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Near-bottom observation data from the manned deep submersible Jiaolongwith high-precision underwater positioning data from Weijia Guyot, Magellan Seamounts in the Western Pacific Ocean are reported. Three substrate types were identified: Sediment, ferromanganese crust, and ferromanganese crust with a thin cover of sediment. The ferromanganese crusts show clear zoning and their continuity is usually disturbed by sediments on areas of the mountainside with relatively gentle slope gradients. The identified substrate spatial distributions correspond to acoustic backscatter intensity data, with regions of high intensity always including crust development and regions of low intensity always having sediment. Therefore, acoustic backscatter intensity surveying appears useful in the delineation and evaluation of crust resources, although further more work is needed to develop a practicable methodology.

The Makran accretionary prism is located at the junction of the Eurasian Plate, Arabian Plate and Indian Plate and is rich in natural gas hydrate (NGH) resources. It consists of a narrow continental shelf, a broad continental slope, and a deformation front. The continental slope can be further divided into the upper slope, middle slope, and lower slope. There are three types of diapir structure in the accretionary prism, namely mud diapir, mud volcano, and gas chimney. (1) The mud diapirs can be grouped into two types, namely the ones with low arching amplitude and weak-medium activity energy and the ones with high arching amplitude and medium-strong activity energy. The mud diapirs increase from offshore areas towards onshore areas in general, while the ones favorable for the formation of NGH are mainly distributed on the middle slope in the central and western parts of the accretionary prism. (2) The mud volcanoes are mainly concentrated along the anticline ridges in the southern part of the lower slope and the deformation front. (3) The gas chimneys can be grouped into three types, which are located in piggyback basins, active anticline ridges, and inactive anticline ridges, respectively. They are mainly distributed on the middle slope in the central and western parts of the accretionary prism and most of them are accompanied with thrust faults. The gas chimneys located at different tectonic locations started to be active at different time and pierced different horizons. The mud diapirs, mud volcanoes, and gas chimneys and thrust faults serve as the main pathways of gas migration, and thus are the important factors that control the formation, accumulation, and distribution of NGH in the Makran accretionary prism. Mud diapir/gas chimney type hydrate develop in the middle slope, mud volcano type hydrate develop in the southern lower slope and the deformation front, and stepped accretionary prism type hydrate develop on the central and northern lower slope. The middle slope, lower slope and deformation front in the central and western parts of the Makran accretionary prism jointly constitute the NGH prospect area.

A material that possesses high loading efficiency (in terms of delivering small molecular drugs, nucleic acids, peptides, and proteins) has various medical applications, such as in tumor diagnosis and gene therapy or chemotherapy of tumors. Mesoporous silica nanoparticles are ideal nanocarriers for constructing drug delivery systems because of the unique mesoporous channels for encapsulation and the sustainable release of anticancer drugs. Herein, we demonstrate a doxorubicin (DOX)–peptides double-loaded and -response nanodrug (DMK nanoplatforms) as a multifunctional nanoplatform for chemotherapy of tumors. The nanoparticles are prepared by a surface modification strategy. The KLAK and DOX release in an acidic/reductive tumor microenvironment, which efficiently penetrate cell nuclei and generate the antitumor effect. Our study provides a new approach for developing a smart drug delivery nanosystem, particularly for peptides-guided pH-sensitive chemotherapy.

A chiral N-heterocyclic carbene (NHC)-catalyzed [4 + 2] annulation of γ-chloroenals and α-arylidene pyrazolinones was developed in the absence of expensive oxidants. The reaction proceeds smoothly via a vinyl enolate intermediate to afford spirocyclohexane pyrazolones in moderate to good yield (up to 86%) with high diastereoselectivities (up to 15:1 dr) and excellent enantioselectivities (up to >99% ee).

In order to solve the embedded NURBS interpolator closed structure problem, this paper proposes a NURBS interpolator based on quantum framework software bus architecture. Firstly, the NURBS interpolator trajectory interpolation algorithm and feedrate scheduling algorithm are presented. The embedded NC system systematic architecture is analyzed based on quantum framework. Secondly, the high-speed and high-precision NURBS curve interpolator and platform based on quantum framework are constructed. Finally, software simulation and actual machining experiment verify the correctness and validity of NURBS interpolator structure based on quantum framework by this paper.

