Calculation of Activity Coefficients for Components in Ti-15-3 Melt

Based on Kohler’s ternary solution model and Miedemaa’s model for calculating the heats of formation-△Hij of binary Systems, the integral equation has ben established for calculating the activity coefficients in ternarysolution. With the equation, the activity coefficients in Ti-15-3 melt have been calculated. The results show that allof components’ activity coefficients are less than 1, in other wolds, compared with ideal solution, all components takeon a negative deviation. At 2000K, the activity coefficients in Ti-15-3 melt are shown as: about 0.9 for Ti, about0.85 for V, about 0. 1 for Al, aboaut 0.5 for Cr and about 0.23 for Sn. me addition of V lowers the activity coefficient of Ti, but raise the ones of Al, Cr and Sn. These results can be directly used to calculate the evaporation loss ofAl, Cr and Sn during the ISM(Induction Skull Melting) process and at the same time estimate the reactivity betweenTi-15-3 melt and refractory during the cast production.

Hydrated coefficient of clathrates and its applications in determination of aqueous inclusions with multivolatile components

During the microthermometric measurement（cooling）of aqueous inclusions with multivolatile components,solid crystals of gas clathrates often occur with snow-flower-or soft-ice appearances.The structural formula of these solids is M·nH2O（where n≥5.67）.Many hydrocarbons,related compounds and their binary or multi-component mixtures may generate gas clathrates.This phenomenum is of fundamental importance to the study of inclusions with hydrocarbon aqueous solutions,because this is related to the determination of inclusion parameters and the computation of thermodynamic parameters. In the nature most aqueous inclusions contain not merely one volatile component but multi-volatile components.Therefore,the measurement of aqueous inclusions with multivolatile components is of universal significance and great importance.There have been many studies and available formula or figures about the computation of thermodynamic parameters for aqueous inclusions with one volatile component.Nevertheless,there are few studies concerning with muhivolatile components and it is very difficult to computate thermodynamic parameters for aqueous inclusions with these components. In this paper,hydrated coefficient K is introduced.Ki is the ratio of molar fraction of component i in the gas phase to that in the gas clathrate,or Ki=yi/xi.Because K is a function of temperatures and pressures,it can be used to evaluate the temperature-pressure conditions on the phase behavior with muhivolatile components. Based on the regression analysis of available experimental data,the authors have developed computational expression of hydrated coefficients in relation to temperature and pressure for most hydrocarbons and other volatile components,which is helpful to conveniently compute thermodynamic parameters on stability state for elathrates with volatile components.As aqueous inclusions with muhivolatile components are common in the nature,by the use of final melting temperatures of clathrates from mierothermometry and these formula,fluid density of gas phase with valotile components and bulk fluid density of inclusions can be accurately calculated. Furthermore,this method may provide foundations to determine the isochores of inclusions and to calculate trapping temperatures and pressures. Finally,detailed analyses for two computational examples about aqueous inclusions with muhivolatile components are presented.

Analysis of stable components in the extended-range forecast for the coming 10-30 days in winter 2010 and 2011

In this paper we try to extract stable components in the extended-range forecast for the coming 10–30 days by using empirical orthogonal function （EOF） analysis, similarity coefficient, and some other methods based on the National Center for Environmental Prediction （NCEP）/National Center for Atmospheric Research （NCAR） reanalysis daily data. The comparisons of the coefficient of variance of climatological background field and truth data in winter between 2010 and 2011 are made. The method of extracting stable components and climatological background field can be helpful to increase forecasting skill. The forecasting skill improvement of air temperature is better than geopotential height at 500 hPa. Moreover, this method improves the predictability better in the Pacific Ocean. In China, the forecast in winter in Northeast China is more uncertain than in the other parts.

Investigation on the factors influencing the thickness distribution of superplastic-formed components

In the superplastic sheet forming process, the uniformity of the sheet's final thickness distribution is vital for ensuring the good mechanical quality of the formed components. The influences of the component shape and the contact friction on the final thickness distribution were investigated in this work by using finite element method on a series of axisymmetric models. It was concluded that shape optimization and friction elimination are required to get uniform thickness distribution, and eventually to improve the mechanical quality of the formed components. The constitutive equation of the Ti-6A1-4V superplastic material was also determined on the basis of experimental data.

