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Homing is a particularly important step to establish the equipment coordinate origin. A reliable method of fast homing based on the PLC system in the automatic production line is discussed, which obtains the position information of each motion axis through Modbus or other networks, and cooperates with PLC’s Homing instruction to static home quickly to avoid complex operations. And the function of returning to the breakpoint in the middle process is proposed, which makes it easy to resume production in the event of power failure or overload, and greatly improves production efficiency. And the above research is transformed into a practical system, which has been verified and has the value of promotion.

Main text The CCQM-K172 key comparison on measurement of Specific Adsorption A [mol/kg] of Ar on zeolite at liquid argon temperature (to enable a traceable determination of the Specific Surface Area by following ISO 9277) has been performed by the Surface Analysis Working Group (SAWG) of the Consultative Committee for Amount of Substance (CCQM). The objective of this key comparison is to compare the equivalency of the National Metrology Institutes (NMIs) and Designated Institutes (DIs) for the measurement of specific adsorption of Ar, BET specific surface area) of microporous substances (zeolites, sorbents, ceramics, catalytic agents, etc) used in advanced technology. In this key comparison, a commercial zeolite was supplied as a sample. Five NMIs/DIs participated in this key comparison. All participants used a gas adsorption method, here argon adsorption at 77.3 K, for analysis according to the international standard ISO 9277. In this key comparison, the degrees of equivalence uncertainties for specific adsorption argon, BET specific surface area were established. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

A single-photon interferometer is a fundamental element in quantum information science. In most previously reported works, single-photon interferometers use an active feedback locking system to stabilize the relative phase between two arms of the interferometer. Here, we use a pair of beam displacers to construct a passively stable single-photon interferometer. The relative phase stabilization between the two arms is achieved by stabilizing the temperature of the beam displacers. A purely polarized single-photon-level pulse is directed into the interferometer input port. By analyzing and measuring the polarization states of the single-photon pulse at the output port, the achieved polarization fidelity of the interferometer is about 99.1±0.1%. Our passively stabilized single-photon interferometer provides a key element for generating high-fidelity entanglement between a photon and atomic memory.

High-accuracy localization is a major problem for intelligent vehicles. With the continuation of traffic scenarios, underground parking lots have become an essential link to intelligent vehicle localization. Current localization methods suitable for ordinary traffic scenes, such as the global localization system and Beidou, cannot obtain stable localization results because the satellite signal is blocked. Thus, localization is a complex problem to solve in this scenario to achieve highly accurate localization. This study proposes a coarse-to-fine multi-scale localization method that can achieve highly precise localization with only one monocular camera based on the constructed multilayer map. First, the visual features of the images to be located are extracted, and the proposed features are counted and matched with the map using the bag of word model to obtain the nearest node for completing node-level coarse localization. Second, the perspective N-point problem model is formed using visual features and structural information in the nearest node. Finally, the positions and attitudes of the vehicles relative to the map node are calculated to complete degree-level fine localization. The error rate of the localization algorithm is verified to be below 7.3%, which is superior to that of other methods. This study provides a new solution for the highly accurate localization of underground parking and other indoor scenes.

A novel dual-band dual-circularly polarized waveguide slot array antenna is designed. The antenna opens two orthogonal slots with different lengths on the standard waveguide and is excited at two frequencies. The electric fields of TE10 and TE01 modes are obtained. To achieve the purpose of dual-band dual-circular polarization. Two orthogonal slots can not only make the antenna elements have slow-wave properties and delay phase, but also make the antenna elements in different frequency bands have the same virtual short-circuit wall, which simplifies the difficulty of design and processing. The antenna can achieve an equidistant array and become an array antenna. Through simulation verification, the S11

