检索结果-南通市图书馆

Finite difference time domain study of light transmission through multihole nanostructures in metallic film

在线全文

学校读者我要写书评

暂无评论

Photonics Research 2013年第4期1卷 154-159页

作者： Mehrdad Irannejad mustafa yavuz Bo Cui Waterloo Institute for Nanotechnology University of WaterlooWaterlooOntario N2L 3G1Canada

The optical transmittance properties of single-hole arrays and three-hole chain(vertical)arrays with different geometrical parameters were numerically *** was shown that on increasing the vertical distance between the holes in the hole chain array,the FWHM of the(1,0)resonance mode was decreased and minimum FWHM of 29 nm was obtained for a vertical gap of 48 nm between each side hole.A 1.5–2.0 times larger transmittance enhancement was observed by varying the incident light polarization from the y axis to the x ***,it was found that the optical transmittance of the hole chain array in the case of linearly x-axis polarized incident electromagnetic(EM)field was∼6 times larger than that linearly y-axis polarized incident EM field.

关键词： polarization arrays light

Physical Effects of Mechanical Processes on Bi-2223 Tapes

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 Electronic Science and Technology of China 2008年第2期6卷 185-190页

作者： Wu-Ming Chen Jian-Xun Jin mustafa yavuz Center of Applied Superconductivity and Electrical Engineering School of Automation Engineering University of Electronic Science and Technology of China Chengdu 610054 China and Mechatronics Program Mechanical Engineering Department University of Waterloo Waterloo ON N2L 3G1 Canada Center of Applied Superconductivity and Electrical Engineering School of Automation Engineering University of Electronic Science and Technology of China Chengdu 610054 China Mechatronics Program Mechanical Engineering Department University of Waterloo Waterloo ON N2L 3G1 Canada

The effects of intermediate mechanical deformation （IMD） and bending processing on Bi-2223 tapes were studied. Bi-2223 tapes were manufactured by powder-in-tube process with an IMD. Normal rolling （NR）, pressing （P） and sandwich rolling （SR） with different reduction rate were used in the IMD. And there were an optimum reduction rate existing for the three MID techniques, at which critical current reached maximum. Critical current densities Jc of Bi-2223 crystals were measured with an applied magnetic field B respectively parallel to ab face and c axis. Relations of Jc dependences of reduction rate and superconducting materials density D were respectively studied and showed a Gaussian distribution law. Maximum pinning force density Fmax and irreversible magnetic field Birr were introduced to describe the effects of mechanical processing. Analysis of experimental results showed that Jcs Fmax and Birr were linear dependence on D. Obviously, increasing D was a vital way to enhance Jc Bending experiments were performed for SR tapes sheathed by Ag and Ag/Sb and Ag/Mg alloy, respectively. Silver alloy sheathed tapes showed better bending properties than pure silver sheathed one. Therefore, silver alloy sheathed, optimum reduction rate of IMD, and increasing D for Bi-2223 tapes＇ applications were important technical strategies to enhance their mechanical, electrical, and magnetic properties.

关键词： Bending Bi-2223 tape critical current,deformation density.

Temperature Dependence of Growth Mechanism forNanoscale High T_c Superconductors

在线全文

学校读者我要写书评

暂无评论

Journal of Electronic Science and Technology of China 2008年第2期6卷 175-180页

作者： Wu-Ming Chen mustafa yavuz Jian-Xun Jin Center of Applied Superconductivity and Electrical Engineering University of Electronic Science and Technology of China Chengdu 610054 China and Nano ＆ Micro-Systems Research Lab Mechanical ＆ Mechatronics Engineering Department University of Waterloo Waterloo ON N2L 3G1 Canada Nano ＆ Micro=Systems Research Lab Mechanical ＆ Mcchatronics Engineering Department University of Waterloo Waterloo ON N2L 3GI Canada Center of Applied Superconductivity and Electrical Engineering University of Electronic Science and Technology of China Chcngdu 610054 China