Principal Component-Discrimination Model and Its Application

Having researched for many years, seismologists in China presented about 80 earthquake prediction factors which reflected omen information of earthquake. How to concentrate the information that the 80 earthquake prediction factors have and how to choose the main factors to predict earthquakes precisely have become one of the topics in seismology. The model of principal component-discrimination consists of principal component analysis, correlation analysis, weighted method of principal factor coefficients and Mahalanobis distance discrimination analysis. This model combines the method of maximization earthquake prediction factor information with the weighted method of principal factor coefficients and correlation analysis to choose earthquake prediction variables, applying Mahalanobis distance discrimination to establishing earthquake prediction discrimination model. This model was applied to analyzing the earthquake data of Northern China area and obtained good prediction results.

Review of All Possible Conversion Equations of Influence Coefficients with Different Formats on Two-Plane Balancing

This article lists all possible conversion equations of influence coefficients(ICs)with different formats when some of these are known to handle two-plane balancing tasks with no or less trial weight runs.There are two approaches for two-plane balancing.One can treat it as a multi-plane balance problem involving a 2×2 matrix of complex ICs where two direct ICs along with two cross-effect ICs are generated so that correction weights at one or two balance planes can be determined.One can also apply a static pare(in-phase)and/or couple pair(180 degrees out-of-phase)weights for balancing.The latter approach has been used quite often in the field,especially on steam turbine and generator rotors.Dependent on vibration mode shapes and combinations as well as balance plane accessibility,sometimes applying static or couple pair weights can be a wise choice;other times weights at one or two end planes are needed.There are totally 4 possible sets of IC data due to weights at plane 1,plane 2,static pair,and couple pair.IC data would typically be obtained by applying trial weights followed by trial weight runs.It is found,however,that all these IC data can be converted easily without trial weight runs once any two of 4 sets are known.The above findings and conversion equations have been obtained analytically and verified by experimental results.Real cases are given to demonstratetheirapplications.

Use of Conversion Equations of Influence Coefficients on Two-Plane Balancing

Typical rotors such as those on steam turbine or generator are often supported by two bearings with two balance planes at both ends.Vibrations are monitored by a pair of proximity probes at each bearing.There are two approaches to reduce 1X vibration due to unbalance at both ends via balancing with influence coefficient method.The first approach is to treat it as a multiple-plane balancing problem involving 2x2 matrix of complex influence coefficients.The second approach is to treat it as two single-plane balance problems using static(in-phase)and couple(180 degree out-of-phase)components,respectively.Conversion equations of influence coefficients between these two approaches have been found previously by the author.The corresponding spreadsheets that convert influence coefficients between these two formats are presented in the current paper.The paper shows effectiveness of these conversion equations in dealing with real balancing problems in the field.A detailed balance case is presented to demonstrate how the conversion equations are used to reduce vibration effectively.

基于PCA-BP神经网络的巷道通风摩擦阻力系数预测模型

根据实测巷道通风摩擦阻力系数数据的特点,建立了主成分分析PCA-BP神经网络预测模型。采用PCA法对影响巷道通风摩擦阻力系数的支护类型、断面形状、巷道宽、巷道高、支护部分周边长、巷道断面积和巷道长度7个因素进行降维。将降维后因素的贡献率进行排序筛选,得到3个主成分指标(F_(1)、F_(2)和F_(3)),作为BP神经网络输入层的神经元。利用实测数据对PCA-BP神经网络模型进行训练和测试,并将测试结果与支持向量机回归(SVM)模型和BP神经网络模型的测试结果进行对比,结果显示:全因素的BP神经网络预测模型和SVM预测模型的平均精度分别为92.9420%、93.0235%,而PCA-BP预测模型的平均精度达到了96.4325%。PCA-BP神经网络模型不但简化了网络结构,更提高了网络的泛化能力,使预测误差更小、精度更高,为更准确地获得巷道通风摩擦阻力系数提供了一种有效的方法。

A Methodology for Identification of Weather Sensitive Component of Electrical Load Using Empirical Mode Decomposition Technique

The expansion planning and operation of all three sectors, generation, transmission and distribution, of power system essentially require load forecasting. Weather conditions have significant impacts on forecasted load, especially short-term and mid-term. A momentous portion of the electrical energy is consumed, especially in cold or hot countries, to mitigate the impact of weather on the daily life of human society. Usually, weather dependent component of load is identified by fitting appropriate non-linear curve to the scatter plot of weather-load model. This technique some times shows lower correlation with weather variables. This paper proposes a new methodology to identify the weather sensitive component of electrical load using empirical mode decomposition (EMD) technique. The proposed methodology is applied to the daily peak load of Dhaka zone of Bangladesh Power System (BPS) of the year 2012. A detailed numerical process to evaluate the weather sensitive portion of the load is also presented. The proposed methodology is validated through statistical error evaluation process. Finally the salient features of the results are discussed.

