http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Graphene Coatings as Barrier Layers to Prevent the Water-Induced Corrosion of Silicate Glass
Wang, Bin,Cunning, Benjamin V.,Park, Sun-Young,Huang, Ming,Kim, Ju-Young,Ruoff, Rodney S. American Chemical Society 2016 ACS NANO Vol.10 No.11
<P>Corrosion-protective coatings for silicate glass based on the transfer of one or two layers of graphene grown on copper by chemical vapor deposition have been demonstrated. The effectiveness of graphene to act as a glass corrosion inhibitor was evaluated by water immersion testing. After 120 days of immersion in water, bare glass samples had a significant increase in surface roughness and defects, which resulted in a marked reduction in fracture strength. In contrast, the single-and double-layer graphene-coated glasses experienced negligible changes in both fracture strength and surface roughness. The anticorrosion mechanism was also studied.</P>
Controlled Folding of Single Crystal Graphene
Wang, Bin,Huang, Ming,Kim, Na Yeon,Cunning, Benjamin V.,Huang, Yuan,Qu, Deshun,Chen, Xianjue,Jin, Sunghwan,Biswal, Mandakini,Zhang, Xu,Lee, Sun Hwa,Lim, Hyunseob,Yoo, Won Jong,Lee, Zonghoon,Ruoff, Rod American Chemical Society 2017 Nano letters Vol.17 No.3
<P>Folded graphene in which two layers are stacked with a twist angle between them has been predicted to exhibit unique electronic, thermal, and magnetic properties. We report the folding of a single crystal monolayer graphene film grown on a Cu(111) substrate by using a tailored substrate having a hydrophobic region and a hydrophilic region. Controlled film delamination from the hydrophilic region was used to prepare macroscopic folded graphene with good uniformity on the millimeter scale. This process was used to create many folded sheets each with a defined twist angle between the two sheets. By identifying the original lattice orientation of the monolayer graphene on Cu foil, or establishing the relation between the fold angle and twist angle, this folding technique allows for the preparation of twisted bilayer graphene films with defined stacking orientations and may also be extended to create folded structures of other two-dimensional nanomaterials.</P>
A multi-institutional analysis of sternoclavicular joint coverage following osteomyelitis
Sammy Othman,Omar Elfanagely,Saïd C. Azoury,Geoffrey M. Kozak,Jessica Cunning,Arturo J. Rios-Diaz,Prashanth Palvannan,Patrick Greaney,Matthew P. Jenkins,Doraid Jarrar,Stephen J. Kovach,John P. Fischer 대한성형외과학회 2020 Archives of Plastic Surgery Vol.47 No.5
Background Sternoclavicular joint (SCJ) osteomyelitis is a rare pathology requiring urgent intervention. Several operative approaches have been described with conflicting reports. Here, we present a multi-institutional study utilizing multiple surgical pathways for SCJ reconstruction. Methods A multi-institutional retrospective cohort study was conducted to identify patients who underwent surgical repair for sternoclavicular osteomyelitis between 2008 and 2019. Patients were stratified according to reconstruction approach: single-stage reconstruction with advancement flap and delayed-reconstruction with flap following initial debridement. Demographics, operative approach, type of reconstruction, and postoperative outcomes were analyzed. Results Thirty-two patients were identified. Mean patient age was 56.2±13.8 years and 68.8% were male. The average body mass index (BMI) was 30.0±8.8 kg/m2. The most common infection etiologies were intravenous drug use and bacteremia (both 25%). Fourteen patients (43.8%) underwent one-stage reconstruction and 18 (56.2%) underwent delayed twostaged reconstruction. Both single and delayed-stage groups had comparable rates of reinfection (7.1% vs. 11.1%, respectively), surgical site complications (21.4% vs. 27.8%), readmissions (7.1% vs. 16.6%), and reoperations (7.1% vs. 5.6%; all P>0.05). The single-stage reconstruction group had a significantly lower BMI (26.2±5.7 kg/m2 vs. 32.9±9.1 kg/m2; P<0.05) and trended towards shorter hospital length of stay (11.3 days vs. 17.9 days; P=0.01). Conclusions Both single and delayed-stage approaches are appropriate methods with comparable outcomes for reconstruction for SCJ osteomyelitis. When clinically indicated, a singlestage reconstruction approach may be preferable in order to avoid a second operation as associated with the delayed phase, and possibly shortening total hospital length of stay.