The growth mechanisms of high temperature Yttrium- and Bismuth-based-superconductors were investigated at nanoscale. We started with studying the growth relationships among the three phases of Bi-2201, Bi-2212, and Bi-2233, and then extended to another growth mechanism of Bi-2223 and the growth of yttrium-based high-temperature nanosuperconductors （nano-YBCO）. A time dependence of growth experiment was performed. In this experiment, the Bi-based superconductors grew within different sintering periods, and its three phases were determined by X-ray diffraction. And then, a time dependence of growth model was suggested to explain the experimental facts. With this model, governing equations were derived to quantitatively describe the growth and decomposition mechanisms during sintering period. The results calculated from the derived equations were well in agreement with the experimental data. We also suggested an alternative growth mechanism for the Bi-2223 phase, which was supported by an observation of transmission electron microscopy （TEM）. The nano-YBCO also grew, and their orthorhombic crystal structures were determined by the TEM. The superconducting properties of Bi-2223 were investigated by the measurements of ac magnetic susceptibility. It is expected that the derived equations will fit the alternative experimental growth mechanism of the Bi-2223 phase and the nano-YBCO growth mechanism, too.

关键词： Bi-2223 growth mechanism model,nanosuperconductor transmission electron microscopy,X-ray diffraction.

Comprehensive Review of Studies on Metamorphic Rocks

在线全文

学校读者我要写书评

暂无评论

International Journal of Geosciences 2023年第10期14卷 999-1035页

作者： Hakan Citak mustafa Coramik Huseyin Gunes Sabri Bicakci yavuz Ege Department of Electric and Energy Balikesir Vocational High School Balikesir University Balikesir Turkey Department of Physics Necatibey Faculty of Education Balikesir University Balikesir Turkey Department of Computer Engineering Faculty of Engineering Balikesir University Balikesir Turkey Department of Electric and Electronics Engineering Faculty of Engineering Balikesir University Balikesir Turkey

Marble is a metamorphic rock, which is one of the 3 basic rock types (magmatic, sedimentary, metamorphic) forming the earth’s crust. The major characteristic sought after in a rock mass in the field for it to be exportable and usable as marble is its suitability to be cut in blocks. In the process of producing marble slabs from marble blocks, the blocks are expected not to contain potentially problematic hard or weak zones and their geomechanical and chemical properties should conform to the relevant standards. Ignoring of the geological properties of the rock in the process of deciding for marble production at a marble site and determination of production location, direction and method is the most important parameter that would increase production loss. In order to reduce losses by determination of geological properties of marble, many academic studies have been conducted on the effects of water saturation, temperature, freezing and thawing on its mechanical and fracture properties. There are further studies on crack propagation in marble under stress. However, even those marble blocks that are obtained based on geological parameters may suffer serious cracks or fractures due to stresses caused by their weight and geometry. Therefore, cutting direction is of critical importance in order to minimize marble waste in the process of cutting a marble block which is brought to the inventory or processing site with cracks, cavities or fractures. Certain studies exist within such context, where the geometry of the discontinuity within a block is determined using non-destructive methods, such as ultrasonic testing, in order to determine the appropriate cutting direction. Such studies made use of ultrasonic waves to determine the physical and chemical structures of magmatic and sedimentary rocks by measuring the progress velocity of sonic waves in the rock. Said studies, however, mostly worked on sedimentary and magmatic rock specimens, focusing less on metamorphic rocks suc

关键词： Marble Metamorphic Rock Ultrasonic Test Crack Cutting Direction

Management of hypotony and flat anterior chamber associated with glaucoma filtration surgery

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Ophthalmology(English edition) 2015年第5期8卷 950-953页

作者： yavuz Tun Mehmet Tetikoglu Necip Kara Haci Murat Sagdik Selahattin zarpaci mustafa Nuri Elioglu Department of Ophthalmology Denizli Government Hospital Department of Ophthalmology Dumlupinar University School of Medicine Department of Ophthalmology Gaziantep University School of Medicine Department of Ophthalmology Okmeydani Education and Research Hospital

AIMTo determine the effectiveness of pharmacological and interventional treatment of hypotony and flat anterior chamber (FAC) resulting from glaucoma filtration *** retrospectively examined the medical records of fifty-two trabeculectomy patients (52 eyes) who developed postoperative hypotony and FAC. The management and associated complications of hypotony, changing intraocular pressure (IOP) and best corrected visual acuity (BCVA) were *** the 52 patients with hypotony, 29 (56%) had a grade 1 FAC, 21 (40%) had a grade 2 FAC, and only 2 had a grade 3 FAC. There was no significant difference between the mean preoperative IOP and the mean IOP at three and six months after surgery. Thirteen eyes (25%) required antiglaucomatous medication three months after surgery. The mean BCVA at 6mo after surgery was significantly reduced as compared with the mean preoperative *** and FAC following trabeculectomy are associated with troublesome complications that require pharmacological and/or surgical treatment. Thus, close follow-up is essential for affected patients.

