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Three groups of composite cementitious materials (CCMs) were prepared by separate grinding, mixed grinding, and cascade grinding using iron and steel solid waste (ISSW) materials (granulated blast furnace slag (GBFS), iron ore tailings (IOTs), steel slag (SS) and desulfurization gypsum (DG)), and the influence on the strength of CCMs was investigated under different water-binder ratios (w/b). Then, the hydration hardening mechanism of the CCMs was revealed via hydration heat analysis, phase composition and structural analysis of hydration products. The results show that the properties of the CCMs prepared by cascade grinding (CGC) is better than that prepared by separate grinding and mixed grinding. When the mass percentage of IOTs and SS in the CGC was 2:3, the mix proportion of CGC is SS+IOTs: GBFS: DG=36:51.5:12.5, mixed with 1.0 % Na2SO4 and 1.2 % Na2SiO3ˑ9 H2O of the CGC, the compressive strength (CS) of mortar sample containing CGC in 28-days and 180-days reach 52.3 MPa and 70.7 MPa respectively under the conditions of standard curing and low water-binder ratios. The hydration degree of pure cement is higher than that of CGC, but types of the hydration products were similar with cement, mainly were Ca(OH)2, iolite, ettringite (AFt) and C-S-H gel. The CGC can greatly reduce the hydration heat of CCMs system in early age, and is suitable for massive concrete structures in which elevated temperature can be kept for a long time.

Abstract Traditional magnetic sub-Kelvin cooling relies on the nearly free local moments in hydrate paramagnetic salts, whose utility is hampered by the dilute magnetic ions and low thermal conductivity. Here we propose to use instead fractional excitations inherent to quantum spin liquids (QSLs) as an alternative, which are sensitive to external fields and can induce a very distinctive magnetocaloric effect. With state-of-the-art tensor-network approach, we compute low-temperature properties of Kitaev honeycomb model. For the ferromagnetic case, strong demagnetization cooling effect is observed due to the nearly free Z 2 vortices via spin fractionalization, described by a paramagnetic equation of state with a renormalized Curie constant. For the antiferromagnetic Kitaev case, we uncover an intermediate-field gapless QSL phase with very large spin entropy, possibly due to the emergence of spinon Fermi surface and gauge field. Potential realization of topological excitation magnetocalorics in Kitaev materials is also discussed, which may offer a promising pathway to circumvent existing limitations in the paramagnetic hydrates.

【Objective】There is a problem that traditional unrepeatered transmission system need to use disturbed Raman amplifier and remote optical pump amplifier, while both of these two amplifiers need to use high power pump laser which will increase the complexity of fiber link in unrepeatered transmission system. In this paper, we propose a new structure of unrepeatered transmission system using Erbium Doped Optical Fiber Amplifier (EDFA) to replace the forward disturbed Raman amplifier.【Methods】We analyze and compare the performance of the proposed unrepeatered transmission system, and realize a real-time unrepeatered transmission experiment with the proposed structure.【Results】The results show that the gain effect of forward Raman pump in traditional unrepeatered communication system can be achieved by using high power amplifier to increase the signal launch power, and the new structure of unrepeatered transmission system is more suitable to achieve higher bitrate with the help of Wavelength Division Multiplexing (WDM) technology. We confirm the unrepeatered transmission system can achieve 500 km span distance at 10 Gbit/s bit rate in single channel communication transmission, and 500 km span distance at 4×10 Gbit/s bit rate in the WDM technology.【Conclusion】The proposed unrepeatered transmission system can simplify the traditional unrepeatered transmission system, and increase the bit rate by using multi-channel WDM system with EDFA. It has important practical significance to simplify the structure and improve the bit rate in future unrepeatered transmission system.

In this study, a composite modifier (CMCDL) containing coal gasification residue, dicyandiamide waste slag, and lake sediments was used to modify steel slag at high-temperature. Five kind of raw materials was analyzed in physicochemical properties, mineral composition and microstructure, cementitious properties and soundness, and particle size analysis, the same to steel slag after high-temperature modification (SHTM). The new mineral phases were found that tricalcium aluminate (C3A), gehlenite (C2AS), magnetite (Fe3O4), spinels (MgFe2O4), quartz (SiO2), celite (C6AF2) and diopside (CMS2) formed in the SHTM when the mass fraction increase from 10% to 30% in CMCDL. The HTM with CMCDL increases the glass phase and hydrated mineral (C3A, C3S, C2S) and in raw steel slag, promoting the disassembled of RO phase, turning the phase from FeO into MgFe2O4 and Fe3O4. MgFe2O4 and Fe3O4 have similar crystal structures, and they form mixed spinels. When the content of CMCCL (coal gasification residue: dicyandiamide waste slag: lake sediments =7:9:4) is 20%, the temperature is 1250 °C, result showed that the mass fraction of f-CaO in SHTM using CMCCL decreases from 4.81% to 1.86%, with a decrease of 61.3%, the 28-day activity index of SHTM increases up to 17.6% compared with raw steel slag, reaching 86.2%. Therefore, the CMCDL-blended SHTM can be applied harmlessly in cement and concrete, enabling low-energy fine grinding of steel slag.

Abstract Quantum loop and dimer models are prototypical correlated systems with local constraints, which are not only intimately connected to lattice gauge theories and topological orders but are also widely applicable to the broad research areas of quantum materials and quantum simulation. Employing our sweeping cluster quantum Monte Carlo algorithm, we reveal the complete phase diagram of the triangular-lattice fully packed quantum loop model. Apart from the known lattice nematic (LN) solid and the even $${{\mathbb{Z}}}_{2}$$ Z 2 quantum spin liquid (QSL) phases, we discover a hidden vison plaquette (VP) phase, which had been overlooked and misinterpreted as a QSL for more than a decade. Moreover, the VP-to-QSL continuous transition belongs to the (2 + 1)D cubic* universality class, which offers a lattice realization of the (fractionalized) cubic fixed point that had long been considered as irrelevant towards the O(3) symmetry until corrected recently by conformal bootstrap calculations. Our results are therefore of relevance to recent developments in both experiments and theory, and facilitate further investigations of hidden phases and transitions.

