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Background. Despite tremendous advances in treating osteosarcoma (OS), the survival rates of patients have failed to improve dramatically over the past decades. Ferroptosis, a newly discovered iron-dependent type of regulated cell death, is implicated in tumors, and its features in OS remain unascertained. We designed to determine the involvement of ferroptosis subcluster-related modular genes in OS progression and prognosis. Methods. The OS-related datasets retrieved from GEO and TARGET database were clustered for identifying molecular subclusters with different ferroptosis-related genes (FRGs) expression patterns. Weighted gene coexpression network analysis (WGCNA) was applied to identify modular genes from FRG subclusters. The least absolute shrinkage and selection operator (LASSO) algorithm and multivariable Cox regression analysis were adopted to develop the prognostic model. Potential mechanisms of development and prognosis in OS were explored by gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and gene set enrichment analysis (GSEA). Then, a comprehensive analysis was conducted for immune checkpoint markers and assessment of predictive power to drug response. The protein expression levels of the three ferroptosis subcluster-related modular genes were verified by immunohistochemistry. Results. Two independent subclusters presenting diverse expression profiles of FRGs were obtained, with significantly different survival states. Ferroptosis subcluster-related modular genes were screened with WGCNA, and the GESA results showed that ferroptosis subcluster-related modular genes could affect the cellular energy metabolism, thus influencing the development and prognosis of osteosarcoma. A prognostic model was established by incorporating three ferroptosis subcluster-related modular genes (LRRC1, ACO2, and CTNNBIP1) and a nomogram by integrating clinical features, and they were evaluated for the predictive power on OS prognosis. The 20 immune checkpoint-related genes confirmed the insensitivity to tumor immunotherapy in high-risk patients. IC50s of Axitinib and Cytarabine suggested a higher sensitivity to the targeted drug. Finally, the quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and immunohistochemistry were consistent with bioinformatics analysis. Conclusion. Ferroptosis are closely associated with the OS prognosis. The risk-scoring model incorporating three ferroptosis subcluster-related modular genes has shown outstanding advantages in predicting patient prognosis.

This paper proposes two fast calculation algorithms for the determination of the saddle-node bifurcation point of islanded microgrids, which use bisection search and parabolic approximation respectively. The Levenberg-Marquardt algorithm is applied to obtain the least-squares solution in the infeasible region of power flow equations. The bisection search algorithm uses the least-squares solution to determine whether the current trial step reaches the power flow infeasible region, and finally approaches the saddle-node bifurcation point. The parabolic approximation algorithm performs a parabolic approximation to ‘the least-squares value’ – ‘load margin’ curve in the infeasible region, and the zero point of the curve is corresponding to the required saddle-node bifurcation point. The case analysis shows that the two algorithms proposed in this paper have the advantages of high accuracy, high computational efficiency, and strong robustness.

Regional integrated energy system (RIES) can realize multi-energy conversion and complementation so as to improve energy efficiency, which also brings more security risks. The regional integrated energy system security region (RIESSR) is a security analysis method to describe the safe area for the operating points of RIES based on the N-1 guideline. As a controllable device, energy storage (ES) which is installed in the energy hub (EH) plays an important role in improving system security. Therefore, this paper establishes the model of practical security region of RIES integrating energy storage, and studies the impact of ES on total supply capability (TSC) and practical security boundary. Finally, a specific case is set to simulate and verify the model. By comparing the scenario with ES and the scenario without ES, it can be seen that the solution result of TSC increases and the security region extends across quadrant when the RIES is integrated with ES system. The capacity and location of the ES also impact on TSC and RIESSR.

Echinococcosis is a chronic neglected zoonotic disease with high endemic in western China. The aim of the study was to evaluate the Health-related Quality of Life (HRQoL) in patients with echinococcosis in Tibetan communities for investigating the physical and mental health challenges faced by the echinococcosis patients and meeting community health needs. The HRQoL was measured with 36-Item Short Form Health Survey (SF-36) questionnaire in the case–control study. Analysis of variance (ANOVA) method was used to analyze the data. 50 echinococcosis patients were collected in study group and divided into three subgroups by the duration of staying on albendazole tablets. 52 healthy individuals were collected in control group. In physical quality of life, the duration of staying on albendazole tables influenced the PF (F = 6.661, P

