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Size effects on process performance and product quality in progressive microforming of shafted gears revealed by experiment and numerical modeling

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Advances in Manufacturing 2023年第1期11卷 1-20页

作者： Jun-yuan Zheng Hui Liu Ming-Wang fu Department of Mechanical Engineering The Hong Kong Polytechnic UniversityHung HomKowloonHong KongPeople’s Republic of China Research Institute for Advanced Manufacturing The Hong Kong Polytechnic UniversityHung HomKowloonHong KongPeople’s Republic of China

As one of the indispensable actuating components in micro-systems,the shafted microgear is in great production *** is a manufacturing process to produce microgears to meet the *** to the small geometrical size,there are uncertain process performance and product quality issues in this production *** this study,the shafted microgears were fabricated in two different scaling factors with four grain sizes using a progressively extrusion-blanking *** explore the unknown of the process,grain-based modeling was proposed and employed to simulate the entire forming *** results show that when the grains are large,the anisotropy of single grains has an obvious size effect on the forming behavior and process performance;and the produced geometries and surface quality are worsened;and the deformation load is *** deformation zones were identified in the microstructures with different hardness and distributions of stress and *** simulation by using the proposed model successfully predicted the formation of zones and revealed the inhomogeneous deformation in the forming *** undesirable geometries of microgears including material unfilling,burr and inclination were observed on the shaft and teeth of gear,and the inclination size is increased obviously with grain *** avoid the formation of inclination and material unfilling,the punch was redesigned,and a die insert was added to constraint the bottom surface of the gear *** new products had then the better forming quality.

关键词： Microforming Microprocess performance Microforming quality Size effect affected deformation behavior Die design optimization

Photocatalytic decarboxylative alkylations of C(sp^(3))–H and C(sp^(2))–H bonds enabled by ammonium iodide in amide solvent

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Science China Chemistry 2021年第3期64卷 439-444页

作者： Guang-Zu Wang Ming-Chen fu Bin Zhao rui Shang Department of Chemistry University of Science and Technology of ChinaHefei 230026China Department of Chemistry School of ScienceThe University of Tokyo7-3-1 HongoBunkyo-kuTokyo 113-0033Japan

A simple ammonium iodide salt in amide solvent catalyzes regioselective decarboxylative alkylation of C(sp^(3))-H bonds of Naryl glycine derivatives, of C(sp^(2))-H bond of heteroarenes, and cascade radical addition to unsaturated bond followed by intramolecular addition to arene, with a broad scope of N-hydroxyphthalimide derived redox active esters under visible light irradiation. The reactions are suggested to proceed through photoactivation of a transiently assembled chromophore from electron-deficient phthalimide moiety and iodide anion through an anion-π interaction in solvent cage followed by diffusion to generate solvated free radical species to react with C-H substrates. The simplicity, practicality, and broad substrate scope of this method highlight the synthetic power of photocatalysis through transiently assembled chromophore, and will hopefully inspire further developments of low cost photocatalysis based on various non-covalent interactions, which are prevalent in supramolecular chemistry and biosystems, for sustainable organic synthesis.

关键词： decarboxylative alkylation transiently assembled chromophore anion-πinteraction ammonium iodide solvent cage

Phase selection and solidification path transition of Ti-48Al-xNb alloys with different cooling rates

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Rare Metals 2023年第1期42卷 288-295页

作者： Tan He rui Hu Jie-Ren Yang Heng-Zhi fu The State Key Laboratory of Solidification Processing School of Materials Science and EngineeringNorthwestern Polytechnical UniversityXi’an710072China

Ti-48Al-xNb alloys were solidified by containerless electromagnetic levitation with quenching system of the conical copper *** influence of cooling rates on phase selection of T1-48Al-xNb alloys was *** near-equilibrium solidification condition,the dendrite βphase is observed as the leading *** other metastable phase(e.g.,α phase) is *** contrast,in rapid solidification condition,the metastable α phase is observed in as-quenched Ti-48Al-2Nb ***,the metastable α phase is replaced by the primary β phase with Nb addition *** Ti-48Al-(x=4,6,8)Nb alloys,increasing cooling rate results in a solidification path *** peritectic reaction(L+β→α) is therefore significantly *** relationships between primary dendrite arm spacing(λ_(1)) and cooling rate(τ) can be described.