Human motion retrieval from motion capture data forms the fundamental basis for computer animation. In this paper, the authors propose an efficient human motion retrieval approach via temporal adjacent bag of words (TA-BoW) and discriminative neighborhood preserving dictionary learning (DNP-DL). The retrieval process includes two phases: offline training and online retrieval. In the first phase, the original skeleton model is first simplified and then pairwise joint distances are computed to characterize each motion frame. Then, a novel motion descriptor, namely TA-BoW, is proposed to discriminatively code the motion appearances, through which the articulated complexity and spatiotemporal dimensionality can be greatly reduced. Subsequently, by considering the neighborhood relationships of intraclass structure and the advantage of Fisher criterion, a DNP-DL method is exploited through which each human action can be discriminatively and sparsely represented by a linear combination of such dictionary atoms. In the second phase, a hierarchical retrieval mechanism is used by incorporating the sparse classification and chi-square ranking, whereby the searching range is significantly reduced. The experimental results show that the proposed human motion retrieval approach performs better than the state-of-the-art competing approaches.

Pneumatic muscles with similar characteristics to biological muscles have been widely used in robots, and thus are promising drivers for frog inspired robots. However, the application and nonlinearity of the pneumatic system limit the advance. On the basis of the swimming mechanism of the frog, a frog-inspired robot based on pneumatic muscles is developed. To realize the independent tasks by the robot, a pneumatic system with internal chambers, micro air pump, and valves is implemented. The micro pump is used to maintain the pressure difference between the source and exhaust chambers. The pneumatic muscles are controlled by high-speed switch valves which can reduce the robot cost, volume, and mass. A dynamic model of the pneumatic system is established for the simulation to estimate the system, including the chamber, muscle, and pneumatic circuit models. The robot design is verified by the robot swimming experiments and the dynamic model is verified through the experiments and simulations of the pneumatic system. The simulation results are compared to analyze the functions of the source pressure, internal volume of the muscle, and circuit flow rate which is proved the main factor that limits the response of muscle pressure. The proposed research provides the application of the pneumatic muscles in the frog inspired robot and the pneumatic model to study muscle controller.

The reinforced concrete bifurcation in hydropower station is consistently under high internal water pressure, and its diameter is usually larger than common duct junctions. To diminish or to decrease the heavy plastic zone and stress concentration, structure rounding is commonly used on bifurcation. This will bring some changes to the flow characteristic of bifurcation, and it is an interesting attempt to figure out the influence of structure rounding optimization. The realizablek–ε model was employed in computational fluid dynamics numerical simulation. The water pressure distribution was compared quantitatively at several certain sections. Furthermore, uneven pressure is analyzed by relative standard deviation. Hydraulic characteristics are discussed as well, including flow pattern, excavation volume and head loss in different working conditions. The results indicate that the pressure of the pipe wall is uneven, and the maximum and minimum pressure value has a differential of 0.3–1.2 % compared to the relative static water pressure. The pressure unevenness will increase after structure rounding, and it has a positive correlation with structure rounding radius. At the same time, it is more reasonable for structure rounding in the obtuse angle region than that in the acute angle region, on account of well-distributed flow conditions and better economic benefit.

A turn-on fluorescence analysis method was established for detection of Pb2+based on aggregation-induced emission. Glutathione-protected non-noble metal copper nanoclusters (Cu NCs@GSH) showed nearly no fluorescence. However, the fluorescence intensity of Cu NCs@GSH was remarkably improved in the presence of Pb2+and showed bright orange fluorescence. A fluorescence method for detection of Pb2+was established based on this principle. The fluorescence change of the Cu NCs@GSH solution showed a linear relationship with Pb2+concentration within the range of 200–700 μM. The limit of detection was 106 μM (S/N= 3). This method is simple, rapid and highly selective, and can be used for the visual qualitative detection of Pb2+under ultraviolet (UV) lamp.