The dovetail attachment between the turbine blade and disk for an aero-engine operates under varying centrifugal load and vibration at elevated temperatures. The fretting fatigue is prone to occur at the contact surface of the dovetail attachment. This paper investigated the fretting fatigue behavior of the dovetail specimen at 630 °C through experiment and numerical simulation, in which the blade-like dovetail specimen is nickel-based single crystal superalloy DD10 while two fretting pads in contact with the dovetail specimen simulating the mortise of the disk are made of powder metallurgy FGH99. It is revealed from all the tests that the fracture induced by the fretting wear occurs at the upper edge area of the contact surface. The contact surface near the upper edge is more severely worn, hence, the phenomenon of partition on the worn contact surface can be observed, which is consistent with the fretting fatigue mechanism. Moreover, the calculated area of maximum contact pressure gradient through finite element method is in good agreement with the experimental position of the initial fretting fatigue cracks.

The construction of smart green city promotes the development of efficient energy use. The development and utilization of user-side demand response resources has become one of the key and difficult problems to be solved urgently in urban sustainable development. This paper first analyzes the multi-dimensional decision-making of multi-objects such as energy demand, distributed renewable power, energy storage device, etc., and then analyzes the "incentive guidance-output correction" between the demand response implementer and the responder. The continuous and interactive process, and then proposes a two-layer topology model that uses the upper layer to guide the lower layer and the lower layer to feedback the upper layer to characterize the user side demand response. Consider the overall goal of maximizing social welfare based on cost considerations, and establish a two-layer topology model designed by user-side demand response incentive mechanism. The validity of the two-layer topology model proposed in this paper is verified by a numerical example. The benefits of the demand response and the influencing factors of the incentive mechanism are discussed. Based on this model, the topology design of the energy interconnection network is proposed. Principles and two new types of energy Internet topologies— the star topology of primary energy plus auxiliary energy and the ring topology with multiple distributed energy systems. Finally, a typical application scenario is selected for analysis and description of the user-side energy interconnection network topology in a typical scenario, and a feasible optimal configuration scheme and network topology are provided.

Energy hub has been widely used in modeling of multi-energy system and energy Internet since it is put forward, and the general model of energy hub is developed and improved in this paper. The existing energy hub model used in previous studies is established based on the steady-state operation model of the energy conversion equipment, which only considers the factors of energy distribution and conversion efficiency in energy hub, but does not consider the off-design properties of energy conversion equipment. Therefore, this paper studies the off-design characteristics of gas turbine and heat recovery steam generator in the cogeneration energy hub, and brings the off-design characteristics of equipment into the energy hub model, so as to obtain off-design analysis model of energy hub. This work has important implications for the comprehensive energy efficiency assessment of multi-energy systems and energy Internet.

New energy value is defined by combining three traditional energy values. The comprehensive energy efficiency evaluation model is established by studying the generation, transformation and transportation of secondary energy. The effect of demand conditions on energy efficiency is analyzed based on data. The application scope of the model is briefly described.

The conventional resonance conditions are derived based on the conventionally designed impellers without splitter blades. This paper proposes the resonance conditions for impellers under the excitation from the impeller&ndash, diffuser interaction with attention paid on the influence of splitter blades. A lumped parameter model is established and the modal analysis is carried out. The blade-based representative modal vector (RMV) is defined. The influence of splitter blades on the impeller&rsquo, s traits of modes is investigated by analyzing the spatial harmonic contents of the RMV. Then, given the specific form of the diffuser-induced engine order excitation acting on the main and splitter blades, the resonance conditions are derived. Tuned and mistuned cases are provided for a practical impeller. The resonance conditions are verified by harmonic response calculations. The applications of the proposed resonance conditions in resonance identification and hazard evaluation of different excitations are given. The differences between the proposed resonance conditions and the conventional ones are discussed. The research indicates that even the RMV of the tuned impeller contains two harmonic components due to the existence of splitter blades. When the excitation frequency equals the natural frequency of the impeller and the excitation order matches with either harmonic index of the two harmonics, the resonance occurs. The results of case studies show that the harmfulness of various engine orders of excitation can be exactly evaluated by the joint use of the spatial harmonic contents analysis result and the proposed resonance conditions, however, analyzing based on the conventional resonance conditions may lead to the misjudgment of the harmfulness of the excitations.

