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Thermal stability improvement and microstructure optimization of high cobalt content Nd-Fe-B magnets via terbium grain boundary diffusion

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Journal of Rare Earths 2024年第8期42卷 1531-1538,I0004页

作者： Jiyuan Xu Ruiyang Meng Jing Liu Jiateng Zhang Rui Han Yikun Fang Shengzhi Dong Wei Li division of Functional Materials research Central Iron and Steel Research InstituteBeijing100081China

The substitution of Fe by Co in the 2:14:1 phase is an effective method to increase the Curie temperature and enhance the thermal stability of the Nd-Fe-B ***,the accumulation of Co ele ment at the grain boundaries(GBs) changes the GBs from nonmagnetic to ferromagnetic and causes the thinlayer GBs to become rare,In this paper,the method of diffusing Tb element was chosen to improve the microstructure and temperature stability of high-Co *** original sintered Nd_(28.5)Dy_(3)-CO_(x)e_(bal)M_(0.6)B_(i)(x=0,6 wt%,12 wt%;M = Cu,Al,Zr) magnets with different Co contents were diffused with Tb by grain boundary diffusion(GBD).After GBD,high-Co magnets exhibit more continuously distributed thin-layer GBs,and their thermal stability is significantly *** high-Co magnets(x=6 wt%),the absolute value of the temperature coefficient of coercivity decreases from 0.603%/K to0.508%/K in the temperature range of 293-413 K,that of remanence decreases from 0.099%/K to 0.091%/K,and the coercivity increases from 18.44 to 25.04 *** electron microscopy(TEM)characterization reveals that there are both the 1:2 phase and the amorphous phase in the high-Co magnet before and after GBD,EDS elemental analysis shows that Tb element is more likely to preferentially replace the rare earth elements in the 2:14:1 main phase than in the 1:2 phase and the amorphous *** concentration of Tb at the edge of the main phase is much higher than that in the 1:2phase and amorphous phase,which is beneficial to the improvement of the *** preferential replacement of Tb elements at the edge of the 2:14:1 phase and thin-layer GBs with a more continuous distribution are synergistically responsible for improving the thermal stability of high-Co *** study indicates that GBD is an effective method to improve the microstructure and thermal stability of high-Co magnets.

关键词： Nd-Fe-B magnets Coercivity Grain boundary diffusion Thermal stability Micro structure Rare earths

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Recent research in mechanical properties of geopolymer-based ultrahigh-performance concrete:A review

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Defence Technology（防务技术） 2024年第2期32卷 67-88页

作者： G.Murali division of research&Innovation Uttaranchal UniversityDehradun 248007India

Due to the growing need for sustainable and ultra-high-strength construction materials,scientists have created an innovative ultra-high-performance concrete called Geopolymer based ultra-highperformance concrete(GUHPC).Besides,in the last few decades,there have been a lot of explosions and ballistic attacks around the world,which have killed many civilians and fighters in border *** this context,this article reviews the fresh state and mechanical properties of ***,the ingredients of GUHPC and fresh properties such as setting time and flowability are briefly ***,the review of compressive strength,flexure strength,tensile strength and modulus of elasticity of fibrous ***,the blast and projectile impact resistance performance was ***,the microstructural characteristics were reviewed using the scanning electron microscope and X-ray Powder *** review outcome reveals that the mechanical properties were increased when 30%silica fume was added to a higher dose of steel fibre to improve the microstructure of *** is hypothesized that the brittleness of GUHPC was mitigated by adding 1.5%steel fibre reinforcement,which played a role in the decrease of contact explosion cratering and *** the need for cement in GUHPC was a key factor in the review,indicating a promising potential for lowering carbon ***,GUHPC research is still in its early stages,so more study is required before its full potential can be utilized.

关键词： Mechanical properties Blast Projectile impact Fibre Geopolymer Silica fume Alkaline activators

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A Novel Prescribed-Performance Path-Following Problem for Non-Holonomic Vehicles

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IEEE/CAA Journal of Automatica Sinica 2024年第6期11卷 1476-1484页

作者： Zirui Chen Jingchuan Tang Zongyu Zuo Seventh research division Beihang University(BUAA)Beijing 100191China IEEE

The issue of achieving prescribed-performance path following in robotics is addressed in this paper,where the aim is to ensure that a desired path within a specified region is accu-rately converged to by the controlled *** this context,a novel form of the prescribed performance guiding vector field is introduced,accompanied by a prescribed-time sliding mode con-trol ***,the interdependence among the pre-scribed parameters is *** validate the effectiveness of the proposed method,numerical simulations are presented to demonstrate the efficacy of the approach.

