Indirect Methods of Detecting and Evaluating Inclusions in Steel—A Review

Indirect methods to detect and evaluate inclusions in steel are extensively reviewed, which include total oxygen content measurement, nitrogen pickup, steel and slag composition measurement, lining refractory observation, tracer studies of determining exogenous inclusions from slag and lining erosion, SEN clogging and final prod- uct tests. There is no single ideal method of detecting and evaluating inclusions in steel, so it is better to use several methods simultaneously to give a more accurate evaluation. Total oxygen content and nitrogen pickup in low carbon aluminum-killed steel as criterion of clean steel in many plants are summarized.

On the parameters for electrocaloric effect predicted by indirect method

The influences of specific heat capacity CP, temperature step ？T, electric field step ？E, and initial electric field E1 on predicted electrocaloric（EC） temperature ？T of monodomain Ba TiO3 are examined by combining the Maxwell equation and phenomenological theory. Since the procedure is similar to indirect measurement of the EC effect, the results can serve as a reference for experiments. The results suggest that（i） it is reasonable to use zero-field CP,（ii） optimized ？T should be 2 K,（iii） it is better to keep △E 〈 EC, and（iv） E1〈 EC. Here, EC is the coercive field of material.

Safety evaluation for railway vehicles using an improved indirect measurement method of wheel–rail forces

The wheel-rail force measurement is of great importance to the condition monitoring and safety evaluation of railway vehicles. In this paper, an improved indirect method for wheel-rail force measurement is proposed to evaluate the running safety of railway vehicles. In this method, the equilibrium equations of a suspended wheelset are derived and the wheel-rail forces are then be obtained from measured suspension and inertia forces. This indirect method avoids structural modifications to the wheelset and is applicable to the long-term operation of railway vehicles. As the wheel-rail lateral forces at two sides of the wheelset are difficult to separate, a new derailment criterion by combined use of wheelset derailment coefficient and wheel unloading ratio is proposed. To illustrate its effectiveness, the indirect method is applied to safety evaluation of rail- way vehicles in different scenarios, such as the cross wind safety of a high-speed train and the safety of a metro vehicle with hunting motions. Then, the feasibility of using this method to identify wheel-rail forces for low-floor light rail vehicles with resilient wheels is discussed. The values identified by this method is compared with that by Simpack simulation for the same low-floor vehicle, which shows a good coincidence between them in the time domain of the wheelset lateral force and the wheel-rail vertical force. In addition, use of the method to determine the high-frequency wheel-rail interaction forces reveals that it is possible to identify the high-frequency wheel-rail forces through the accelerations on the axle box.

Investigation of a cyanine dye assay for the evaluation of the biocompatibility of magnesium alloys by direct and indirect methods

Magnesium and its alloys are promising candidates for a new generation of biodegradable metals in orthopaedic applications due to their excellent biocompatibility,biodegradability,and mechanical properties that are similar to natural bone.However,direct in vitro assessment of these materials in the presence of cells is complicated by degradation products from the alloy that lead to a false positive for the most commonly used cell adhesion and cell proliferation assays.In this paper,a cyanine dye was used to quantitatively evaluate the in vitro biocompatibility of a Mg AZ31 alloy by both direct and indirect methods.The cytotoxicity of the corrosion products was evaluated via an indirect method;a 25%decrease in cell viability compared to control samples was observed.Moreover,direct assessment of cell adhesion and proliferation showed a statistically significant increase in cell number at the surface after 72 h.In addition,the degradation rate and surface characteristics of the Mg AZ31 alloy were evaluated for both direct and indirect tests.The degradation rate was unaffected by the presence of cells while evidence of an increase in calcium phosphate deposition on the magnesium alloy surface in the presence of cells was observed.This study demonstrates that a cyanine dye based assay provides a more accurate assessment of the overall in vitro biocompatibility of biodegradable metals than the more commonly used assays reported in the literature to date.

A data-driven indirect method for nonlinear optimal control

Nonlinear optimal control problems are challenging to solve due to the prevalence of local minima that prevent convergence and/or optimality.This paper describes nearest-neighbors optimal control(NNOC),a data-driven framework for nonlinear optimal control using indirect methods.It determines initial guesses for new problems with the help of precomputed solutions to similar problems,retrieved using k-nearest neighbors.A sensitivity analysis technique is introduced to linearly approximate the variation of solutions between new and precomputed problems based on their variation of parameters.Experiments show that NNOC can obtain the global optimal solution orders of magnitude faster than standard random restart methods,and sensitivity analysis can further reduce the solving time almost by half.Examples are shown on optimal control problems in vehicle control and agile satellite reorientation demonstrating that global optima can be determined with more than 99%reliability within time at the order of 10-100 milliseconds.