Blind quantum computation allows a client without enough quantum technologies to delegate her quantum computation to a remote quantum server, while keeping her input, output and algorithm secure. In this paper, we propose a universal single-server and almost-classical-client blind quantum computation protocol. In this protocol, the client interfaces with only one server and the only ability of the client required is to get particles from the trusted center and forward them to the server. We present an analysis of this protocol and modify it to a universal single-server and fully-classical-client blind quantum computation protocol by improving the ability of the trusted center. Based on our protocols and recent works, a new "Cloud + Certificate Authority (CA)" style is proposed for the blind quantum computation., Comment: 7 pages, 3 figures, Close to the published version

In this work, we reported the room-temperature continuous-wave operation of 6.0 W GaN-based blue laser diode (LD), and its stimulated emission wavelength is around 442 nm. The GaN-based high power blue LD is grown on a c-plane GaN substrate by metal organic chemical vapor deposition (MOCVD), and the width and length of the ridge waveguide structure are 30 and 1200 μm, respectively. The threshold current is about 400 mA, and corresponding threshold current density is 1.1 kA/cm2.

This paper reports the development of a critical-angle transmission (CAT) grating fabrication process based on metal-assisted chemical etching (MACE), from which grating prototypes with a period of 1 μm were fabricated. The prototype was composed of four 5 mm × 5 mm membrane cells, each of which comprising freestanding grating lines and a large-period cross-support structure. The support structure had a 60 μm period and a 4.5 μm line width. The grating line width was about 200 nm, the duty cycle was about 0.2, and the aspect ratio was up to 50. The effective open grating area reached 92.5%, and the grating sidewall had a roughness less than 0.8 nm and a perpendicularity reaching 89.2°. For the MACE process, the influence of etching solution ratio on the grating sidewall roughness and perpendicularity was explored on a 〈100〉 silicon wafer.

As an important part of photovoltaic power stations, daily monitoring and maintenance of photovoltaic array are quite necessary. In order to be able to accurately locate the faulty module and diagnose fault types. The fault diagnosis model which based on XGBoost optimized by GridSearchCV on optimal sensor placement is proposed in this article. First, the change laws of external electrical characteristics of photovoltaic modules under the control of MPPT technology are analyzed in different fault states. On this basis, the parameters which can locate the faulty PV modules and the input of the XGBoost PV fault diagnosis model are obtained. Finally, during the process of the simulation and experiment, the failure data measured by the multi-sensor method can be used as a positioning quantity to locate the faulty module. The comparison results with the other three algorithms (LR, RF, XGBoost) prove that the performance of GS-XGBoost algorithm has great advantages in judging PV fault types (short circuit, open circuit, aging).

Main text A pilot study for the thickness measurement of HfO2 films was performed by the Surface Analysis Working Group (SAWG) of the Consultative Committee for Amount of Substance (CCQM). The aim of this pilot study was to ensure the equivalency in the measurement capability of national metrology institutes for the thickness measurement of HfO2 films. In this pilot study, the thicknesses of six HfO2 films with nominal thickness from 1 nm to 4 nm were measured by X-ray Photoelectron Spectroscopy (XPS), X-ray Reflectometry(XRR), X-ray Fluorescence Analysis (XRF), Transmission Electron Spectroscopy (TEM), Spectroscopic Ellipsometry (SE) and Rutherford Backscattering Spectrometry (RBS). The reference thicknesses were determined by mutual calibration of a zero-offset method (Medium Energy Ion Scattering Spectroscopy (MEIS) of KRISS) and a method traceable to the length unit (the average thicknesses of three XRR data except the thinnest film). These reference thicknesses are traceable to the length unit because they are based on the traceability of XRR. For the thickness measurement by XPS, the effective attenuation length of Hf 4f electrons was determined. In the cases of XRR and TEM, the offset values were determined from a linear fitting between the reference thicknesses and the individual data by XRR and TEM. The amount of substance of HfO2, expressed as thickness of HfO2 films (in both linear and areal density units), was found to be a good subject for a CCQM key comparison. To reach the main text of this paper, click on Final Report. The final report has been peer-reviewed and approved for publication by the CCQM.