【Objective】With the continuous advancements in satellite and communication technologies, the integration of space laser communication and ranging technology becomes more mature. As deep space exploration, satellite navigation, and other fields continue to develop, there is a growing demand for higher communication capacity and ranging accuracy between satellites. Thus, the need to achieve laser satellite high-speed communication while completing ranging and further improving ranging accuracy, under the premise of considering satellite payload and power consumption, has become an urgent issue.【Methods】This article designs and implements a coherent communication and ranging integrated system that supports both QPSK and BPSK, based on the principle of dual one way ranging. To further improve the ranging performance, the differential time sampling method is used to obtain the frequency difference and phase difference between the sending clock and the receiving clock through frequency and phase discrimination, thereby achieving higher clock accuracy and correcting the ranging value.【Results】The system can operate stably in an environment where the received optical power is greater than-48 dBm. Different rates can be set for different application requirements, with a maximum rate of 5 Gbit/s in QPSK mode and rates of 2.5 Gbit/s, 1.25 Gbit/s, and 625 Mbit/s in BPSK mode. The theoretical ranging accuracy of the system can reach a minimum of 53 ps. In normal communication, using Matlab and Vivado to calculate and process ranging data, the ranging accuracy of the system is verified to be less than 0.1 ns. Furthermore, using the differential time sampling method under simulation conditions, the ranging accuracy can be improved to the order of 10-3 of the symbol width, reaching±0.36 cm.【Conclusion】The proposed communication and ranging integrated system can achieve high-precision ranging while achieving high-speed communication, which is of practical significance for future applications of laser satellites.

AIM: To investigate the effects of hypobaric hypoxia in plateau on tear indexes and related anatomical structures in rabbits.METHODS: A total of 18 healthy New Zealand rabbits were selected and randomly divided into plateau group and control group, with 9 rabbits(18 eyes)in each group. The plateau group was housed in the Simulated Climate Cabin for Special Environment of Northwest of China, simulating hypobaric hypoxia at an altitude of 6 000 m. The control group was housed in a clean animal room with atmospheric pressure and oxygen. Changes in the tear meniscus height and non-invasive tear break-up time were detected by using RHCT-1 corneal topographer dry eye comprehensive analysis system, changes in tear secretion was measured by Schirmer Ⅰ test, before intervention and on the 3, 7 d, 2 and 4 wk. Meanwhile, the changes in tear composition before and after intervention in the plateau environment were analyzed using Raman Spectroscopy. The histopathological changes of the lower lid conjunctiva, cornea, lacrimal gland, and Hardarian gland were observed by hematoxylin-eosin(HE)staining after 4 wk of intervention, and the expression of mucin 5AC(MUC5AC)in conjunctiva was detected by immunohistochemistry.RESULTS: Compared with the control group, Schirmer Ⅰ test, tear meniscus height, first and average non-invasive tear break-up time in the plateau group decreased significantly since 3 d, and the difference was significant with the extension of observation time(P

IntroductionLung image segmentation plays an important role in computer-aid pulmonary disease diagnosis and treatment.MethodsThis paper explores the lung CT image segmentation method by generative adversarial networks. We employ a variety of generative adversarial networks and used their capability of image translation to perform image segmentation. The generative adversarial network is employed to translate the original lung image into the segmented image.ResultsThe generative adversarial networks-based segmentation method is tested on real lung image data set. Experimental results show that the proposed method outperforms the state-of-the-art method.DiscussionThe generative adversarial networks-based method is effective for lung image segmentation.

With the sustained growth of renewable energy, the flexibility of the power system has emerged as a critical indicator, influenced by frequent peak regulation. However, a dilemma exists between maximizing flexibility and optimizing economy, and a multi-objective optimization can serve as means of coordinating conflicts. In this study, condensing cogeneration units equipped with a molten salt heat storage system is research object, an optimization model for day-ahead scheduling is established, with flexibility and economy as the primary optimization objectives. To account for various constraint condition such as unit ramp rate, unit output and thermoelectric coupling properties, an enhanced version of the non-dominated sorting genetic algorithm-Ⅱ (NSGA-Ⅱ) is proposed to efficiently solve the optimization problem of a molten salt heat storage system. Flexibility and economy are used to compare and analyze the non dominated solution set obtained from the Pareto front. At the same time, the heat storage and release characteristics of a molten salt heat storage system are analyzed. The findings reveal that a focus on flexibility necessitates great motten salt heat storage to manage insufficient heating during low-load operations. Conversely, an emphasis on economy leads to frequent adjustments in heat storage to maintain optimal unit performance.

The surface of large structural components is composed of materials with different hardness and complex shapes, and it presents significant challenges in achieving precise and efficient positioning as well as high-precision grinding. In-situ processing machine overcomes the limitations of grinding machines such as poor adaptability to different materials and limited travel, and becomes a promising solution for efficient processing of large complex structural components. In-situ processing machine is composed of car, positioning and different processing devices. The positioning mechanism with full-symmetrical layout in parallel topology can effectively guarantee the positioning accuracy and machining stiffness, and is the best scheme for in-situ machining mechanism. Aiming to provide a novel topology structure for subsequent mechanism development. This paper carries out theoretical research on the composition of its topological structure. As an efficient configuration synthesis theory combining numerical and geometrical aspects, finite and instantaneous screw (FIS) theory is applied in this paper. Firstly, the required motions for the grinding operation are characterized based on finite screw, representing the desired motion of the mechanism. Then, single-degree-of-freedom factors are added afterwards to obtain the standard type of the limb structure. Secondly, the factors in the standard type are equivalent transformations and displacements based on the properties of screw triangle product to obtain the derivative and expanded types of limb structure. The feasibility is verified through the synthesis algorithm or transformation properties of finite screw. Finally, taking three feasible limb structures as examples, three fully-symmetrical parallel positioning mechanisms are configured based on assembly conditions and actual requirements. This paper presents a configuration synthesis process for the fully-symmetrical parallel positioning mechanism, obtaining various new topology structures and laying a theoretical foundation for subsequent research.

Traditional aluminum alloys are unsuitable for structural use above 200 ℃ due to precipitate coarsening or dissolution. Laser powder bed fusion (LPBF) additive manufacturing technique enables fabricating novel aluminum alloys with enhanced high-temperature properties. This study focuses on investigating the mechanical properties and microstructural evolution of a novel LPBF-fabricated Al-Cu-Li-Sc-Zr alloy at elevated temperatures. The microstructure is characterized by nano-scale grains and precipitates. Excellent grain structure and precipitate stability result in superior high-temperature mechanical properties. This study advances additively manufactured aluminum alloy design for potential high-temperature applications, offering valuable insights into their behavior in extreme environments.