关键词： TiAl alloy Cooling rate Microstructure Phase selection

Outcomes of 957 preterm neonatal fundus examinations in a Guangzhou NICU through 2008 to 2011

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International Journal of Ophthalmology(English edition) 2012年第4期5卷 469-472页

作者： rui-Hong Ju, Min fu Department of Ophthalmology Zhujiang Hospital Southern Medical University Guangzhou 510280 Guangdong Province China Department of Cardiothoracic Surgery Zhujiang Hospital Southern Medical University Guangzhou 510280 Guangdong Province China

AIM: To take fundus examination in the preterm neonates to observe the common diseases and report the outcomes in a neonatal intensive care unit (NICU) in Guangzhou between May 2008 and May 2011. METHODS: fundus examinations were performed with Retcam II in 957 prematures. RESULTS: There were 957 prematures in this study, including 666 males and 291 females, 2 triple births, 152 twins and 803 singletons. During the three years, 86 infants with any stage retinopathy of prematurity (ROP) (9.0%), 123 infants with retinal hemorrhage (12.9%), 10 infants with neonatal fundual jaundice (1.0%) and 3 babies with congenital choroidal coloboma (0.3%) were found. CONCLUSION: Early detection and prompt treatment of ocular disorders in neonates is important to avoid lifelong visual impairment. Examination of the eyes should be performed in the newborn period and at all well-child visits.

关键词： fundus examination premature retinopathy of prematurity retinal hemorrhage choroidal coloboma early detection

Single and competitive adsorption affinity of heavy metals toward peanut shell-derived biochar and its mechanisms in aqueous systems

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Chinese Journal of Chemical Engineering 2020年第5期28卷 1375-1383页

作者： rui Shan Yueyue Shi Jing Gu YazhuoWang Haoran yuan Guangzhou Institute of Energy Conversion Chinese Academy of SciencesGuangzhou 510640China Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou) Guangzhou 511458China CAS Key Laboratory of Renewable Energy Guangzhou 510640China Guangdong Provincial Key Laboratory of New and Renewable Energy Research and Development Guangzhou 510640China Nano Science and Technology Institute University of Science and Technology of ChinaSuzhou 215123China

Converting peanut shells into biochar by pyrolysis was considered an environmentally friendly and efficient method for agricultural solid waste *** properties of peanut shell-derived biochar(PBC)under different temperature and its adsorption capacity of heavy metals were *** was found that PBC400 exhibited the highest cumulative capability for heavy metals elimination in single solute because of its high specific surface area and rich functional ***,the competitive adsorption revealed that PBC had a substantial difference in adsorption affinity from diverse heavy metal ions,sorption capacity decreased as Pb2+>Cu2+>Cd2+>Ni2+>Zn2+,which was lower than in a single *** adsorption process using selected biochar was optimized with respect to p H,reaction time,adsorbent dose,and initial concentration of heavy *** kinetic data was well fitted with PSO model,and the Langmuir model was adopted for adsorption equilibrium data in both cases of single solutes and mixed solutes for all heavy metals,which indicated that the removal course was primarily explained by monolayer adsorption,and chemical adsorption occupied an important ***,peanut shells derived biochar could be a potential and green adsorbent for wastewater treatment.

关键词： Pyrolysis Biochar Heavy metal removal Competitive adsorption

Growth inhibition of high-intensity focused ultrasound on hepatic cancer in vivo

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World Journal of Gastroenterology 2005年第28期11卷 4317-4320页

作者： Xiu-Jie Wang Shu-Lan yuan Yan-Rong Lu Jie Zhang Bo-Tao Liu Wen-fu Zeng Yue-Ming He Yu-rui fu Division of Experimental Oncology Key Laboratory of Biotherapy of Human Diseases of Ministry of Education PR China West China Hospital Sichuan University. Chengdu 610041. Sichuan Province. China Mianyang Electronic Equipment Factory Mianyang 621000 Sichuan ProvinceChina

AIM： To investigate the damaging effect of high-intensity focused ultrasound （HIfu） on cancer cells and the inhibitory effect on tumor growth. METHODS： Hurine H22 hepatic cancer cells were treated with HIfu at the same intensity for different lengths of time and at different intensities for the same length oftime in vitro, the dead cancer cells were determined by trypan blue staining. Two groups of cancer cells treated with HIfu at the lowest and highest intensity were inoculated into mice. Tumor masses were removed and weighed after 2 wk, tumor growth in each group was confirmed pathologically.RESULTS： The death rate of cancer cells treated with HIfu at 1 000 W/cm^2 for 0.5, 1, 2, 4, 8, and 12 s was 3.11±1.21%, 13.37±2.56%, 38.84±3.68%, 47.22±5.76%,87.55±7.32%, and 94.33±8.11%, respectively. A positive relationship between the death rates of cancer cells and the length of HIfu treatment time was found （r = 0.96,P〈0.01）. The death rate of cancer cells treated with HIfu at the intensity of 100, 200, 400, 600, 800, and 1 000 W/cm^2 for 8 s was 26.31±3.26%, 31.00±3.87%, 41.97±5.86%,72.23±8.12%, 94.90±8.67%, and 99.30±9.18%, respectively. A positive relationship between the death rates of cancer cells and the intensities of HIfu treatment was confirmed （r= 0.98, P〈0.01）. The cancer cells treated with HIfu at 1 000 W/cm^2 for 8 s were inoculated intomice ed into. The tumor inhibitory rate was 90.35% compared to the control （P〈0.01）. In the experimental group inoculated with the cancer cells treated with HIfu at 1 000 W/cm^2 for 0.5 s, the tumor inhibitory rate was 22.9% （P〈0.01）. By pathological examination, tumor growth was confirmed in 8 out of 14 mice （57.14%, 8/14） inoculated with the cancer cells treated with HIfu at 1 000 W/cm^2 for 8 s, which was significantly lower than that in the control （100%, 15/15, P〈O.05）.CONCLUSION： HIfu is effective on killing or damage of H22 hepatic cancer cells in vitro and on inhibiting tumor growth in mice ex vivo.