A hydropower house substructure, which is also called a spiral case structure (SCS), is usually made of steel-lined concrete. The research to date has tended to focus on the material non-linearity rather than the contact non-linearity in SCSs. The aim of this study is thus to examine the contact friction between the two components of a SCS, namely, the steel liner and the concrete. A structural finite element analysis (FEA) of a SCS was performed using commercial software. The available Coulomb friction model used to describe the contact nonlinearity has been validated based on the well-known push-off tests in 1985. The findings of this study suggest that, under internal water pressure (IWP), the steel liner will significantly slide towards the membrane's extension range along the internal surface of the surrounding concrete in a c-cross-section of a SCS. Stronger friction leads to more IWP-resisting participation by the surrounding concrete. Based on this understanding, we argue that the friction coefficient should be recognized as an important design parameter. The exterior surface condition of steel spiral cases should be given a greater role in engineering practices of SCSs.

The real-time prediction of network security situation can significantly improve the monitoring and emergency response capability of the network. However, in practice, if there are a large amount of false predictions, the network administrators should become insensitive and will finally ignore all prediction results. In this paper, we try to solve this issue and propose a novel False Positive Adaptive (FPA) method for network security situation prediction. The main idea of our method is using extra information to reduce the number of false positives in prediction. In the model training step, we take advantage of host and network information to eliminate meaningless alerts produced by security tools such as Intrusion Detection System (IDS) and firewall, thus assuring the accuracy of the training samples. In the prediction step, we utilize the detection information from security tools to confirm the prediction results automatically. If the previous predictions are not detected, they will be considered as false positives and the prediction model will be retrained by incremental learning. In our work, the model training and incremental learning is accomplished efficiently by neural network and boosting algorithm.

A novel method was proposed to solve the problem which was caused by high dimensions. Minimum Noise Fraction was used for dimension reduction. And then the RX algorithm and KRX algorithm was used to detect the data after dimensional reduction. The method proposed was better by comparing the ROC of four detection results.

Recently there has been a new kind of attacks, browser-based attacks, against anonymous communication systems, such as Tor. This kind of attacks exploits JavaScript in the browser or the HTML meta refresh to generate some predefined signals to correlate users and their visited websites. A novel and efficient defense against such attacks is proposed in this paper. Our main observation is that the attacker must generate enough signals from the client site (the browser) to correlate the user and the website while we can detect the attack at the client site. More specifically, when a user is browsing a specific website and a browser-based attack is in progress, the number of outgoing flows and the total byte counts generated by the browser should be much larger compared with the normal browsing behavior. So we can set up fingerprints (number of outgoing flows and total byte counts) for normal browsing of web pages for a period of time and utilize these fingerprints to detect browser-based attacks. We have also found that some JavaScript codes must be executed many times if the attacker uses JavaScript to communicate. We have modified the Mozilla Firefox JavaScript engine to audit execution times of JavaScript code to defend these attacks, including browser-based attacks.

This paper describes a system; CODESSEAL can provide protection and evaluation to system software. CODESSEAL was designed to protect embedded systems with sufficient expertise and resources to capture attack equipment and manipulator, not only to protect software but also to protect hardware. By using the reconfigurable hardware allows CODESSEAL to provide confidentiality, integrity of security services and a platform-independent program flow without having to redesign the processor. System uses software and data protection technology and designs cycle simulation methods for data analysis. Experimental results show that the protected instructions and data with a high level of safety can be realized a low, which in most cases the performance loss can be reduced to below 10%, so the research of software protection methods of the embedded operating system of hardware compiler has important practical significance.

Based on the studying of IEEE145 international standard and achievement of hardware and software of TEDS intelligent sensor, it suggested designing an intelligent unit that wont change the input / output interface of the sensor but enables device plug-and-play. The system still can operate normally when the intelligent unit was removed. The intelligent unit includes various modules or functions, such as the logo of IEEE1415 standard device, humiture measurement, nonlinear data table, unified model as well as MCU achievement, normalized treatment and synthesis of signals, aiming to realize the normalization of sensors output signals and achieve the quick connection of test system as well as plug-and-play.

After the technologies of measurement for thin-film thickness were analyzed, the method of real-time measurement for coating thickness based on quartz crystal oscillation was proposed. The principle of the thickness measured by frequency shifting was analyzed on theory, the functional relationship between the resonant frequency shifting and the film thickness changing was deduced. Aim at the complicated working condition in coating machine, the structure of the measuring system for reducing the influence from external pressure and temperature was designed. The circuit for detecting the frequency shift was designed. Final, according to the experiment result, the resolution of thickness measurement can achieve sub-micrometer level.

