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The Diagnosis of Human Liver Cancer by using THz Fiber-Scanning Near-Field Imaging
CHEN Hua, MA Shi-Hua, YAN Wen-Xing, WU Xiu-Mei, WANG Xiao-Zhou
Chin. Phys. Lett. 2013, 30 (3):
030702
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DOI: 10.1088/0256-307X/30/3/030702
Based on a room-temperature-operated THz fiber-scanning near-field imaging system, we demonstrate the capability of THz imaging for diagnosing human liver cancer. By THz near-field mapping of the absorption constants of liver tissues, the acquired images can clearly distinguish cancer from normal tissues fast, automatically, and correctly without pathological H&E staining examination. Accordingly, the studied THz imaging system has valuable potential applications in clinical cancer diagnosis. With the help of THz imaging, we can expect to economize the use of hospital and human resources.
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The Statistical Origin of Constituent-Quark Scaling in QGP Hadronization
TANG Ze-Bo, YI Li, RUAN Li-Juan, SHAO Ming, LI Cheng, CHEN Hong-Fang, Bedanga Mohanty, XU Zhang-Bu
Chin. Phys. Lett. 2013, 30 (3):
031201
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DOI: 10.1088/0256-307X/30/3/031201
Nonextensive statistics in a blast-wave model is implemented to describe the identified hadron production in relativistic p+p and nucleus-nucleus collisions. Incorporating the core and corona components within the TBW formalism allows us to describe simultaneously some of the major observations in hadronic observables at the Relativistic Heavy-Ion Collider (RHIC): the amount of constituent quark scaling (NCQ), the large radial and elliptic flow, the effect of gluon saturation, and the suppression of hadron production at high transverse momentum (pT) due to jet quenching. In this formalism, the NCQ scaling at the RHIC appears as a consequence of a non-equilibrium process. Our study also provides concise reference distributions with a least χ2 fit of the available experimental data for future experiments and models.
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A Tm-Bi Co-Doped Fiber Laser with Dual Pumping Operation
N. Saidin, S. W. Harun, S. S. A. Damanhuri, S. M. M. Ali, H. Ahmad, A. Halder, M. C. Paul, S. Das, M. Pal, S. K. Bhadra
Chin. Phys. Lett. 2013, 30 (3):
034204
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DOI: 10.1088/0256-307X/30/3/034204
We demonstrate an efficient fiber laser operating at 1901.6 nm using a newly developed thulium bismuth co-doped fiber (TBF) with dual pumping at 792 nm and 1552 nm. The fiber was fabricated using modified chemical vapor deposition and solution doping processes. The dopant concentrations (wt%) and compositions inside the core are 0.15 Bi2O3, 0.3 Tm2O3, 1.0 Al2O3 and 12.0 GeO2. The TBF laser operates at 1901.6 nm with a lasing efficiency of 33.2% and pump power threshold of 85 mW using a 2-m-long TBF in a linear cavity with two fiber Bragg gratings (FBGs). The high efficiency is attributed to the use of additional 1552 nm pump to complement 792 nm pumping. The maximum output power of 225 mW is achieved at the pump power of 820 mW with the optimum length of 2 m.
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Ultracompact, Reflection-Free and High-Efficiency Channel Drop Filters Based on Photonic Crystal Nanobeam Cavities
YU Ping, HU Ting, QIU Chen, SHEN Ao, QIU Hui-Ye, WANG Fan, JIANG Xiao-Qing, WANG Ming-Hua, YANG Jian-Yi
Chin. Phys. Lett. 2013, 30 (3):
034210
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DOI: 10.1088/0256-307X/30/3/034210
We propose an ultracompact channel drop filter (CDF) based on photonic crystal nanobeam cavities. The conditions for implementing such an ideal CDF are derived from the temporal coupled-mode equations governing the operation of the CDF. By considering the intercoupling of the two involved nanobeam cavities, some ambiguities of the previous equivalent circuit model analysis are cleared up. Practical configurations on silicon-on-insulator (SOI) for the proposed CDF are suggested with a typical length less than 15 μm . Finite difference time domain (FDTD) method calculations show that the proposed filter can achieve drop efficiency higher than 99% without any reflection. Compared to the λ/4-shifted Bragg grating resonators based CDF, the proposed CDF is more compact, high-efficient and reflection-free. It is also easy to implement a low-power tunable filter due to the ultrahigh quality factor Q and ultrasmall modal volume V of the involved photonic crystal nanobeam cavities.
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A Computational Study of Radio Frequency Atmospheric Pressure Discharge in Nitrogen and Oxygen Mixture Gases
WANG Yi-Nan, LIU Yue, LIN Guo-Qiang
Chin. Phys. Lett. 2013, 30 (3):
035201
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DOI: 10.1088/0256-307X/30/3/035201
The characteristics of radio frequency atmospheric pressure discharge in nitrogen and oxygen mixture gases are investigated by using a one-dimensional fluid model. The model consists of equations of particle continuity, Poisson's equation, and the electron energy equation. The effect of the concentrations of O2 in N2 on the discharge characteristics is analyzed. The results show that when the concentration of O2 in N2 is less than 12%, as the amount of O2 grows, the electron density and the N4+ ion density decrease; the main negative particles are electrons. When the concentration of O2 in N2 is greater than 12%, the electron density and the N4+ ion density increase with the increasing admixture of oxygen; the main negative particle is the O? ion. Moreover, the O? ion density, the O2+ ion density, the electron temperature and the mixture gases electronegativity increase with growth of O2 in the range from 4% to 20% and with density of O2 in N2.