关键词： hypotony flat anterior chamber trabeculectomy

Presence of Fragmented QRS Complexes in Patients with Obstructive Sleep Apnea Syndrome

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Medical Journal 2015年第16期128卷 2141-2146页

作者： Muhammet Rasit Sayin Murat Altuntas Ziyaeddin Aktop Ibrahim I Oz Nesimi yavuz Ibrahim Akpinar Erol Sagatli Turgut Karabag mustafa Aydin Department of Cardiology School of MedicineBulent Ecevit UniversityZonguldakTurkey Department of Pulmonology Uzun Mehmet State HospitalZonguldakTurkey Department of Radiology School of MedicineBulent Ecevit UniversityZonguldakTurkey Department of Cardiology Ataturk State Hospital Zonguldak Turkey

Background：Obstructive sleep apnea syndrome （OSAS） is a disease with increasing prevalence,which is mainly characterized by increased cardiopulmonary mortality and *** is well-known that OSAS patients have increased prevalence of cardiovascular diseases including coronary heart disease,heart failure,and *** aim of this study was to evaluate the presence of prolonged and fragmented QRS complexes,which have previously been associated with cardiovascular mortality,in OSAS ***：Our study included 51 patients （mean age 41.6 ± 10.1 years） who were recently diagnosed with OSAS （apnea-hypopnea index [AHI] ≥5 events/h） and never received *** control group consisted of 34 volunteers （mean age 43.1 ± 11.6 years） in whom OSAS was excluded （AHI 〈5 events/h）.The longest QRS complexes was measured in the 12-lead electrocardiogram （ECG） and the presence of fragmentation in QRS complexes was ***：Fragmented QRS frequency was significantly higher in patients with OSAS （n =31 [61%] vs.n =12 [35%],P =0.021）.QRS and QTc durations were also significantly longer in OSAS patients than controls （99.8 ± 13.9 ms vs.84.7 ± 14.3 ms,P 〈 0.001;411.4 ± 26.9 ms vs.390.1 ± 32.2 ms,P =0.001,respectively）.Analysis of the patient and controls groups combined revealed a weak-moderate correlation between AHI and QRS duration （r =0.292,P =0.070）.OSAS group had no correlation between AHI and QRS duration （r =-0.231,P =0.203）.Conclusions：In our study fragmented QRS frequency and QRS duration were found to increase in OSAS *** parameters are related with increased cardiovascular *** the prognostic importance of ECG parameters,it may be reasonable to recommend more detailed evaluation of OSAS patients with fragmented or prolonged QRS complexes with respect to presence of cardiovascular diseases.

关键词： Electrocardiogram Fragmented QRS Obstructive Sleep Apnea QRS Duration QT Duration

Ovarian carcinoma in two patients with chronic liver disease

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2005年第28期11卷 4445-4446页

作者： Mehlika Lsildak Murat Kekilli yavuz Beyazit Gulay Sain Guven mustafa Erman Gulay Sain Guverl mustafa Ermall Department of Internal Medicine Faculty of Medicine Ha cettepe University Sihhiye Ankara 06100 Turkey Department of Internal Medicine Section of General Internal Medicine Faculty of Medicine Hacettepe University. Sihhiye Ankara 06100 Turkey Department of internal Medicine Section of Medical Oncology Faculty of Medicine Hacettepe UniversitySihhiye Ankara 06100 Turkey

Ascites is a common and debilitating complication of cirrhosis. However, patients with chronic liver disease are not spared from other causes of ascites and physicians should be careful not to miss an underlying *** cancer is an insidious disease, which is difficult to diagnose and it ranks first in mortality among all gynecological cancers. Here, we present two cases of patients with chronic liver disease that developed ascites not simply because of cirrhosis but as a manifestation of ovarian cancer. We would like to emphasize that the causes of ascites, other than the liver itself, should not be overlooked in patients with chronic liver disease.

