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Search Results: 1 - 10 of 20630 matches for " GUAN Jie "
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The Adjustment and Effects of Vocabulary Teaching Strategies in Flipped Classroom  [PDF]
Hongwei Zhang, Jie Li, Liping Jiao, Weilian Ma, Chen Guan
Creative Education (CE) , 2016, DOI: 10.4236/ce.2016.714199
Abstract: The importance of vocabulary teaching is self-evident. Yet, the present English vocabulary teaching model is still far more traditional than modern because of the inadequacy of education revolution. The flipped classroom teaching model brings a new horizon to the field of vocabulary teaching. This paper takes the freshmen in the English department of a college in northern part of China as the main body of research analyzes the results of the experimental vocabulary teaching and gets the conclusion that the flipped classroom teaching model promotes English vocabulary teaching outcomes.
Unusual Electronic Structure of Few-Layer Grey Arsenic: A Computational Study
Zhen Zhu,Jie Guan,David Tomanek
Physics , 2014,
Abstract: We use ab initio density functional theory to study the equilibrium geometry and electronic structure of few-layer grey arsenic. In contrast to the bulk structure that is semimetallic, few-layer grey As displays a significant band gap that depends sensitively on the number of layers, in-layer strain, layer stacking and inter-layer spacing. A metal-semiconductor transition can be introduced by changing the number of layers or the in-layer strain. We interpret this transition by an abrupt change in the spatial distribution of electronic states near the top of the valence band.
Phase coexistence and metal-insulator transition in few-layer phosphorene: A computational study
Jie Guan,Zhen Zhu,David Tománek
Physics , 2014, DOI: 10.1103/PhysRevLett.113.046804
Abstract: Based on {\em ab initio} density functional calculations, we propose $\gamma$-P and $\delta$-P as two additional stable structural phases of layered phosphorus besides the layered $\alpha$-P (black) and $\beta$-P (blue) phosphorus allotropes. Monolayers of some of these allotropes have a wide band gap, whereas others, including $\gamma$-P, show a metal-insulator transition caused by in-layer strain or changing the number of layers. An unforeseen benefit is the possibility to connect different structural phases at no energy cost. This becomes particularly valuable in assembling heterostructures with well-defined metallic and semiconducting regions in one contiguous layer.
High stability of faceted nanotubes and fullerenes of multi-phase layered phosphorus: A computational study
Jie Guan,Zhen Zhu,David Tománek
Physics , 2014, DOI: 10.1103/PhysRevLett.113.226801
Abstract: We present a paradigm in constructing very stable, faceted nanotube and fullerene structures by laterally joining nanoribbons or patches of different planar phosphorene phases. Our ab initio density functional calculations indicate that these phases may form very stable, non-planar joints. Unlike fullerenes and nanotubes obtained by deforming a single-phase planar monolayer at substantial energy penalty, we find faceted fullerenes and nanotubes to be nearly as stable as the planar single-phase monolayers. The resulting rich variety of polymorphs allows to tune the electronic properties of phosphorene nanotubes (PNTs) and fullerenes not only by the chiral index, but also by the combination of different phosphorene phases. In selected PNTs, a metal-insulator transition may be induced by strain or changing the number of walls.
Tiling Phosphorene
Jie Guan,Zhen Zhu,David Tománek
Physics , 2014,
Abstract: We present a scheme to categorize the structure of different layered phosphorene allotropes by mapping their non-planar atomic structure onto a two-color 2D triangular tiling pattern. In the buckled structure of a phosphorene monolayer, we assign atoms in "top" positions to dark tiles and atoms in "bottom" positions to light tiles. Optimum $sp^3$ bonding is maintained throughout the structure when each triangular tile is surrounded by the same number $N$ of like-colored tiles, with $0{\le}N{\le}2$. Our ab initio density functional calculations indicate that both the relative stability and electronic properties depend primarily on the structural index $N$. The proposed mapping approach may also be applied to phosphorene structures with non-hexagonal rings and 2D quasicrystals with no translational symmetry, which we predict to be nearly as stable as the hexagonal network.
Structural Transition in Layered As$_{\sf\textbf{1-x}}$P$_{\sf\textbf{x}}$ Compounds: A Computational Study
Zhen Zhu,Jie Guan,David Tomanek
Physics , 2015, DOI: 10.1021/acs.nanolett.5b02227
Abstract: As a way to further improve the electronic properties of group V layered semiconductors, we propose to form in-layer 2D heterostructures of black phosphorus and grey arsenic. We use \textit{ab initio} density functional theory to optimize the geometry, determine the electronic structure, and identify the most stable allotropes as a function of composition. Since pure black phosphorus and pure grey arsenic monolayers differ in their equilibrium structure, we predict a structural transition and a change in frontier states, including a change from a direct-gap to an indirect-gap semiconductor, with changing composition.