Main text Electrolytic conductivity in aqueous solutions is a common electrochemical measurement technique in industry. Since it is sensitive to the amount content of dissolved ions in a solution, a limiting value for conductivity is a clear and simple quality criterium for the ionic purity of pure water, roughly ranging from 0.055 μS/cm to 150 μS/cm at 25 °C. International regulations are becoming stricter with regards to metrological traceability to guarantee compliance of measurement results with relevant standards. Consequently, the NMIs active in this area have been facing an increasing request for the calibration of respective conductivity sensors and for adequate CRMs over the past years. A first, regional comparison has been conducted in 2013/14 (EURAMET 1271). Since an increasing number of NMIs, also from other regions, seek providing respective services and establishing CMCs, EURAMET, i.e. the Sub-Committee on Electro Analysis of TC-MC, opened a follow-up comparison to other regions in terms of a supplementary CCQM comparison (EURAMET.QM-S12). The comparison has been conducted in terms of a Round Robin scheme. A conductivity sensor has been sent around between ten participants for calibration at four conductivity levels (0.055, 0.5, 5 and 50 μS/cm at 25 °C). Basically, the measured measurement errors of the device have been compared in terms of conductivity. Additionally, the cell constants calculated from the calibration results have been compared. Apart from very few outliers, the comparison has demonstrated good equivalence of the calibration capabilities. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

In 2011, Qu et al. proposed a quantum information hiding protocol based on the entanglement swapping of χ-type quantum states. Because a χ-type state can be described by the 4-particle cat states which have good symmetry, the possible output results of the entanglement swapping between a given χ-type state and all of the 16 χ-type states are divided into 8 groups instead of 16 groups of different results when the global phase is not considered. So it is difficult to read out the secret messages since each result occurs twice in each line (column) of the secret messages encoding rule for the original protocol. In fact, a 3-bit instead of a 4-bit secret message can be encoded by performing two unitary transformations on 2 particles of a χ-type quantum state in the original protocol. To overcome this defect, we propose an improved quantum information hiding protocol based on the general term formulas of the entanglement swapping among χ-type states.

Antiferromagnetic material possesses excellent robustness to an external magnetic field perturbation, which makes it promising in application of spintronic devices. The magnon-phonon interaction plays a vital role in spintronic devices. In this work, we performed first-principles calculation to study the effect of magnon-phonon interaction on magnon spectra of the antiferromagnetic MXenes Cr2TiC2FCl, and calculated the phonon dominated magnon relaxation time based on the magnon spectra broadening. Due to the large exchange constants across Cr-Cr pairs, high magnon energy is found in Cr2TiC2FCl. We find that compared with the acoustic magnons, the optical magnons have stronger interaction with phonon modes. Moreover, relaxation time of optical magnons and acoustic magnons have quite different wavevector dependence. Our results about spin coupling to specific phonon polarizations can shed light on the understanding of magnon damping and energy dissipation in two-dimensional antiferromagnetic materials.

The article proposes a network dynamic defense model based on the DHCP protocol for enterprise internal network security protection needs, which not only implements network terminal access verification, but also it realizes the periodic dynamic adjustment of the IP address, and increases the difficulty of network detection and attack. So, the security of the enterprise intranet is improved.

In this paper, four units of a power plant are taken as the research object, and the air pollutant emission performance standards, equipment installed economic efficiency, operational economic efficiency and energy saving potential of four units using different technical methods for ultra-low emission transformation are analyzed. Take unit 4 as an example, the ultra-low emission operation cost is discussed. The results show that the operation performance, stability and reliability of some units of low-temperature economizer need to be improved; the K values of different ultra-low emission technology methods were between 7.6∼12kW/MW. The installation of a low temperature economizer allows the wet desulfurization facility to have a greater water saving capacity.

