检索结果-南通市图书馆

Thin-Wall Aluminum Die-Casting Technology for Development of Notebook Computer Housing

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2008年第1期24卷 65-69页

作者： chang-Seog Kang Jae-Ik Cho chang- Yeol Jeong Se- Weon Choi young-chan kim Korea Institute of Industrial Technology Gwangju Korea

Silicon-based aluminum casting alloys are known to be one of the most widely used alloy systems mainly due to their superior casting characteristics and unique combination of mechanical and physical properties. However,manufacturing of thin-walled aluminum die-casting components,less than 1.0 mm in thickness,is generally known to be very difficult task to achieve aluminum casting alloys with high ***,in this study,the optimal die-casting conditions for producing 297 mm×210 mm×0.7 mm thin-walled aluminum component was examined experimentally by using 2 different gating systems,tangential and split type,and vent ***,computational solidification simulation was also *** results showed that split type gating system was preferable gating design than tangential type gating system at the point of view of soundness of casting and distortion generated after *** was also found that proper vent design was one of the most important factors for producing thin-wall casting components because it was important for the fulfillment of the thin-wall cavity and the minimization of the casting distortion.

关键词： Aluminum Thin-wall die-casting Notebook computer housing Cold chamberdie-casting machine

Die Casting Mold Design of the Thin-walled Aluminum Case by Computational Solidification Simulation

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2008年第3期24卷 383-388页

作者： young-chan kim chang-Seog Kang Jae-Ik Cho chang-Yeol Jeong Se-Weon Choi Sung-Kil Hong Korea Institute of Industrial Technology Chonnam National University

Recently, demand for the lightweight alloy in electric/electronic housings has been greatly increased. However, among the lightweight alloys, aluminum alloy thin-walled die casting is problematic because it is quite difficult to achieve sufficient fluidity and feedability to fill the thin cavity as the wall thickness becomes less than 1mm. Therefore, in this study, thin-walled die casting of aluminum （Al-Si-Cu alloy： ALDC 12） in size of notebook computer housing and thickness of 0.8 mm was investigated by solidification simulation （MAGMA soft） and actual casting experiment （Buhler Evolution B 53D）. Three different types of gating design, finger, tangential and split type with 6 vertical runners, were simulated and the results showed that sound thin-walled die casting was possible with tangential and split type gating design because those gates allowed aluminum melt to flow into the thin cavity uniformly and split type gating system was preferable gating design comparing to tangential type gating system at the point of view of soundness of casting and distortion generated after solidification. Also, the solidification simulation agreed well with the actual die-casting and the casting showed no casting defects and distortion.

关键词： Aluminum casting alloy Thin-wall die casting Solidification simulation

Interface properties and phase formation between surface coated SKD61 and aluminum alloys

在线全文

学校读者我要写书评

暂无评论

中国有色金属学会会刊：英文版 2009年第4期19卷 875-878页

作者： Se-Weon CHOI young-chan kim Se-Hun chanG Ik-Hyun OH Joon-Sik PARK chang-Seog KANG Automotive Components Center Korea Institute of Industrial Technology Division of Advanced Materials Engineering Hanbat National University

The intermediate phase formation and surface protection effects between SKD61 die mold alloys and aluminum alloys were investigated during a simulated die-casting *** surface coatings of SKD61 alloy were carried out via Si pack cementation coatings at 900 ℃ for 10 h and the ε-FeSi phase *** the coated SKD61 alloy was dipped in the liquid aluminum alloy(ALDC12),the surface coated SKD61 alloys showed better surface properties compared with uncoated SKD61 alloys,i.e.,the intermediate phases(FeSiAl compound) were not produced for the coated SKD61 *** coating layer of ε-FeSi served as a diffusion barrier for the formation of FeSiAl compounds.

关键词：表面涂层铝合金接口特性表面合金涂层表面保护合金生产化合物中间相

Surface plasmon excitation in semitransparent inverted polymer photovoltaic devices and their applications as label-free optical sensors

在线全文

学校读者我要写书评

暂无评论

Light(Science & Applications) 2014年第1期3卷 5-12页

作者： Byoungchoo Park Soo Hong Yun chan Youn Cho young chan kim Jung Chul Shin Hong Goo Jeon Yoon Ho Huh Inchan Hwang Ku Youn Baik young In Lee Han Sup Uhm Guang Sup Cho Eun Ha Choi Department of Electrical and Biological Physics Kwangwoon UniversitySeoul 139-701Republic of Korea Department of Electronic Materials Engineering Kwangwoon UniversitySeoul 139-701Republic of Korea

Herein,we report on surface plasmon(SP)-sensitive semitransparent inverted polymer photovoltaic(PV)devices that are based on multilayered material systems consisting of poly(3-hexylthiophene):fullerene-derivative bulk-heterojunction PV layers and thin gold or silver *** demonstrate that these PV devices allow the simultaneous generation of both electrical power and SPs on their anodes for photoexcitation just above the optical absorption edge of the PV layers,resulting not only in attenuated total reflection,but also in attenuated photocurrent generation(APG)under the SP resonance(SPR)***,we also confirm that the biomolecular interaction of biotin–streptavidin on the PV devices can be precisely detected via apparent SPR angle shifts in the APG spectra,even without the need for complex attenuated total reflection *** highlight our view that APG measurements made using these PV devices show great potential for the development of future generations of compact and highly sensitive SPR-based optical sensors.