Lattice structures are crucial for weight reduction, and laser powder bed fusion (LPBF) is an efficient fabrication method. However, there's a notable research gap in understanding the residual deformation of LPBF-fabricated lattice structures. This study investigates the residual deformation of three basic lattice structures, body centre cell (BCC), face centre cell (FCC), and diamond cell (DC), fabricated via LPBF to reveal their deformation mechanisms. Analysis covers horizontal direction, building direction, and total deformations, unveiling complex structural responses. Lower relative densities exhibit a prevalent structural deformation mode (SDM) causing significant deformations, while higher densities shift to an intrinsic deformation mode (IDM) dominated by contraction during fabrication. The FCC structure shows optimal stability with minimal residual deformation across most densities. This study offers insightful findings and a detailed mechanistic analysis of residual deformation in LPBF-fabricated lattice structures, applicable across various configurations, ensuring design process uniformity and reliability.

Due to the differences in the treatment methods of the electron–ion interaction and the critical strain mode of the transition from semimetals to semiconductors, the corresponding strain modulation mechanism in layered bismuth (Bi) crystals remains elusive. In this work, the effects of van der Waals (vdW) correction on the crystal structure and electrical properties of Bi in an equilibrium/strained state are comparatively studied based on the density functional theory. It is found that vdW corrections can better describe the layered crystal and bandgap structure of Bi under equilibrium/strain conditions. With the vdW modification, bismuth can be converted from a semimetal to a semiconductor within a small compression range that is experimentally available. This transition is induced by the transfer of the conduction band minimum and the valence band maximum and is related to the competition of the near-band edge energy state near the Fermi level of bismuth. The present results not only provide guidance for the accurate study of the crystal structure and electronic properties of complex model systems, such as Bi or Bi-based inherently nanostructured materials, but also reveal strain regulation mechanism of Bi and predict its potential application in the semiconductor electronic devices.

To satisfy the requirements of large workspace, high capability, and low inertia demanded by the high precision and high stiffness aerospace equipment, serial manipulator with insufficient intersection joints is proposed in this article based on finite and instantaneous screw theory. Due to the specific topology structure with no intersecting joints at both ends, the explicit solution of forward and inverse kinematics for the serial manipulator with insufficient intersection joints proposed in this article is extremely difficult. Therefore, an analytical method based on finite and instantaneous screw theory is proposed for this serial manipulator, and the explicit kinematic solution is derived in this article. According to particular calculation principle of finite and instantaneous screw theory, the finite motion of this serial manipulator is described. Based on this description, the product of exponentials formula of the kinematics of the serial manipulator with insufficient intersection joints is established on the basic of finite and instantaneous screw theory for the first time, and a novel subproblem is arose during the decomposition of product of exponentials formula. Regarding this issue, an innovative approach to this subproblem is proposed by introducing the new Paden–Kahan subproblem with elimination, and the explicit solution for the inverse kinematics is derived. Finally, the numerical examples are simulated, and the correctness of the method proposed in this article is verified.

Interventional ultrasound (IUS) is an important branch of modern minimally invasive medicine that has been widely applied in clinical practice due to its unique techniques and advantages. As a relatively emerging field, IUS has progressed towards standardization, precision, intelligence, and cutting-edge directions alone with more than 40 years of development, which is becoming increasingly important techniques in clinical medicine. This article will briefly review the development and advancement of IUS for diagnosis and treatment in China in the era of precision medicine from the aspects of artificial intelligence, virtual navigation, molecular imaging, and nanotechnology.

Support structures are widely used in laser powder bed fusion (LPBF) for overhanging features. However, the majority of works carried out on support modeling were to obtain the best trade-off between production time, cost, and accuracy. A notable absence in the existing literature pertains to investigate support structure modeling for optimizing heat dissipation and residual stresses for improving the support structure, thus, enhancing the final part quality. In this study, the effects of the support structure on residual stress were investigated systematically. The influences of the support on residual stress in LPBF sample were categorized into the effect of the constraints and heat conduction area. The rigidity and area of the support structure are used to describe the effect of the support structure on the residual stress. The results showed that the constrain of LPBF samples mainly depends on their inherent characteristics, with limited impact from external constraints. The residual stress in the samples increased as the support area increased. Therefore, when designing the support, priority should be given to reduce its thermal conductivity area. In addition, the hardness of the support added sample were lower than that of the sample without the support, but the hardness distribution is uniform along the deposition height regardless of whether the support is added or not. Therefore, the introduction of support does not result in performance irregularities along the sample height direction.

Objective To understand the current status of surgical treatment for hemophilia osteoarthropathy (HO) in China.Methods Using an online questionnaire, select domestic hospitals that partici-pated in the compilation of the 'Guideline for perioperative management of hemophilia patients undergoing orthopaedic surgery in China ', in addition to members of the National Joint Surgery Group, and the Orthopedic Branch of the Chinese Medical Association for targeted investigation and analysis.Results A total of 17 domestic hospitals were included, all of which were general hospitals. Hospitals that started HO surgery treatment before 2000 accounted for 35.29%. A total of 3057 surgical cases of HO were reported by those hospitals. The most commonly performed surgical procedures were hip and knee joint replacement. The most commonly used coagulation factor replacement regimen was recombinant coagulation factor preparation. Ten hospitals reported finding patients with transfusion-related infectious diseases. Bleeding and hematoma formation were the most frequently reported surgical complications. Excessive length of hospital stay and high economic costs were the most frequently reported problems.Conclusions Surgical treatment for HO in 17 hospitals is mainly carried out in some large comprehensive medical centers in the eastern region. Compared with the patient base, the popularity and number of surgeries are still relatively insufficient. It is necessary to further standardize the treatment system by standardizing factor replacement and strengthening rehabilitation to improve surgical treatment outcomes.