关键词： Guiding vector field non-holonomic vehicle path following prescribed performance sliding mode control

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High-performance anisotropic SmCo-based magnet with novel microstructure

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Journal of Rare Earths 2024年第8期42卷 1539-1545,I0005页

作者： Yingchang Li Zicao Xing Nengjun Yu Zesong Ren Minxiang Pan Qiong Wu Hongliang Ge Minggang Zhu Wei Li College of Materials and Chemistry China jiliang UniversityHangzhou 310018China division of Functional Materials research Central Iron and Steel Research InstituteBeijing 100081China

A novel micro structure of magnetically anisotropic Sm Co-based magnet with high-performance is *** magnet consists of SmCo_(7)-H(TbCu_(7)-hexagonal type),Sm_(2)Co_(17)-H(Th_(2)Ni_(17)-hexagonal type)and SmCo_(3)-R(SmCo_(3)-rhombohedral type)*** maximum magnetic energy product of the magnet is 231.69 kj/m^(3),and the intrinsic coercivity is 1005.47 kA/*** outstanding intrinsic coercivity temperature coefficient(β)of-0.125%/K between 298 and 773 K is obtained,which is very close to theβof commercial high-temperature Sm_(2)Co_(17)-based sintered *** initial magnetization curve indicates that the coercivity mechanism is controlled by a domain wall pinning *** SmCo_(3)-R lamellar phase may be a potential pinning center or self-pinning *** microstructure of the magnet is different from that of any previous SmCo-based *** findings provide a new idea for preparing high-performance SmCo-based permanent magnets.

关键词： Rare earths Permanent magnet Composite magnet Melt-spinning Microstructure

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Diagnostic and prognostic performances of GALAD score in staging and 1-year mortality of hepatocellular carcinoma: A prospective study

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World Journal of Gastroenterology 2024年第17期30卷 2343-2353页

作者： Oraphan Jitpraphawan Witchakorn Ruamtawee Mala Treewatchareekorn Supatsri Sethasine division of Gastroenterology and Hepatology Department of MedicineNavamindradhiraj UniversityDusit 10300BangkokThailand Clinical research Center Research Facilitation DivisionNavamindradhiraj UniversityDusit 10300BangkokThailand division of Clinical Chemistry and Immunology Navamindradhiraj UniversityDusit 10300BangkokThailand

BACKGROUND The GALAD score has improved early hepatocellular carcinoma(HCC)detection *** role of the GALAD score in staging and predicting tumor characteristics or clinical outcome of HCC remains of particular *** To determine the diagnostic/prognostic performances of the GALAD score at various phases of initial diagnosis,tumor features,and 1-year mortality of HCC and compare the performance of the GALAD score with those of other serum *** This prospective,diagnostic/prognostic study was conducted among patients with newly diagnosed HCC at the liver center of Vajira *** patients had HCC staging allocation using the Barcelona Clinic Liver Cancer(BCLC)***,HCC etiology,and HCC features were *** and the GALAD score were obtained at *** performance of the GALAD score and biomarkers were prospectively *** Exactly 115 individuals were diagnosed with *** GALAD score increased with disease *** BCLC-0/A and BCLC-B/C/D,the GALAD score predicted HCC staging with an area under the curve(AUC)of 0.868(95%CI:0.80–0.93).For identifying the curative HCC,the AUC of GALAD score was significantly higher than that of Alpha-fetoprotein(AFP)(0.753)and Lens culinaris agglutinin-reactive fraction of AFP-L3(0.706),and as good as that of Protein induced by vitamin K absence-II(PIVKA-II)(0.897).For detecting aggressive features,the GALAD score gave an AUC of 0.839(95%CI:0.75–0.92)and significantly outperformed compared to that of AFP(0.761)and AFP-L3(0.697),with a trend of superiority to that of PIVKA-II(0.772).The performance to predict 1-year mortality of GALAD score(AUC:0.711,95%CI:0.60–0.82)was better than that of AFP(0.541)and as good as that of PIVKA-II(0.736).The optimal cutoff value of GALAD score was≥6.83,with a specificity of 72.63%for exhibiting substantial reduction in the 1-year *** The GALAD model can diagnose HCC at the curative stage,includin

