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The non-reciprocity of Sagnac interferometer provides ultra-high sensitivity for parameter estimation and offers a wide range of applications, especially for optical fiber sensing. In this work, we study a new type of non-reciprocity existed in optical fiber Sagnac interferometer where the polarization dependent loss is taken into consideration. In particular, this non-reciprocity is irrelevant to the physical effects that being considered in previous studies, which originates from the geometric phases induced by continuous-weak-measurement. In consequence, it has a unique phenomenon of sudden phase transition, which may open a new way for the future design of high precision optical fiber sensors., Comment: 10 pages, 11 figures. The wrong author list in v1 has been corrected

An adaptive correction algorithm is demonstrated based on weak measurement, which introduces a feedback and an additional interaction to the system and can dynamically adjust the operating point in accordance with the condition of the estimated phase change. Two schemes, fast adaptive correction and slow adaptive correction, are proposed for different conditions of the modulation device. Fast adaptive correction scheme can realize a real-time correction and maintain the high sensitivity. Slow adaptive correction scheme, as a supplement, can correct the distortion of the measured parameter by changing the measuring period. These two schemes are useful for high precision phase estimation with time in modern physics and practical applications, including, but not limited to, timing synchronization, accurate distance measurement, and gravity wave detection. Moreover, we discuss the deviation of the adaptive correction for considering system noise in practical measurement.

Tumor-derived exosomes have been recognized as promising biomarkers for early-stage cancer diagnosis, tumor prognosis monitoring and individual medical treatment. However, it is a huge challenge to separate exosomes from trace biological samples in clinics for disease diagnosis. Herein, we propose a simple, quick, and label-free method for isolating circulating exosomes from serum of patients. The strategy synergistically integrates chitosan electrostatic-adsorption, micro-patterned substrates, and microfluidic shuttle flow control to enable the capture/release of circulating exosomes in a simple manner. Using this microchip, we can isolate exosomes from trace samples (10 μl) with relative purity over 90% and high RNA recovery ratio over 84% within 15 minutes, which is impossible for traditional ultracentrifugation methods. We then validate the application of the microchip using 24 serum samples from clinical breast cancer and breast fibroma patients. The isolated exosomes are subjected to miRNA sequencing and RT-PCR, followed by pathway prediction analysis. The results showed that exosomes were relevant to the invasion and metastasis of breast cancer cells and hsa-miR-18a-3p might have the potential to become a new biomarker for distinguishing breast cancer from breast fibroma (AUC = 0.83, P value = 0.019). This established method is simple, quick and easy to operate with integration. And it may pave a new way for clinical research on exosomes and tumor relevant diagnosis.

Knowledge base question answering(KBQA) is the key technology of natural language processing. How to understand the semantic information of the natural language problem and capture the semantic relationship between the problem and the structured triples are the problems that KBQA needs to solve. The boundary of subject entities in Chinese questions is not as clear as English, which increases the difficulty of entity recognition. Besides, the variable Chinese grammar makes predicate mapping more difficult for semantic analysis. Existing KBQA is usually implemented using a pipeline model, which has two disadvantages: (1) Errors caused by entity recognition will be propagated to predicate mapping. (2) Neither entity recognition nor predicate mapping can benefit from the information available to each other. So we propose a BERT-based KBQA to joint entity recognition and predicate mapping tasks that use their dependencies to improve model performance. BERT can solve the semantic ambiguity of the Chinese Q&A databases and improve the accuracy of Chinese Knowledge Base Question Answering(CKBQA). The model achieved an F1 score of 92.04% on the NLPCC 2016 KBQA dataset.

This study investigated the effect of variable axial loads (time-varying axial loads) on the seismic performance and failure mechanism of reinforced concrete (RC) columns with different constraints at the top. The contribution of horizontal and vertical ground motions to the variation in the axial force was revealed by evaluating the axial forces on the RC frame columns and bridge piers under the action of near-fault ground motions. The variation law of the axial force was arrived at using the fast Fourier transform (FFT). Based on previous experiments, 30 cases were designed to discuss the effect of various parameters, namely amplitude, frequency and phase of the variable axial load on the seismic performance of the column. The hysteresis behaviour of specimens under different variable axial loads in terms of hysteresis loops, skeleton curves, stiffness degradations, and energy dissipations were analysed. The results indicated that the frequencies of the variable axial load and lateral displacement of the RC column were constants related to the characteristics of the structure. In addition, variable axial loads were detrimental to the seismic performance of the RC columns, especially those with a large amplitude variation, high frequency, and an identical phase as the lateral drift. It is unsafe to design or evaluate the column based on a constant axial load. Furthermore, constraints at the top of the column strengthened the effect of the variable axial load on the seismic performance of the column, and this resulted in an opposite influence rule of the variable axial load.

Thermo-optical properties of push–pull azobenzene dyes doped nematic liquid crystals was investigated and experimentally demonstrated. The dynamical variations of transmission upon a CW Nd:YAG laser exposure at room temperature were determined by laser intensity, azobenzene dye concentration and sample temperature. Transmission behaviors at different temperatures were distinct, which resulted from oscillation transmittance performance of nematic liquid crystals with temperature variation and photoisomerization process of azobenzene dye. Our experimental results demonstrated that the dynamical thermo-optical change in azobenzene dye doped nematic liquid crystals could be a promising candidate for thermo-optical controller.