Unexpected metastasis of intraductal papillary neoplasm of the bile duct without an invasive component to the brain and lungs:A case report

BACKGROUND Despite an expanding number of studies on intraductal papillary neoplasm of the bile duct(IPNB),distant metastasis remains unexplained especially in cases of carcinoma in situ.In the present study,we report a rare and interesting case of IPNB without invasive components that later metastasized to lungs and brain.CASE SUMMARY A 69-year-old male was referred to our hospital due to suspected cholangiocarcinoma.Laboratory tests on admission reported a mild elevation of alkaline phosphatase,γ-glutamyl transpeptidase,and total bilirubin in serum.Endoscopic retrograde cholangiography revealed a filling defect in the common bile duct(CBD)extending to the left hepatic duct.Peroral cholangioscopy delineated a tumor in the CBD that had a papillary pattern.Multidetector computed tomography and magnetic resonance cholangiopancreatography detected partial blockage ot interlude in the CBD leading to cholestasis without evidence of metastasis.Therefore,a diagnosis of IPNB cT1N0M0 was established.Left hepatectomy with bile duct reconstruction was performed.Pathological examination confirmed an intraepithelial neoplasia pattern without an invasive component and an R0 resection achievement.The patient was monitored carefully by regular examinations.However,at 32 mo after the operation,a 26 mm tumor in the lungs and a 12 mm lesion in the brain were detected following a suspicious elevated CA 19-9 level.Video-assisted thoracoscopic surgery of left upper lobectomy and stereotactic radiotherapy are indicated.In addition to histopathological results,a genomic profiling analysis using whole exome sequencing subsequently confirmed lung metastasis originating from bile duct cancer.CONCLUSION This case highlights the important role of genomic profiling analysis using whole exome sequencing in identifying the origin of metastasis in patients with IPNB.

基于不同因子筛选方法的LightGBM-SHAP滑坡易发性研究

以重庆市黔江区为例,选取23个评价因子构建滑坡致灾因子数据库,利用地理探测器与皮尔逊-主成分分析2种因子筛选方法选择因子最优组合;基于Bayesian-LightGBM-SHAP混合模型进行滑坡易发性评价,并对模型精度进行验证,分析影响黔江区滑坡发生的主导因子.初始模型的AUC值为0.801,Pearson Correlation Coefficient-BayesianLightGBM模型AUC值为0.824,GeoDetector-Bayesian-LightGBM模型AUC为0.835;由因子重要性可知,多年平均降雨量、高程、POI核密度与距河流距离是滑坡发生的最主要因子,而输沙指数、水流动力指数与坡位对滑坡的发生影响较弱.因子筛选法-Bayesian-LightGBM相结合的混合模型能够提高模型的准确性,为构建合理因子数据库提供参考框架;通过与因子重要性的结合分析,验证了地理探测器能够准确探测各因子对滑坡发生的贡献值,突出各滑坡地理因子组合之间的相关性,从而探究各因子与滑坡之间的关系.

Diffusion coefficients of natural gas in foamy oil systems under high pressures

The diffusion coefficient of natural gas in foamy oil is one of the key parameters to evaluate the feasibility of gas injection for enhanced oil recovery in foamy oil reservoirs. In this paper, a PVT cell was used to measure diffusion coefficients of natural gas in Venezuela foamy oil at high pressures, and a new method for deter- mining the diffusion coefficient in the foamy oil was de- veloped on the basis of experimental data. The effects of pressure and the types of the liquid phase on the diffusion coefficient of the natural gas were discussed. The results indicate that the diffusion coefficients of natural gas in foamy oil, saturated oil, and dead oil increase linearly with increasing pressure. The diffusion coefficient of natural gas in the foamy oil at 20 MPa was 2.93 times larger than that at 8.65 MPa. The diffusion coefficient of the natural gas in dead oil was 3.02 and 4.02 times than that of the natural gas in saturated oil and foamy oil when the pressure was 20 MPa. However, the gas content of foamy oil was 16.9 times higher than that of dead oil when the dissolution time and pressure were 20 MPa and 35.22 h, respectively.