关键词：卵巢癌慢性肝疾病病理机制临床表现

Beneficial effects of Foeniculum vulgare on ethanol-induced acute gastric mucosal injury in rats

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2007年第4期13卷 607-611页

作者： Fatih Mehmet Birdane mustafa Cemek yavuz Osman Birdane lhami Gülin Mehmet Emin Büyükokuro■lu Department of Internal Medicine Faculty of Veterinary Medicine Afyon Kocatepe University Afyon Turkey Department of Chemistry (Biochemistry Division) Faculty of Science and Arts Afyon Kocatepe University Afyon Turkey Department of Pharmacology and Toxicology Faculty of Veterinary Medicine Afyon Kocatepe University Afyon Turkey Department of Chemistry Faculty of Science and Arts Atatürk University Erzurum Turkey Department of Pharmacology Faculty of Medicine Afyon Kocatepe University Afyon Turkey

AIM: To examine the anti-ulcerogenic and antioxidant effects of aqueous extracts of Foeniculum vulgare (FVE) on ethanol-induced gastric lesions in rats. METHODS: FVE was administered by gavage at doses of 75, 150 and 300 mg/kg, and famotidine was used at the dose of 20 mg/kg. Following a 60 min period, all the rats were given 1 mL of ethanol (80%) by gavage. One hour after the administration of ethanol, all groups were sacrificed, and the gastric ulcer index was calculated; whole blood malondialdehyde (MDA) and reduced glutathione (GSH), serum nitrate, nitrite, ascorbic acid, retinol and β-carotene levels were measured in all the groups. RESULTS: It was found that pretreatment with FVE significantly reduced ethanol-induced gastric damage. This effect of FVE was highest and statistically significant in 300 mg/kg group compared with the control (4.18 ± 2.81 vs 13.15 ± 4.08, P < 0.001). Also, pretreatment with FVE significantly reduced the MDA levels, while significantly increased GSH, nitrite, nitrate, ascorbic acid, retinol and β-carotene levels. CONCLUSION: FVE has clearly a protective effect against ethanol-induced gastric mucosal lesion, and this effect, at least in part, depends upon the reduction in lipid peroxidation and augmentation in the antioxidant activity.

关键词：溃疡胃病疼痛感强饲法

Oxidative stress in portal hypertension-induced rats with particular emphasis on nitric oxide and trace metals

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2005年第23期11卷 3570-3573页

作者： Titiz Izzet Krand Osman Unal Ethem yavuz Nihat Kusaslan Ramazan Dogan mustafa Uzun Hafize Kiziler Ali Riza Aydemir Birsen Genc Habibe Aydin Seval Simsek Gonul Department of Surgery Department of Biochemistry Department of Biophysics Department of Physiology

AIM: To investigate the oxidative-stress-related changes in rats with portal hypertension with particular emphasis on nitric oxide (NO) and trace metals. METHODS: Cirrhosis was induced by partial portal vein ligation (PVL) in Wistar rats. The lipid peroxidation marker (malondialdehyde, MDA), antioxidant defense enzymes including superoxide dismutase (SOD), catalase (CAT), glutathione (GSH), and agents known to have antioxidant features including nitric oxide (NO), zinc (Zn), copper (Cu) were determined both in serum and in liver tissue at 4 wk after surgery in PVL and sham-operated rats. Portal pressure of all experimental animals was measured. MDA was detected by thiobarbituric acid reactivity *** activity was determined by inhibition of nitroblue tetrazolium reduction with xanthine/xanthine oxidase used asa superoxide generator. CAT activity was determined by the breakdown of hydrogen peroxide. GSH concentrations were measured by using metaphosphoric acid for protein precipitation and 5'-5'-dithio-bis-2-nitrobenzoic acid for color development. NO was detected by the Griess method after reduction of nitrate to nitrite with nitrate reductase, and the concentrations of Zn and Cu were measured by a Shimadzu 680 AA atomic absorption spectrometer. Histopathological confirmation was done under light microscope. Statistical analyses were done by Student's t-test, and significance of the difference was tested by the unpaired Mann-Whitney test. P＜0.05 was considered statistically ***: Histopathological studies confirmed PVL induced cirrhotic changes. There was a statistically significant difference in portal pressure between PVL and control groups (P＜0.001). The results showed significant increases in the levels of MDA and NO in both tissue and serum (P＜0.05 and P＜0.001, respectively in tissue; P＜0.001 for each in serum), and Zn only in tissue (P＜0.001)in rats with PVL compared with sham-operated rats. Besides, PVL rats exhibited reduced plasma and tis

关键词：肝门静脉高压氧化损伤小鼠动物实验一氧化氮