In order to meet the growing requirements of users for wireless services in various scenarios, highly densely deployed wireless local area network(WLAN) will be developed. However, due to the limited frequency resources, there must be a large number of wireless access points(APs) in the same channel. But APs which are located in the same channel will interfere with each other, resulting in a decline in the fairness of throughput in the network. And it can not provide users with good quality of service. In order to improve the fairness of throughput and experience of users, it is necessary to formulate the reasonable network parameter adjusting methods. A method based on neural network and genetic algorithm is proposed. The neural network is used to build the relationship between the parameters of WLAN and the fairness of throughput. The trained model is used as the fitness evaluation function of the genetic algorithm. And the genetic algorithm is used to solve the optimization parameter combination configuration to improve the fairness of throughput in WLAN. Simulation results show that the present algorithm can improve the fairness of throughput in the whole network.

Abstract The Mermin-Wagner theorem states that spontaneous continuous symmetry breaking is prohibited in systems with short-range interactions at spatial dimension D ≤ 2. For long-range interactions with a power-law form (1/r α ), the theorem further forbids ferromagnetic or antiferromagnetic order at finite temperature when α ≥ 2D. However, the situation for α ∈ (2, 4) at D = 2 is not covered by the theorem. To address this, we conduct large-scale quantum Monte Carlo simulations and field theoretical analysis. Our findings show spontaneous breaking of S U(2) symmetry in the ferromagnetic Heisenberg model with 1/r α -form long-range interactions at D = 2. We determine critical exponents through finite-size analysis for α

Bi2212 high-temperature superconducting films (HTSFs) have garnered significant interest as a potential material for the development of high-Tc microwave and terahertz (THz) devices due to their intrinsic Josephson effect. This work presents the utilization of the polyvinyl pyrrolidone (PVP) -assisted sol-gel dip coating (PSGDC) method for the large-scale production of Bi2212 HTSFs. Initially, Bi2212 HTSFs were prepared on a small-scale single crystal (001)-oriented SrTiO3 substrates, and comprehensive characterization of their phase purity, crystal structure, surface morphology, microstructure, stress state, and transport properties was conducted as a foundation for further analysis. By optimizing the crystallization conditions and PVP content, the Bi2212 HTSF achieved improved performance, including a higher onset superconducting transition temperature (Tc, onset) of 94 K, zero-resistance temperature (Tc, zero) of 86 K, and a critical current density (Jc) of 6.8 × 104 A/cm2 under a zero magnetic field at 2 K. Subsequently, the optimized process was applied to successfully prepare a large-scale Bi2212 HTSF with a diameter of 50 mm, exhibiting uniform phase composition, surface morphology, and superconducting properties, expanding the potential applications of Bi2212 HTSFs.

Objective: For enhancing the flavor characteristics and nutritional value of crayfish balls, and enriching the diversity of crayfish processed products. Methods: Determined the process of preparing the enzymatic hydrolysate from crayfish shell using compound enzymatic by single-factor and orthogonal array design. The nutritional quality of crayfish whole balls containing enzyme hydrolysate lyophilized powder and crayfish meat was analyzed. Results: The optimum condition for the preparation of crayfish shells enzymatic hydrolysate solution showed that 1 g crayfish shells powder with 0.5 mL of lactic acid was pretreated at 60 ℃ for 40 min. The dosage of compound enzymatic （papain and flavor protease mass ratio was 3∶1） was 5% （mass fraction）, the enzymatic hydrolysis temperature was 60 ℃, time was 4 h, and solid/liquid ratio was 1∶100 （g/mL）, and the protein extraction efficiency in the enzymatic hydrolysis was 64.69%. The content of heavy metals in enzyme hydrolysate lyophilized powder was in line with the limit of heavy metals in aquatic products, and contains calcium, magnesium, iron, selenium and other macro and trace elements required by the human body. Its composition analysis showed that the enzymatic hydrolysate lyophilized powder had a certain nutritional value, which could increase the fresh flavor of the food and met the safety standards. The nutrition and texture analysis of crayfish balls showed that the crayfish whole balls had high protein content, rich in a variety of amino acids, comprehensive in nutrition, unique flavor, and with good viscoelasticity and chewiness. Conclusion: The crayfish whole balls added with crayfish shell enzyme hydrolysate lyophilized powder and crayfish meat have a certain nutritional value, which enriches the variety of crayfish ready-to-eat products, improves the utilization rate of whole crayfish.

ObjectiveTo provide a scientific basis for formulating prevention and control strategies， the epidemic characteristics of mushroom poisoning in Guizhou Province from 2011 to 2021 were analyzed.MethodsA descriptive analysis of mushroom poisoning incidents reported to the surveillance system of foodborne disease outbreaks was conducted in the Guizhou Province from 2011 to 2021.ResultsA total of 1 527 cases of mushroom poisoning were reported in Guizhou province from 2011 to 2021， including 5 312 cases and 95 deaths， with a fatality rate of 1.79%. The largest number of reports was published in 2020. A high incidence was observed in the second and third quarters. The poisoning place mainly occurred in the family. Fifty-five deaths incidents were reported.ConclusionMushroom poisoning is one of the most reported and fatal foodborne diseases in Guizhou Province， with the highest incidence in rural families. Effective publicity and education should be provided for rural families to reduce mushroom poisoning incidences in Guizhou Province.

Recently, Radio over Fiber (RoF) technology has become a hot research topic in the broadband communication access network field and has attracted much attention in the industry. This is mainly because the technology makes full use of the massive bandwidth of optical fiber transmission and the application advantages of flexible coverage of wireless communication. In the evolution and development of RoF technology, multi-dimensional multi-order modulation has important scientific research significance and practical value because it can improve the system bandwidth utilization and reduce the signal transmission and receiving cost. This paper summarizes the research progress of traditional amplitude modulation, typical multi-dimensional multi-order modulation and some representative new multi-dimensional multi-order modulation technologies. We also briefly analyzes the application prospect of multi-dimensional multi-order modulation technology in RoF system.