Colossal grain growth yields single-crystal metal foils by contact-free annealing
Jin, Sunghwan,Huang, Ming,Kwon, Youngwoo,Zhang, Leining,Li, Bao-Wen,Oh, Sangjun,Dong, Jichen,Luo, Da,Biswal, Mandakini,Cunning, Benjamin V.,Bakharev, Pavel V.,Moon, Inyong,Yoo, Won Jong,Camacho-Mojica American Association for the Advancement of Scienc 2018 Science Vol.362 No.6418
<P><B>Turning many into one</B></P><P>Single-crystal metal foils are valuable for their surface properties that allow for synthesis of materials like graphene. Jin <I>et al.</I> present a strategy for creating colossal single-crystal metal foils called “contact-free annealing” (see the Perspective by Rollett). The method relies on hanging and heating commercially available, inexpensive, cold-rolled metal foils. Almost as if by magic, the polycrystalline grains rotate and anneal into a large single-crystal sheet with a specific crystal orientation. The strategy allows for the creation of much larger and much cheaper single-crystal metal foils.</P><P><I>Science</I>, this issue p. 1021; see also p. 996</P><P>Single-crystal metals have distinctive properties owing to the absence of grain boundaries and strong anisotropy. Commercial single-crystal metals are usually synthesized by bulk crystal growth or by deposition of thin films onto substrates, and they are expensive and small. We prepared extremely large single-crystal metal foils by “contact-free annealing” from commercial polycrystalline foils. The colossal grain growth (up to 32 square centimeters) is achieved by minimizing contact stresses, resulting in a preferred in-plane and out-of-plane crystal orientation, and is driven by surface energy minimization during the rotation of the crystal lattice followed by “consumption” of neighboring grains. Industrial-scale production of single-crystal metal foils is possible as a result of this discovery.</P>
자가골 이식술에 대한 임상적고찰 : 장골의 골재취 술식에 대하여 Techniques of Taking the Iliac-Bone Graft
인주철,김익동,한천수 慶北大學校 醫科大學 1979 慶北醫大誌 Vol.20 No.2
저자는 경북대학교 의과대학 정형외과학교실에서 1979년 1월부터 10월까지 장골이식 수술을 시행한 30례중 분석 관찰이 가능했던 16례를 분석하여 몇가지 의의 있는 결과를 얻었기에 문헌적고찰과 아울러 보고 하는 바이다. 1. 골재취부위는 전례에서 장골의 전방극치부를 택하였으며, 골이식을 시행한 질병은 지연유합 및 불유합이 11례로 가장 많았고 신선골절 4례, 골종양 1례였다. 2. 골채취 술식으로는 3가지 술식을 사용하였다. 제1형 및 2형은 과거의 술식은 술후에 많은 문제점을 남기는데 비해 제3형 술식은 술식이 간편하며 주위조직 손상이 적고 술후 수술부에 남는 기형이 거의 없어 성인에 있어서 장골채취 술실중 권장할만한 좋은 방법이라 사료된다. 3. 장골 채취후 골채위부위에 발생한 통증의 소실시기는 통증민감도의 개인차 및 술식의 차이로 비교하기가 어려우나 술식 제1형에서 통증 소실시기가 더 길게 나타났다. Experimental studies on bone grafts and its clinical applications have been described in enormous number of papers since early 1900. The bone grafts have been widely applied in orthopedic surgery, mostly for the purposes to get better union in the fractures or diseases or to fill up the bony defect. Surgical procedures of taking the iliac-bone graft were carried out on 16 cases at Deparment of Orthopedic surgery, Kyungpook National University Hospital, from Jan. to Dec. 1979. The author used three different techniques of taking the iliac-bone graft, so called sliver, outer cortex only and revere “V”techniques. Reverse “V”technique was introduced by Dr, Paul Tessier, in Paris, and Dr. Wolfe and Dr. Kawamoto were present with minor modifications. The author also observed, the duration of pain at the site of excision of an iliac-bone graft. But it needs further evaluation.
Adaptive Learning Path Recommendation based on Graph Theory and an Improved Immune Algorithm
( Cun-ling Bian ),( De-liang Wang ),( Shi-yu Liu ),( Wei-gang Lu ),( Jun-yu Dong ) 한국인터넷정보학회 2019 KSII Transactions on Internet and Information Syst Vol.13 No.5
Adaptive learning in e-learning has garnered researchers’ interest. In it, learning resources could be recommended automatically to achieve a personalized learning experience. There are various ways to realize it. One of the realistic ways is adaptive learning path recommendation, in which learning resources are provided according to learners’ requirements. This paper summarizes existing works and proposes an innovative approach. Firstly, a learner-centred concept map is created using graph theory based on the features of the learners and concepts. Then, the approach generates a linear concept sequence from the concept map using the proposed traversal algorithm. Finally, Learning Objects (LOs), which are the smallest concrete units that make up a learning path, are organized based on the concept sequences. In order to realize this step, we model it as a multi-objective combinatorial optimization problem, and an improved immune algorithm (IIA) is proposed to solve it. In the experimental stage, a series of simulated experiments are conducted on nine datasets with different levels of complexity. The results show that the proposed algorithm increases the computational efficiency and effectiveness. Moreover, an empirical study is carried out to validate the proposed approach from a pedagogical view. Compared with a self-selection based approach and the other evolutionary algorithm based approaches, the proposed approach produces better outcomes in terms of learners’ homework, final exam grades and satisfaction.
Cun-ming Ma,Qing-song Duan,Haili Liao 대한토목학회 2018 KSCE JOURNAL OF CIVIL ENGINEERING Vol.22 No.7
Su-tong Bridge is a cable-stayed bridge with a main span of 1088 m whose stiffness is small and it is sensitive to wind action. Thelength of the bridge girder at maximum single cantilever stage can reach up to 540 m, much attention should be paid in theaerodynamic performances of the under construction bridge. Based on wind tunnel tests, the aerodynamic characteristics of thegirder, free standing pylon are considered. Also, field measurements of the pressure distribution on girder surface are presented. Theexperimental results show that only torsional vibration is found in the smooth flow at wind attack angle of 3°. Considering theinfluence of turbulence, the vortex-induced vibration of the girder is disappeared. The pressure coefficient values on the uppersurface obtained from the wind tunnel tests are relatively larger than that obtained from field measurement. The drag coefficientsvalues obtained from the wind tunnel tests are about 20% larger than that from field measurement. The crane can reduce theamplitude values of the free standing pylon at an incident angle of 0°, corresponding to along bridge axis. The turbulent flow can alsoreduce the amplitude values of vortex-induced vibration.