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A Novel Micro-Scale Plastic Deformation Feature on a Bulk Metallic Glass Surface under Laser Shock Peening
WEI Yan-Peng, WEI Bing-Chen, WANG Xi, XU Guang-Yue, LI Lei, WU Xian-Qian, SONG Hong-Wei, HUANG Chen-Guang
Chin. Phys. Lett. 2013, 30 (3):
036201
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DOI: 10.1088/0256-307X/30/3/036201
Laser shocking peening is a widely applied surface treatment technique that can effectively improve the fatigue properties of metal parts. We observe many micro-scale arc plastic steps on the surface of Zr47.9Ti0.3Ni3.1Cu39.3Al9.4 metallic glass subjected to the ultra-high pressure and strain rate induced by laser shock peening. The scanning electronic microscopy and atomic force microscopy show that the arc plastic step (APS) has an arc boundary, 50–300 nm step height, 5–50 μm radius and no preferable direction. These APSs have the ability to accommodate plastic deformation in the same way as shear band. This may indicate a new mechanism to accommodate the plastic deformation in amorphous metallic glass under high pressure, ultra-high strain rates, and short duration.
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Effects of 3 GPa High Pressure Treatment on the β1→α+β2 Phase Transition Dynamics of TC4 Titanium Alloy
WANG Hai-Yan, CHEN Yan, LIU Jian-Hua, WANG Wen-Kui
Chin. Phys. Lett. 2013, 30 (3):
036202
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DOI: 10.1088/0256-307X/30/3/036202
The temperature, duration, activation energy, and Avrami exponent of the solid phase transformation β1→α+β2 of TC4 titanium alloy treated at 3 GPa in a cooling process are calculated by means of differential scanning calorimetric curves. Then the effects of high pressure on the β1→α+β2 phase transformation dynamics of TC4 alloy in a cooling process are investigated. The results show that 3 GPa high pressure treatment can increase the activation energy of the TC4 alloy. The beginning time, end time, and duration of the β1→α+β2 phase transition of the 3 GPa high pressure treated TC4 alloy at the cooling rate of 10°C/min are increased by 2.90°C, 7.78°C and ?29.28 s respectively. It is known that 3 GPa high pressure treatment has little effect on the phase transition mechanism.
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AlGaN/GaN Based Diodes for Liquid Sensing
LUO Wei-Jun, CHEN Xiao-Juan, YUAN Ting-Ting, PANG Lei, LIU Xin-Yu
Chin. Phys. Lett. 2013, 30 (3):
037301
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DOI: 10.1088/0256-307X/30/3/037301
The characteristics of AlGaN/GaN Schottky diodes as polar liquid sensors are reported. Circular structures, with a gate metal diameter of 200 μm , are designed and fabricated by using a optical lithography process. Ni/Au and Ti/Al/Ni/Au metals are used as the Schottky contact and the ohmic contact, respectively. The Schottky diodes exhibit large changes in reverse leakage current at a bias of ?20 V in response to the surface exposed to various polar liquids, such as acetone and ethanol. The effective Schottky barrier height of the diodes is also changed with the polar liquids. The polar nature of the liquids leads to a change of surface charges, producing a change in surface potential at the semiconductor/liquid interface. The effect of the SiNx passivation layer thickness on the liquid sensing is also discussed. The results demonstrate that the AlGaN/GaN heterostructures are promising for polar liquids, combustion gas, biological, and strain sensing applications.
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An Improvement of the Thermal Stability of SnTe through Nitrogen Doping
XIA Meng-Jiao, RAO Feng, SONG Zhi-Tang, REN Kun, WU Liang-Cai, LIU Bo, FENG Song-Lin
Chin. Phys. Lett. 2013, 30 (3):
037401
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DOI: 10.1088/0256-307X/30/3/037401
Nitrogen doping is applied to improve the thermal stability of SnTe. The crystallization temperature Tc of SnTe is below room temperature, which can be elevated to 216°C by 7.65at.% nitrogen doping. Nitrogen doping results in the formation of SnNx in the nitrogen doped SnTe (N-SnTe) materials, which hinders the movement of atoms and suppresses the crystallization, leading to a better thermal stability. The crystallization activation energy (Ea) and data retention for ten years of 7.65at.% N-SnTe are 1.89 eV and 81°C, respectively. Moreover, the voltage pulses have successfully triggered the SET and RESET operations of the N-SnTe based device at the voltage of 0.9 V and 2.6 V. The good thermal stability and reversible phase-change ability have proved the potential of N-SnTe for phase-change memory application.