关键词： attenuated total reflection optical sensors photocurrent generation polymer photovoltaic devices surface plasmon

Feature Estimation of AE Signals caused by Rotating Shaft with Crack Growth

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

Feature Estimation of AE Signals caused by Rotating Shaft wi...

A New Encryption Mechanism Supporting the Update of Encrypted Data for Secure and Efficient Collaboration in the Cloud Environment

第六届材料与热加工物理模拟及数值模拟国际会议

作者： Dongsik Gu Jae Gu kim young chan kim Won Jo Park Byeong Keun Choi Department of Precision and Mechanical Engineering Gyeongsang National University Graduate School

Vibration analysis is widely used in machinery diagnosis,and the wavelet transforms and envelope analysis had also been implemented in many applications in the condition monitoring of *** transform is using in researches for detection of the faults in *** are applied for a development of the condition monitoring system for early detection of the faults generated in several key components of *** detection of the faults is a very important factor for condition monitoring and a basic component to extend CBM （Condition-Based Maintenance） to PM （Prediction Maintenance）.And AE （acoustic emission） sensor has a specific characteristic on the high sensitivity of the signal,high frequency and low energy,so recently AE technique is applied in some research papers for the early detection of machine *** this paper,the AE signals caused by the crack growth on the rotating shaft were acquired through AE *** AE signals were preprocessed by wavelet transforms,and then the power spectrums of the frequency domain were generated using the FFT result of *** the power spectrum,some peaks were presented on the several frequencies,and the characteristics considered on the crack growth were found out.

关键词： Acoustic Emission Crack Growth Rotating Shaft Wavelet Transform Feature Tendency.

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Computer Modeling in Engineering & Sciences 2025年第1期142卷 813-834页

作者： chanhyeong Cho Byeori kim Haehyun Cho Taek-young Youn Department of Cyber Security Dankook UniversityYongin16890Republic of Korea Department of Software Soongsil UniversitySeoul07027Republic of Korea

With the rise of remote collaboration,the demand for advanced storage and collaboration tools has rapidly ***,traditional collaboration tools primarily rely on access control,leaving data stored on cloud servers vulnerable due to insufficient *** paper introduces a novel mechanism that encrypts data in‘bundle’units,designed to meet the dual requirements of efficiency and security for frequently updated collaborative *** bundle includes updated information,allowing only the updated portions to be reencrypted when changes *** encryption method proposed in this paper addresses the inefficiencies of traditional encryption modes,such as Cipher Block Chaining(CBC)and Counter(CTR),which require decrypting and re-encrypting the entire dataset whenever updates *** proposed method leverages update-specific information embedded within data bundles and metadata that maps the relationship between these bundles and the plaintext *** utilizing this information,the method accurately identifies the modified portions and applies algorithms to selectively re-encrypt only those *** approach significantly enhances the efficiency of data updates while maintaining high performance,particularly in large-scale data *** validate this approach,we conducted experiments measuring execution time as both the size of the modified data and the total dataset size *** show that the proposed method significantly outperforms CBC and CTR modes in execution speed,with greater performance gains as data size ***,our security evaluation confirms that this method provides robust protection against both passive and active attacks.

关键词： Cloud collaboration mode of operation data update efficiency

Maximizing biomass utilization: An integrated strategy for coproducing multiple chemicals

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 Energy Chemistry 2025年第1期100卷 180-191页

作者： Byeongchan Ahn Sua Jo Jonggeol Na J.Jay Liu young-Ju kim Wangyun Won Department of Chemical and Biological Engineering Korea University Department of Chemical Engineering (Integrated process) Kyung Hee University Department of Chemical Engineering and Materials Science Ewha Womans University Department of Chemical Engineering Pukyong National University Resources Engineering Plant Research Department Korea Institute of Geoscience and Mineral Resources

Lignocellulosic biomass is one of the viable solutions to alleviate the global warming. However, the limited utilization of biomass majorly focused on cellulose and hemicellulose restricts the economic and environmental feasibilities. To cope with this issue, we proposed an integrated process of co-producing 1,6-hexanediol（1,6-HDO） with tetrahydrofuran and adipic acid from biomass, referred to as Strategy A. To compare the impacts of lignin upgrading and feedstock, Strategy B, which co-produces tetrahydrofuran alone, and Strategy C, which is the traditional route to produce 1,6-HDO from fossil fuels, were used. Heat networks are also designed to reduce operating costs and indirect carbon emissions due to energy consumption, saving 87% and 83% of the heat and cooling requirements, respectively, in Strategy A. The market competitiveness of Strategy A was evaluated by determining the minimum selling price through techno-economic analysis, and sustainability was thoroughly investigated by quantifying the environmental impacts through both midpoint and endpoint life-cycle assessments（LCAs）.Strategy A was found to be the most favorable both economically（USRDSCHARDOLLAR3,402/ton） and environmentally（-26.9 kg CO2eq.）. This indicates that lignin valorization is not only economically but also environmentally preferred. Finally, changes in economic and environmental feasibilities depending on economic, process, and environmental parameters were investigated using sensitivity and uncertainty analyses. The results of these analyses provide valuable insight into bio-based chemical production.