Optimization of Culture Components for Laccase Activity from Pleurotus Ostreatus P40 Using Response Surface Methodology

High enzymatic activity is required for laccase applications.Central composite design （CCD）-based response surface methodology （RSM） can effectively increase the enzymatic activity of Pleurotus ostreatus P40 in liquid substrate fermentation.Initial screening of the nutritional components was performed using a Plackett-Burman design.The variables,namely,bran,bagasse,Tween 80,and yeast extract,were found to have statistically significant effects on laccase activity.These variables were further optimized using CCD-based RSM.Optimal concentrations for the maximum laccase activity were 8.144 2 g/L bran,50 g/L bagasse,0.424 1 mL/L Tween 80,and 2.832 5 g/L yeast extract.Under optimized conditions,the maximum measured laccase activity reached 96 480 U/L,which was close to the predicted value （104 830 U/L） by RSM.Therefore,RSM can be used to optimize culture components for laccase activity from Pieurotus ostreatus P40.

Feature Extraction of Fabric Defects Based on Complex Contourlet Transform and Principal Component Analysis

To extract features of fabric defects effectively and reduce dimension of feature space,a feature extraction method of fabric defects based on complex contourlet transform （CCT） and principal component analysis （PCA） is proposed.Firstly,training samples of fabric defect images are decomposed by CCT.Secondly,PCA is applied in the obtained low-frequency component and part of highfrequency components to get a lower dimensional feature space.Finally,components of testing samples obtained by CCT are projected onto the feature space where different types of fabric defects are distinguished by the minimum Euclidean distance method.A large number of experimental results show that,compared with PCA,the method combining wavdet low-frequency component with PCA （WLPCA）,the method combining contourlet transform with PCA （CPCA）,and the method combining wavelet low-frequency and highfrequency components with PCA （WPCA）,the proposed method can extract features of common fabric defect types effectively.The recognition rate is greatly improved while the dimension is reduced.

Surface Energetics Study and Determination of the Combined Negative Hamaker Coefficient for Hepatitis C Virus Infected Human Blood Cells

This study investigated the interactive effects of Hepatitis C virus on human cells using the contact angle approach. The methodology involves the use of sessile drop approach to determine the contact angle formed on the infected and uninfected blood cells in the presences of glycerin as the probe liquid. It was observed that the presence of the virus in the human blood cells depleted the immune system of infected cells giving rise to a decreased CD4 count on the average of 514.5 ± 243.10 when compared with the uninfected cells CD4 count of 1267.2 ± 368.27. The measurement of contact angle also unveils that among the blood components separated in the course of the experiment, the white blood cell is the principal target of the virus with the highest average contact angle of 63.4 ± 3.20 while the uninfected white blood cells have a lower contact angle of 48.5 ± 2.75. The result of the measured contact angle was used for MATLAB computation to determine the surface energy, force of adhesion and the Hamaker coefficient. Response surface methodology was also employed in this study to visualize the viral impact on the blood cells as well as generating model equations for prediction of the interaction between the virus and the blood cells. Infected surfaces on the average have higher values of Hamaker coefficient than uninfected surfaces. It was discovered that an increase in the contact angles causes a significant increase in Hamaker coefficient with a corresponding decrease in the CD4 counts on the infected surfaces. This increase is attributed to the presence of the HCV virus in the infected samples and the highest value was observed in the white blood cell component. Computation of the combined negative Hamaker coefficient revealed that there exists a possibility of separating the virus from the human lymphocyte, hence a negative value of the A132 of the infected sample was seen to be −0.150 × 10−18 mJ/m2 (−0.150 × 10−25 J). This is in agreement with the value reported in literature when an alternative method to contact angle was used (ultraviolent spectrophotometer approach) to investigate HIV infected human cells. The combined negative Hamaker coefficient of −0.281 × 10−25 J was obtained in that study. Both results have unveiled the possibility of applying the concept of combined negative Hamaker coefficient as a means of separating the virus from the lymphocytes. It therefore implies that additives in the form of drug(s) to the serum (as an intervening medium) which could alter the surface energy of the serum to a value of ≥−0.150 × 10−25 J can have the capability of totally isolating the virus from the lymphocytes.