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Bubble Motion in Transformer Oil under Non-Uniform Electric Fields
CAI Dan, LIU Lie, CHENG Guo-Xin, ZHANG Qiang, ZHAO Xue-Long, ZHAO Qi
Chin. Phys. Lett. 2013, 30 (3):
037701
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DOI: 10.1088/0256-307X/30/3/037701
We investigate the bubble motion in transformer oil under a typical non-uniform electric field. Based on the principle of virtual work, an analytical equation is derived for the electric force putting on the bubbles. The bubble's visualized motion graphics are then obtained by using the finite-element method, which utilizes Comsol Multiphysics software. The effects of bubble radius and release position on the motion trajectory are studied. It is found that, under the non-uniform electric field, the bubbles have a long residence time between the electrodes. This accordingly can lead to a higher probability of forming a bubble-bridge along the bubble motion trajectory. The bubbles with a particular radius or release position are easier to form bubble-bridge between the electrodes. They can increase the chance of liquid breakdown.
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The Influence of Strong Laser Fields on the Interaction between Fast B3+ Clusters and Plasmas
E Peng, WANG Gui-Qiu, YAO Li, GAO Hong, WANG Yao-Chuan, ZHONG Hai-Yang, LIU Wei, YANG Kun, SUN Min, XU Dian-Guo
Chin. Phys. Lett. 2013, 30 (3):
037901
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DOI: 10.1088/0256-307X/30/3/037901
The influence of a high-intensity laser field on the inelastic interactions between a swift B3+ cluster ion and a plasma target is studied by means of the linearized Vlasov–Poisson theory. Excitations of the plasma are described by the classical plasma dielectric function. In the presence of the laser field, the general expressions for the induced potential in the target and the interaction force among the ions within the cluster are derived. Based on the numerical solution of the equations of motion for the constituent ions, the Coulomb explosion patterns and the cluster's energy losses are discussed for a range of laser parameters.
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First-Principles Study of Hydrogen Binding Property in Alkaline-Earth (Be, Mg, Ca) Metal-Doped Closo-Boranes
REN Juan , ZHANG Hong, CHENG Xin-Lu
Chin. Phys. Lett. 2013, 30 (3):
038801
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DOI: 10.1088/0256-307X/30/3/038801
Using the first-principles method based on density functional theory (DFT), we investigate the stability of alkaline-earth (AE) metal-doped (AE = Be, Mg, and Ca) dodecaborane(12) and the interactions of H2 molecules with the B12H12Be, B12H12Mg, and B12H12Ca clusters. Our calculated results show that the metal sites carry a partial negative/positive charge. The binding energies of metal cations and the boron framework are calculated to be 28.21, 21.92, and 18.79 eV, respectively, which are large enough to prevent metal atoms clustering and ensure the stability toward recyclability. These charge surfaces created at the metal site, which can induce a dipole in the molecular hydrogen, can bind to the hydrogen molecule through the ion-quadrupole as well as through ion-induced dipole interactions. The results show that B12H12Mg and B12H12Ca complexes can store up to 3.52 and 5.26wt% hydrogen, respectively. These studies may provide guidance for designing new 3D hydrogen storage materials with the icosahedra twelve-member boron cluster doped with AE metals as the building blocks.
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Long Division Unites or Long Union Divides: a Model for Social Network Evolution
JIANG Jian, WANG Ru, Pezeril Michel, Wang Qiuping Alexandre
Chin. Phys. Lett. 2013, 30 (3):
038901
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DOI: 10.1088/0256-307X/30/3/038901
A remarkable phenomenon in the time evolution of many networks such as cultural, political, national and economic systems is the recurrent transition between the states of union and the division of nodes. We propose a phenomenological modeling, inspired by the maxim "long union divides and long division unites" to investigate the evolutionary characters of these networks composed of the entities whose behaviors are dominated by these two events. The nodes are endowed with quantities such as identity, ingredient, richness (power), openness (connections), age, distance, and interaction, which determine collectively the evolution in a probabilistic way. Depending on a tunable parameter, the time evolution of this model is mainly an alternative domination of union or division state, with a possible state of final union dominated by one single node.
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Comment on "A Quantum Network System of QSS-QDC Using χ-Type Entangled States" [Chin. Phys. Lett. 29 (2012) 050303]
LIU Zhi-Hao, CHEN Han-Wu, LIU Wen-Jie, XU Juan
Chin. Phys. Lett. 2013, 30 (3):
039901
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DOI: 10.1088/0256-307X/30/3/039901
Two quantum secret sharing (QSS) protocols in a multiuser quantum direct communication (QDC) network system were put forward by Hong et al. [ Chin. Phys. Lett. 29 (2012) 050303]. However, we find that either agent (Bob or Charlie) alone can obtain half the information about the sender's secret without collaboration with the other, which does not satisfy the security requirement of QSS. Moreover, the secret message sent by Alice in the second protocol can be eavesdropped on or its communication can be disturbed by the builder of quantum channels (Trent).
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55 articles
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