A geometric modeling method for cold blade is proposed based on hot-to-cold finite element (FE) transformation calculation. The main idea is to interpolate the deformation result calculated from hot-to-cold transformation to the control points of the hot blade profile. Subtract the interpolated displacement values from the coordinates of the hot control points then the coordinates of the cold control points are obtained. The resulting coordinates could be directly used for solid modeling in commercial CAD programs. Both the hot-to-cold FE transformation calculation part and the output part of the cold blade profile’s control point coordinates could be accomplished in a whole process automatically in the commercial FE program ANSYS15.0. The flow chart of the entire process is given attached with ANSYS APDL commands. Finally, a numerical example based on a blisk sector model is provided. The hot-to-cold FE transformation calculation is performed, the finite element model (FEM) is obtained and solid model is built. Additionally, the effect of mesh density on the modeling accuracy is investigated.

With the introduction and development of modern working process control technology theories, people are more convenient and flexible in controlling the working process of energy storage power generation equipment, and thus their application scope and space have also been greatly expanded and expanded. In this paper, the main technical approaches, functions and feasibility of the application of energy storage power generation equipment in the load system microgrid are extensively studied.

With the rapid growth of energy consumption, how to utilize energy in an efficient and cheap way becomes an intensive problem. This paper proposes an optimal operation strategy to reduce system fuel costs and increase system stability by independently considering cooling loads and adjusting CHP heat to power ratio seasonally. In this paper, a mathematical model of CHP operation is introduced to reveal the relationship between the supplementary volume of diesel oil and CHP heat to power ratio. Meanwhile, by analyzing the influence of seasonal factor on energy consumption, CHP heat to power ratio is optimized seasonally. Then, by independently considering the impacts of the cooling loads on system operation, the particle swarm optimization (PSO) algorithm is used to optimize the operation strategy of each device. Finally, this paper validates the positive effects of storage devices on improving system economy and stability under the premise of the time-of-use gas price. Results show that system fuel costs can be reduced by 5.2% if the seasonal factor is considered. Additionally, by optimizing the operation strategy, the peak valley gap of electrical loads in summer reduces by 40.7%. Moreover, the proposed strategy successfully utilizes storage capacity to shift loads and respond to gas price.

Distributed energy systems are the focus of energy issues, and the existing energy system evaluation methods are mostly established for single-energy systems. Based on the characteristics of distributed energy system, a comprehensive energy efficiency evaluation system and method are presented for distributed energy system based on entropy weight method in this paper. It integrates economic indicators, energy efficiency technical indicators and environmental indicators. The traditional indicators have been filtered and the concept of construction cost growth coefficient is first put forward. The expert evaluation system and the purpose bias weight are added to the evaluation method at the same time. Finally, an example is given to compare the evaluation results of traditional system, PV system and gas turbine system under different evaluation.

In order to overcome the limitation of traditional single-objective optimal operation method for the multiple energy flows system combined cooling, heat and power (CCHP), this paper presents a multi-objective comprehensive optimization model for CCHP with renewable energy resources and energy storage devices based on the fuzzy theory and PSO. The model utilizes the membership function to fuzzify each objective function. Then linearly weighted sums the objective functions with coefficient of variation method and solve the model by PSO algorithm. The simulation results based on the case of a real district show that compared with traditional optimization method, the comprehensive optimization model established in this paper can take each important performance index into account and effectively optimize the dispatch of energy resources of the CCHP system with renewable energy.

Double nodal diameter spectrum (DNDS) method which is used to analyze nodal diameter (ND) components of the vibration modes of impellers with splitters is proposed and its application in quantification of mode localization has been studied. Firstly, ND characteristics of the typical impeller with splitter blades are analyzed by mode shapes and representative subeigenvectors. Secondly, DNDS method is proposed and DNDSs of the representative modes indicate that the tuned modes of impellers with splitter blades contain two ND components. By applying the simplified engine order (EO) excitation in the form of a travelling wave, harmonic response analysis has been carried out by which double nodal diameter vibration characteristics of the structure and the effectiveness of the DNDS method are both validated. Lastly, in terms of quantifying mode localization, the definition of mode localization factor (MLF) is improved based on DNDS. The numerical example proves that the pairing process of choosing the tuned mode corresponding to the mistuned one by utilizing both DNDS and the vibration pattern of blades when calculating the improved MLF could pick out the closest tuned mode to the mistuned one, which has a more explicit physical meaning.