关键词： Alpha-fetoprotein Barcelona clinic liver cancer GALAD score Hepatocellular carcinoma Lens culinaris agglutinin-reactive fraction of alpha-fetoprotein Protein induced by vitamin K absence-II

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Advances in DNA methylation and its role in cytoplasmic male sterility in higher plants

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Journal of Integrative Agriculture 2024年第1期23卷 1-19页

作者： Atiqur Rahman Hasan Sofiur Rahman Shakil Uddin Naima Sultana Shirin Akhter Ujjal Kumar Nath Shamsun Nahar Begum Mazadul Islam Afroz Naznin Nurul Amin Sharif Ahmed Akbar Hossain Department of Genetics and Plant Breeding Bangladesh Agricultural UniversityMymensingh 2202Bangladesh Plant Breeding division Bangladesh Institute of Nuclear AgricultureMymensingh 2202Bangladesh Tuber Crop research Centre Bangladesh Agricultural Research Institute(BARI)Joydebpur 1701Bangladesh Horticulture research Centre Bangladesh Agricultural Research Institute(BARI)Joydebpur 1701Bangladesh Biotechnology division Bangladesh Agricultural Research Institute(BARI)Joydebpur 1701Bangladesh International Rice research Institute Bangladesh OfficeDhaka 1213Bangladesh division of Soil Science Bangladesh Wheat and Maize Research InstituteDinajpur 5200Bangladesh

The impact of epigenetic modifications like DNA methylation on plant phenotypes has expanded the possibilities for crop *** methylation plays a part in the regulation of both the chromatin structure and gene expression,and the enzyme involved,DNA methyltransferase,executes the methylation process within the plant *** regulating crucial biological pathways,epigenetic changes actively contribute to the creation of the ***,epigenome editing may assist in overcoming some of the drawbacks of genome editing,which can have minor off-target consequences and merely facilitate the loss of a gene’s *** drawbacks include gene knockout,which can have such off-target *** review provides examples of several molecular characteristics of DNA methylation,as well as some plant physiological processes that are impacted by these epigenetic changes in the *** also discuss how DNA alterations might be used to improve crops and meet the demands of sustainable and environmentally-friendly farming.

关键词： DNA methylation epigenetics CMS male sterility chromatin architecture gene expression higher plants

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Advancements in nanotechnology for the delivery of phytochemicals

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Journal of Integrative Medicine 2024年第4期22卷 385-398页

作者： Divya Chauhan Pavan K.Yadav Nazneen Sultana Arun Agarwal Saurabh Verma Manish K.Chourasia Jiaur R.Gayen division of Pharmaceutics and Pharmacokinetics Central Drug Research InstituteCouncil of Scientific and Industrial ResearchLucknow 226031Uttar PradeshIndia Academy of Scientific and Innovative research Ghaziabad 201002Uttar PradeshIndia

Phytosomes(phytophospholipid complex) are dosage forms that have recently been introduced to increase the stability and therapeutic effect of herbal medicine. Currently, bioactive herbs and the phytochemicals they contain are considered to be the best remedies for chronic diseases. One promising approach to increase the efficacy of plant-based therapies is to improve the stability and bioavailability of their bio-active ingredients. Phytosomes employ phospholipids as their active ingredients, and use their amphiphilic properties to solubilize and protect herbal extracts. The unique properties of phospholipids in drug delivery and their use in herbal medicines to improve bioavailability results in significantly enhanced health benefits. The introduction of phytosome nanotechnology can alter and revolutionize the current state of drug delivery. The goal of this review is to explain the application of phytosomes, their future prospects in drug delivery, and their advantages over conventional formulations.

