检索结果-南通市图书馆

AP assembled on ultrafine aluminum particle and its application to NEPE propellant

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2024年第6期36卷 20-29页

作者： Huixin Wang qiang Li Hui Ren Liangjun xie Tingting Liu Zhihong Chen State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing 100081China Inner Mongolia Institute of Synthetic Chemicals Hohhot 010010China

Coating modification is an important way to enhance the reactivity of aluminum *** this paper,ammonium perchlorate and aluminum powder were assembled into energetic microunits by liquid deposition *** particles with AP as shell and ultrafine aluminum powder as the core(Al@AP)were *** micromorphology results show that the coated particles are about 5μm,and the coating layer is evenly distributed on the outer surface of aluminum powder,indicating a complete *** energetic microunits were implanted into the nitrate ester plasticizing adhesive system(NEPE)as solid phase *** effect of filler on the rheological properties,safety,mechanical properties,thermal reaction and energy properties of the system was analyzed by comparing with the raw aluminum *** test results show that the rheological properties,mechanical properties and pressure index of NEPE containing system Al@AP meets the requirements of solid propellant *** with Al based propellant,the mechanical sensitivity and thermal sensitivity are decreased,the safety is better,and the explosion heat of the propellant is increased by 7.8%.The engine test shows that the specific impulse is increased by 1.2 ***@AP can improve the energy output and safety of NEPE propellant,and has potential application prospects in high-energy propellants.

关键词： Aluminum powder Coating NEPE propellant Energy output Applied research

An NMOS output-capacitorless low-dropout regulator with dynamic-strength event-driven charge pump

在线全文

学校读者我要写书评

暂无评论

Journal of Semiconductors 2024年第6期45卷 23-34页

作者： Yiling xie Baochuang Wang Dihu Chen Jianping guo School of Electronics and Information Technology Sun Yat-sen UniversityGuangzhou 510006China School of Microelectronics University of Science and Technology of ChinaHefei 230000China

In this paper,an NMOS output-capacitorless low-dropout regulator(OCL-LDO)featuring dual-loop regulation has been proposed,achieving fast transient response with low power *** event-driven charge pump(CP)loop with the dynamic strength control(DSC),is proposed in this paper,which overcomes trade-offs inherent in conventional *** presented design addresses and resolves the large signal stability issue,which has been previously overlooked in the event-driven charge pump *** breakthrough allows for the full exploitation of the charge-pump structure's poten-tial,particularly in enhancing transient ***,a dynamic error amplifier is utilized to attain precise regulation of the steady-state output voltage,leading to favorable static characteristics.A prototype chip has been fabricated in 65 nm CMOS *** measurement results show that the proposed OCL-LDO achieves a 410 nA low quiescent current(IQ)and can recover within 30 ns under 200 mA/10 ns loading change.

关键词： output-capacitorless low-dropout regulator fast transient low quiescent current event-driven charge pump

Experimental study on shock interaction control of double wedge in high-enthalpy hypersonic flow subject to plasma synthetic jet

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2024年第4期37卷 151-165页

作者： Xuzhen xie qiang LIU Yan ZHOU Zhenbing LUO Wei xie Guanghui BAI Kai LUO Qiu WANG Jianjun WU College of Aerospace Science and Engineering National University of Defense TechnologyChangsha 410073China China Academy of Launch Vehicle Technology Beijing 100076China Institute of Mechanics Chinese Academy of SciencesBeijing 100190China

The hypersonic shock-shock interaction flow field at double-wedge geometries controlled by plasma synthetic jet actuator is experimentally studied in a Ma = 8 high-enthalpy shock tunnel with the purpose of exploring a novel technique for reducing surface heat flux in a real flight environment. The results demonstrate that increasing the discharge energy is advantageous in eliminating the shock wave, shifting the shock wave interaction point, and shortening the control response time. The oblique shock wave can be completely removed when the actuator's discharge energy grows from 0.4 J to 11.5 J, and the displacement of the shock wave interaction point increases by 124.56%, while the controlled response time is shortened by 30 μs. Besides, the reduction in diameter of the jet exit is firstly proved to have a negative impact on energy deposition in a working environment with incoming flow, which reduces the discharge energy and hence decreases the control effect. The shock wave control response time lengthens when the jet exits away from the second wedge. Along with comparing the change in wall heat flux at the second wedge over time, the control effect of plasma synthetic jet actuator with and without inflation is also analyzed. When plasma synthetic jet works in inflatable mode, both the ability to eliminate shock waves and the shifting effect of the shock wave interaction point are increased significantly, and the wall heat flux is also reduced.

