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3D printing for ultra-precision machining:current status,opportunities,and future perspectives

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Frontiers of Mechanical Engineering 2024年第4期19卷 1-28页

作者： Tao he Wai Sze YIP Edward hengzhou YAN Jiuxing TANG Muhammad REHAN long TENG Chi Ho WONG Linhe SUN Baolong zhang Feng GUO Shaohe zhang Suet TO State Key Laboratory of Ultra-precision Machining Technology Department of Industrial and Systems EngineeringThe Hong Kong Polytechnic UniversityHong KongChina Department of Industrial and Systems Engineering The Hong Kong Polytechnic UniversityHong KongChina Department of Physics The Hong Kong University of Science and TechnologyHong KongChina School of Geosciences and Info-Physics Central South UniversityChangsha 410083China

Additive manufacturing,particularly 3D printing,has revolutionized the manufacturing industry by allowing the production of complex and intricate parts at a lower cost and with greater ***,3D-printed parts frequently require post-processing or integration with other machining technologies to achieve the desired surface finish,accuracy,and mechanical ***-precision machining(UPM)is a potential machining technology that addresses these challenges by enabling high surface quality,accuracy,and repeatability in 3D-printed *** study provides an overview of the current state of UPM for 3D printing,including the current UPM and 3D printing stages,and the application of UPM to 3D *** the presentation of current stage perspectives,this study presents a detailed discussion of the benefits of combining UPM with 3D printing and the opportunities for leveraging UPM on 3D printing or supporting each *** particular,future opportunities focus on cutting tools manufactured via 3D printing for UPM,UPM of 3D-printed components for real-world applications,and post-machining of 3D-printed ***,future prospects for integrating the two advanced manufacturing technologies into potential industries are *** study concludes that UPM is a promising technology for 3D-printed components,exhibiting the potential to improve the functionality and performance of 3D-printed products in various *** also discusses how UPM and 3D printing can complement each other.

关键词： ultra-precision machining 3D printing additive manufacturing future perspectives start-of-the-art-review

Efficient DIPA-CRISPR-mediated knockout of an eye pigment gene in the white-backed planthopper,Sogatella furcifera

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Insect Science 2024年第4期31卷 1015-1025页

作者： Meng-Qi zhang Lang-Lang Gong Ya-Qin Zhao Yun-Feng Ma Gui-Jun long Huan Guo Xuan-Zheng Liu J.Joe Hull Youssef Dewer Chao Yang Ning-Ning zhang Ming he Peng he National Key Laboratory of Green Pesticides Key Laboratory of Green Pesticide and Agricultural BioengineeringMinistry of EducationCenter for R&D of Fine Chemicals of Guizhou UniversityGuiyangChina Pest Management and Biocontrol Research Unit US Arid Land Agricultural Research CenterUSDA Agricultural Research ServicesMaricopaArizonaUSA Phytotoxicity Research Department Central Agricultural Pesticide LaboratoryAgricultural Research CenterDokkiGizaEgypt Guizhou Jifeng Seed Industry Limited Liability Company XingyiGuizhou ProvinceChina Shandong Facility Horticulture Bioengineering Research Center Weifang University of Science and TechnologyWeifangShandong ProvinceChina

Although CRISPR/Cas9 has been widely used in insect gene editing,the need for the microinjection of preblastoderm embryos can preclude the technique being used in insect species with eggs that are small,have hard shells,and/or are difficult to collect and maintain outside of their normal *** is the case with Sogatella furcifera,the white-backed planthopper(WBPH),a significant pest of Oryza sativa(rice)that oviposits inside rice *** extraction from the stem runs the risk of mechanical damage and hatching is heavily influenced by the micro-environment of the rice *** bypass these issues,we targeted embryos prior to oviposition via direct parental(DIPA)-CRISPR,in which Cas9 and single-guide RNAs(sgRNAs)for the WBPH eye pigment gene tryptophan 2,3-dioxygenase were injected into the hemocoel of adult *** at varying numbers of days posteclosion were evaluated to determine at what stage their oocyte might be most capable of taking up the gene-editing *** evaluation of the offspring indicated that the highest G0 gene-edited efficacy(56.7%)occurred in females injected 2 d posteclosion,and that those mutations were heritably transmitted to the G1 *** study demonstrates the potential utility of DIPA-CRISPR for future gene-editing studies in non-model insect species and can facilitate the development of novel pest management applications.