This study deals with guaranteed state estimation of power systems in the bounded-error context, which avoids the effect of inexact matching of the assumed statistical hypotheses on the error. A new approach, based on interval constraint propagation, is proposed to compute guaranteed estimates of state variables and measurements. According to the feature of power systems, two improvements based on interval constraint propagation are presented to improve contraction and obtain narrow interval images. First, a monotonicity-based contractor is exploited because of the monotonicity of measure function to part of state variables. Second, the constraints set are extended by combining the measurement constraints. The improved method is guaranteed, contraction efficient and time efficient. The results, achieved using the proposed method, are compared with those typical existing methods to demonstrate its effectiveness. Tests are carried out on the IEEE 14-bus system and the IEEE 118-bus system, respectively.

Different from other options which usually required strict conditions, a method combining atmospheric oxidization and chemical cleaning with alkali solutions was employed to desulphur coals at temperature around 90 °C. The data show that 66% organic sulphur, 44% sulphide sulphur, and 15% pyrite sulphur were lost when the coal was treated in 0.25 M NaOH at 90 °C, while the solution being aerated at the flow rate of 0.136 m3 h−1. The rate increased to 73% for organic sulphur, 83% for sulphide sulphur and 84% for pyrite sulphur when the previous coal was further treated in acidic solution containing HCl at pH 1 for another hour. The mechanism of desulphurization was explored using inductively coupled plasma mass spectrometry, X-ray photoelectron spectroscopy and infrared. It was found out that the bond of –C S was broken by atmospheric oxygen in basic environment, leading to the lost of organic sulphur in coal. Scanning electron microscope data show that the physical structure of the coal was not adversely affected by the treatment and thermogravimetric analysis results prove that the pyrolysis behavior remained unchanged, indicating that the burning process of the coal would not be adversely affected. Unlike other oxidizing methods, this technique does not lower the heating value of the coal which was manifested by relevant data.

The effect of temperature, pH, the rate and time of oxidation, the concentration of ferrous ion in the starting suspensions as well as the amount of oxidant acting on the process of Fe(3)O(4) synthesis by Fe(OH)(2) suspensions are investigated. After 2h reaction at 90 degrees C under the oxidation of 10 g/L NH(4)NO(3), solution containing 0.25-0.35 mol/L iron(II) ion initially would yield the greatest amount of Fe(3)O(4), up to 95% Fe(3)O(4) could be formed. pH of the solution should be controlled between 9.0 and 11.0. X-ray diffraction (XRD) analysis shows that the product has spinel structure, which indicated that the product is Fe(3)O(4). Transmission electron microscopy (TEM) images show that the crystal size of ferrite is around 0.2 microm. The equilibrium composition of the synthesis reaction of Fe(3)O(4) is optimized by the minimization of the free energy of thermodynamics. It was found that the optimal condition for the synthesis of Fe(3)O(4) obtained through experiment is correspondent with that obtained through computer calculation. In the Fe(3)O(4) formation area given by Kiyama [M. Kiyama, Conditions for the formation of Fe(3)O(4) by the air oxidation of Fe(OH)(2) suspensions, Bull. Chem. Soc. Jpn. 47 (7) (1974) 1646-1650], the content of the product formed is not the same everywhere. The main factor that influences the content of the product is the amount of oxidant.

A heuristic method for estimating the shortest radius of power system security region in node injection space is proposed based on sensitivities of the stability indexes to node injections. The closest boundary of security region in node injection space is approached step by step, and all kinds of power system operating constraints can also be considered. This method has no numerical convergence problem. Theoretically, this method can be used to estimate the shortest radius of all kinds of parameter security regions such as voltage security region, small-signal security region and transient security region, which provides a unified approach to estimate all kinds of power system security regions. Numerical results manifest that the proposed method is valid and effective.

Wet method was employed to the treatment of heavy metal-contaminated wastewater, and Zn(x)Fe(3-x)O(4), Ni(x)Fe(3-x)O(4) and Cr(x)Fe(3-x)O(4) (0x1) were synthesized. Phase identification of the prepared samples was done by X-ray diffraction (XRD), which indicates that the products are spinel-structured; transmission electron microscopy (TEM) images show that crystal size of the ferrite products synthesized is 0.1-0.4 microm. Thermostability of the products was characterized by differential thermal analysis (DTA) and thermal gravimetric analysis (TGA). It was found that when the doped ferrite is qualified, the highest content of doped ion (Zn(2+), Ni(2+) and Cr(3+)) that could enter ferrite lattice is: 0.08, 0.049 and 0.02, respectively. At low concentration the capability of doped ions entering ferrite product is Ni(2+) approximately Zn(2+)Cr(3+) and the influence of the three ions on sample thermostability is Zn(2+)Ni(2+)Cr(3+).