关键词： Hypersonic flow High-enthalpy flow Plasma synthetic jet Shock wave Flow control

Protective Effects of Phellodendron Species on Bone Health: A Novel Perspective on Their Potentials in Treating Osteoporosis and Osteoarthritis

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Integrative Medicine 2024年第4期30卷 379-384页

作者： XIN Li TAN guo-yao ZHANG qiang ZHANG Qun Good Clinical Practice Development Guangdong Provincial Key Laboratory of Bone and Joint Degeneration DiseasesThe Third Affiliated Hospital of Southern Medical UniversityGuangzhou(510630)China Department of Pharmacy Sun Yat-sen Memorial HospitalSun Yat-sen UniversityGuangzhou(510120)China

Phellodendron(PN)species,traditionally used in Chinese medicine for centuries,hold promise as a potential treatment for osteoporosis(OP)and osteoarthritis(OA)due to their bioactive *** bioactive compounds,including berberine and palmatine,exhibit anti-inflammatory,antioxidant,and bone-protective properties,contributing to their potential therapeutic benefits in promoting bone health and preventing bone ***,challenges such as the need for standardized preparation and dosing,limited clinical studies,and potential interactions with other medications hinder their clinical ***,the rich history of PN species in Chinese medicine provides a promising foundation for future investigation into their potential as alternative treatments for OP and *** research is needed to fully understand the underlying mechanisms of action and explore the clinical implications of PN for bone health.

关键词： Phellodendron species bone health osteoporosis osteoarthritis review

Experimental Study of Local Scour Around Four Piles Under Different Attack Angles and Gap Ratios

在线全文

学校读者我要写书评

暂无评论

China Ocean Engineering 2024年第4期38卷 612-624页

作者： LIU Ming-ming TANG guo-qiang JIN Xin GENG Shao-yang School of Architecture and Engineering Liaocheng UniversityLiaocheng 252000China Water-Sediment Regulation and Sand Effective Utilization Special Laboratory of Shandong Provincial Education Department Liaocheng UniversityLiaocheng 252000China State Key Laboratory of Coastal and Offshore Engineering Dalian University of TechnologyDalian 116024China College of Electronic Engineering Chengdu University of Information TechnologyChengdu 610225China College of Energy Chengdu University of TechnologyChengdu 610059China

In an effort to investigate and quantify the patterns of local scour,researchers embarked on an in-depth study using a systematic experimental *** research focused on the effects of local scour around a set of four piles,each subjected to different hydromechanical *** particular,this study aimed to determine how different attack angles—the angles at which the water flow impinges on the piles,and gap ratios—the ratios of the spacing between the piles to their diameters,influence the extent and nature of scour.A comprehensive series of 35 carefully designed experiments were orchestrated,each designed to dissect the nuances in how the gap ratio and attack angle might contribute to changes in the local scour observed at the base of pile *** these experimental trials,a wealth of local scour data were collected to support the *** data included precise topographic profiles of the sediment bed around the pile groups,as well as detailed scour time histories showing the evolution of scour at strategic feature points throughout the test *** analysis of the experimental data provided interesting *** study revealed that the interplay between the gap ratio and the attack angle had a pronounced influence on the scouring dynamics of the pile *** of the key observations was that the initial phases of scour,particularly within the first hour of water flow exposure,were characterized by a sharp increase in the scour depth occurring immediately in front of the *** this initial rapid development,the scour depth transitioned to a more gradual change *** contrast,the scour topography around the piles continuously *** suggests that sediment displacement and the associated sculpting of the seabed around pile foundations are sustained and progressive processes,altering the underwater landscape over *** results of this empirical investigation have significant implications for the design and constructio

关键词： local scour piles gap ratio attack angle

Halogen-bond induced unusual polyhalogen anions formation in hydrogen-bonded frameworks to secure iodine sequestration

在线全文

学校读者我要写书评

暂无评论

Nano Research 2024年第7期17卷 6766-6772页

作者： Yi xie Pengling Huang qiang Gao Shiyu Wang Jianchen Wang Gang Ye Collaborative Innovation Center of Advanced Nuclear Energy Technology Institute of Nuclear and New Energy TechnologyTsinghua UniversityBeijing 100084China

Safe confinement of fission iodine isotopes for long-term radioactive waste disposal remains a formidable challenge,as conventional sorbents provide inherently weak iodine-host *** report here a novel halogen bond(X-bond)directed strategy to sequester volatile iodine in hydrogen-bonded(H-bonded)frameworks with unprecedented ***-assisted Hbonded frameworks bearing open halide sites are developed,showing distinctive iodine encapsulation behaviors without compromising the *** crystallographic evidence indicates the formation of X-bonds,i.e.,I–I···Cl^(−) and I–I···Br^(−),within the confined pore *** polyhalogen anions,i.e.,[I_(2)Cl_(2)]^(2−)and[I_(2)Br_(2)]^(2−),sustained in H-bonded frameworks are identified for the first *** X-bond reinforced host-guest interaction affords robust iodine trapping without leaking out even at elevated temperatures up to 180℃.By integrating the halogen-bond chemistry with H-bonded frameworks,this study offers fresh concepts for developing effective host reservoirs to secure fission iodine isotopes from spent fuel reprocessing off-gases.

