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Atomically Dispersed Ruthenium Catalysts with Open Hollow Structure for Lithium-Oxygen Batteries

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Nano-Micro Letters 2024年第2期16卷 154-164页

作者： Xin chen yu Zhang Chang chen Huinan Li yuran Lin Ke yu Caiyun Nan chen chen Beijing Advanced Innovation Center for Materials Genome Engineering Institute of Solid State ChemistryUniversity of Science and Technology BeijingBeijing 100083People’s Republic of China Engineering Research Center of Advanced Rare Earth Materials Department of ChemistryTsinghua UniversityBeijing 100084People’s Republic of China Beijing Key Laboratory of Energy Conversion and Storage Materials Institution College of ChemistryBeijing Normal UniversityBeijing 100875People’s Republic of China

Lithium–oxygen battery with ultrahigh theoretical energy density is considered a highly competitive next-generation energy storage device,but its practical application is severely hindered by issues such as difficult decomposition of discharge products at ***,we have developed N-doped carbon anchored atomically dispersed Ru sites cathode catalyst with open hollow structure(h-RuNC)for Lithium–oxygen *** one hand,the abundance of atomically dispersed Ru sites can effectively catalyze the formation and decomposition of discharge products,thereby greatly enhancing the redox *** the other hand,the open hollow structure not only enhances the mass activity of atomically dispersed Ru sites but also improves the diffusion efficiency of catalytic ***,the excellent activity from atomically dispersed Ru sites and the enhanced diffusion from open hollow structure respectively improve the redox kinetics and cycling stability,ultimately achieving a high-performance lithium–oxygen battery.

关键词： Atomically dispersed Open hollow structure Discharge product Lithium Oxygen battery

State-of-the-art on the anchorage performance of rock bolts subjected to shear load

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International Journal of Coal Science & Technology 2024年第1期11卷 1-30页

作者： yu chen Haodong Xiao School of Civil Engineering Sun Yat-sen UniversityZhuhai519082China

Rock bolts are extensively utilized in underground engineering as a means of offering support and stability to rock masses in tunnels,mines,and other underground *** environments of high ground stress,faults or weak zones can frequently arise in rock formations,presenting a significant challenge for engineering and potentially leading to underground engineering *** bolts serve as a crucial structural element for the transmission of tensile stress and are capable of withstanding shear loads to prevent sliding of weak zones within rock ***,a complete understanding of the behavior of rock bolts subjected to shear loads is *** paper presents a state-of-the-art review of the research progress of rock bolts subjected to shear load in three categories:experiment,numerical simulation,and analytical *** review focuses on the research studies and developments in this area since the 1970s,providing a comprehensive overview of numerous factors that influence the anchorage performance of rock *** factors include the diameter and angle of the rock bolt installation,rock strength,grouting material,bolt material,borehole diameter,rock bolt preload,normal stress,joint surface roughness and joint expansion *** paper reviews the improvement of mechanical parameter setting in numerical simulation of rock bolt ***,it delves into the optimization of the analytical model concerning rock bolt shear theory,approached from the perspectives of both Elastic foundation beam theory coupled with Elastoplasticity theory and Structural mechanic *** significance of this review lies in its ability to provide insights into the mechanical behavior of rock *** paper also highlights the limitations of current research and guidelines for further research of rock bolts.

关键词： Rock bolt Shear load Shear test Numerical simulation Analytical model

Mott insulator-density ordered superfluid transition and‘shamrock transition’in a frustrated triangle lattice

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Communications in Theoretical Physics 2024年第3期76卷 157-164页

作者： Ce Wang yu chen School of Physics Science and Engineering Tongji UniversityShanghai200092China Institute for Advanced Study Tsinghua UniversityBeijing100084China Graduate School of China Academy of Engineering Physics Beijing100193China

Density order is usually a consequence of the competition between long-range and short-range *** we report a density ordered superfluid emergent from a homogeneous Mott insulator due to the competition between frustrations and local *** transition is found in a Bose–Hubbard model on a frustrated triangle lattice with an extra pairing ***,we find a quantum phase transition between two different density ordered superfluids,which is beyond the Landau–Ginzburg(LG)paradigm.A U(1)symmetry is emergent at the critical point,while the symmetry in each density ordered superfluid is Z_(2)×Z_(3).We call the transition a‘shamrock transition’,due to its degenerate ground state in the parameter space being a shamrock-like curve rather than a circle in an LG-type *** low energy theories are established for the two transitions mentioned above and we find their resemblance and differences with clock models.