关键词： Biorefinery Carbon mitigation Climate change Global warming Lignin utilization Bioeconomy

High mobility group box 1 in the central nervous system:regeneration hidden beneath inflammation

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Neural Regeneration Research 2025年第1期20卷 107-115页

作者： Hanki kim Bum Jun kim Seungyon Koh Hyo Jin Cho Xuelian Jin Byung Gon kim Jun young Choi Department of Brain Science Ajou University School of MedicineSuwonSouth Korea Department of Biomedical Sciences Ajou University Graduate School of MedicineSuwonSouth Korea Department of Neurology Ajou University School of MedicineSuwonSouth Korea Department of Geriatrics The Affiliated Suqian First People’s Hospital of Nanjing Medical UniversitySuqianJiangsu ProvinceChina

High-mobility group box 1 was first discovered in the calf thymus as a DNA-binding nuclear protein and has been widely studied in diverse fields,including neurology and ***-mobility group box 1 in the extracellular space functions as a pro-inflammatory damage-associated molecular pattern,which has been proven to play an important role in a wide variety of central nervous system disorders such as ischemic stroke,Alzheimer’s disease,frontotemporal dementia,Parkinson’s disease,multiple sclerosis,epilepsy,and traumatic brain *** drugs that inhibit high-mobility group box 1 as a damage-associated molecular pattern,such as glycyrrhizin,ethyl pyruvate,and neutralizing anti-high-mobility group box 1 antibodies,are commonly used to target high-mobility group box 1 activity in central nervous system *** it is commonly known for its detrimental inflammatory effect,high-mobility group box 1 has also been shown to have beneficial pro-regenerative roles in central nervous system *** this narrative review,we provide a brief summary of the history of high-mobility group box 1 research and its characterization as a damage-associated molecular pattern,its downstream receptors,and intracellular signaling pathways,how high-mobility group box 1 exerts the repair-favoring roles in general and in the central nervous system,and clues on how to differentiate the pro-regenerative from the pro-inflammatory *** targeting high-mobility group box 1 in the central nervous system may benefit from differentiating between the two functions rather than overall suppression of high-mobility group box 1.

关键词： central nervous system damage-associated molecular pattern ethyl pyruvate glycyrhizzin high mobility group box 1 inflammation neural stem cells neurodevelopment oligodendrocyte progenitor cells redox status regeneration

A Rapid Adaptation Approach for Dynamic Air‑Writing Recognition Using Wearable Wristbands with Self‑Supervised Contrastive Learning

在线全文

学校读者我要写书评

暂无评论

Nano-Micro Letters 2025年第2期17卷 417-431页

作者： Yunjian Guo Kunpeng Li Wei Yue Nam‑young kim Yang Li Guozhen Shen Jong‑Chul Lee Department of Electronic Convergence Engineering Kwangwoon UniversitySeoul 01897South Korea Radio Frequency Integrated Circuit(RFIC)Bio Centre Kwangwoon UniversitySeoul 01897South Korea Department of Electronic Engineering Kwangwoon UniversitySeoul 01897South Korea School of Microelectronics Shandong UniversityJinan 250101People’s Republic of China State Key Laboratory of Integrated Chips and Systems Fudan UniversityShanghai 200433People’s Republic of China School of Integrated Circuits and Electronics Beijing Institute of TechnologyBeijing 100081People’s Republic of China

Wearable wristband systems leverage deep learning to revolutionize hand gesture recognition in daily *** existing approaches that often focus on static gestures and require extensive labeled data,the proposed wearable wristband with selfsupervised contrastive learning excels at dynamic motion tracking and adapts rapidly across multiple *** features a four-channel sensing array composed of an ionic hydrogel with hierarchical microcone structures and ultrathin flexible electrodes,resulting in high-sensitivity capacitance *** wireless transmission from a Wi-Fi module,the proposed algorithm learns latent features from the unlabeled signals of random wrist ***,only few-shot labeled data are sufficient for fine-tuning the model,enabling rapid adaptation to various *** system achieves a high accuracy of 94.9%in different scenarios,including the prediction of eight-direction commands,and air-writing of all numbers and *** proposed method facilitates smooth transitions between multiple tasks without the need for modifying the structure or undergoing extensive task-specific *** utility has been further extended to enhance human–machine interaction over digital platforms,such as game controls,calculators,and three-language login systems,offering users a natural and intuitive way of communication.

关键词： Wearable wristband Self-supervised contrastive learning Dynamic gesture Air-writing Human-machine interaction