Taking a 75t/h circulating fluidized bed boiler cyclone separator in a boiler manufacturing plant as the research object, this study uses FLUENT fluid calculation software and the balanced orbit and dwell time model to analyze the influence of the particle trajectory tracking, exhausting pipe length and pipe diameter on the separation efficiency The calculation results show that when the relative diameter is equal to 0.3∼0.5, the separation efficiency is already high. If the diameter of the core tube is reduced, the separation efficiency is not improved much. However, this will lead to a sharp increase in pressure loss; The increase of the powder concentration is markedly increased; the larger the particle size is, the higher the separation efficiency is. The separation efficiency is obviously improved after the particle size is larger than 30 μm. The separation efficiency is already high after the particle size is larger than 80 μm, and the increase of the particle size is not significant.

The main influential factors affecting the traffic safety of tunnel group sections of expressway in mountainous areas and their effect on the accident rate are analyzed, this paper analyzes the accident rate of the tunnel group sections of expressway from the aspect of the road alignment and the anti-sliding ability of the road surface. According to the principle of the road sections, the accident rate prediction models for four different sections are established, which are the curve section of the tunnel entrance, the straight section of the tunnel entrance, the curve section of the tunnel exit, and the straight section of the tunnel exit. For different types of road sections, the corresponding road data and independent variables are selected, multiple linear regression is performed by spss software, and an accident rate prediction model is constructed. The results show that under the worst condition of linear condition, the demand value of SFC side-way force coefficient is much larger than the specified value, the required anti-sliding performance of the road surface is the highest for the tunnel entrance straight section, and the anti-sliding performance of the road surface required for the tunnel exit curve section is the lowest. The reason for this is that the direct line segment is better than the curve line segment condition, resulting in faster driving speed, and therefore the demand for anti-sliding performance of the road surface is also higher.

A 10-channel H α diagnostic system has been designed with the rapid response rate of 300 kHz, spatial resolution of about 40 mm, and overlap between adjacent channels of about 3%, and it has been implemented successfully on Keda Torus eXperiment (KTX), a newly constructed, reversed field pinch (RFP) experimental device at the University of Science and Technology of China (USTC). This diagnostic system is a very important tool for the initial KTX operations. It is compact, with an aperture slit replacing the traditional optical lens system. A flexural interference filter is designed to prevent the center wavelength from shifting too much as the increase of angle from vertical incidence. To eliminate the stray light, the interior of the system is covered with the black aluminum foil having a very high absorptivity. Using the H α emission data, together with the profiles of electron temperature and density obtained from the Langmuir probe, the neutral density profiles have been calculated for KTX plasmas. The rapid response rate and good spatial resolution of this H α diagnostic system will be beneficial for many studies in RFP plasma physics.

The Keda Torus eXperiment (KTX) is still operated in the commissioning phase, and preparation for the operation capability of the KTX phase II upgrade is underway. The diagnostics in the KTX have been greatly developed: (1) the terahertz interferometer has been upgraded to seven chords for electron density profile inversion; (2) a Thomson scattering system with a 5 Joule laser has been installed and commissioning is in progress; (3) a 3D movable probe system has been developed for the electromagnetic turbulence measurement; (4) double-foil soft x-ray imaging diagnostics have been set up and a bench test has been completed; (5) an edge capacitive probe has been installed for the radial electrical field measurement; (6) a multi-channel spectrograph system has been built for detecting impurities of carbon and oxygen. In addition, the design of a new compact torus injection system has been completed for feeding and momentum driving. Pilot research, such as the 3D reversed field pinch physics and electromagnetic turbulence, etc, have been conducted in the discharge status of the KTX. The 3D spectra characters of electromagnetic turbulence are firstly measured using a classical two-point technique by Langmuir probe arrays set on the 3D movable probe system and edge magnetic sensors. The forward scattering is collected by the interferometer system, which shows the potential for turbulence research. The electromagnetic turbulence is tentatively investigated in the KTX. The formation of a quasi-single-helicity state in the KTX regime is also preliminarily explored in simulation.

