slopes have inflection points in the relative displacement curve located at the slip surface.The acceleration curves of B-type slopes exhibit clustering characteristics during the sliding interval,while the scattered acceleration data demonstrate wandering characteristics.Consequently,the slip surface location can be revealed by solving the depth corresponding to the maximum acceleration with cubic spline interpolation.The approach proposed in this paper was applied to the monitoring data of a landslide in Yunnan Province,China.The results indicate that our approach can accurately identify the slip surface location and enable computability of its position,thereby enhancing applicability and reliability of the deep-hole displacement monitoring data.

Characterization of the generalized permeability jail in tight reservoirs by analyzing relative-permeability curves and numerical simulation

This study comprehensively characterizes the boundary values of generalized permeability jail in tight reservoirs through relative-permeability curve analysis,numerical simulation,and economic evaluation.A total number of 108 relative-permeability curves of rock samples from tight reservoirs were obtained,and the characteristics of relative-permeability curves were analyzed.The irreducible water saturation(Swi)mainly ranges from 20% to 70%,and the residual gas saturation(Sgr)ranges from 5% to 15% for 55% of the samples.The relative-permeability curves are categorized into six types(Category-Ⅰ to Ⅵ)by analyzing the following characteristics:The relative permeability of gas at Swi,the relative permeability of water at Sgr,and the relative permeability corresponding to the isotonic point.The relative permeability curves were normalized to facilitate numerical simulation and evaluate the impact of different types of curves on production performance.The results of simulation show significant difference in production performance for different types of relative-permeability curves:Category-Ⅰ corresponds to the case with best well performance,whereas Categories-Ⅴ and Ⅵ correspond to the cases with least production volume.The results of economic evaluation show a generalized permeability jail for Categories-Ⅳ,Ⅴ,and Ⅵ,and the permeability jail develops when the relative permeability of gas and water is below 0.06.This study further quantifies the range of micro-pore parameters corresponding to the generalized permeability jail for a tight sandstone reservoir.

TWO PRIVACY-PRESERVING PROTOCOLS FOR POINT-CURVE RELATION

Numerous privacy-preserving issues have emerged along with the fast development of Internet, both in theory and in real-life applications. To settle the privacy-preserving problems, secure multi-party computation is essential and critical. In this paper, we have solved two problems regarding to how to determine the position relation between points and curves without revealing any private information. Two protocols have been proposed in order to solve the problems in different conditions. In addition, some building blocks have been developed, such as scalar product protocol, so that we can take advantage of them to settle the privacy-preserving computational geometry problems which are a kind of special secure multi-party computation problems. Moreover, oblivious transfer and power series expansion serve as significant parts in our protocols. Analyses and proofs have also been given to argue our conclusion.

Classification Study on Relative Permeability Curves

The classification method of relative permeability curves is rarely reported, when relative permeability curves are applied;if the multiple relative permeability curves are normalized directly, but not classified, the calculated result maybe cause a large error. For example, the relationship curve between oil displacement efficiency and water cut, which derived from the relative permeability curve in LD oilfield is uncertain in the shape of low water cut stage. If being directly normalized, the result of the interpretation of the water flooded zone is very high. In this study, two problems were solved: 1) The mathematical equation of the relationship between oil displacement efficiency and water cut was deduced, and repaired the lost data of oil displacement efficiency and water cut curve, which solve the problem of uncertain curve shape. After analysis, the reason why the curve is not available is that relative permeability curves are not classified and optimized;2) Two kinds of classification and evaluation methods of relative permeability curve were put forward, the direct evaluation method and the analogy method;it can get the typical relative permeability curve by identifying abnormal curve.

A Method for Calculating Oil Field Relative Permeability Curve by Using Water Drive Characteristic Curve in High Water Cut Stage

With the production of strong bottom water reservoir, it will soon enter the ultra-high water cut stage. After entering the ultra-high water cut period, the main means of stable production is liquid extraction. Large liquid volume has a certain impact on the physical property distribution and fluid seepage law of the oilfield. The relative permeability curve measured according to the industry standard is not used for the prediction of development indicators and the understanding of the dynamic law of the oilfield. In order to understand the characteristics of water drive law in high water cut stage of water drive oilfield, starting from the water drive characteristic curve in high water cut stage, the method for calculating the relative permeability curve is deduced. Through numerical simulation verification and fitting the actual production data, it is confirmed that the obtained relative permeability curve is in line with the reality of the oilfield, It can provide some guiding significance for understanding the production law and water drive law of strong bottom water reservoir in ultra-high water cut stage.

