红外热不对称分析用于面神经功能损伤的客观评估

健康人体的温度分布存在一种双侧对称性,当面神经功能受损时,将改变这种热分布的对称性。人体热量大多通过红外辐射的形式散发,因此利用红外热成像技术可以有效捕捉这种红外热辐射分布的改变。本文提出一种新的热不对称分析的方法——有效热面积比,即计算面部特定区域与对侧区域的温差乘以温度异常区面积与总面积之比。利用这种方法对面神经功能损伤的患者和健康人群作对照性试验,结果显示:此方法的特异性和敏感性平均为0.90和0.87,比常规方法提高了7%和26%,有效热面积比与面神经功能的损伤程度正相关,平均为0.664。因此,关于诊断和评估面神经功能,红外热成像是一种有力的工具,有效热面积比是一项高效的临床指标。     

Photocatalytic degradation of methyl orange by nano-TiO_2 thin films prepared by RF magnetron sputtering

Nano-TiO2 thin films are deposited by radio frequency （RF） magnetron sputtering using TiO2 ceramic target and characterized by X-ray diffractometer, atomic force microscope, and ultraviolet-visible spectrophotometer. The photocatalytic activity is evaluated by light-induced degradation of methyl orange solutions （5, 10, and 20 ppm） using a high pressure mercury lamp as the light source. The film is amorphous, and its energy gap is 3.02 eV. The photocatalytic degradation of methyl orange solution is the first-order reaction and the apparent reaction rate constants are 0.00369, 0.0024, and 0.00151 for the methyl orange solution concentrations of 5, 10, and 20 ppm, respectively.     

Epidemic spreading in scale-free networks including the effect of individual vigilance

In this paper, we study the epidemic spreading in scale-free networks and propose a new susceptible-infected-recovered (SIR) model that includes the effect of individual vigilance. In our model, the effective spreading rate is dynamically adjusted with the time evolution at the vigilance period. Using the mean-field theory, an analytical result is derived. It shows that individual vigilance has no effect on the epidemic threshold. The numerical simulations agree well with the analytical result. Furthermore, we investigate the effect of individual vigilance on the epidemic spreading speed. It is shown that individual vigilance can slow the epidemic spreading speed effectively and delay the arrival of peak epidemic infection.     

Temperature dependence of radiation-induced attenuation of optical fibers

We investigate the temperature dependence of radiation-induced attenuation (RIA) at 1 310 nm for a Ge/P co-doped fiber after a steady-state γ-ray irradiation.A γ irradiation facility 60Co source is used to irradiate the fiber at a dose rate of 0.5 Gy/min,satisfying a total dose of 100 Gy.The test temperature ranges from-40 to 60℃ by 20℃,and the RIA of the fiber is obtained using a power measuring device.The experimental result demonstrates that RIA exhibits a steady,monotonic,and remarkable temperature dependence after approximately 48h of accelerated annealing at 70℃.The optical fiber irradiated with a high dose and annealed sufficiently can be used as a temperature sensor.     

The magnetic entropy change in the double perovskite La2NiMnO6 with strong spin–phonon coupling

The magnetocaloric effect and the critical behavior of La₂NiMnO₆ are investigated by measurement of the magnetization around $T_C$. The magnetic entropy change $\left|\Delta S\right|$ of La₂NiMnO₆ for a field change of 0–45 kOe near the Curie temperature is about 5% of the theoretical expectation. The critical behavior of the La₂NiMnO₆ deviates from the mean field theory. These abnormal phenomena are understood in the context of the strong spin–phonon coupling in La₂NiMnO₆. It is suggested that a method of modulating this coupling would enhance the magnetic entropy change greatly, which makes the La₂NiMnO₆ a promising candidate for room-temperature magnetic refrigeration.     

基于虚拟现实的动车组维修性验证系统研究与设计

针对动车组维修性验证方法不足的问题,提出了采用虚拟仿真手段对维修性进行验证的方法;结合动车组系统的特点,对基于虚拟现实的动车组维修性验证系统进行了方案设计,给出了维修性验证具体流程,研究了三维虚拟样机建模的基本方法;虚拟维修性验证系统有效提高了动车组维修性设计效率,缩短了研制周期,是一种实现动车组维修性并行优化设计的有效方法。     

Deterministic Bidirectional Remote State Preparation of a- and Symmetric Quantum States with a Proper Quantum Channel

We present a new scheme for deterministically realizing the mutual interchange of quantum information between two distant parties via selected quantum states as the shared entangled resource. We first show the symmetric bidirectional remote state preparation (BRSP), where two single-qubit quantum states will be simultaneously exchanged in a deterministic manner provided that each of the users performs single-qubit von Neumann measurements with proper measurement bases as well as appropriate unitary operations, depending essentially on the outcomes of the prior measurements. Then we consider to extend the symmetric protocol to an asymmetric case, in which BRSP of a general single-qubit state and an arbitrary two-qubit state is investigated successfully. The necessary quantum operations and the employed quantum resources are feasible according to the present technology, resulting in that this protocol may be realizable in the realm of current physical experiment.     

Progress of nanoscience in China

Fast evolving nanoseienees and nanotechnology in China has made it one of the front countries of nanotechnology development. Ill this review, we summarize some most recent progresses in nanoseienee research and nanotechnology development in China. The topics we selected in this article include llano-fabrication, nanocatalysis, bioinspired nanoteehnology, green printing nanotechnology, nanoplasmonics, nanomedicine, nanomaterials and their applications, energy and environmental nanoteehnology, nano EHS （nanosafety）, etc. Most of them have great potentials in applications or application-related key issues in future.     

Photovoltaic effect of TiO2 thick films with an ultrathin BiFeO3 as buffer layer

The photovoltaic (PV) effect of a bilayer anatase TiO₂/BiFeO₃ (BFO) film has been studied. The 20-nm ultrathin BFO layers were deposited on the fluorine-doped tin oxide (FTO) glass substrates by the chemical solution deposition method. An anatase TiO₂ layer is deposited subsequently on the BFO surface via a screen-printing technique. It is found that the FTO/TiO₂/Au cell exhibits negligible PV effect under solar exposure, while the one after introducing an ultrathin BFO film between TiO₂ and FTO leads to a considerable PV effect with an open-circuit voltage of ?0.58 V and a photocurrent density of 18.27 µA/cm². The FTO/BiVO₄ (BVO)/TiO₂/Au cell was constructed to investigate the underlying mechanism for the observed effect. A negligible PV effect of the FTO/BVO/TiO₂/Au cell indicates that the PV effect of the FTO/BFO/TiO₂/Au cell arises mainly from a built-in electric field in the BFO film induced by the self-polarization. Our work opens up a new path to utilize TiO₂ and may influence the future design of solar cells.     

Fabrication of widely tunable ridge waveguide DBR lasers for WDM-PON

We report the fabrication of widely tunable ridge waveguide distributed Bragg reflector(DBR) lasers with InGaAsP butt-joint as grating material. The shape of the butt–joint interface is found to have significant effect on the properties of the lasers. It is shown that irregular mode jumps during wavelength tuning can be avoided by a V-shaped butt–joint interface. From the fabricated device, 23 channels with 0.8 nm spacing and greater than 35 dB side mode suppression ratios are obtained. The different tuning characteristics of the ridge waveguide and the previously reported buried ridge stripe DBR lasers are discussed. Combined with the wide tuning range and the simple structure, the ridge waveguide DBR lasers are promising for use in wavelength division multiplexing passive optical networks(WDM-PONs).