Abstract The success of any educational organization depends heavily on the effectiveness of its teachers, who are tasked with transferring knowledge, supervising students, and enhancing the standard of instruction. Teachers’ job satisfaction has a significant impact on the lessons they teach since they are directly involved in transferring knowledge to students. In order to determine the effect of teachers’ job satisfaction (TJS) on students’ accomplishments, the researchers sought to analyze the empirical studies conducted over the previous 12 years (SA). To determine the characteristics that link to instructors’ job satisfaction and their effect on students’ achievement, thirty-two empirical studies were examined. The analysis of world-wide empirical research findings shows four types of results: (i) In some countries, teachers’ job satisfaction is low, but students’ achievement is high (Shanghai, China, South Korea, Japan, Singapore) (ii) In some countries, teacher job satisfaction is high, but student achievement is low (Mexico, Malaysia, Chile, Italy). (iii) In some countries, teachers’ job satisfaction is high, and so is student achievement (Finland, Alberta, Canada, Australia). (iv) In some countries, teacher job satisfaction is low, which has a negative impact on student achievement (Bulgaria, Brazil, Russia). In sum, irrespective of countries, highly satisfied teachers give their best to their students’ success, not only by imparting knowledge but also by giving extra attention to ensure the better achievement of each student. The review of this study makes it even more worthwhile to reflect on the need to avoid stereotypical considerations and assessments of any objective presentation of the phenomenon and to reflect more deeply on the need to assess the validity of the relationship study.

The power unit on board the ship generates periodic low-frequency vibration that affects the normal operation of the equipment on board, and the adaptive feedforward control algorithm can effectively suppress such harmful vibration noise. But the adaptive feedforward control algorithm needs to obtain the identification model of the secondary channels, and the frequency domain least squares method based on the linear Extended auto-regressive model (ARX) is difficult to obtain the identification model with nonlinear characteristics. The nonlinear auto-regressive model (NARX) adds nonlinear mapping layers to the topology of the ARX model to enhance the identification capability of the NARX model for complex systems. In this paper, a block diagram of the Fx-LMS feedforward control algorithm based on the NARX model is proposed, then the initial parameters of the NARX neural network are optimized using the Quantum Particle Swarm Optimization (QPSO) algorithm and the secondary channel is identified, and the identification results show that the accuracy of identifying the secondary channel using the NARX neural network is higher than that of the ARX model. The simulation and experimental results show that the vibration damping effect of the proposed method is better than the traditional Fx-LMS method for both single-line spectrum and multi-line spectrum periodic low-frequency disturbances, which provides a new method for the suppression of periodic low-frequency disturbances.

Abstract Complete regeneration of damaged tissues/organs has always been the ultimate challenge in regenerative medicine. Aging has long been considered the basis of age‐related diseases, as senescent cells gradually accumulate in tissues with increasing age, tissues exhibit aging and normal physiological functions are inhibited. In recent years, in damaged tissues, scholars have found that the number of cells with features of cellular senescence continues to increase over time. The accumulation of senescent cells severely hinders the healing of damaged tissues. Furthermore, by clearing senescent cells or inhibiting the aging microenvironment, damaged tissues regained their original regenerative and repair capabilities. On the other hand, various biomaterials have been proved to have good biocompatibility and can effectively support cell regeneration after injury. Combining the two solutions, inhibiting the cellular senescence in damaged tissues and establishing a pro‐regenerative environment through biomaterial technology gradually reveals a new, unexpected treatment strategy applied to the field of regenerative medicine. In this review, we first elucidate the main characteristics of senescent cells from morphological, functional and molecular levels, and discuss in detail the process of accumulation of senescent cells in tissues. Then, we will explore in depth how the accumulation of senescent cells after damage affects tissue repair and regeneration at different stages. Finally, we will turn to how to promote tissue regeneration and repair in the field of regenerative medicine by inhibiting cellular senescence combined with biomaterial technology. Our goal is to understand the relationship between cellular senescence and tissue regeneration through this new perspective, and provide valuable references for the development of new therapeutic strategies in the future.

To simplify the structure of real-time coherent Free-Space Optical (FSO) / wireless systems and reduce costs, this paper implements a low-cost FSO system based on bandpass Delta-Sigma Modulation (DSM) technology. A 256-ary Quadrature Amplitude Modulation (256-QAM) signal with a bandwidth of 400 MHz and a rate of 1.6 Gbit/s is generated to realize a 10 Gbit/s Polarization Division Multiplexed-Quadrature Phase Shift Keying (PDM-QPSK) signal after DSM. The real-time transmission in a 50 m FSO link with a sensitivity of -46.2 dBm is achieved. The experimental results indicate that the combination of coherent detection and DSM is a promising technology for future optical wireless scenarios.

In order to minimize the maximum weighted response time for any node in the network to reach the central control node, a central control node election algorithm based on dynamic programming is proposed. Firstly, the response times of nodes and links in the wireless network are modeled as the node weights and edge weights in the network topology, and then the central control node election problem that minimizes the maximum weighted response time for any node in the network to reach the central control node is modeled as the central problem, where represents the number of central control nodes. Then, by using the interpolation method based on dynamic programming, the weighted response time between the two points can be obtained, and the K-central problem modeled is transformed into several R-control set problems. Then, several control R-set problems are transformed into several 0-1 integer programming problems, and each integer programming problem can be solved one by one by using the branch and bound method. Finally, a simplified implementation method based on the above algorithm is given when K=1, the optimality of the proposed algorithm is proved and the complexity of the algorithm is analyzed. Simulation results show that the proposed central control algorithm can minimize the maximum weighted response time of the network.

Driven by the significant demand for space control mechanism in the development of national space field, topology synthesis method for the hybrid mechanism based on finite and instantaneous screw (FIS theory) is studied in this paper. The number and types of degrees of freedom (DOF) required for capturing, detumbling, screwing and plugging control tasks are analyzed in depth, and the simplest mathematical expression of continuous motion corresponding to space control tasks are formed. According to the requirements of space control task, the synthesis principle of serial and parallel mechanism is proposed, and the arrangement principle of expected motion pattern is summarized. The standard limb is analytically characterized based on the expected motion pattern, and derivative limbs satisfying the expected motion pattern are derived based on joint equivalent transformation. By determining assembly conditions, the available topological structures satisfying the requirements of space control tasks are generated. Based on serial and parallel mechanisms that satisfy design principles, the simplest analytical expression of the topology of hybrid space control mechanism is obtained using finite screw principle. The general topology synthesis method of hybrid mechanisms is established, and various topological structures of hybrid space control mechanism are obtained, which lays a foundation for the research and development of novel hybrid space control mechanisms.