关键词： CRISPR/Cas9 DIPA-CRISPR gene editing tryptophan 2,3-dioxygenase WBPH

Global well-posedness for 2D inhomogeneous asymmetric fluids with large initial data

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Science China Mathematics 2024年第3期67卷 527-556页

作者： Chenyin Qian Beibei he Ting zhang School of Mathematical Sciences Zhejiang Normal UniversityJinhua 321004China School of Mathematical Sciences Zhejiang UniversityHangzhou 310058China

In this paper, by using time-weighted global estimates and the Lagrangian approach, we first investigate the global existence and uniqueness of the solution for the 2D inhomogeneous incompressible asymmetric fluids with the initial(angular) velocity being located in sub-critical Sobolev spaces H^(s)(R^(2))(0he initial density being bounded from above and below by some positive constants. The global unique solvability of the 2D incompressible inhomogeneous asymmetric fluids with the initial data in the critical Besov space(u_(0), w_(0))∈˙B^(0)_(2,1)(R^(2))andρ^(−1)−1∈˙B^(ε)_(2/ε),1(R^(2))is established. In particular, the uniqueness of the solution is also obtained without any more regularity assumptions on the initial density which is an improvement on the recent result of Abidi and Gui(2021) for the 2D inhomogeneous incompressible NavierStokes system.

关键词： inhomogeneous asymmetric fluids Littlewood-Paley theory Besov spaces global well-posedness

Design and high-power testing of offline conditioning cavity for CiADS RFQ high-power coupler

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Nuclear Science and Techniques 2024年第9期35卷 18-27页

作者： Ruo-Xu Wang Yuan he long-Bo Shi Chen-Xing Li Zong-heng Xue Tian-Cai Jiang Xian-Bo Xu Lie-Peng Sun Zhou-Li zhang Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000China Lanzhou University Lanzhou 730000China

To validate the design rationality of the power coupler for the RFQ cavity and minimize cavity contamination,we designed a low-loss offline conditioning cavity and conducted high-power *** offline cavity features two coupling ports and two tuners,operating at a frequency of 162.5 MHz with a tuning range of 3.2 *** the installation angle of the coupling ring and the insertion depth of the tuner helps minimize cavity *** performed electromagnetic structural and multiphysics simulations,revealing a minimal theoretical power loss of 4.3%.However,when the cavity frequency varied by110 kHz,theoretical power losses increased to10%,necessitating constant tuner adjustments during *** simulations indicated that increased cavity temperature did not affect frequency *** completion of the offline high-power conditioning platform,we measured the transmission performance,revealing a power loss of 6.3%,exceeding the theoretical *** utilized efficient automatic range scanning and standing wave resonant *** fully condition the power coupler,a 15°phase difference between two standing wave points in the condition-ing system was ***,the maximum continuous wave power surpassed 20 kW,exceeding the expected target.

关键词： RFQ cavity Power coupler Offline conditioning Resonant cavity

Image Segmentation-P300 Selector: A Brain–Computer Interface System for Target Selection

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Computers, Materials & Continua 2024年第5期79卷 2505-2522页

作者： Hang Sun Changsheng Li he zhang Mechanical Engineering Nanjing University of Science and TechnologyNanjing210018China