Combined indirect and direct method for adaptive fuzzy output feedback control of nonlinear system

A novel control method for a general class of nonlinear systems using fuzzy logic systems （FLSs） is presertted. Indirect and direct methods are combined to design the adaptive fuzzy output feedback controller and a high-gain observer is used to estimate the derivatives of the system output. The closed-loop system is proven to be semiglobally uniformly ultimately bounded. In addition, it is shown that if the approximation accuracy of the fuzzy logic system is high enough and the observer gain is chosen sufficiently large, an arbitrarily small tracking error can be achieved. Simulation results verify the effectiveness of the newly designed scheme and the theoretical discussion.

Correlations between direct and indirect strength test methods

The difficulties associated with performing direct compression strength tests on rocks lead to the development of indirect test methods for the rock strength assessment. Indirect test methods are simple, more economical, less time-consuming, and easily adaptable to the field. The main aim of this study was to derive correlations between direct and indirect test methods for basalt and rhyolite rock types from Carlin trend deposits in Nevada. In the destructive methods, point load index, block punch index, and splitting tensile strength tests are performed. In the non-destructive methods, Schmidt hammer and ultrasonic pulse velocity tests are performed. Correlations between the direct and indirect compression strength tests are developed using linear and nonlinear regression analysis methods. The results show that the splitting tensile strength has the best correlation with the uniaxial compression strength.Furthermore, the Poisson's ratio has no correlation with any of the direct and indirect test results.

Indirect-approach method for specified-end points seismic ray tracing in three dimen-sional inhomogeneous media

Generally speaking, the factors of both medium and tectonic that give rise to heterogeneity of the earth crust and mantle structures should be taken into account simultaneously in three dimensional seismic ray tracing. In this paper, the three dimensional structure models are constructed with the model similar to generation system in computer aid design and manufacturing (CAD/CAM). Based on the algorithm proposed by Cerveny et al . for complete seismic ray tracing in complex three dimensional structures, a new technique called the indirect approach method for two point seismic ray tracing in three dimensional laterally heterogeneous media has been put forward, and its numerical computing examples were given.

近距离大埋深金属管线探测方法及应用

随着工程建设的发展,近距离大埋深地下管线的探测成为当前工程领域的难点。针对近距离大埋深金属管线探测,本文研究了水平电磁剖面法,首次提出了间接充电法信号加载方法,并采用了带地形改正的磁感应强度反演方法。文章结合一个多条近距离敷设埋深大于12m的地下管线探测实例,详细阐述了探测过程中的关键技术及解决方案。探测结果经人工开挖验证,完全符合实际,精度满足要求,可为类似工程提供参考和借鉴。

A Hybrid Decoupled Power Flow Method for Balanced Power Distribution Systems

This paper proposes a hybrid decoupled power flow method for balanced power distribution systems with distributed generation sources. The method formulates the power flow equations in active power and reactive power decoupled form with polar coordinates. Second-order terms are included in the active power mismatch iteration, and constant Jacobian and Hessian matrices are used. A hybrid direct and indirect solution technique is used to achieve efficiency and robustness of the algorithm. Active power correction is solved by means of a sparse lower triangular and upper triangular （LU） decomposition algorithm with partial pivoting, and the reactive power correction is solved by means of restarted generalized minimal residual algorithm with an incomplete LU pre-conditioner. Typical distribution generation models and distribution load models are included. The impact of zero-impedance branches is explicitly modeled through reconfiguring of the adjacent branches with impedances. Numerical examples on a sample distribution system with widespread photovoltaic installations are given to demonstrate the effectiveness of the proposed method.

Re-measuring International Short-term Capital Flow into China with Varying Methods

This paper.fi＇rst conducts a systematic review of domestic and foreign scholars＇ approaches to predicting short-term capital flows, then employs a combination of both direct and indirect methods to carry out its analysis. Three kinds of indicators, both specific and general, are applied in both methods. Thorough consideration is given to short-term international capital inflow from trade, other current account items, capital account, and errors and omissions, as well as other channels through which short term capital might accrue to a nation＇s balance. Based on a comprehensive comparison of year-on-year data, this paper also estimates monthly data using a simplified, indirect calculation approach. Estimates show that, despite a degree of difference in results between methods, most estimates are highly consistent for a given period. Based on monthly estimates, we conclude that turbulence in international financial markets （i.e., the United States subprime mortgage crisis and the European sovereign debt crisis） has had a major impact on China ＇s short-term capital flow.