Optimal Weights in Nonparametric Analysis of Clustered ROC Curve Data

In diagnostic trials, clustered data are obtained when several subunits of the same patient are observed. Within-cluster correlations need to be taken into account when analyzing such clustered data. A nonparametric method has been proposed by Obuchowski (1997) to estimate the Receiver Operating Characteristic curve area (AUC) for such clustered data. However, Obuchowski’s estimator gives equal weight to all pairwise rankings within and between cluster. In this paper, we modify Obuchowski’s estimate by allowing weights for the pairwise rankings vary across clusters. We consider the optimal weights for estimating one AUC as well as two AUCs’ difference. Our results in this paper show that the optimal weights depends on not only the within-patient correlation but also the proportion of patients that have both unaffected and affected units. More importantly, we show that the loss of efficiency using equal weight instead of our optimal weights can be severe when there is a large within-cluster correlation and the proportion of patients that have both unaffected and affected units is small.

明渠非标准断面法测流水位流量关系的率定及影响因素分析

为探究明渠非标准断面法测流的水位流量关系曲线的率定问题,以新疆第三师某团场25处渠道量水断面为研究对象,利用FlowTracker 2手持式声学多普勒流速仪进行了水位流量关系率定工作.根据实测结果,率定了各渠道量水断面的水位流量关系曲线,并对所率定出的曲线进行了符号检验、适线检验和偏离数值检验及误差分析,在此基础上,对流量拟合参数的影响因素进行了分析.结果表明:所率定的25处渠道量水断面中,14处具有稳定的水位流量关系,5处受回水影响、6处受渠道淤积影响为不稳定的水位流量关系;在渠道粗糙系数Ra、边坡系数m及坡降i相同的条件下,流量拟合参数与渠道底宽b总体上呈正相关;在渠道粗糙系数Ra、边坡系数m及底宽b相同的条件下,流量拟合参数与渠道坡降i总体上呈负相关.研究结果可以为灌区自动化量水设备测流准确性的校核提供参考依据.

市售头孢克肟颗粒质量分析与风险评价

目的对市售头孢克肟颗粒进行质量分析,为提高产品质量的均一性和标准检验方法的改进提供参考。方法采用法定检验方法对7家生产企业共28批头孢克肟颗粒进行全项检验,并对检验结果进行统计分析;测定溶出度曲线,找出仿制样品体外溶出行为与原研药物的差异;测定产品聚合物和有关物质,考察不同温湿度存储条件下聚合物和特定杂质的变化。结果28批样品按法定检验标准检查均合格,但部分产品检验标准、储存条件、是否含糖和产品标签之间存在不一致;水分、体外溶出曲线和聚合物三个项目上存在较大差异。7家生产企业中仅1家生产企业对聚合物进行了控制,在未进行聚合物控制的6家生产企业中有3家生产企业的产品聚合物检测结果偏高,接近或等于标准限值,A生产企业的溶出曲线与其他企业存在较大差异,D生产企业的水分平均值远高于其他生产企业。高湿条件下导致聚合物和特定杂质含量上升。结论头孢克肟颗粒总体质量合格,但仍需要进一步完善统一标准,加强质量控制。

现代有轨电车小半径曲线轮轨关系改善及噪声控制

以某市有轨电车项目为依托,研究分析典型小半径曲线的轮轨噪声特性和发生机理,通过钢轨打磨改善轮轨关系;研究弹性车轮、轮缘润滑、轨道润滑轮轨曲线对于噪声控制的影响规律。研究表明列车通过曲线半径时,弹性车轮产生的轮轨噪声明显低于传统车轮;轮缘润滑可在有轨电车小半径曲线地段广泛使用;通过测试发现在轮轨之间加入轨顶摩擦改进剂,可使摩擦系数控制在恒定合理范围内,从而降低轮轨间蠕变,有效降低噪声。

