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.

Test of the Relative Permeability Curve of a Gas and Oil Condensate System and its Effect on the Recovery of Oil and Gas

The relative permeability curve has been measured with simulation oil (refined oil) and gas (nitrogen or air) at room temperature and a lowpressure, both of which are very important parameters for depicting the flow of fluid through porous media in a hydrocarbon reservoir. This basic measurement is often applied in exploitation evaluation, but the underground conditions with high temperature and pressure, and the phase equilibrium of oil and gas, are not taken into consideration when the relative permeability curve is tested. There is an important theoretical and practical sense in testing the diphase relative permeability curve of the equilibrium of oil and gas under the conditions of high temperature and pressure. The test method for the relative permeability curve is proposed in this paper. The relative permeability of the equilibrium of oil and gas and the standard one are tested in two fluids, and the differences between these two methods are stated. The research results can be applied to the simulation and prediction of CVD in long cores and then the phenomenon can better explain that the recovery of condensate gas rich in condensate oil is higher than that of CVD test in PVT. Meanwhile, the research shows that the relative permeability curve of equilibrium oil and gas is sensitive to the rate of exploitation, and the viewpoint proves that an improved gas recovery rate can properly increase the recovery of condensate oil.

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.

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.

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.

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.

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.

颅脑创伤患者早期并发心脏收缩功能不全存在较多影响因素

目的:研究颅脑创伤患者早期并发心脏收缩功能不全相关因素。方法:收集123例单纯性颅脑创伤(iTBI)患者的临床资料,均行超声心动图检测,根据检测结果将患者分为心脏收缩功能正常组(100例)及心脏收缩功能不全组(23例)。比较2组患者的临床资料,采用Logistic回归分析影响患者并发心脏收缩功能不全的相关因素,绘制受试者工作特征(ROC)曲线评估各指标对iTBI患者并发心功能不全的预测价值。结果:与心脏收缩功能正常组比较,心脏收缩功能不全组入院时格拉斯哥昏迷(GCS)评分更低;而入院时心率、收缩压及血清hs-cTnT水平更高(P均<0.05)。多因素Logistic回归分析显示,入院时心率、GCS评分、血清hs-cTnT是iTBI患者并发心脏收缩功能不全的影响因素(P均<0.05)。经ROC曲线分析入院时血清hs-cTnT水平预测iTBI患者并发心脏收缩功能不全的曲线下面积、灵敏度、特异性及约登指数高于入院时心率和GCS评分预测(P均<0.05)。结论:iTBI患者早期并发心脏收缩功能不全相关因素包括入院时心率、GCS评分、血清hs-cTnT水平,其中入院时血清hs-cTnT水平预测iTBI患者早期并发心脏收缩功能不全的效能较高。

新型硬质聚氨酯泡沫抗压性能及本构关系研究

聚氨酯发泡材料拥有快速早强、轻质等优点,在很多基础设施建筑及修复上都有应用.本文在未浸水与浸水两种条件下,通过对聚氨酯发泡材料2h内的单轴抗压强度进行测试,得到材料的应力-应变曲线,并通过分析认为:曲线无明显的峰值点,随着时间的增加,试样的抗压强度不断增加,并在90min时能达到最大强度95%以上;浸水后试样的抗压强度有10%左右的增幅;试样的强度与密度相关,密度越大,试样的强度越大.通过引入时间特征参数,同时结合试验结果,提出2h内浸水下不同时间内聚氨酯材料的单轴抗压本构模型,验证了时间参数拟合公式的合理性,可为聚氨酯材料在路面修复以及抢险救灾工程的应用提供理论依据.

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.

三焦点与双焦点人工晶体植入术后视觉质量的1年随访研究

目的:对比分析三焦点人工晶体(intraocular lens,IOL)植入与双焦点IOL植入术后12个月患者视觉相关生活质量。方法:回顾性收集2019年1月—2021年11月在宜兴市人民医院行白内障超声乳化摘除联合IOL植入的患者40例40眼,按植入不同IOL分为两组,其中植入AT LISA tri 839MP IOL的20例20眼纳入观察组;植入AT LISA 809M IOL的20例20眼纳入对照组。术后12个月检测两组患者远、中、近视力情况,绘制IOL离焦曲线,测试不同空间频率下的对比敏感度,问卷调查眼镜依赖程度和视觉满意度,并通过美国国家眼科学会视功能问卷(National Eye Institute Visual Function Questionnaire 25,NEI-VFQ-25量表)评价视觉相关生活质量。结果:术后12个月,两组患者裸眼远视力、矫正远视力、裸眼近视力、矫正远视力下近视力和对比敏感度差异均无统计学意义(均P>0.05);观察组裸眼中视力、矫正远视力下中视力明显优于对照组(P<0.05),且离焦曲线中间焦段下降平缓;观察组视中活动区眼镜依赖程度、满意度及NEI-VFQ-25量表评分均优于对照组(均P<0.05)。结论:双焦点及三焦点IOL可以为患者长期提供良好稳定的全程视力康复。三焦点IOL植入患者中距离视力更佳,术后视觉相关生活质量更高。

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。

基于NURBS曲线的小半径钢轨打磨措施研究

为提升列车小半径曲线通过性能,减少小半径曲线钢轨磨耗,运用NURBS曲线设计个性化钢轨打磨廓形。首先,基于三次NURBS曲线,推导我国现有标准钢轨打磨廓形CHN60;其次,通过弗雷歇距离法选取实测小半径曲线磨耗钢轨代表廓形;再次,基于差分进化算法,迭代优化个性化钢轨打磨廓形;最后,基于SIMPACK软件建立耦合动力学模型,计算个性化打磨廓形与CHN60标准打磨廓形相关参数。研究结果表明:与CHN60标准打磨廓形相比,个性化打磨廓性磨耗指数降低17.76%;脱轨系数、轮重减载率、轮轨横向力、轮轨垂向力分别降低30.38%、11.84%、21.28%和0.37%。

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。

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。