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To Establish Reference Interval for Serum Thyroid Hormone in Adults of Subaltitude Determined by indirect method

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To Establish Reference Interval for Serum Thyroid Hormone in...

Perturbed low-thrust geostationary orbit transfer guidance via polynomial costate estimation

第十三届全国免疫学学术大会

作者： Yan Lu Jian-yun Yue De-hong Li Shu-hong Zhou First Hospital of Chinese People’s Liberation Army

Objective: To establish reference interval for serum thyroid hormone in adults of subaltitude determined by Siemens CP chemiluminescence instrument by indirect ***: fifteen thousand two hundreds and ninety three results of thyroid gland from the physical examination center were extracted from 2014.01.01-2017.06.30 LIS *** of Data was tested by Skewness-Kurtosis test *** data were identified and excluded according to the detection limit and then by quartile spacing *** reference interval was obtained by Hoffman method and was compared with the biological reference interval of guideline and ***: There were no significant differences in thyroid hormone between men and *** biological reference interval of thyroid hormone was T3(0.67-1.7 ng/ml), FT3(2.3-3.6 pg/ml), T4(5.5-10.9μg/ml) and FT4(0.89-1.75 ng/dl).The relative deviations of the reference interval of T3, FT3, T4 and FT4 from manual were(-9.57%,-14.10%),(2.56%, 69.12%),(-8.86%, 11.34%) and(-9.33%, 27.14%).The relative deviations of the reference interval of T3, FT3, T4 and FT4 from guide were(-5.85%, 8.97%),(-17.09%, 0.00%),(0.00%, 20.24%),(-0.52%, 0.00%).Conclusion: the biological reference interval in subaltitude established by indirect method in present has a deviation compared with the biological reference interval provided by guidelines and instructions provided.

关键词： thyroid hormone biological reference interval indirect method chemiluminescence

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Chinese Journal of Aeronautics 2024年第3期37卷 181-193页

作者： Zhao LI Hengnian LI Fanghua JIANG Junfeng LI State Key Laboratory of Astronautic Dynamics Xi’an Satellite Control CenterXi’an 710043China School of Aerospace Engineering Tsinghua UniversityBeijing 100084China

This paper proposes an optimal,robust,and efficient guidance scheme for the perturbed minimum-time low-thrust transfer toward the geostationary *** Earth’s oblateness perturbation and shadow are taken into *** is difficult for a Lyapunov-based or trajectory-tracking guidance method to possess multiple characteristics at the same time,including high guidance optimality,robustness,and onboard computational *** this work,a concise relationship between the minimum-time transfer problem with orbital averaging and its optimal solution is identified,which reveals that the five averaged initial costates that dominate the optimal thrust direction can be approximately determined by only four initial modified equinoctial orbit elements after a coordinate *** on this relationship,the optimal averaged trajectories constituting the training dataset are randomly generated around a nominal averaged *** polynomial regression models are trained on the training dataset and are regarded as the costate *** the transfer,the spacecraft can obtain the real-time approximate optimal thrust direction by combining the costate estimations provided by the estimators with the current state at any ***,all these computations onboard are *** simulation results show that the proposed guidance scheme possesses extremely high guidance optimality,robustness,and onboard computational efficiency.

关键词： Low thrust Orbital transfer Trajectory optimization Guidance indirect method Orbital averaging Machine learning Geostationary satellites

indirect methods of Detecting and Evaluating Inclusions in Steel—A Review

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Journal of Iron and Steel Research International 2006年第3期13卷 1-8页

作者： ZHANG Li-feng Department of Materials Science and Engineering Norwegian University of Science and TechnologyHogskoleringen 8 7491 Trondheim Norway

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.

关键词： inclusion indirect method total oxygen nitrogen pickup

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

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Bioactive Materials 2020年第1期5卷 26-33页

作者： Afrah Al Hegy Ryan Smith Eric R.Gauthier Joy E.Gray-Munro Dept.of Chemistry and Biochemistry Laurentian UniversitySudburyOntarioP3E 2C6Canada

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 ***,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 *** this paper,a cyanine dye was used to quantitatively evaluate the in vitro biocompatibility of a Mg AZ31 alloy by both direct and indirect *** cytotoxicity of the corrosion products was evaluated via an indirect method;a 25%decrease in cell viability compared to control samples was ***,direct assessment of cell adhesion and proliferation showed a statistically significant increase in cell number at the surface after 72 *** addition,the degradation rate and surface characteristics of the Mg AZ31 alloy were evaluated for both direct and indirect *** 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 *** 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.