Mini-Margin Nephron Sparing Surgery for Renal Cell Carcinoma 4?cm or Less
Quanlin Li,Hongwei Guan,Jie Qin,Tao Jiang
Advances in Urology , 2010, DOI: 10.1155/2010/145942
Abstract: Objectives. To explore the safety and efficacy of mini-margin nephron sparing surgery (NSS) for renal cell carcinoma (RCC) 4?cm or less. Methods. Total of 389 cases of RCC 4?cm or less with normal contralateral kidneys were included in the study, including 135 cases treated by mini-margin NSS, 98 by 1?cm-NSS and 156 by radical nephrectomy (RN). The clinical results were followed-up and comparatively analyzed. Results. The mean and median margin width for mm-NSS was 2.2 and 2.0?mm (range 0 to 5). Of them, 112 (83.0%) cases had margins of 3?mm or less, and 26 had margins of 0?mm (19.3%). The mean width of margin for 1?cm-NSS was 11.6?mm (median 12, range 10 15). None of the NSS patients had positive surgical margins. The mean follow-up for mm-NSS, 1?cm-NSS and RN patients was 69, 82 and 82 months, respectively. Three mm-NSS patients, two 1?cm- NSS and four RN patients died of non-cancer related causes. Two mm-NSS patient (1.6%) experienced local recurrence. No distant metastasis was detected in all the patients. The over all 5-year survivals for NSS and RN patients were 100%, 100% and 98.7%, respectively ( ). Conclusions. Mini-margin NSS is as safe and effective as 1?cm-NSS and RN in treating early localized RCC 4?cm or less. 1. Introduction Nephron sparing surgery (NSS) has proven to be a safe and effective approach for renal cell carcinoma (RCC), with comparable clinical results to radical nephrectomy, especially for the tumors 4?cm or less, even in patients with completely normal opposite kidneys. For many years, surgical practice for NSS was to have a more than 1?cm margin of normal tissue around the tumor [1, 2]. However, more recent studies show that the width of the margin seems not important. NSS with a smaller margin is as well safe and effective in tumor control [3]. And even pure enucleation is as effective as partial nephrectomy with a rim of healthy parenchyma [4]. From January 1998 to December 2008, based on the previous studies in our institute, 135 cases of RCC 4?cm or less in diameter and staged as T1aN0M0 with normal contralateral kidney were treated with 5?mm mini-margin NSS (mm-NSS). The clinical results were followed and compared with 99 cases of NSS with margin 1?cm or more (1?cm-NSS) and 156 cases of radical nephrectomy (RN) for RCC of same stage. The Data were comparatively analyzed to evaluate the safety and efficacy of mini-margin NSS in treating early localized RCC 4?cm or less. 2. Materials And Methods 2.1. Patient Selection Only patients with RCC 4?cm or less, with normal contralateral kidney, without lymph node or distant
Photochemical characteristics of diclofenac and its photodegradation of inclusion complexes with β-cyclodextrins
Qin, Minmin;Yang, Haifeng;Chen, Shengwen;Xie, Hongyong;Guan, Jie;
Química Nova , 2012, DOI: 10.1590/S0100-40422012000300022
Abstract: diclofenac is one of most frequently detected compounds in the water cycle. in this work, the effect of initial concentration, liquid inclusion complexes with β-cyclodextrins (β-cds) on the photodegradation of diclofenac were studied. six phototransformation products were detected by hplc chromatograms. uv-absorption spectra of diclofenac and phototransformation products were determined. one of the phototransformation products was identified. the degradation followed pseudo-first-order kinetics. the experiment showed that irradiation of diclofenac in the presence of β-cds increase photodegradation rate and determined the optimal molar ratio of diclofenac to β-cds as 1:2. the reduced photohaemolytic activity of diclofenac in the presence of β-cds may be attributed to the sequestering and stabilizing of the radical intermediates and /or photoproducts by complexation.
Differential Characteristic Probability of Added Key on Modulo 2n Operation
“与密钥模2n加运算”的差分性质研究

Zheng Bin,Guan Jie,
郑 斌
,关 杰

电子与信息学报 , 2009,
Abstract: “与密钥K模2n加”-Y=X+Kmod2n是密码算法中一个常用的基本编码环节,在SAFER++,RC6 Phelix等算法中有广泛的应用。该文对Y=X+Kmod2n进行了差分分析,首次给出了当差分转移概率取最大值1,次大值1-1/2n-2,次小值1/2n-2以及1/2时,输入差,输出差及密钥的结构特点和计数公式。
Effectiveness of laparoscopic treatment for deep infiltrating type endometriosis
Jie ZOU,Zheng GUAN,Yuan-guang MENG,Yan ZHANG
Medical Journal of Chinese People's Liberation Army , 2011,
Abstract: Objective To analyze the effect of laparoscopic excision on deep infiltrating type endometriosis(DIE) in posterior pelvis.Methods Data of 35 cases of posterior pelvic DIE admitted to General Hospital of PLA from Jan.2006 to Jan.2009 were retrospectively analyzed.All the cases were pathologically confirmed and treated with laparoscopic surgery.10-point linear visual analog scale(VAS) was used to estimate the degree of pre-and post-operative pain.Results Thirty-four patients were treated successfully by laparoscopic surgery,in one case it was shifted to open laparotomy because of malignant transformation of endometriosis.No complication occurred.There was an obvious decline of VAS score for dysmenorrhoea after operation compared with that before operation(5.8±1.7 vs 1.2±1.3,P < 0.001).Thirteen cases with dysmenorrhoea(39.3%) showed significant improvement of symptoms,and satisfactory improvement was found in 20 cases(60.7%).Conclusion Laparoscopic excision for posterior type of DIE is effective and safe,it can ameliorate dysmenorrhoea and improve patient’s quality of life.
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