关键词： frustrated magnets superfluid mott insulator density wave ordered phase clock model

Cooperative game penetration guidance for multiple hypersonic vehicles under safety critical framework

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Chinese Journal of Aeronautics 2024年第1期37卷 247-255页

作者： Jieqing chen Ruisheng SUN yu LU School of Energy and Power Engineering Nanjing University of Science and TechnologyNanjing 210094China

The rapid development of the anti-missile weapon technology brings new challenges to the cooperative penetration strategy solution and the guidance law design for Hypersonic Vehicles(HVs).This paper studies the coordinated game penetration guidance problem for multiple hypersonic vehicles faced with space threat areas.A scheme for seeking cooperative game penetration guidance strategy under safety critical control framework is *** this scheme,a multiHV cooperative game model is proposed in a minimum optimization form which can simplify the solving process and accelerate the computing ***,a second-order control barrier function is developed to transform the implicit nonlinear constraints of the proposed model into linear *** order to obtain better performance of guidance strategy,a composite guidance law under the safety critical control framework is presented to allocate guidance strategies appropriately in the whole *** is shown that the proposed scheme can guarantee successful penetration while avoiding threat ***,a comparative simulation with a two-on-three game is conducted to verify the effectiveness of the proposed method.

关键词： Hypersonic vehicles Safety critical control Penetration game Space constraints Cooperative guidance

Terahertz sensing with a 3D meta-absorbing chip based on two-photon polymerization printing

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Photonics Research 2024年第5期12卷 895-903页

作者： XUEER chen LONGFANG YE DAQUAN yu School of Electronic Science and Engineering Xiamen UniversityXiamen 361005China Institute of Electromagnetics and Acoustics Xiamen UniversityXiamen 361005China Xiamen Sky Semiconductor Technology Co. Ltd.Xiamen 361026China

The narrowband meta-absorbers exhibit significantly enhanced electromagnetic confinement capabilities, showcasing broad application prospects in sensing fields. They can be applied for biomarker detection, chemical composition analysis, and monitoring of specific gas in the environment. In this work, we propose a 3D meta-absorber with an out-of-plane plasma mechanism based on a two-photon printing system. Compared to the conventional fabrication of a metal-insulator-metal 2D meta-absorber, the 3D absorber is composed of a metal layer and a resin layer from top to bottom;its manufacturing process is simpler, only including two-photon printing and magnetron sputtering deposition. A noticeable absorbing resonance appears at 0.3142 THz with perfect absorbance with a high Q-factor of 104.67. The theoretical sensitivity to the refractive index of the sensor reaches up to172.5 GHz/RIU, with a figure of merit (FOM) of 19.56. In the experiments, it was validated as a meta-absorber with high sensitivity for doxycycline (DCH). As the DCH concentration increases from 0 to 4 mg/mL, the absorption intensity decreases around 49%, while the resonant frequency shift is around 70 GHz. It reflects the real-time residual content of DCH, and is potentially applied in trace antibiotic detection. The results showcase a perfect narrowband absorption capability with strong electromagnetic confinement in the terahertz spectrum, along with high-Q sensing characteristics of DCH. Compared to 2D metamaterials, the diversity of3D metamaterial significantly expands, and introduces additional effects to provide greater flexibility in manipulating electromagnetic waves. The 3D device offers opportunities for the application of terahertz biochemical sensing.

关键词： absorber printing absorbing

Stercoral perforation of the cecum:A case report

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World Journal of Gastrointestinal Surgery 2024年第4期16卷 1189-1194页

作者： Hung-Chun yu Ta-Wei Pu jung-cheng Kang Chao-Yang chen Je-Ming Hu Ruei-yu Su Department of Surgery Taichung Armed Forces General HospitalTaichung 411228Taiwan Department of Surgery Tri-Service General HospitalNational Defense Medical CenterTaipei 11490Taiwan Division of Colon and Rectal Surgery Department of SurgeryTri-Service General Hospital Songshan BranchNational Defense Medical CenterTaipei 105Taiwan Division of Colon and Rectal Surgery Department of SurgeryTaiwan Adventist HospitalTaipei 105Taiwan Division of Colon and Rectal Surgery Department of SurgeryTri-Service General HospitalNational Defense Medical CenterTaipei 114Taiwan Department of Pathology Tri-Service General HospitalNational Defense Medical CenterTaipei 105Taiwan Department of Pathology and Laboratory Medicine Taoyuan Armed Forces General HospitalTaoyuan 325Taiwan