乙型肝炎相关性肝细胞癌患者组织NQO1表达水平对预后的影响

目的研究乙型肝炎相关性肝细胞癌(HBV-HCC)患者组织醌氧化还原酶-1(NQO1)表达水平对预后的影响。方法选取2019年3月至2020年1月于上海中医药大学附属第七人民医院行手术治疗的103例HBV-HCC患者,术中取癌组织与癌旁组织备用;采用免疫组织化学染色法检测NQO1在组织中的表达情况。收集患者临床病理资料,比较NQO1高表达、低表达与患者病理特征的关系。对患者行3年随访,绘制Kaplan-Meier生存曲线,对中位生存时间行Log-rank检验;采用COX模型分析影响患者预后的危险因素。结果NQO1在HBV-HCC组织中阳性率为84.47%(87/103),高表达率为59.22%(61/103);HBV-HCC组织中NQO1阳性率、高表达率高于癌旁组织(P<0.05)。NQO1高表达与低表达患者肿瘤最大径、病灶数量、美国癌症联合委员会(AJCC)分期、血管侵犯比较差异有统计学意义(P<0.05)。3年随访结果显示,患者中位生存时间为37个月,无失访病例;103例患者中死亡34例,总生存率为66.99%(69/103),复发42例,无复发生存率为59.23%(61/103)。Kaplan-Meier生存曲线分析结果显示,NQO1高表达组总生存率[52.46%(32/61)]与无复发生存率[50.82%(31/61)]低于NQO1低表达组[88.10%(37/42)、71.43%(30/42)](P<0.05)。COX模型分析结果显示,NQO1高表达、肿瘤最大径≥5 cm、病灶多发、AJCC分期为Ⅲ~Ⅳ期、血管侵犯是影响患者预后的独立危险因素(P<0.05)。结论NQO1在HBV-HCC组织中高表达,与患者临床病理特征有关,可作为评估预后的独立生物标志物。

中心静脉导管相关性血流感染的危险因素分析

目的探究中心静脉导管相关性血流感染(catheter-related bloodstream infection,CRBSI)的危险因素。方法回顾性分析2019年2月至2023年2月于简阳市人民医院行中心静脉置管患者的临床资料,依据患者是否发生CRBSI分为CRBSI组与非CRBSI组。比较两组患者基线资料,采用多因素Logistic回归分析明确接受中心静脉置管患者发生CRBSI的危险因素。采用受试者工作特征(ROC)曲线构建预测模型。结果共纳入304例患者,其中CRBSI组47例(15.46%)、非CRBSI组257例(84.54%)。CRBSI组年龄、BMI、APACHEⅡ评分显著高于非CRBSI组,置管时间显著长于非CRBSI组,合并糖尿病、置管地点为ICU、置管部位为颈内静脉或股静脉的占比显著高于非CRBSI组,差异均有统计学意义(P<0.05)。多因素Logistic回归分析显示,高龄[OR=3.067,95%CI(1.238,7.598)]、高BMI[OR=1.894,95%CI(1.215,2.952)]、合并糖尿病[OR=1.609,95%CI(1.129,2.293)]、高APACHEⅡ评分[OR=2.287,95%CI(1.174,4.455)]、置管地点为ICU[OR=4.106,95%CI(1.600,10.537)]、置管部位为颈内静脉或股静脉[OR=3.416,95%CI(1.583,7.371)]、置管时间长[OR=1.416,95%CI(1.019,1.968)]为中心静脉置管患者发生CRBSI的危险因素。ROC分析证实,年龄、BMI、APACHEⅡ评分、置管时间及多因素Logistic回归模型等均能用于中心静脉置管患者发生CRBSI的预测,且多因素Logistic回归模型可获得更高的曲线下面积[AUC=0.981,95%CI(0.967,0.996)]及敏感度(0.957)、特异度(0.961)。结论中心静脉置管患者CRBSI的发生受到年龄、BMI、APACHEⅡ评分、置管地点、置管部位、置管时间等因素的影响,临床应综合考虑上述因素,及时采取针对应的干预措施,尽早预防。

塑性变形对低合金钢拉伸性能的影响

对10CrNi3MoV低合金结构钢进行不同塑性变形处理和时效热处理,对试样进行拉伸试验,研究塑性变形处理和时效热处理对材料拉伸性能的影响规律,建立塑性变形量与材料拉伸参数之间的关系模型,并对试样的断口形貌进行观察。结果表明:随着塑性变形率的增大,材料的屈服强度和抗拉强度逐渐增大,断后伸长率和最大力总延伸率逐渐降低,纤维区产生的裂纹尺寸先增大后减小,不同塑性变形处理后试样的断裂形式均为韧性断裂;随着时效温度的升高,材料的屈服强度和抗拉强度均呈先增大后减小的变化趋势,最大力总延伸率不断增大;建立了塑性变形量与材料拉伸参数之间的关系模型,可用于预测不同塑性变形后材料的拉伸性能。