关键词： HIfu Uver cancer Growth inhibition

Conodont Biostratigraphic Constraint on the Lower Taiyuan Formation in Southern North China and Its Paleogeographic Implications

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Journal of Earth Science 2022年第6期33卷 1480-1493页

作者： yuan Wang Jianghai Yang Dong-Xun yuan Jia Liu rui Ma School of Earth Sciences China University of GeosciencesWuhan430074China State Key Laboratory of Biogeology and Environmental Geology China University of GeosciencesWuhan430074China School of Resources and Geosciences China University of Mining and TechnologyXuzhou221116China State Key Laboratory of Palaeobiology and Stratigraphy Nanjing Institute of Geology and Palaeontology and Center for Excellence in Life and PaleoenvironmentChinese Academy of SciencesNanjing210008China

The Late Paleozoic Taiyuan Formation in North China is mainly composed of a mixed shallow-marine carbonate and terrigenous clastic *** basal limestones have been constrained in the late Pennsylvanian to Early *** further constrain the age of the lowest Taiyuan Formation,we obtained two genera and 16 species of conodonts from the bottom limestones of the Taiyuan Formation in two sections in Henan Province,southern North *** fauna includes Idiognathodus hebeiensis,Streptognathodus isolatus,***,***,***,***,***,***,***,***,***,***,***,***,***,and ***.A genus of Streptognathodus dominated conodont assemblage with some Idiognathodus *** indicates a late Gzhelian(latest Pennsylvanian)age for the lowest Taiyuan Formation in southern North *** is consistent with recently published high-precision zircon U-Pb ages from ash *** on conodont biostratigraphy,the basal limestones of the Taiyuan Formation in Henan Province(southern North China)can be correlated with the upper part of Miaogou limestones of the Taiyuan Formation in Shanxi Province(northern North China).This correlation might reflect a significant sea-level rise in North China,possibly corresponding to a deglaciation event at the Permo-Carboniferous transition.

关键词： Taiyuan Formation conodonts Gzhelian southern North China biostratigraphy

Mechanism of hydro-viscous soft start of belt conveyor

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Journal of China University of Mining and Technology 2008年第3期18卷 459-465页

作者： MENG Qing-rui HOU You-fu School of Mechanical and Electrical Engineering China University of Mining ＆ Technology Xuzhou Jiangsu 221008 China

The mechanism of a hydro-viscous soft start is of great importance in the design of a hydro-viscous clutch and its control system. To explain the mechanism of a hydro-viscous soft start, the startup process of a belt conveyor was numerically analyzed with the modified Reynolds equation, an energy equation and a temperature-viscosity equation. The effect of temperature and grooves of the friction disk surface on torque transfer and load capacity of the oil film have also been analyzed. The results show that 1) the grooves are the basis of forming dynamic pressure but they may reduce the capacity of torque transfer to a certain extent, 2) during the startup process, temperature has little effect on torque transfer and load capacity and the variation in load capacity of the oil film is very small, indicating that it is preferable to use the flow rate as a control object than the pressure of the feed cylinder. The results have been verified by an experiment.

关键词： hydro-viscous clutch soft start belt conveyor torque transfer load capacity

Temperature-dependent of Nonlinear Optical Conductance of Graphene-based Systems in High-intensity Terahertz Field

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Nano-Micro Letters 2014年第2期6卷 153-162页

作者： Jing Lv rui-yang yuan Hui Yan Laboratory of Thin Film Materials Beijing University of Technology Center of Theoretical Physics Department of PhysicsCapital Normal University

For multi-photon processed with the linear dispersion in the high-intensity terahertz(THz) field,we have systematically investigated the temperature-dependent nonlinear optical response of graphene-based systems, including single layer graphene, graphene superlattice and gapped graphene. In the intrinsic single layer graphene system, it demonstrates that, at low temperature, nonlinear optical conductivities of the thirdand fifth-order are respectively five and ten orders of magnitude larger than the universal conductivity with high-intensity and low frequency THz *** the graphene superlattice and gapped graphene systems, the optical responses enhanced because of the anisotropic massless and massive Dirac fermions.

关键词： Nonlinear Graphene Terahertz Conductance Transmittance