As the technology of gravitational-wave and neutrino detectors becomes increasingly mature, a multimessenger era of astronomy is ushered in. Advanced gravitational-wave detectors are close to making a ground-breaking discovery of gravitational-wave bursts (GWBs) associated with mergers of double neutron stars (NS-NS). It is essential to study the possible electromagnetic and neutrino emission counterparts of these GWBs. Recent observations and numerical simulations suggest that at least a fraction of NS-NS mergers may leave behind a massive millisecond magnetar as the merger product. Here we show that protons accelerated in the forward shock powered by a magnetar wind pushing the ejecta launched during the merger process would interact with photons generated in the dissipating magnetar wind and emit high-energy, neutrinos and photons. We estimate the typical energy and fluence of the neutrinos from such a scenario. We find that ~PeV neutrinos could be emitted from the shock front as long as the ejecta could be accelerated to a relativistic speed. The diffuse neutrino flux from these events, even under the most optimistic scenarios, is too low to account for the two events announced by the IceCube Collaboration, but it is only slightly lower than the diffuse flux of GRBs, making it an important candidate for the diffuse background of ~PeV neutrinos. The neutron-pion decay of these events make them a moderate contributor to the sub-TeV gamma-ray diffuse background. [ABSTRACT FROM AUTHOR]

Emergency exercises are an efficient approach for preventing serious damage and harm, including loss of life and property and a wide range of adverse social effects, during various public emergencies. Among various factors affecting the value of emergency exercises, including their design, development, conduct, evaluation, and improvement planning, this paper emphasizes the focal role of evacuees and their behavior. We address two concerns: What are the intrinsic reasons behind human behavior? How do we model and exhibit human behavior? We review studies investigating the mechanisms of psychological behavior and crowd evacuation animation. A comprehensive analysis of logical patterns of behavior and crowd evacuation is presented first. The interactive effects of information (objective and subjective), psychology (panic, small groups, and conflicting roles), and six kinds of behavior contribute to a more effective understanding of an emergency scene and assist in making scientific decisions. Based on these studies, a wide range of perspectives on crowd formation and evacuation animation models is summarized. Collision avoidance is underlined as a special topic. Finally, this paper highlights some of the technical challenges and key questions to be addressed by future developments in this rapidly developing field.

A comparative evaluation of three different methods for fabrication of SiO2/epoxy nanocomposite was investigated. The methods evaluated in this study were mechanical blending, traditional sol-gel approach and novel microemulsion polymerization. The nanocomposites were characterized by tensile tests and SEM studies. It was found that microemulsion polymerization is a more satisfying method for generation of epoxy-based nanocomposites.

Because of the large number of operating and equipment parameters of the reactive distillation(RD) and a strong coupling between them, it is difficult to find the optimal process parameters. A novel hybrid method on process parameters optimization of methyl tertiary butyl ether (MTBE) RD was developed in the paper. MTBE RD process was firstly simulated with Aspen Plus. Then based on the MTBE RD model, sensitivity analysis of various parameters was accomplished to determine the key decision parameters. After that, the orthogonal numerical tests were performed in feasible fields to obtain nearly optimal parameters. Finally, with the orthogonal numerical test results, the least square method was used to regress equation, which showed the relationship between objective function and the key decision parameters, thus determining the optimal operating parameters and equipment parameters. Results of analysis indicated that the combination of orthogonal numerical test and the least square method can be attractive since the number of tests was reduced substantially while the specification of the products can be met.

Based on the construction application of C50 anti-cracking pumping concrete, the influence of the polypropylene fiber and expansive agent on the concrete was studied. The workability, mechanical property, drying shrinkage and crack resistance of the pumping concrete and their mechanisms were tested. The results indicated that the workability achieve the standard of pumping concrete through increasing the dosage of polycarboxylic superplasticizers. The incorporation of polypropylene fiber and expansive agents has little influence on the compressive strength and elastic modulus, but will significantly enhance split tensile strength and decrease the drying shrinkage and cracking.

The self-cleaning technology for solar cell array can promote efficiency of electricity produced and protect the solar cell. In this paper, a method of dusts-removal based on travelling-wave dielectrophoretic force was proposed. The theory of travelling-wave dielectrophoresis and the adhesion model between the dusts and the surface of the solar cell array were analyzed. According to the theory and the fabricating process of the film, the structure of the self-cleaning film for large solar cell array was designed.