碱矿渣再生混凝土单轴受压应力-应变关系研究

为获取碱矿渣再生混凝土(AASRAC)的力学性能参数,对18个混凝土试件进行单轴受压试验,分析再生骨料取代率对受压应力-应变全曲线的影响,并建立AASRAC单轴受压应力-应变曲线全曲线方程。研究结果表明,AASRAC试件均呈现明显脆性破坏特征,随着再生骨料取代率增大,混凝土峰值强度、弹性模量呈现先小幅增加后降低的趋势。由于碱性激发基体更为致密的孔隙结构以及再生骨料中未水化水泥颗粒在碱激发剂作用下的二次水化作用,当再生骨料取代率为75%时,AASRAC的抗压强度与未掺组强度基本相同。所建立的应力-应变关系方程的计算结果与试验结果吻合良好,该曲线方程能够较好地预测AASRAC在单轴受压荷载下的力学性能参数。

A GENERAL CONSTITUTIVE RELATION FOR FATIGUE CRACK GROWTH ANALYSIS OF METAL STRUCTURES

Crack growth rate curves are the fundamental material property for metal structures under fatigue loading. Although there are many crack growth rate curves available in the literature, few of them showed the capability to explain various special phenomena observed in tests. A modified constitutive relation recently proposed by McEvily and his co-workers showed very promising capability. This modified constitutive relation is further generalized by (1) introducing an unstable fracture condition; (2) defining a virtual strength to replace the yield stress; and (3) defining an overload and underload parameter. The performances of this general constitutive relation for fatigue crack growth is extensively studied and it is found that this general constitutive relation is able to explain various phenomena observed with particular strong capability on load sequence effect.

The Influence Law of Oil Relative Permeability on Water Cut

Water cut is a key evaluation parameter for reservoir development evaluation. Relative permeability curve reflects reservoir characteristics and fluid characteristics. It is important to figure out the influence law of oil relative permeability on water cut. Based on the 269 relative permeability curves of Bohai oilfields, the distribution of oil index of Bohai oilfields were studied. On the basis, combined with Corey expression of relative permeability and fractional flow equation, the theoretical relationship between oil index and water cut increasing rate was established. Three end points of water cut increasing rate curve were proposed and the influence law between three end points and oil index was studied. The results show that the oil index has a linear relationship with three end points. When the value of water oil mobile ratio is large than 1, with the increase of oil index, maximum value of water cut increasing rate gradually increase. When the value of water oil mobile ratio is less than 10, oil index has great effect on recovery percent when water cut increasing rate reaches to the maximum value as well as water cut when water cut increasing rate reaches to the maximum value. The application of SS field shows that the theoretical value is consistent with the field data.

Numerical simulation-based correction of relative permeability hysteresis in water-invaded underground gas storage during multi-cycle injection and production

By conducting relative permeability experiments of multi-cycle gas-water displacement and imbibition on natural cores,we discuss relative permeability hysteresis effect in underground gas storage during multi-cycle injection and production.A correction method for relative permeability hysteresis in numerical simulation of water-invaded gas storage has been worked out using the Carlson and Killough models.A geologic model of water-invaded sandstone gas storage with medium-low permeability is built to investigate the impacts of relative permeability hysteresis on fluid distribution and production performance during multi-cycle injection and production of the gas storage.The study shows that relative permeability hysteresis effect occurs during high-speed injection and production in gas storage converted from water-invaded gas reservoir,and leads to increase of gas-water transition zone width and thickness,shrinkage of the area of high-efficiency gas storage,and decrease of the peak value variation of pore volume containing gas,and then reduces the storage capacity,working gas volume,and high-efficiency operation span of the gas storage.Numerical simulations exhibit large prediction errors of performance indexes if this hysteresis effect is not considered.Killough and Carlson methods can be used to correct the relative permeability hysteresis effect in water-invaded underground gas storage to improve the prediction accuracy.The Killough method has better adaptability to the example model.