A novel π-shape device (π-D) was developed based on air full pressure supply theory to realize the uniform air/smoke exhaust for long duct with enormous vents in subway tunnel. To validate its performance, numerical simulation of internal flow field of the duct with π-D was conducted. Then an experimental 65-meter-long exhaust duct with π-Ds was set up in accordance with the real size. The air exhaust velocities of each vent and the total head losses along the main duct were measured. Both experimental and simulation results showed that the proposed new device could be designed and equipped flexibly into the long air/smoke exhaust duct. It would significantly enhance the ventilation uniformity, reduce the airflow resistance by 50%-65%, and achieve above 20% of distribution energy saving as well.

The dynamic recrystallization (DRX) behavior of Inconel 718 superalloy containing second phase particles (δ phase) was investigated through isothermal compression deformation tests under the deformation temperatures of 960 °C–1000 °C and strain rates of 0.01, 0.1, 1 s−1. A developed cellular automaton (CA) model was established to describe the DRX process, considering the ellipsoid particle effects of particle stimulated nucleation and pinning grain boundary mobility. The comparisons of average grain size evolution and DRX kinetics were carried out between the studied superalloy with and without a δ phase. The results show that the δ phase could reduce the critical strain triggering DRX, average grain size at steady state and peak stress while increase the value of the Avrami exponent. And the effects of δ phase on average grain size is more and more obvious with the increase of strain rate. A great agreement between the simulated and experimental results was obtained, which indicates that the developed CA model considering the δ phase effects could well describe the DRX process of the studied superalloy.

GaN-based continuous-wave operated blue-violet laser diodes (LDs) with long lifetime are demonstrated, which are grown on a c-plane GaN substrate by metal organic chemical vapor deposition with a 10 × 600 μm2 ridge waveguide structure. The electrical and optical characteristics of a blue-violet LD are investigated under direct-current injection at room temperature (25 °C). The stimulated emission wavelength and peak optical power of the LD are around 413 nm and over 600 mW, respectively. In addition, the threshold current density and voltage are as small as 1.46 kA/cm2 and 4.1 V, respectively. Moreover, the lifetime is longer than 1000 hours under room-temperature continuous-wave operation.

CCQM key comparison K-153 Measurement of Specific Adsorption A [mol/kg] of N2 and Kr on nonporous SiO2 at LN temperature (to enable a traceable determination of the Specific Surface Area (BET) following ISO 9277) has been performed by the Surface Analysis Working Group (SAWG) of the Consultative Committee for Amount of Substance (CCQM). The objective of this key comparison is to compare the equivalency of the National Metrology Institutes (NMIs) and Designated Institutes (DIs) for the measurement of specific adsorption, BET specific surface area) of nonporous substances (sorbents, ceramics, catalytic agents, etc) used in advanced technology. In this key comparison, a commercial nonporous silicon dioxide was supplied as a sample. Eight NMIs participated in this key comparison, but only five NMI's have reported in time. All participants used a gas adsorption method, here nitrogen and (or) krypton adsorption at 77.3 K, for analysis according to the international standards ISO 15901-2 and 9277. In this key comparison, the degrees of equivalence uncertainties for specific adsorption nitrogen and krypton, BET specific surface area were established. KEY WORDS FOR SEARCH nonporous SiO2, Specific Adsorption of N2 and Kr, BET specific surface area Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Cancer biology and drug discovery are heavily dependent on conventional 2D cell culture systems. However, a 2D culture is significantly limited by its ability to reflect 'true biology' of tumor in vivo. Three-dimensional (3D) in vitro cell culture models have been introduced to aid cancer drug discovery by better modeling the tumor microenvironment. Here, decellularized lung scaffolds cultured with MCF-7 cancer cells were bioengineered as a platform to study tumor development and anti-cancer drug evaluation. Excellent cell compatibility of decellularized lung scaffolds promoted cell growth and proliferation. Multicellular tumor cell spheroids (tumoriods) were formed and enlarged exclusively in decellularized lung scaffolds over time. The expression of breast cancer biomarkers (BRCA1 and HER2) in MCF-7 cells significantly increased in the lung matrix compared to those cultured in 2D systems. Insufficient oxygen and nutrient diffusion into the internal surface of lung scaffolds resulted in intracellular hypoxia, quantified by a significant upregulation of HIF-1α protein expression compared to that of cell monolayers. Higher survival rates after exposure to 5-FU were observed in lung scaffolds (52.04%) compared to that in 2D systems (18.39%) on day 3 of culture. Overall, this new breast tumor system provides a promising platform to study breast cancer progression and develop new targeted therapeutic strategies.

The Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST, also called the Guo Shou Jing Telescope) is a special reflecting Schmidt telescope. LAMOST's special design allows both a large aperture (effective aperture of 3.6 m–4.9 m) and a wide field of view (FOV) (5°). It has an innovative active reflecting Schmidt configuration which continuously changes the mirror's surface that adjusts during the observation process and combines thin deformable mirror active optics with segmented active optics. Its primary mirror (6.67 m × 6.05 m) and active Schmidt mirror (5.74m × 4.40m) are both segmented, and composed of 37 and 24 hexagonal sub-mirrors respectively. By using a parallel controllable fiber positioning technique, the focal surface of 1.75 m in diameter can accommodate 4000 optical fibers. Also, LAMOST has 16 spectrographs with 32 CCD cameras. LAMOST will be the telescope with the highest rate of spectral acquisition. As a national large scientific project, the LAMOST project was formally proposed in 1996, and approved by the Chinese government in 1997. The construction started in 2001, was completed in 2008 and passed the official acceptance in June 2009. The LAMOST pilot survey was started in October 2011 and the spectroscopic survey will launch in September 2012. Up to now, LAMOST has released more than 480000 spectra of objects. LAMOST will make an important contribution to the study of the large-scale structure of the Universe, structure and evolution of the Galaxy, and cross-identification of multi-waveband properties in celestial objects.

This paper describes the data release of the LAMOST pilot survey, which includes data reduction, calibration, spectral analysis, data products and data access. The accuracy of the released data and the information about the FITS headers of spectra are also introduced. The released data set includes 319 000 spectra and a catalog of these objects.

In this paper, we propose a method for the projective synchronization between two different chaotic systems with variable time delays. Using active control approach, the suitable controller is constructed to make the states of two different diverse time delayed systems asymptotically synchronize up to the desired scaling factor. Based on the Lyapunov stability theory, the sufficient condition for the projective synchronization is calculated theoretically. Numerical simulations of the projective synchronization between Mackey—Glass system and Ikeda system with variable time delays are shown to validate the effectiveness of the proposed algorithm.

We study different types of projective synchronization (projective-anticipating, projective, and projective-lag synchronization) in a class of time-delayed chaotic systems related to optical bistable or hybrid optical bistable devices. We relax some limitations of previous work, where the scaling factor α can not be any desired value. In this paper, we achieve projective-anticipating, projective, and projective-lag synchronization without the limitation of α. A suitable controller is chosen using active control approach. Based on the Lyapunov stability theory, we derive the sufficient stability condition through theoretical analysis. The analytical results are validated by the numerical simulations using Ikeda model and Mackey—Glass model.

By using the density matrix renormalization group technique, the phase diagram of the half-filling extended Hubbard model is investigated. The conventional order parameter, the two-site entanglement entropy, and the block-block entanglement entropy are analyzed in detail. According to the numerical results, in the weak coupling region, an intermediate bond-order-wave (BOW) phase is shown to exist indeed between the charge-density-wave (CDW) and the spin-density-wave (SDW) phases. The critical phase transition points are determined by the singularity of the first order derivative of two-site entanglement entropy. In strong coupling region, a direct phase transition occurs from SDW phase to CDW phase, and shows discontinuous (first order) character accompanied with energy level crossing. The numerical results support the phase diagram proposed previously by some authors Sengupta et al., (2002); Sandvik et al., (2004); Zhang, (2004). Therefore, the quantum entanglement is a sensitive tool to describe quantum phase transitions in strongly correlated electron systems.