To track moving targets and signals in space, multiple characteristics as large orientational workspace and excellent kinematic performance are required for the satellite antenna driving mechanism. Due to variable orientational center and axes, the 3-RSR mechanism is capable of 1T2R with continuous workspace and becomes a promising solution for the satellite antenna driving mechanism. Influenced by the topological structure characteristics as none fixed orientation center and axes, the performances of 3-RSR mechanism are significantly impacted by the parameter perturbation. According to the differential mapping between finite screw and instantaneous screw, the structure, kinematics, performance, and optimization are unified under the FIS theory. To be applied for the satellite antenna driving mechanism, this paper carries out the multi-objective optimization of 3-RSR mechanism under the influence of parameter perturbation based on the FIS theory. Firstly, the orientational workspace is obtained by finite screw and the instantaneous motion description of the mechanism is derived through calculation principle of FIS theory. Secondly, the orientational workspace and kinematics indices of the mechanism are proposed towards the actual requirements of the satellite antenna driving, and the relationship with the parameters is established. The discrete operation becomes extremely complex owing to parameter perturbation, and the RSMs (response surface model) of indices without considering and considering parameter perturbation are modeled. The multi-objectives optimization of 3-RSR mechanism influenced by parameter perturbation is carried out and its Pareto frontier is obtained. Finally, a point preferred strategy is proposed and the optimum value of the parameter from Pareto frontier is selected.

To meet the requirements of high flexibility, high stiffness, and large working range of space debris cleaning technology, a foldable composite space capture mechanism is proposed based on the finite screw theory in this paper. The degree of freedom of the mechanism is analyzed by using the screw theory and its degree of freedom is obtained. The closed-loop vector method and DH method are used to analyze the kinematics of the mechanism, and the position solution of the mechanism is derived. The analytical expressions of velocity and acceleration solutions are obtained by differential calculation. According to the analysis of numerical example, the kinematic model of the mechanism is built in the simulation environment, and the simulation experiment is carried out for the motion trajectory of the mechanism. The correctness of theoretical analysis solution and method is proved by contrasting and analyzing motion trajectory, and it is verified that the space capture mechanism uses the foldable property to form large workspace to complete the capture of the target.

Steel slag (SS) is a kind of industrial solid waste, and its accumulation brings certain harm to the ecological environment. In order to promote the building material utilization of SS, high-temperature modification (HTM) of SS is performed using a composite modifier (CMSFR) containing silicon calcium slag (SCS), fly ash (FA), and reservoir sediment (RS). Then, the authors investigated the effect of CMSFR on the cementitious properties and volume soundness of SS mixture after HTM (SMHTM). After that, the mineral composition and microstructure of SMHTM were investigated through X-ray fluorescence analysis (XRF), X-ray diffraction (XRD), scanning electronic microscopy (SEM), energy dispersive spectrometry (EDS), and particle size analysis. It was found that the free CaO (f-CaO) content obviously decreased, and the cementitious properties improved in SMHTM. When the CMSFR content was 20% (SCS: FA: RS = 9:7:4), and the modification temperature (MT) was 1,250°C, the mass fraction of f-CaO in SMHTM dropped from 4.81% to 1.90%, down by 60.5%; the 28-day activity index of SMHTM increased to 85.4%, 14.3% higher than that of raw SS, which meets the technical requirement of Steel slag powder used for cement and concrete (GB/T 20491-2017): the activity index of grade I SS powder must be greater than or equal to 80%. As the mass fraction of CMSFR grew from 10% to 30%, new mineral phases formed in SMHTM, including diopside (CMS2), ceylonite (MgFe2O4), gehlenite (C2AS), tricalcium aluminate (C3A), and magnetite (Fe3O4). The HTM with CMSFR promotes the decomposition of RO phase (a continuous solid solution composed of divalent metal oxides like FeO, MgO, MnO, and CaO) in raw SS, turning the FeO in that phase into Fe3O4. The above results indicate that the SMHTM mixed with CMSFR can be applied harmless in cement and concrete, making low-energy fine grinding of SS a possibility.

In order to maintain the stability of the transmitter to ensure the quality of the output signal, we propose a novel technique of automatic bias control based on the pilot signal that can be used in high-order modulation formats. The proposed scheme requires loading a pair of orthogonal pilot signals to the modulator and tapping the frequency-shifted local oscillation light with the signal light output from the modulator to achieve coherent detection. The control of the bias voltage is achieved by means of correlation operation and monitoring the value of the correlation coefficient. This scheme combines coherent detection and correlation detection techniques, which can effectively improve the sensitivity and control accuracy of the system. The feasibility of this scheme in high-order modulation systems and the improvement of sensitivity are also fully verified by simulation.

Objective To evaluate the application effect of integrated interventions on improving the ultrasound examination rate of early pregnancy in Tibetan primary hospitals. Methods The status of fetal ultrasound examination in women with early pregnancy admitted to Department of Obstetrics and Gynecology of the People’s Hospital of Chaya County in Tibet was investigated. The causes for the low ultrasound examination rate during early pregnancy were analyzed, and corresponding measures were formulated. The differences in ultrasound examination rate of early pregnancy and awareness rate of ultrasound knowledge were statistically compared before and after integrated interventions. Results After the integrated interventions, the ultrasound examination rate of early pregnancy was increased from 30.3% （96/317） to 70.7% （65/92）, and the difference was statistically significant （P < 0.01）. The awareness rate of ultrasound knowledge during early pregnancy was increased from 24.0% to 76.1%, and the difference was statistically significant （P < 0.01）. Conclusion Integrated interventions can effectively improve the ultrasound examination rate during early pregnancy and pregnant women’s awareness rate of ultrasound knowledge in primary hospitals from Tibetan areas.

Background: To explore the correlations of cofilin1 (CFL1) and phosphorylation level of locus serine residue at position 3 (Ser3) with the sensitivity of elderly patients with non-small cell lung cancer (NSCLC) to radiotherapy.