Brain–computer interface (BCI) systems, such as the P300 speller, enable patients to express intentions withoutnecessitating extensive ***, the complexity of operational instructions and the slow pace of characterspelling pose challenges for some patients. In this paper, an image segmentation P300 selector based on YOLOv7-mask and DeepSORT is proposed. The proposed system utilizes a camera to capture real-world objects forclassification and tracking. By applying predefined stimulation rules and object-specificmasks, the proposed systemtriggers stimuli associated with the objects displayed on the screen, inducing the generation of P300 signals in thepatient’s brain. Its video processing mechanism enables the system to identify the target the patient is focusing oneven if the object is partially obscured, overlapped, moving, or changing in number. The system alters the target’scolor display, thereby conveying the patient’s intentions to caregivers. The data analysis revealed that the selfrecognitionaccuracy of the subjects using this method was between 92% and 100%, and the cross-subject P300recognition precision was 81.9%–92.1%. This means that simple instructions such as “Do not worry, just focuson what you desire” effectively discerned the patient’s intentions using the Image Segmentation-P300 selector. Thisapproach provides cost-effective support and allows patients with communication difficulties to easily express theirneeds.

关键词： Brain-computer interface deep learning electroencephalogram P300 YOLOv7-mask

Quantum search with prior knowledge

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Science China(Information Sciences) 2024年第9期67卷 321-329页

作者： Xiaoyu he Xiaoming SUN Jialing zhang State Key Lab of Processors Institute of Computing Technology Chinese Academy of Sciences School of Computer Science and Technology University of Chinese Academy of Sciences

The combination of contextual side information and search is a powerful paradigm in the scope of artificial intelligence. The prior knowledge enables the identification of possible solutions but may be imperfect. Contextual information can arise naturally, for example in game AI where prior knowledge is used to bias move decisions. In this work we investigate the problem of taking quantum advantage of contextual information, especially searching with prior knowledge. We propose a new generalization of Grover's search algorithm that achieves the optimal expected success probability of finding the solution if the number of queries is fixed. Experiments on small-scale quantum circuits verify the advantage of our algorithm. Since contextual information exists widely, our method has wide applications. We take game tree search as an example.

关键词： quantum computing quantum search quantum query algorithm prior knowledge

Flexible interdigitated layered framework with multiple accessible active sites for high-performance CH_(3)I capture

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Science China Chemistry 2024年第5期67卷 1569-1577页

作者： Bo Tai Baoyu Li Linwei he Zhonglin Ma Shujing Lin Mingxing zhang Junchang Chen Fuqi Wu long Chen Xing Dai Fuyin Ma Zhifang Chai Shuao Wang State Key Laboratory of Radiation Medicine and Protection School for Radiological and interdisciplinary Sciences(RAD-X)and Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education InstitutionsSoochow UniversitySuzhou 215123China

The development of adsorbent materials for effective capture of radioactive iodomethane(CH_(3)I) from the off-gas of used nuclear fuel reprocessing, remains a significant and challenging line of research because currently state-of-art adsorbents still suffer from low binding affinity with CH_(3)I. here, we proposed a brand-new adsorption topological structure by developing a 2D interdigitated layered framework, named SCU-20, featuring slide-like channel with multiple active sites for CH_(3)I capture. The responsive rotating-adaptive aperture of SCU-20 enables the optimal utilization of all active sites within the pore for highly selective recognition and capture of CH_(3)I. A record-breaking CH_(3)I uptake capacity of 1.84 g/g was achieved under static sorption conditions with saturated CH_(3)I vapor. Both experimental and theoretical findings demonstrated that the exceptional uptake of SCU-20 towards CH_(3)I can be attributed to the confined physical electrostatic adsorption of F sites, coupled with the chemical nitrogen methylation reaction with uncoordinated N atoms of pyrazine. Moreover, dynamic CH_(3)I uptake capacity potentially allows for the capture of CH_(3)I in simulated real-world off gas reprocessing conditions. This study highlights the potential of SCU-20 as a promising candidate for efficient capture of iodine species and contributes to the development of effective solutions for radioactive iodine remediation.