The introduction of Keggin-type polyoxometalate (POM) K4SiW12O40 into the solvothermal synthesis system of Cu3SnS4 (CTS) led to the formation of a new CTS-POM particle. The structure and composition were characterized by x-ray diffraction, scanning electronic microscopy and transmission electron microscopy. The results revealed that the CTS-POM particles exhibit multiporous microsphere morphology, which was first observed in CTS materials. A possible growing mechanism was proposed based on POM concentration-dependent growth study of the microspheres. The photodegradation of RhB and H2 production under UV–vis irradiation was done to evaluate the photocatalytic activities of the samples. The results indicated that the as-synthesized CTS-POM exhibited enhanced photodegration of RhB and photocatalytic H2 generation compared to pure CTS particles, and the content of loaded POM has an important impact on the catalytic activity of CTS-POM. The 5% POM-loaded CTS microspheres reached the best photocatalytic activity in H2 production. Meanwhile, increased stability of photocatalytic activity of CTS-POM was also observed.

We report the discovery of eight new quasars in one extragalactic field (five degree centered at RA=$08^h58^m08.2^s$, Dec=$01^o32'29.7''$) with the LAMOST commissioning observations on December 18, 2009. These quasars, with $i$ magnitudes from 16.44 to 19.34 and redshifts from 0.898 to 2.773, were not identified in the SDSS spectroscopic survey, though six of them with redshifts less than 2.5 were selected as quasar targets in SDSS. Except one source without near-IR $Y$-band data, seven of these eight new quasars meet a newly proposed quasar selection criterion involving both near-IR and optical colors. Two of them were found in the 'redshift desert' for quasars ($z$ from 2.2 to 3), indicating that the new criterion is efficient for recovering the missing quasars with similar optical colors as stars. Although LAMOST met some problems during the commissioning observations, we were still able to identify other 38 known SDSS quasars in this field, with $i$ magnitudes from 16.24 to 19.10 and redshifts from 0.297 to 4.512. Our identifications imply that a substantial fraction of quasars may be missing in the previous quasar surveys. The implication of our results to the future LAMOST quasar survey is discussed.

We present preliminary analyses of spectra of quasar candidates in two Guoshoujing Telescope (GSJT, formerly named the Large Sky Area Multi-Object Fiber Spectroscopic Telescope - LAMOST) test fields near M 31 where one is close to the optical center of the disk and the other is towards the northeastern outskirts of the halo, obtained during the early stage of the GSJT commissioning in the last season of 2009. Both fields contain background low-redshift quasar candidates selected from the SDSS photometry. In total, 14 new quasars with redshifts up to 2 and i magnitudes between 16.7 and 19.2, are discovered, including 7 within the 2.5° central region of M 31. We briefly discuss the potential applications of these newly discovered bright quasars.

By employing perturbation theory, a technique called the 'equivalent rectangular waveguide method' is proposed for analyzing the transmission characteristics of polymeric arrayed waveguide grating (AWG) multiplexers with non-ideal core cross sections, which are modeled by the 'tanh' function. Simulation results show that the non-ideal core cross sections cause the shift of the transmission spectrum, and result in the increase of crosstalk compared with the device originally designed with exact rectangular core cross sections. In order to eliminate the shift of the transmission spectrum, reduce the crosstalk and further realize accurate demultiplexing, the redesign of the AWG device is carried out.

This paper presents a novel 3D porous micromixer fabricated using a selective ultrasonic foaming technique. The 3D porous structure can split, stretch, fold and break the mixing flows effectively and thus dramatically improves the mixing efficiency of microfluidic flows. In the paper, we report on the fabrication and performance of the 3D porous micromixer. The effects of flow rate, mixing length and pore size were studied using flow visualization experiments. It is shown that the proposed micromixer performs very well for flows with a wide range of Reynolds numbers. Sufficient mixing results can be achieved with a short mixing length for flows with Reynolds numbers as low as 0.1.