铁精矿电化学湿法氧化脱硫试验研究

以鄂东某铁矿磁选和反浮选后的铁精矿为原料,采用电化学湿法氧化脱硫工艺,通过调节催化剂种类、电解质掺量、电解电压、电解温度和电解时间等参数,考察脱硫效果,结果表明:在电化学体系下最佳脱硫反应条件为电解质HCl质量分数2.5%,催化剂MnCl 2掺量2.5%,电解电压3 V,电解温度65℃,电解时间4 h,在该条件下可使高硫铁精矿的硫含量降至0.3%以下,且矿粉经洗涤后氯含量极低,满足冶炼优质钢铁的标准要求;同时,脱硫后铁精矿中的硫以可溶态(SO_(3)^(2-)和SO_(4)^(2-))溶解在电解液中,电解液可以循环利用。电化学湿法脱硫相较于其他湿法脱硫方法具有更显著的脱硫效果。

THE COLLOCATION METHODS FOR SINGULAR INTEGRAL EQUATIONS WITH CAUCHY KERNELS

This paper applies the singular integral operators, singular quadrature operators and discretization matrices associated with singular integral equations with Cauchy kernels, which are established in [1], to give a unified framework for various collocation methods of numerical solutions of singular integral equations with Cauchy kernels. Under the framework, the coincidence of the direct quadrature method and the indirect quadrature method is very simple and obvious.

火山灰质材料的火山灰活性检测方法综述

本文将火山灰质材料的火山灰活性检测方法分为直接法和间接法两大类。其中,直接法包括石灰吸收值法,火山灰反应程度评定法和酸、碱溶出度法;而间接法包括物理性能法,水化反应放热量法和物理、化学特征参数法。为正确指导火山灰活性检测方法的应用,本文详细介绍并比较了各检测方法的原理和特点。笔者认为,直接法可直接测定出火山灰质材料与Ca(OH)2反应的程度,但其操作和分析过程相对复杂;间接法可通过测定火山灰质材料对体系物化性能的影响或材料自身的物理、化学特征参数来评价其火山灰活性。本文从材料科学的角度厘清了各检测方法的适用对象,认为应根据不同的火山灰质材料的特性选择与其相适应的火山灰活性检测方法。

Indirect Measurement of Torque Ripple for Permanent Magnet Brushless DC Torque Motor

Torque ripple is one of the most important specification indexes of brushless DC torque motors. This paper analyzes the torque ripple of a sinusoidal-driven three-phase permanent magnet(PM) brushless DC (BLDC) torque motor and approaches the expression of torque ripple. An indirect method using armature currents to measure torque ripple and its implementation by hardware are presented. The torque ripple of the motor is measured by the indirect and the direct methods respecively. The validity of the indirect method is demonstrated by the comparative analysis of the experimental results.

成都市郫都区人群TSH参考区间的建立及验证

目的采用间接法建立适用于成都市郫都区人群的性别、年龄特异的促甲状腺激素(TSH)参考区间。方法收集2022年3月至2023年8月成都市郫都区中医医院37514例患者的TSH数据,根据筛选标准对数据进行删减,采用偏度-峰度法进行正态性检验,Turkey法剔除离群值。不同性别和年龄TSH水平比较分别采用Mann-Whitney U检验、Kruskal-Wallis H检验。应用非参数法建立TSH参考区间,并采用2种方法验证其可靠性,当其与试剂说明书参考区间的相对偏差小于参考变化值(RCV)或用于验证人群时>90%的TSH结果在参考区间内,则证明结果可靠。结果共纳入25761例患者的有效TSH数据,男9363例,女16398例。按年龄段将其分为8个亚组,即10~<18、18~30、>30~40、>40~50、>50~60、>60~70、>70~80、>80~90岁,男性TSH参考区间依次为0.457~4.884、0.465~4.229、0.445~4.918、0.457~4.826、0.471~5.160、0.425~5.477、0.456~5.645、0.465~6.418μIU/mL,女性TSH参考区间依次为0.546~5.196、0.592~5.499、0.606~5.815、0.549~5.915、0.527~6.099、0.457~5.927、0.435~6.078、0.415~6.321μIU/mL。参考区间上限、下限与试剂说明书的相对偏差均小于RCV(49.85%);在用于验证人群时,各组均有大于90%的TSH结果在参考区间内。结论采用间接法建立了性别和年龄特异的成都市郫都区人群TSH参考区间,可为甲状腺疾病的精准诊疗提供参考依据。