It is the latest trend of recent research to handle a multi-media picture by using parallel processing technology.Image processing based on the embedded parallel computation is a new field, while not using a parallel processing technique to process the image in the traditional sense. This paper investigates an embedded image processing application parallel to reduce the load imbalance in order to achieve parallel structure.

Current MEMS design methods do not fulfill the needs of emerging complex MEMS devices. In this paper, a systematic direct solid modeling approach for surface micromachined MEMS design is proposed. In this approach, practical model of a surface micromachined MEMS device, designed in a traditional CAD environment, is simplified firstly; after simplification, masks and process sequences are generated through solid-based mask synthesis; then local variation is used to refining the 3D layer model; finally masks and process sequences are verified in rough simulation and accurate simulation. The approach aims at enabling designers to focus on creative design activity in an intuitive mode.

During space capture process, because of the joints flexibility and the distortion of long tubular booms, high precision tracking and positioning performance of large space manipulator can hardly be achieved. As a result, it is difficult to realize successful capture. To solve this problem, a typical kind of netting interface fit for space capture application is introduced to improve the capture ability of the end effecter. Moreover, an equivalent capture strategy is put forward to avoid the complicate modeling problem of the unknown correcting force that acts on the grapple of the target during capture process. The proposed strategy makes the complicate capture problem to be a simple position tracking problem, thus capture can be achieved even a relative velocity exit between the end effecter and the target. Experiments show that the proposed strategy can improve the autonomous capture ability of the large end effecter.

The newly interfere and integrated fiber electro-optic intensity modulator was researched, it was made into Michelson interferometer by thermal poled hollow two-core fiber, and researched the modulation effect of the electro-optic intensity modulator. The result indicate that the poled fiber modulator have low half-wave voltage, and achieved a good effect on intensity modulate, it also realized electro-optic fiber modulator and Michelson interferometer integrated in one optical fiber. The electro-optic intensity modulator have good stability, simple structure and so on.

The 3-D numerical model of bifurcation embedded in anchor block concrete of a diversion type power station is built. And FEM is adopted to analyze the pipe stresses and displacement. The influence of initial gap along the penstock outside, concrete’s crack status of anchor block and deformation modulus of the bed rock is discussed. Some conclusions can be achieved as follows. Safe factor is enough when the exposed-penstock design scheme is adopted. But enough rebar is required to guarantee the integrity of anchor block. The initial gap, concrete’s crack and the deformation modulus of bed rock has marked influence on the stresses of penstock. According to the design criteria of reinforced concrete penstocks, combined bearing ability of bifurcation steel and anchor block concrete is advised to reduce the thickness of penstock. As a result, the difficulty of construction is reduced and the investment is more economized than before.

The space manipulator which is mounted on a space structure or spacecraft to manipulate space payloads is important for the on-orbit-servicing. Its manipulation tasks depend on its end-effector. The flexibility of the large space manipulator will result in residual vibration on its tip, and let the manipulator have poor capability of end positioning. To overcome the drawbacks mentioned-above, the end-effector needs strong capability of misalignment tolerance and soft capturing. On the base of these requirements and analysis, two kinds of end-effector schemes are presented and designed in detail. The essential performances are in comparison based on the results of dynamic simulations and experiments. Consequently, the conclusion is drawn that the steel cable-snared end-effector which captures the interface by winding the grapple fixture probe, is the best scheme that can combine the ability of soft capturing and great misalignment tolerance perfectly.

The cantilever with a high-aspect-ratio and long probe is a key sub-system of the atomic force microscopes (AFMs) used to measure the surface aspect of the mechanical and optical devices. In this paper, a novel cantilever with a 50μm-length-probe and self-sensing piezoresistor was designed; and based on the micro fabrication technology, the processes were planned. The dynamic and static characteristics of the cantilever were analyzed on theory and finite element method (FEM). The results show that the length of the probe has no effect on the cantilever’s dynamic and static performance.