MgO-barrier-based magnetic double tunnel junctions including Au or Cr nanoparticles were prepared by molecular beam epitaxy, and their magnetotransport properties were investigated. A double junction sample including Au nanoparticles showed the Coulomb blockade effect and clear magnetoresistive hysteresis loops. The observed bias voltage dependence of the resistance and magnetoresistance (MR) suggested that the MR effects of 1?2% at high bias voltages were caused by spin accumulation in the Au nanoparticles. In the case of Cr nanoparticles, a double junction with relatively low sample resistance was obtained, showing a clear Coulomb threshold.

We investigate the dynamics of random walks on weighted networks. Assuming that the edge's weight and the node's strength are used as local information by a random walker, we study two kinds of walks, weight-dependent walk and strength-dependent walk. Exact expressions for stationary distribution and average return time are derived and confirmed by computer simulations. We calculate the distribution of average return time and the mean-square displacement for two walks on the BBV networks, and find that a weight-dependent walker can arrive at a new territory more easily than a strength-dependent one., Comment: 4 pages, 5 figures. minor modifications. Comments and suggestions are favored by the authors

We directly measure the cross-phase shift and nonlinear refractive index of a three-level Λ-type hot atomic coherence system inside an optical ring cavity. The cross-phase nonlinear index of refraction n2 is significantly enhanced and sharply changed when the conditions of atomic two-photon resonance are closed. The cross-phase shift of π induced by controlling light on the probe wave has been observed under a relatively low controlling power of 16.2 mW. The system is valuable in developing optical devices for the optical information process.

Two kinds of continuous-wave GaN-based ultraviolet laser diodes (LDs) operated at room temperature and with different emission wavelengths are demonstrated. The LDs epitaxial layers are grown on GaN substrate by metalorganic chemical vapor deposition, with a 10 × 600 μm2 ridge waveguide structure. The electrical and optical characteristics of the ultraviolet LDs are investigated under direct-current injection at room temperature. The stimulated emission peak wavelength of first LD is 392.9 nm, the threshold current density and voltage is 1.5 kA/cm2 and 5.0 V, respectively. The output light power is 80 mW under the 4.0 kA/cm2 injection current density. The stimulated emission peak wavelength of second LD is 381.9 nm, the threshold current density the voltage is 2.8 kA/cm2 and 5.5 V, respectively. The output light power is 14 mW under a 4.0 kA/cm2 injection current density.

Ultra-thin optical coating comprising nanometer-thick silicon absorbing films on iron substrates can display strong optical interference effects. A resonance peak of longitudinal Kerr rotation with the silicon thickness of was found at the wavelength of 660 nm. The optical properties of silicon thin films were well controlled by the sputtering power. Non-iridescence color exhibition and Kerr rotation enhancement can be manipulated and encoded individually.

A high-performance supercapacitor electrode is designed and fabricated with the 3D interconnected continuous nanoporous Co/CoO core-shell hybrid nanostructure grown on nickel foam. The Co/CoO core-shell hybrid nanostructures are obtained via a hydrothermal method, followed by high-temperature annealing in hydrogen atmosphere, and finally placed in air at 50 °C for 1 h. The Co/CoO core-shell nanostructure assembled by a conductive metal-core and a CoO shell, brings low resistance, high specific capacitance of 5.632 F cm-2 and good capability stability (81.5% capacitance retention after 6000 cycles). An asymmetric supercapacitor device built by the Co/CoO (positive electrode) and activated carbon (negative electrode) can deliver a working voltage of 1.7 V and display a high energy density of 0.002 67 Wh cm-2 at a power density of 0.001 62 W cm-2, which is far superior to that of a supercapacitor at a similar power density.