基于间接核查法的流量计云在线运行核查方法

在供热物理设备网中,除不同规模的流量计群外,还设有大量与流量有关的设备及部件。本文研究了利用供热系统的机理、被核查流量计的相关参数、供热物理设备网中设置的具有流量特性的设备或部件来判断被核查流量计工作状态的方法,并在此基础上提出了流量计的云在线运行核查技术流程,以快速判断在线应用的流量计的技术性能是否满足使用要求,解决供热企业核查人员及核查仪器设备不足的缺陷,有效提升智慧供热系统数据质量和提高控制系统的安全。

水蒸气载热式锅炉烟气余热回收系统的节能量测量方法

烟气余热回收可有效降低锅炉的排烟热损失,减少燃料耗量和温室气体排放。近年来,作为一种高效的全热热回收方式,水蒸气载热式锅炉烟气余热回收系统已在实际工程中得到一定的应用,但由于其流程及能量转化关系较为复杂,人们对该系统节能量如何判定存在争议。本文在分析烟气余热回收系统及其各环节的能量平衡与转化关系基础上,提出了采用温度传感器、热计量表等常规仪表间接测量整个余热回收系统及其锅炉助燃风预热节能量的方法,并以山东临邑恒利热电厂为例给出了采用水蒸气载热式锅炉烟气余热回收前、后的测量结果。数据分析表明,对于蒸发量为176.90 t/h的锅炉,整个烟气余热回收系统的总节能量为10.86 MW,占锅炉产热量的8.46%,其中通过锅炉的进风预热加湿使锅炉加热助燃风节能1.73 MW,占余热总回收量的16%。该测量方法为水蒸气载热式锅炉烟气余热回收系统规模化应用提供了节能量在线实时监测的技术支撑。

Recent progress in nuclear astrophysics research and its astrophysical implications at the China Institute of Atomic Energy

Nuclear astrophysics is a rapidly developing interdisciplinary feld of research that has received extensive attention from the scientifc community since the midtwentieth century.Broadly,it uses the laws of extremely small atomic nuclei to explain the evolution of the universe.Owing to the complexity of nucleosynthesis processes and our limited understanding of nuclear physics in astrophysical environments,several critical astrophysical problems remain unsolved.To achieve a better understanding of astrophysics,it is necessary to measure the cross sections of key nuclear reactions with the precision required by astrophysical models.Direct measurement of nuclear reaction cross sections is an important method of investigating how nuclear reactions infuence stellar evolution.Given the challenges involved in measuring the extremely low crosssections of nuclear reactions in the Gamow peak and preparing radioactive targets,indirect methods,such as the transfer reaction,coulomb dissociation,and surrogate ratio methods,have been developed over the past several decades.These are powerful tools in the investigation of,for example,neutron-capture(n,r)reactions with short-lived radioactive isotopes.However,direct measurement is still preferable,such as in the case of reactions involving light and stable nuclei.As an essential part of stellar evolution,these low-energy stable nuclear reactions have been of particular interest in recent years.To overcome the diffculties in measurements near or deeply within the Gamow window,the combination of an underground laboratory and high-exposure accelerator/detector complex is currently the optimal solution.Therefore,underground experiments have emerged as a new and promising direction of research.In addition,to better simulate the stellar environment in the laboratory,research on nuclear physics under laser-driven plasma conditions has gradually become a frontier hotspot.In recent years,the CIAE team conducted a series of distinctive nuclear astrophysics studies,relying on the Jinping Underground Nuclear Astrophysics platform and accelerators in Earth’s surface laboratories,including the Beijing Radioactive Ion beam Facility,as well as other scientifc platforms at home and abroad.This research covered nuclear theories,numerical models,direct measurements,indirect measurements,and other novel approaches,achieving great interdisciplinary research results,with high-level academic publications and signifcant international impacts.This article reviews the above research and predicts future developments.

鸡马立克氏病火鸡疱疹病毒间接免疫荧光检测方法的建立与比较

为建立鸡马立克氏病火鸡疱疹病毒(MDV HVT)的间接免疫荧光方法,将MDV HVT病毒接种96孔细胞板培养(CEF),72 h后用鸡抗马立克氏病病毒阳性血清作为一抗和兔抗鸡荧光抗体作为二抗,对反应条件进行优化,建立了间接免疫荧光方法(IFA)。并与经典的马立克蚀斑计数方法进行病毒滴度的测定比较,运用统计学方法分析,P小于0.05,相关系数为0.995,说明两种方法相关性很好,两种方法均可用于马立克氏病病毒的滴度测定。IFA方法较蚀斑计数方法操作简便快捷,可代替蚀斑计数方法用于马立克氏病活疫苗的病毒含量的初步测定,同时为2025年版《中国兽药典》马立克氏病活疫苗增加IFA鉴别检验方法积累实验数据。