关键词： Magnesium alloys Biocompatibility Direct method indirect method Cyanine dye Cell adhesion Cell proliferation Cytotoxicity

Time-optimal rendezvous transfer trajectory for restricted cone-angle range solar sails

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Acta Mechanica Sinica 2014年第5期30卷 628-635页

作者： Jing He Sheng-Ping Gong Fang-Hua Jiang Jun-Feng Li School of Aerospace Tsinghua University

The advantage of solar sails in deep space exploration is that no fuel consumption is required. The heliocentric distance is one factor influencing the solar radiation pressure force exerted on solar sails. In addition, the solar radiation pressure force is also related to the solar sail orientation with respect to the sunlight direction. For an ideal flat solar sail, the cone angle between the sail normal and the sunlight direction determines the magnitude and direction of solar radiation pressure force. In general, the cone angle can change from 0° to 90°. However, in practical applications, a large cone angle may reduce the efficiency of solar radiation pressure force and there is a strict requirement on the attitude control. Usually, the cone angle range is restricted less more than an acute angle （for example, not more than 40°） in engineering practice. In this paper, the time-optimal transfer trajectory is designed over a restricted range of the cone angle, and an indirect method is used to solve the two point boundary value problem associated to the optimal control problem. Relevant numerical examples are provided to compare with the case of an unrestricted case, and the effects of different maximum restricted cone angles are discussed. The results indicate that （1） for the condition of a restricted cone-angle range the transfer time is longer than that for the unrestricted case and （2） the optimal transfer time increases as the maximum restricted cone angle decreases.

关键词： Solar sail - Time-optimal rendezvous indirect method Restricted cone-angle range

Real-time trajectory optimization for powered planetary landings based on analytical shooting equations

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Chinese Journal of Aeronautics 2022年第7期35卷 91-99页

作者： Lin CHENG Peng SHI Shengping GONG Zhenbo WANG School of Astronautics Beihang UniversityBeijing 100191China Department of Mechanical Aerospaceand Biomedical EngineeringUniversity of TennesseeKnoxville 37996USA

Traditionally,numerical trajectory integration for shooting equation calculation and iterations for shooting with randomly guessed initial solutions deteriorate the real-time performance of indirect methods for on-board *** this study,the indirect method is improved to achieve real-time trajectory optimization of fuel-optimal powered planetary landings with the help of analytical shooting equation derivations and a practical homotopy ***,the contributions of this paper are ***,the analytical expressions for shooting equation calculation are derived to replace the traditional time-consuming trajectory ***,the computational efficiency is significantly ***,the original three-dimensional landing problem is connected with a simplified one-dimensional problem that only involves the vertical dynamics,and its analytical solution is obtained based on Pontryagin’s minimum ***,starting with the analytical solution,the accurate solution of the original landing problem can be obtained through an adaptive homotopy *** results of Earth landing scenarios are given to substantiate the effectiveness of the proposed techniques and illustrate that the developed method can obtain a fuel-optimal landing trajectory in 5 ms with 100%success rate.

关键词： Adaptive homotopy Analytical solution Fuel-optimal landings indirect method Real-time control

Numerical simulation on butt-welding of CLAM steel

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China Welding 2010年第4期19卷 44-48页

作者：雷玉成李涛尹莎朱强巨新 School of Materials Science and Engineering Jiangsu University Zhenjiang 212013 Physics Department University of Science and Technology of Beijing Beijing 100083

Thermo-mechanical simulations of single butt welding were performed ,for CLAM steel, utilizing commercial software, ANSYS, in which double ellipsoid heat source model was introduced and phase transition action was precluded. The residual stress distributions based on the calculated temperature field were calculated and ahnost coincided with those from the experimental results. Based on the simulation, it was also found that tensile stress exists in the partial melting region and bond area; whilst compressive stress turns on away from weld zone. The residual stress over the cross section is very little and it is also confirmed to be tensile stress.

关键词： CLAM steel finite element analysis indirect method residual stress birth-death element

A Hybrid Decoupled Power Flow method for Balanced Power Distribution Systems

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Journal of Electronic Science and Technology 2012年第1期10卷 15-21页

作者： Hongbo Sun Daniel Nikovski Tetsufumi Ohno Tomihiro Takano Yasuhiro Kojima the Mitsubishi Electric Research Laboratories CambridgeMA 02139USA the Mitsubishi Electric Corporation Hyogo 661-8661Japan

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.

关键词： Direct method distributed generations,distribution systems indirect method power flow,zero-impedance branches.