Abstract Prototypical models and their material incarnations are cornerstones to the understanding of quantum magnetism. Here we show theoretically that the recently synthesized magnetic compound Na2BaCo(PO4)2 (NBCP) is a rare, nearly ideal material realization of the S = 1/2 triangular-lattice antiferromagnet with significant easy-axis spin exchange anisotropy. By combining the automatic parameter searching and tensor-network simulations, we establish a microscopic model description of this material with realistic model parameters, which can not only fit well the experimental thermodynamic data but also reproduce the measured magnetization curves without further adjustment of parameters. According to the established model, the NBCP hosts a spin supersolid state that breaks both the lattice translation symmetry and the spin rotational symmetry. Such a state is a spin analog of the long-sought supersolid state, thought to exist in solid Helium and optical lattice systems, and share similar traits. The NBCP therefore represents an ideal material-based platform to explore the physics of supersolidity as well as its quantum and thermal melting.

Dynamics of neural circuits mapping brain functions such as sensory processing and decision making, can be characterized by probabilistic representations and inference. The authors elaborate the role of spatiotemporal neural dynamics for more efficient performance of probabilistic computations.

Objective The exact mechanism of patellofemoral instability has not been clearly clarified. The current study aims to explore the correlation between the tibial tuberosity‐trochlear groove (TT‐TG) distance and other patellar stability parameters. Methods A total of 60 individuals aged 18 to 40 years who underwent knee computed tomography (CT) examination between September 2014 and December 2017 were retrospectively recruited. Five reference sites were selected on the femoral trochlear articular surface in every CT image. The TT‐TG distance and the trochlear groove angles (TGA) at the five reference sites were measured. The patellar ligament length (PLL), patellar length (PL), medial patellar retinaculum length (MPRL) and lateral patellar retinaculum length (LPRL) were quantitatively analyzed. The TT‐TG distances on different knee sides or in different sexes were compared. The relationships between the TT‐TG distance and TGA, PLL/PL, MPRL, and LPRL were analyzed by Spearman's method. Comparison analysis among patellar stability parameters was analyzed using ANOVA or two‐tailed Student's t test. Results Variance analysis revealed no significant differences in the TT‐TG distances among the five positions of the femoral trochlea (F = 0.67, P = 0.62) but significant differences among the five femoral TGAs at the five reference sites (F = 380.37, P

Objective: In order to increase the added value of crayfish by-products. Methods: With chromatographic peaks and peak areas as the inspection indicators, the optimization on equilibrium time, addition of sodium chloride, extraction time and extraction temperature were optimized, and the composition of volatile flavor compounds was analyzed. Results: The optimal extraction conditions were equilibrium time 0 min, extraction temperature 75 ℃, extraction time 50 min, addition of sodium chloride 30% with 50/30 μm DVB/CAR/PDMS solid phase microextraction head. Under these conditions, a total of 34 volatile flavor compounds, including 5 alcohols, 12 aldehydes, 5 alkanes, 5 aromatic, 5 heterocyclic compounds and 2 esters, were detected in the crayfish boiled liquid. The total peak area was 5.54×108, and the comprehensive score was 95.47. The relative error between the experimental results and the predicted value was 4.53%. Conclusion: The 34 volatile flavor compounds can be extracted from the crayfish boiled liquid by headspace solid phase microextraction.

Introduction: The vanadium-titanium iron ore tailings (VTIOTs) has a significant amount of discharge, and serious pollution, which makes it difficult to use directly as a resources resource.Methods: High-strength fired water permeable brick (HSFWPB) was prepared using VTIOTs as the main raw material. The orthogonal test, X-ray diffraction analysis (XRD), scanning electron microscope (SEM), energy dispersive spectrometry (EDS), and synthetic precipitation leaching procedure (SPLP) were obtained to study the basic properties and firing mechanism of HSFWPB containing VTIOTs, and an economic benefit evaluation was conducted on the project investment of HSFWPB containing VTIOTs.Results: The results show that when the content of VTIOTs in HSFWPB is 78%, the firing temperature (FT) is 1080°C and the holding time is 120 min, the compressive strength and permeability coefficient of the fired product reach 70.4 MPa and 0.055 cmˑs−1, respectively, which meet the requirements of Cc60 grade products in Water permeable brick (JC/T 945–2005). The products of HSFWPB containing VTIOTs after firing are diopside (CaMgSi2O6) and augite (Ca (Mg, Fe, Al) (Si, Al)2O6), with the increase of FT and the extension of HT, the low melting point elements of P, Na, K dissolve out, and the content of Fe and Al in the firing products increases, most of Ca2+ in diopside is replaced by Fe3+, so that augite becomes the main crystal phase. With the increase of FT, the pores in the fired products are changed from: closed pores with different sizes→ connected pores with irregular diameters→ irregular collapse pores→ small and uniform circular pores, which provides a guarantee for the permeability of HSFWPB containing VTIOTs.Discussion: The full investment payback period of the project of HSFWPB containing VTIOTs is 1.77 years. When the production reaches 48.585% of the design output, it reaches a breakeven point, and the project has strong risk resistance ability. The research has improved the utilization rate of VTIOTs and provided a new approach for the large-scale application of VTIOTs.

Introduction: In our study, various test methods were adopted to explore the mineralogical characteristics, grindability, particle morphology, particle size distribution, and environmental leaching toxicity of iron ore tailings (lOTs).Methods: The methods include petrographic analysis, X-ray diffraction (XRD), scanning electronic microscopy (SEM), synchronous thermal analyzer (DSC-TGA), electron probe X-ray microanalyser (EPMA), and synthetic precipitation leaching Procedure (SPLP).Results: The results show that the used IOTs contained 14.54% iron which was mainly stored in magnetite and pyrite. The content of iron silicate accounted for 11.82% of the total iron content. Most of it existed in silicate minerals, including grunerite and hornblende. A small amount of iron was contained in biotite, chlorite and augite. Besides, the grindability of lOTs was much better than that of granulated blast furnace slag (GBFS). After grinding for 140 min, the mass fraction of lOTs particles with the particle size less than 5 um was 44.19%. These particles could be used to fill in the voids in the cement-powder-packed structure. lOTs also contained a large number of submicron and nanoscale particles.Discussion: With great strength and environmental friendliness, the composite cementitious material (CCM) prepared from lOTs can be well applied to the building material field and environmental remediation.