Study on the correlation between ambient environment-meteorological factors and the number of visits of acute otitis media,Lanzhou,China

To investigate the correlation between environmental-meteorological factors and daily visits for acute otitis media(AOM)in Lanzhou,China.Methods:Data were collected in 2014e2016 by the Departments of Otolaryngology-Head and Neck Surgery at two hospitals in Lanzhou.Relevant information,including age,sex and visiting time,was collected.Environmental data included air quality index,PM10,PM2.5,O3,CO,NO2 and SO2,and meteorological data included daily average temperature(T,C),daily mean atmospheric pressure(AP,hPa),daily average relative humidity(RH,%)and daily mean wind speed(W,m/s).The SPSS22.0 software was used to generate Spearman correlation coefficients in descriptive statistical analysis,and the R3.5.0 software was used to calculate relative risk(RR)and to obtain exposure-response curves.The relationship between meteorological-environmental parameters and daily AOM visits was summarized.Results:Correlations were identified between daily AOM visits and CO,O3,SO2,CO,NO2,PM2.5 and PM10 levels.NO2,SO2,CO,AP,RH and T levels significantly correlated with daily AOM visits with a lag exposure-response pattern.The effects of CO,NO2,SO2 and AP on daily AOM visits were significantly stronger compared to other factors(P<0.01).O3,W,T and RH were negatively correlated with daily AOM visits.The highest RR lagged by 3e4 days.Conclusions:The number of daily AOM visits appeared to be correlated with short-term exposure to mixed air pollutants and meteorological factors from 2014 through 2016 in Lanzhou.

A Statistical Model for the Relative Hydraulic Conductivity of Water Phase in Unsaturated Soils

Permeability coefficients of fluids occupying the pore space of a porous medium have significant influence on the flow of these fluids through the porous medium. In the case of unsaturated soils, in addition to other parameters such as void ratio, void distribution, particle size distribution and initial density the degree of saturation also affects the permeability coefficient of water. The degree of saturation, in unsaturated soil, is directly related to the matric suction of the soil through soil water characteristic curve. Matric suction is one of the two stress state variables widely used to characterize the deformation behavior of unsaturated soils. Therefore, it can be stated that both flow and deformation behaviors of unsaturated soil are affected by the permeability coefficient of water. Numerical modeling of coupled deformation-flow behavior of unsaturated soil requires a mathematical equation that relates the permeability coefficient to the degree of saturation. Since the parameters that affect the permeability coefficient of water in unsaturated soil have similar direct or indirect effects on the soil water characteristic curve, permeability can be effectively predicted using the soil water characteristic curve as done in statistical models. In this paper, a statistical model is proposed for the permeability of water in unsaturated soil using soil water characteristic curve of the soil. The calibrated parameters of the soil water characteristic curve are directly used in the prediction of permeability with- out additional calibration using measured permeability data. The predictive capability of the new equation is verified by matching the measured data of eight different soils found in the literature.

General Relativity and the Tully-Fisher Relation for Rotating Galaxies

The flat limit of rotational velocity (vφ) approximately equal to the “edge”-velocity of a galaxy is related to the baryonic mass (MB) via the T-F relationship with n ≈ 4. We explore the connection between mass and the limiting velocity in the framework of general relativity (GR) using the Weyl metric for axially-symmetric galaxies that are supported entirely by their rotational motion. While for small distances from the center, the Newtonian description is accurate as one moves beyond the (baryonic) edge of the galaxy, Lenz’s law and non-linearity of the gravitational field inherent in GR not only lead to a flat velocity (obviating its Keplerian fall), but also provide its tight log-log relationship with the enclosed (baryonic) mass.

Variable Speed of Light with Time and General Relativity

In a previous article entitled: “Evidences for varying speed of light with time” [1], a series of observational evidence was presented in favor of the hypothesis that the speed of light varies with time according to the relationship dc/dt = -Hc, where H is the Hubble constant which is considered a universal constant. In this paper we propose to elaborate on the observational evidence supporting the hypothesis, and to probe the consequences of this relationship on General Relativity. Also we will provide a theoretical justification of the previous relationship and we will show how from it we can deduce galactic velocity curves. We can deduce the important empirical Tully-Fisher relation linking these curves to the baryonic mass of the galaxy and we can justify the apparent accelerated expansion of the universe without intervening elusive entities such as dark matter and dark energy.