关键词： Phytochemical Bioavailability Drug delivery system Phytosome Plant extracts

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Finite-Time Stabilization for Constrained Discrete-time Systems by Using Model Predictive Control

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IEEE/CAA Journal of Automatica Sinica 2024年第7期11卷 1656-1666页

作者： Bing Zhu Xiaozhuoer Yuan Li Dai Zhiwen Qiang IEEE the Seventh research division Beihang UniversityBeijing 100191China the School of Automation Beijing Institute of TechnologyBeijing 100081China

In this paper, a model predictive control(MPC)framework is proposed for finite-time stabilization of linear and nonlinear discrete-time systems subject to state and control constraints. The proposed MPC framework guarantees the finite-time convergence property by assigning the control horizon equal to the dimension of the overall system, and only penalizing the terminal cost in the optimization, where the stage costs are not penalized explicitly. A terminal inequality constraint is added to guarantee the feasibility and stability of the closed-loop *** feasibility can be improved via augmentation. The finite-time convergence of the proposed MPC is proved theoretically,and is supported by simulation examples.

关键词： Constraints deadbeat control finite-time stabilization model predictive control(MPC)

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Evaluation of excavation damaged zones(EDZs)in Horonobe Underground research Laboratory(URL)

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第2期16卷 365-378页

作者： Koji Hata Sumio Niunoya Kazuhei Aoyagi Nobukatsu Miyara Obayashi Corporation Technology Research InstituteTechnology DivisionKiyoseTokyo204-8558Japan Obayashi Corporation Nuclear Facilities DivisionSinagawaTokyo108-8502Japan Japan Atomic Energy Agency Horonobe Underground Research CenterHoronobeHokkaido098-3224Japan

Excavation of underground caverns,such as mountain tunnels and energy-storage caverns,may cause the damages to the surrounding rock as a result of the stress *** this influenced zone,new cracks and discontinuities are created or propagate in the rock ***,it is effective to measure and evaluate the acoustic emission(AE)events generated by the rocks,which is a small elastic vibration,and permeability *** authors have developed a long-term measurement device that incorporates an optical AE(O-AE)sensor,an optical pore pressure sensor,and an optical temperature sensor in a single multi-optical measurement probe(MOP).Japan Atomic Energy Agency has been conducting R&D activities to enhance the reliability of high-level radioactive waste(HLW)deep geological disposal *** a high-level radioactive disposal project,one of the challenges is the development of methods for long-term monitoring of rock mass ***,in January 2014,the long-term measurements of the hydro-mechanical behavior of the rock mass were launched using the developed MOP in the vicinity of 350 m below the surface at the Horonobe Underground research *** measurement results show that AEs occur frequently up to 1.5 m from the wall during *** addition,hydraulic conductivity increased by 2e4 orders of *** analysis revealed that the hydraulic behavior of the rock mass affected the pore pressure fluctuations and caused *** on this,a conceptual model is developed to represent the excavation damaged zone(EDZ),which contributes to the safe geological disposal of radioactive waste.

关键词： Excavation damaged zone(EDZ) Optical sensor Long-term monitoring Acoustic emission(AE) Shaft sinking

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Performance assessment of prefabricated vertical drains in mitigating soil reliquefaction subjected to repeated seismic events using shaking table experiments

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Frontiers of Structural and Civil Engineering 2024年第3期18卷 411-427页

作者： Gowtham PADMANABHAN Ganesh Kumar SHANMUGAM Department of Earthquake Engineering Indian Institute of Technology RoorkeeUttarakhand 247667India Geotechnical Engineering division CSIR-Central Building research Institute Academy of Scientific and Innovative Research(AcSIR)Uttarakhand 247667India

The use of prefabricated vertical drains(PVD)in liquefiable deposits is gaining attention due to enhanced ***,investigations on PVD in mitigating re-liquefaction during repeated shaking events are not *** study performed a series of shaking table experiments on untreated and PVD-treated specimens prepared with 40%and 60%relative *** sinusoidal loading was applied with an incremental peak acceleration of 0.1g,0.2g,0.3g,and 0.4g,at 5 Hz shaking frequency with 40 s *** performance of treated ground was evaluated based on the generation and dissipation of excess pore water pressure(EPWP),induced sand densification,subsidence,and cyclic stress *** addition,the strain accumulated in fresh and exhumed PVD was investigated using geotextile tensile testing apparatus aided with digital image *** evidence of pore pressure was reported up to 0.2g peak acceleration for 40%and 60%relative density *** continuous occurrence of soil densification and drainage medium restrained and delayed the generation of EPWP and expedited the dissipation *** study demonstrates PVD can mitigate re-liquefaction,without suffering from deterioration,when subjected to medium to high intense repeated shaking events.

关键词： prefabricated vertical drains drainage re-liquefaction shaking table digital image correlation

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