As to the production of degreasing unit, fully integrated with the equipment and technological features of the line, the approach for the setting of coiling tension was changed, which was mainly tabular method in the past. Under the new idea, the degreasing process was closely integrated with the bell-type annealing for the first time. Then, to minimize the severity of stick breaks was set as the objective function, and no loose coil and no heart-shaped coil is took as the constraint condition. On these bases, a new comprehensive optimization model for the setting of coiling tension in degreasing unit was put forward. The relation between coiling tension and coil radius was obtained, which was a quadratic curve. This simple and practical technology can make the distribution of internal stress of coil more reasonable, and reduce the incidence of stick breaks, loose coil and heart-shaped coil defects effectively and improve production efficiency, quality and the metal yield.

Handheld electronic devices promote M-learning greatly. Foreign language learners favour the learning environment in handheld electronic devices. The authors explore the features of language learning in handheld electronic devices from the prospective of language input theory.The paper discusses the comprehension, nature and authenticity, abundance and varieties in language learning with handheld electronic devices.

In order to achieve large tolerance capture and high stiffness connection for space payload operations, a Chinese large-scale space end-effector (EER) was developed. Three flexible steel cables were adopted to capture the payload with large capture allowance. Ball screw transmission mechanism and plane shape-constraint four bar linkage mechanism were utilized to connect the payload with high stiffness. The experiments show that capture tolerances in X, Y, Z, Pitch, Yaw, Roll directions are 100 mm, 100 mm, 120 mm, 10.5°, 10.5°, 12°, respectively. The maximum connection stiffness is 4 800 N·m. The end-effector could meet the requirements for space large tolerance capture and high stiffness connection in the future.

The purpose of this article is to introduce the results of free tissue transfers using the technique of the cross-bridge microvascular anastomosis when the recipient lacks suitable vessels for anastomosis. Between May of 1982 and June of 2002, a series of 85 patients underwent this procedure. The transferred tissues were the free latissimus dorsi myocutaneous flap, the free vascularized fibula, the free fibular osteocutaneous flap, and the free iliac osteocutaneous flap, alone or in combination. The donor vessels were the anterior tibial artery and great saphenous vein, the posterior tibial artery and its venae comitantes, and the radial artery and cephalic vein. Good results were achieved. The success rate reached 95.29 percent. The authors believe this procedure can be performed in the event of serious tissue defect where the vessels are unsuitable for anastomosis.

Existing design models of soil pressure at the top of buried steel pipes are limited to small-diameter pipes. This study aims to investigate the behavior and design model on the soil pressure for large-diameter pipes considering the pipe diameter, diameter-to-thickness ratio, and cover depth. The distribution and size of soil pressure are obtained from finite element models and compared with traditional design models. Sensitivity studies of soil parameters, trench parameters, and friction coefficients are discussed. Furthermore, an innovative design model of soil pressure for large-diameter pipes is proposed. The results indicate that the basic distribution pattern of soil pressure is “inverted basin”/parabola for large/small-diameter pipes, respectively. Peak soil pressure typically appears in the pleura of pipes with great flexibility and deep cover depth. The modulus and Poisson's ratio of backfill and soil-soil friction coefficient have an influence range within 10% for soil pressure, while trench parameters have a more significant influence. Prism load is too large at high cover depth, and Marston load is small at low cover depth. The basin model for soil pressure adopts the form of “straight line + parabola” for distribution and “Marston + pleura” load for size, with high accuracy and strong adaptability.

This paper investigates the potential for using acoustic emission signal analysis for a monitoring technique for process automation as well as a sensitive tool for investigation of grinding fundamentals. The acoustic emission generated during the grinding process is analyzed to determine its sensitivity to process efficiency and the condition of the grinding wheel. Acoustic emission from surface grinding is used to measure wear-related loading of the grinding wheel and sparkout (or loss of contact) between the wheel and the work surface. A discussion of energy dissipation in grinding and the generation of acoustic emission is included. This investigation showed that the acoustic emission energy, (RMS)2, increases with the combined effects of wheel wear and loading, the signal energy, (RMS)2, is a function of the undeformed chip thickness and that the signal accurately detects work-wheel contact and sparkout with a higher sensitivity than force measurements.

This paper developed an intelligent optical fiber refractive index profile measurement system. This system is based on the principle of the refracted near-field measurement. The whole system is the use of a unique high-resolution non-contact capacitive displacement sensor to monitor the scanning position of the fiber measured. At the same time we used a shading screen which was embedded into the sample pool. Using this method, we can totally save space. Finally, we used a high curvature condenser to collection of reflected light which we used a photo detector to collect. The collected signal was brought into the computer to calculate the optical fiber refractive index. The whole system is totally enclosed operating instrument with an easy-to-use software interface for performing measurements of both multi mode and single mode optical fiber, which can easy pick up the signal automatically and processing in computer. Measurement accuracy can reach 10-4. It is fit for measuring the refractive index of single-mode fibers and multi-mode fibers.