BACKGROUND With less than 90 reported cases to date,stercoral perforation of the colon is a rare *** ulceration is thought to occur due to ischemic pressure necrosis of the bowel wall,which is caused by the presence of a stercoraceous *** underscore this urgent surgical situation concerning clinical presentation,surgical treatment,and results,we present the case of a 66-year-old man with a stercoral *** SUMMARY A 66-year-old man with a history of hypertension,hyperlipidemia,and gout presented at the emergency department with lower abdominal pain and a low-grade fever lasting for a few *** computed tomography indicated a suspected bezoar(approximately 7.6 cm)in the dilated cecum,accompanied by pericolic fat stranding,mild proximal dilatation of the ileum,pneumoperitoneum,and minimal ***,feculent peritonitis with isolated cecal perforation were ***,a right hemicolectomy with peritoneal lavage was performed.A histopathological examination supported the intraoperative *** In stercoral perforations,a diagnosis should be diligently pursued,especially in older adults,and prompt surgical intervention should be implemented.

关键词： Acute abdomen Colectomy Peritoneal lavage Pneumoperitoneum Bezoars Case report

Generic Existence of Infinitely Many Non-contractible Closed Geodesics on Compact Space Forms

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Acta Mathematica Sinica,English Series 2024年第7期40卷 1674-1684页

作者： Hui Liu yu chen Wang School of Mathematics and Statistics Wuhan UniversityWuhan430072P.R.China School of Mathematics Tianjin Normal UniversityTianjin300384P.R.China

Let M=S^(n)/Γand h be a nontrivial element of finite order p inπ_(1)(Μ),where the integers n,p≥2,Γis a finite abelian group which acts freely and isometrically on the n-sphere and therefore M is diffeomorphic to a compact space *** this paper,we prove that there are infinitely many non-contractible closed geodesics of class[h]on the compact space form with C^(r)-generic Finsler metrics,where 4≤r≤∞.The conclusion also holds for Cr-generic Riemannian metrics for 2≤r≤∞.The proof is based on the resonance identity of non-contractible closed geodesics on compact space forms.

关键词： Compact space forms non-contractible closed geodesics generic Finsler metrics resonance identity

Advances in large viewing angle and achromatic 3D holography

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Light(Science & Applications) 2024年第7期13卷 1224-1225页

作者： Jiaming Huang yu chen Guixin Li Department of Materials Science and Engineering Southern University of Science and TechnologyShenzhen 518055China Institute for Applied Optics and Precision Engineering Southern University of Science and TechnologyShenzhen 518055China

Optical holography is a promising technique to achieve a naked-eye 3D ***,the narrow viewing angle and chromatic aberration are the two key issues that usually limit the holographic display performance.A recent work proposes a novel way to circumvent these constraints by introducing a color liquid crystal grating into a timesequenced holography system.

关键词： angle chromatic holographic

Combining stochastic density functional theory with deep potential molecular dynamics to study warm dense matter

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Matter and Radiation at Extremes 2024年第1期9卷 44-57页

作者： Tao chen Qianrui Liu yu Liu Liang Sun Mohan chen HEDPS CAPTCollege of Engineering and School of PhysicsPeking UniversityBeijing 100871People’s Republic of China

In traditional finite-temperature Kohn–Sham density functional theory(KSDFT),the partial occupation of a large number of high-energy KS eigenstates restricts the use of first-principles molecular dynamics methods at extremely high ***,stochastic density functional theory(SDFT)can overcome this ***,SDFT and the related mixed stochastic–deterministic density functional theory,based on a plane-wave basis set,have been implemented in the first-principles electronic structure software ABACUS[*** and ***,***.B 106,125132(2022)].In this study,we combine SDFT with the Born–Oppenheimer molecular dynamics method to investigate systems with temperatures ranging from a few tens of eV to 1000 ***,we train machine-learning-based interatomic models using the SDFT data and employ these deep potential models to simulate large-scale systems with long ***,we compute and analyze the structural properties,dynamic properties,and transport coefficients of warm dense matter.

关键词： stochastic theory functional