关键词： halogen-bond chemistry anion coordination chemistry hydrogen-bonded organic frameworks polyhalogen anions iodine confinement

Maximum Power Point Tracking Technology for PV Systems: Current Status and Perspectives

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Energy Engineering 2024年第8期121卷 2009-2022页

作者： Bo Yang Rui xie Zhengxun guo Faculty of Electric Power Engineering Kunming University of Science and TechnologyKunming650500China Intelligent Electric Power Grid Key Laboratory of Sichuan Province Chengdu610065China Foshan Graduate School of Innovation Northeastern UniversityFoshan528311China College of Information Science and Engineering Northeastern UniversityShenyang110819China

Maximum power point tracking(MPPT)technology plays a key role in improving the energy conversion efficiency of photovoltaic(PV)systems,especially when multiple local maximum power points(LMPPs)occur under partial shading conditions(PSC).It is necessary to modify the operating point efficiently and accurately with the help of MPPT technology to maximize the collected *** though a lot of research has been carried out and impressive progress achieved for MPPT technology,it still faces some challenges and ***,the mathematical model established for PV cells is not precise ***,the existing algorithms are often optimized for specific conditions and lack comprehensive adaptability to the actual operating ***,a single algorithm may not be able to give full play to its *** the end,the selection criteria for choosing the suitable MPPT algorithm/converter combination to achieve better performance in a given scenario is very ***,this paper systematically discusses the current research status and challenges faced by PV MPPT technology around the three aspects of MPPT models,algorithms,and hardware *** in-depth thinking and discussion,it also puts forward positive perspectives on future development,and five forward-looking solutions to improve the performance of PV systems MPPT are suggested.

关键词： PV systems MPPT partial shading condition DC-DC converter

Nutrition impacts of non-solid cooking fuel adoption on under-five children in developing countries

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Integrative Agriculture 2024年第2期23卷 397-413页

作者： Yalin Tang Yuhe guo Gang xie Chengfang Liu China Center for Agricultural Policy School of Advanced Agricultural SciencesPeking UniversityBeijing 100871China Agricultural Information Institute Chinese Academy of Agricultural SciencesBeijing 100081China

This paper examines the nutrition impacts of using non-solid cooking fuel on under-five children in developing *** draw on data from more than 1.12 million children in 62 developing countries from the Demographic and Health Surveys(DHS).Results from both fixed effects(FE)and instrumental variable(IV)estimates show that using non-solid cooking fuel significantly improves the nutrition outcomes of under-five *** with their peers from households mainly using solid fuel,children from households mainly using non-solid fuel exhibit a lower probability of experiencing stunting(by 5.9 percentage points)and being underweight(by 1.2 percentage points).Our further investigation provides evidence for several underlying mechanisms,such as improved indoor air quality,induced reduction in children’s respiratory symptoms,benefits on maternal health,and reduction in maternal time spent on fuel collection or *** analyses suggest that the nutrition benefits of using non-solid cooking fuel are more prominent among boys,children above three years old,and those from households of lower socioeconomic status,rural areas,and Southeast Asia.

关键词： non-solid cooking fuel nutrition benefits under-five children developing countries

Correlation between longitudinal crack occurrence and mold heat transfer in continuous casting based on process data mining

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2024年第5期31卷 1139-1152页

作者： Zhi-qiang Peng Zi-bing Hou Kai Yi Kun-hui guo Dong-wei guo Guang-hua Wen College of Materials Science and Engineering Chongqing UniversityChongqing400044China Chongqing Key Laboratory of Vanadium-Titanium Metallurgy and New Materials Chongqing UniversityChongqing400044China

The correlation between the longitudinal crack occurrence and integrated heat transfer of the mold with data mining methods was ***,three kinds of support vector machine models based on principal component analysis with different input features were established to explore the effect of integrated heat transfer on the accuracy of the prediction model for the longitudinal *** results show that the accuracy was improved while features including mean and standard deviation of integrated heat transfer were ***,the difference in integrated heat transfer between defect and normal samples under the same process parameters was quantitatively *** with normal samples,the temperature difference of cooling water for defect samples decreased by 0.65%,and the temperature difference fluctuation increased by 31.1%.Finally,the literature data were used to provide support for the quantitative correlation according to defect formation mechanism.A new criterion for the prediction of longitudinal crack and a discovering method for correlation between product quality and process parameters in the manufacturing industry have been provided.

关键词： Continuous casting slab Longitudinal surface crack Heat transfer Data mining Quantitative correlation