关键词： 2D interdigitated layered framework iodomethane dual-sites electrostatic interaction physisorption and chemisorption

Engineering hierarchical quaternary superstructure of an integrated MOF-derived electrode for boosting urea electrooxidation assisted water electrolysis

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Green Energy & Environment 2024年第4期9卷 695-701页

作者： Jianjun Tian Changsheng Cao Yingchun he Muhammad Imran Khan Xin-Tao Wu Qi-long Zhu State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of MatterChinese Academy of Sciences(CAS)Fuzhou350002China Fujian Science&Technology Innovation Laboratory for Optoelectronic Information of China Fuzhou350108China University of Chinese Academy of Sciences Beijing100049China Research Institute of Sciences and Engineering(RISE) University of SharjahSharjah27272United Arab Emirates

Controllable design of the catalytic electrodes with hierarchical superstructures is expected to improve their electrochemical ***,a self-supported integrated electrode(NiCo-ZLDH/NF)with a unique hierarchical quaternary superstructure was fabricated through a self-sacrificing template strategy from the metal–organic framework(Co-ZIF-67)nanoplate arrays,which features an intriguing well-defined hierarchy when taking the unit cells of the NiCo-based layered double hydroxide(NiCo-LDH)as the primary structure,the ultrathin LDH nanoneedles as the secondary structure,the mesoscale hollow plates of the LDH nanoneedle arrays as the tertiary structure,and the macroscale three-dimensional frames of the plate arrays as the quaternary ***,the distinctive structure of NiCo-ZLDH/NF can not only accelerate both mass and charge transfer,but also expose plentiful accessible active sites with high intrinsic activity,endowing it with an excellent electrochemical performance for urea oxidation reaction(UOR).Specially,it only required the low potentials of 1.335,1.368 and 1.388 V to deliver the current densities of 10,100 and 200 mA cm^(-2),respectively,much superior to those for typical *** NiCo-ZLDH/NF as the bifunctional electrode for both anodic UOR and cathodic heR,an energy-saving electrolysis system was further explored which can greatly reduce the needed voltage of 213 mV to deliver the current density of 100 mA cm^(-2),as compared to the conventional water electrolysis system composed of *** work manifests that it is prospective to explore the hierarchically nanostructured electrodes and the innovative electrolytic technologies for high-efficiency electrocatalysis.

关键词： Hierarchical superstructures Metal–organic frameworks Layered double hydroxides Urea oxidation reaction Hydrogen evolution reaction

Phase-field simulation of precipitation kinetics and creep properties of Ni-Al-Cr/Ta superalloys

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Science China(Technological Sciences) 2024年第4期67卷 1139-1150页

作者： YANG ShuaiGe zhang Zan ZHUO JiCheng long HongLi LI YongSheng National Key Laboratory of Advanced Casting Technologies MIIT Key Laboratory of Advanced Metallic and Intermetallic Materials TechnologyEngineering Research Center of Materials Behavior and DesignMinistry of EducationNanjing University of Science and TechnologyNanjing 210094China

The precipitation kinetics ofγ'-Ni_(3)(Al,Ta)phase and creep properties of Ni-15Al-x Ta at.%superalloys are investigated by the crystal plasticity phase-field *** results show that the high Ta content brings a lower creep strain for the deceleration and steady creep stage,while the creep lifetime is *** large external strain intensifies the creep damage and shortens the creep life of Ni-15Al-3Ta at.%*** kinetics evolution and elements distribution are revealed in the quaternary Ni-10Al-8.5Cr-xT a(x=1.5 at.%,2.0 at.%,2.5 at.%)superalloys by the multi-component phase-field *** anti-phase boundary(APB)changes the coarsening mechanism ofγ'phase,and Ta promotes the precipitation ofγ'phase with an increasing volume fraction and particle *** composition difference betweenγ'andγphases increases with the rising of Ta content,the strong partitioning of Ta toγ'phase strengthens the partitioning of Ni and Cr toγmatrix,and Ta shows a superiority than Al in the lattice site occupation of L1_(2)-Ni_(3)(Al,X)*** an importantγ'phase forming element,the optimization of Ta content is essential for improving the mechanical properties of Ni-based superalloys.

关键词： Ni-Al-Ta alloys creep properties kinetics phase-field