极化调控PIN-PMN-PT铁电单晶压电性能的均匀性

弛豫铁电单晶具有优异的压电性能,在医学超声换能器、水声器件等领域有重要应用。坩埚下降法生长的弛豫铁电单晶不可避免地存在组分偏析,导致材料利用率极低。本工作测试了0.24PIN-0.46PMN-0.30PT铁电单晶沿生长方向压电系数(d_(33))和介电常数(ε_(33)^(T)/ε_(0))的变化,结果显示d_(33)和ε_(33)^(T)/ε_(0)沿着生长方向变化极大,能保持性能接近的区域不足20 mm。通过针对不同区域的极化设计,对铁电-铁电相变温度接近的区域进行极化调控,使超过60%晶体部分的d_(33)和ε_(33)^(T)/ε_(0)分别维持在(1500±140)pC·N-1和4900±350。为了验证极化调控后的晶体谐振区域是否一致,测试了两端区域的k_(33)振子的谐振谱,结果显示两者的机电耦合系数接近,谐振和反谐振的峰位置也接近,而且不存在额外的寄生振动,说明采用极化调控PIN-PMN-PT铁电单晶沿生长方向的均匀性是可行的。本工作为提高PIN-PMN-PT铁电单晶的利用率提供了一种参考方案。

基于RF-MIC-PCA的股票趋势预测

股票因子具有丰富性、相似性等特点,但对其进行趋势预测较难得到良好效果。针对此问题,提出了一种基于RF-MIC-PCA的股票趋势预测算法。首先,利用随机森林(RF)的基尼指数构建因子与类别间的重要性评分规则,剔除低分因子;然后,利用最大信息系数(MIC)构建因子间的相关性评价方法,并融合主成分分析法(PCA)减少因子冗余度;最后,通过随机森林算法预测的分类准确率作为衡量标准,建立基于RF-MIC-PCA的股票趋势预测算法。为验证算法的有效性,从沪深300中选取10只代表性股票进行实验,结果显示RF-MIC-PCA算法在数据集维度降低了20.45%的同时有效提升了算法的预测性能。另外对沪深300、上证50指数进行趋势预测,准确率分别提高了4.1%和5.0%,验证了算法的普适性,具有一定的实用价值。

跨座式单轨独柱大悬挑钢-混组合框架高架车站抗震设计探讨

针对跨座式单轨独柱大悬挑钢-混组合框架高架车站结构抗震冗余度低,在高烈度地区应用较少,为更好地分析高架车站抗震受力全过程,以某跨座式单轨独柱大悬挑钢-混组合框架高架车站工程实例为背景,根据建筑规范和城市轨道交通规范要求设定合理的抗震性能目标,并研究构件抗震受力历时过程中的受力情况。采用大型有限元Midas作为主要计算软件,选取合理的地震波,进行多遇地震和设防地震有限元计算时采用弹性时程分析方法,且对振型分解反应谱法地震作用进行相应的放大,结果分析构件满足抗震性能目标要求。进行罕遇地震计算时,为更好地模拟工程实际情况,计算模型考虑桩土共同作用,采用结构-承台-桩基整体计算建模方法,进行弹塑性时程分析,关键构件采用截面纤维模型进行计算,能够反映关键构件在大震作用下进入破损阶段之后的行为,可以查看关键构件截面混凝土的开裂和压碎历史,钢材或钢筋的屈服和硬化过程。研究结果表明结构构件均满足抗震性能目标:(1)关键构件的钢材纤维受拉受压均未超过屈服强度,保持弹性工作状态,混凝土纤维受拉开裂,受压未达到屈服强度,同时延性系数D/D1小于1,均说明关键构件满足抗震性能为压弯、抗剪不屈服的目标;(2)桩基的钢筋纤维受拉、受压均未超过屈服强度,混凝土纤维受拉开裂,受压未达到屈服强度,满足抗震性能为压弯、抗剪不屈服的目标;(3)地震作用下,带有桩模型与无桩模型的基底剪力有一定差距,表现为带有桩基模型的地震剪力较大,设计时应考虑桩土共同作用。

忻州地震监测中心站YRY-4分量钻孔应变仪气压干扰定量识别及特征分析

选取忻州地震监测中心站所辖代县、原平、宁武、繁峙、神池5个子台四分量钻孔应变仪记录数据,采用S变换、回归分析和小波变换等分析方法,对各仪器气压干扰特征进行量化和对比分析。结果表明:气压对钻孔应变观测的影响具有普遍性,气压干扰信号的归一化优势频率分布在0—0.05 Hz;气压干扰系数具有各异性,5个子台2023年3—6月的日变化气压干扰系数分别为-2.5×10^(-9)/hPa、-2.6×10^(-9)/hPa、-1.3×10^(-9)/hPa、-2.1×10^(-9)/hPa、-91.1×10^(-9)/hPa,其中神池子台所受气压干扰程度最高。