Fast radio bursts (FRBs) are highly dispersed and probably extragalactic radio flashes with millisecond duration. Recently, the Canadian Hydrogen Intensity Mapping Experiment (using the CHIME/FRB instrument) has reported detections of 13 FRBs during a pre-commissioning phase. It is more exciting that one of the 13 FRBs is a second source of repeaters which suggests that CHIME/FRB and other wide-field sensitive radio telescopes will find a substantial population of repeating FRBs. We have proposed strongly lensed repeating FRBs as a precision cosmological probe, e.g., constraining the Hubble constant and model independently estimating the cosmic curvature. Here, we study complementary constraints on the equation of state of dark energy from strongly lensed FRBs to currently available popular probes. It is found that, in the framework of Chevalier-Polarski-Linder parametrization, adding time delay measurement of 30 strongly lensed FRB systems to cosmic microwave background radiation and type Ia supernovae can improve the dark energy figure of merit by a factor 2. In the precision cosmology era, this improvement is of great significance for studying the nature of dark energy. [ABSTRACT FROM AUTHOR]

Einstein's weak equivalence principle (WEP) states that any freely falling, uncharged test particle follows the same identical trajectory independent of its internal structure and composition. Since the polarization of a photon is considered to be part of its internal structure, we propose that polarized photons from astrophysical transients, such as gamma-ray bursts (GRBs) and fast radio bursts (FRBs), can be used to constrain the accuracy of the WEP through the Shapiro time delay effect. Assuming that the arrival time delays of photons with different polarizations are mainly attributed to the gravitational potential of the Laniakea supercluster of galaxies, we show that a strict upper limit on the differences of the parametrized post-Newtonian parameter γ value for the polarized optical emission of GRB 120308A is Δγ < 1.2 × 10-10, for the polarized gamma-ray emission of GRB 100826A is Δγ < 1.2 × 10-10, and for the polarized radio emission of FRB 150807 is Δγ < 2.2 × 10-16. These are the first direct verifications of the WEP for multiband photons with different polarizations. In particular, the result from FRB 150807 provides the most stringent limit to date on a deviation from the WEP, improving by one order of magnitude the previous best result based on Crab pulsar photons with different energies. [ABSTRACT FROM AUTHOR]

A supramassive, strongly magnetized millisecond neutron star (NS) has been proposed to be the candidate central engine of at least some short gamma-ray bursts (SGRBs), based on the "internal plateau" commonly observed in the early x-ray afterglow. While a previous analysis shows a qualitative consistency between this suggestion and the Swift SGRB data, the distribution of observed break time tb is much narrower than the distribution of the collapse time of supramassive NSs for the several NS equations-of-state (EoSs) investigated. In this paper, we study four recently constructed "unified" NS EoSs (BCPM, BSk20, BSk21, and Shen) as well as three developed strange quark star (QS) EoSs within the new confinement density-dependent mass (CDDM) model, labelled as CIDDM, CDDM1, and CDDM2. All the EoSs chosen here satisfy the recent observational constraints of the two massive pulsars of which the masses are precisely measured. We construct sequences of rigidly rotating NS/QS configurations with increasing spinning frequency f, from nonrotating (f=0) to the Keplerian frequency (f=fK), and provide convenient analytical parametrizations of the results. Assuming that the cosmological NS-NS merger systems have the same mass distribution as the Galactic NS-NS systems, we demonstrate that all except the BCPM NS EoS can reproduce the current 22% supramassive NS/QS fraction constraint as derived from the SGRB data. We simultaneously simulate the observed quantities (the break time tb, the break time luminosity Lb, and the total energy in the electromagnetic channel Etotal) of SGRBs and find that, while equally well reproducing other observational constraints, QS EoSs predict a much narrower tb distribution than that of the NS EoSs, better matching the data. We therefore suggest that the postmerger product of NS-NS mergers might be fast-rotating supramassive QSs rather than NSs. [ABSTRACT FROM AUTHOR]