Introduction: In order to promote the comprehensive utilization of iron and steel solid waste, steel slag (SS), granulated blast furnace slag (GBFS), and flue gas desulfurization gypsum (FGDG) were used as raw materials to replace cement to prepare the full solid waste premixed solidified agent (PSA). Then PSA, iron ore tailings (IOTs), and water were mixed to prepare building foundation pit backfilling materials (BFPBM).Methods: Various tests were conducted to investigate the effects of SS fineness, SS content and mixing ratio of PSA on the properties of PFPBM, including mechanical property test, X-ray diffraction (XRD), scanning electronic microscopy (SEM), energy dispersive spectrometry (EDS) and synthetic precipitation leaching procedure (SPLP). The stability of the BFPBM was tested and the hydration mechanism of the PSA was analyzed.Results: The results show that when the specific surface area (SSA) of SS is 457 m2ˑkg-1, the paste mass concentration (PMC) is 79%, the mixing ratio of PSA is 20%, and the mix proportion of PSA is SS: FGDG: GBFS = 58:10:32. In this case, water-reducing agent (WRA) accounting for 0.18% of the total amount of PSA is added. The 28d compressive strength of BFPBM is greater than 0.40 MPa with the maximum value of 6.22 MPa, and the mixture slump of BFPBM is greater than 215 mm, which meets the index requirements of Chinese National Standard T/CECS 1037-2022 Technical Standard for Backfilling Project by Using Premixed Fluidized Solidified Soil.Discussion: According to the mechanism study, the mineral phases of the PSA after hydration are: C2S, C3S, Ca (OH)2, ettringite (AFT), C-S-H gel, and RO phase. C2S, C3S, CaSO4 and other substances gradually disappeared with the hydration, while the content of AFt and C-S-H gel substances increased. BFPBM prepared from iron and steel waste has high strength and environmental friendliness, making it have good application prospects in foundation pit backfilling and mine filling.

Introduction: In order to improve the utilization efficiency of industrial waste discharged in the process of iron and steel metallurgy, a kind of material that can replace cement for mine filling is sought. In the test, steel slag (SS) and vanadium-titanium slag (VTS) were used as the primary raw materials to prepare cementing agents (CA). Then, combine it with vanadium-titanium iron ore tailings (VTIOTs) to make mine cemented paste backfill material (CPBM).Methods: The composition, properties and hydration mechanism of CPBM are studied through various tests, in-cluding mechanical property test, hydration heat test, X-ray diffraction (XRD), scanning electronic mi-croscopy (SEM), and fourier transform-infrared spectroscopy (FT-IR).Results: The results show that when the following conditions are met, the slump is 216 mm, and the 28-day flexural strength and compressive strength of CPBM reach 4.25 and 9.41 MPa, respectively, which meets the requirements of Chinese National Standard GB/T 39489-2020 Technical specification for the total tailings paste backfill: the mass percentage SS: VTS: phosphogypsum (PG): dicyandiamide waste slag (DWS) = 31:59:6:4; the content of compound phosphoric acid (CPA) accounts for 4% of the dry material; the cement sand ratio of CPBM is 1:4; the paste mass concentration (PMC) is 80%; and the content of water reducing agent (WRA) is 0.18%.Discussion: Mechanism studies show that the hydration product of the CA is mainly ettringite (AFt) and C-S-H gel. The addition of CPA promotes the hydration of active minerals in SS and VTS. The existence of PG pro-motes the formation of AFt, and the formation of AFt further promotes the fracture of [AlO4]5− and [SiO4]4− along the bridge oxygen in VTS and SS.

We present here a performance comparison of quantum-dash (Qdash) semiconductor amplifiers (SOAs) with three, five, eight, and twelve InAs dash layers grown on InP substrates. Other than the number of Qdash layers, the structures were identical. The eight-layer Qdash SOA gave the highest amplified spontaneous emission power (4.3 dBm) and chip gain (26.4 dB) at 1550 nm, with a 300 mA CW bias current and at 25 °C temperature, while SOAs with fewer Qdash layers (for example, three-layer Qdash SOA), had a wider ASE bandwidth (90 nm) and larger 3 dB gain saturated output power (18.2 dBm) in a shorter wavelength range. The noise figure (NF) of the SOAs increased nearly linearly with the number of Qdash layers. The longest gain peak wavelength of 1570 nm was observed for the 12-layer Qdash SOA. The most balanced performance was obtained with a five-layer Qdash SOA, with a 25.4 dB small-signal chip gain, 15.2 dBm 3 dB output saturated power, and 5.7 dB NF at 1532 nm, 300 mA and 25 °C. These results are better than those of quantum well SOAs reported in a recent review paper. The high performance of InAs/InP Qdash SOAs with different Qdash layers shown in this paper could be important for many applications with distinct requirements under uncooled scenarios.

The Common Public Radio Interface (CPRI) used in mobile fronthaul has low spectrum efficiency. In this paper, we propose to use Delta-Sigma Modulation (DSM) technology as a new fronthaul interface. In addition, to solve the problem of high computational complexity in the parameter searching of high-order stable Delta-Sigma modulator, Genetic Algorithm (GA) is used to search and optimize the structural parameters of the fourth-order Delta-Sigma modulator. The simulation results under the optimized structural parameters are compared with those under the original structural parameters. Under the condition of 1 bit quantization, the Delta-Sigma modulator with optimized parameters increases the transmission capacity of the system while the average Error Vector Magnitude (EVM) decreases from 0.031 to 0.028. In the case of 2 bit quantization, the average EVM decreases from 0.013 to 0.011.

The microstructure evolution and mechanical behavior of an Fe-33Mn-4Si alloy steel under low-cycle fatigue deformation were investigated by using the X-ray diffraction and electron backscatter diffraction techniques.Results show that the experimental steel has an initial microstructure consisting of austenite and thermally induced ε-martensite. The initial microstructure remarkably affects the low-cycle fatigue property of the experimental steel through influencing the ε-martensitic transformation during deformation. At the early stage of fatigue deformation (first 100 deformation cycles), with increasing deformation cycles, a rapid increase in the volume fraction of ε-martensite and the frequency of the intersection of ε-martensite with different variants result in a quick rise in cyclic average peak stress and work hardening degree. With the continuation of cyclic deformation up to fatigue fracture, the ε-martensite becomes the dominant constituent phase in the deformation microstructure, and the volume fraction of ε-martensite and the frequency of the intersection of ε-martensite increase at an appreciably slower rate, thereafter significantly slowing the increase in cyclic average peak stress and work hardening degree.