Breast cancer is one of the most commonly diagnosed malignancies and the leading cause of cancer death in women worldwide. Although many factors associated with breast cancer have been identified, the definite etiology of breast cancer is still unclear. In addition, early diagnosis of breast cancer remains challenging. Exosomes are membrane-bound nanovesicles secreted by most types of cells and contain a series of biologically important molecules, such as lipids, proteins, and miRNAs, etc. Emerging evidence shows that exosomes can affect the status of cells by transmitting substances and messages among cells and are involved in various physiological and pathological processes. In breast cancer, exosomes play a significant role in breast tumorigenesis and progression through transfer miRNAs which can be potential biomarkers for early diagnosis of breast cancer. This review discusses the potential utility of exosomal miRNAs in breast cancer progression such as tumorigenesis, metastasis, immune regulation and drug resistance, and further in breast cancer diagnosis.

Holographic gratings in nematic liquid crystals doped with Disperse Red 1 (DR1) were investigated using a linearly polarised He–Ne laser. Although the electric transitions of the samples were almost off-resonant, the diffraction of the transient holographic grating was found to exhibit a sinusoidal feature with changing the polarisation of recording beams, and the diffraction intensities and response time of the gratings were strongly dependent on DR1 concentration. The results revealed that the diffraction of holographic grating depends on the rate of trans–cis isomerisation of DR1 molecules. Moreover, the temperature dependence of diffraction indicated that the grating formation mechanism was attributed to photoinduced reorientation of photoisomerisation effect.

High-precision temperature sensor is demonstrated based on weak measurement using spectrum domain analysis. By introducing an extra phase to the postselection, the operating temperature range and temperature precision can be conveniently modulated. Spectral shifts resulted from temperature variation are robust to practical imperfections. The precision of 2.4 × 10−6°C can be achieved by a currently available spectrometer. The maximum operating range is associated with the nematic temperature range of nematic liquid crystals (NLCs) sample. Moreover, the temperature sensitivity of 16.16 nm/°C is obtained experimentally in different linear operating intervals.

Achieving higher sensitivity is an earnest purpose for precision metrology. As a response to this goal, the weak value amplification approach has been developed for measuring ultra-small physical effects, realizing sensitivity that had never been reached before. Encouraged by the successes, many efforts have been devoted to obtain ultimate sensitivity of weak value amplification. However, the benefit would be easily compromised in practice, because the cost of significant reduction on signal intensity leads to an ultra-low signal-to-noise ratio. In this work, we bridge this gap by proposing an alternative weak value amplification approach, which provides sensitivity several orders of magnitude higher than the standard approach while being compatible with practical imperfections. In the proof-of-principle experiment of measuring longitudinal phase change in time-domain, sensitivity up to $5\times10^{-4}$ attosecond is exemplified. Our approach can be applied to measure other small parameters with extremely high sensitivity, providing a new method for future precision metrology., 6 pages, 4 figures. Accepted by Phys.Rev.A

High-precision temperature measurement with adjustable operating range is investigated and experimentally demonstrated based on weak measurement in the frequency domain. The operating range of measurement is precisely modulated by introducing a dynamic extra time delay to the post-selection pumped by a femtosecond laser. By choosing appropriate nonlinear materials and the attenuation, the resolution of the optimized extra time delay can be improved by two orders of magnitude over that of a traditional phase delay compensator. Considering the influence of noise in the experiment, the highest precision of 8.03 × 10−7 °C can be achieved by using a currently available spectrometer. Moreover, the average sensitivity can reach to 38 nm/°C. Taking advantage of the high precision and adjustable operating range, the proposed method has great potential applications in high-precision temperature measurements.

A polarization holographic grating, which integrates the functions of a grating and a wave plate and is called a diffractive wave plate, is recorded by two beams (left and right circularly polarized) of a 532 nm laser in an azo polymer with a liquid-crystal structure. The polarization conversion characteristics of the diffractive wave plates are investigated with a detecting light of 650 nm by metering the polarization state of first-order diffracted light. It is confirmed that the diffractive wave plates convert the incident linear polarization into circular polarization for a linearly polarized probe laser and reverse the sense of rotation of the circular polarization when the detecting light is circularly polarized light.

Modeling laser beam as a tapered wave with a Gaussian spectrum, The temperature fields in HfO 2 /SiO 2 high-reflection (HR) film, induced by 1 ms long-pulse and 10 ns short-pulse lasers, under different incident angles are calculated. The damage differences between long-pulse and short-pulse-induced damage in the HR film are analyzed. The results show for long-pulse laser, the temperature distribution is much less affected by the laser field effect than short-pulse case. Furthermore, as the irradiation angles increase from 0 to 35° for 1 ms and 10 ns lasers, the peak temperature rises in the HR film increase for s polarized laser. Other than long-pulse laser, for short-pulse laser, the positions of the peak temperature shift gradually toward the air–film interface as the incident angle increases, which may have a great influence on the position of thermal stress coupling and damage probability.

Energy optimization with Quality-of-Service (QoS) constraint has become a timely and significant challenge for the cloud datacenters. In this paper, a hardware and software collaborative optimization strategy is implemented to minimize the energy cost while satisfying the time constraint of the cloud-computing datacenters. In the hardware aspect, a DVFS-capable CPU/GPU/FPGA heterogeneous cloud infrastructure is built. This infrastructure has high flexibility, and can adjust its hardware characteristics dynamically in terms of the software run-time contexts, so that a hardware platform which matches the software can be built. Based on this hardware platform, the cloud applications can be executed more efficiently with less energy cost. In the software aspect, the deadline-aware energy-efficient task scheduling algorithms are investigated. Different from the traditional approaches which search for the optimal scheduling solution by the heuristic approaches, a new scheduling approach based on the improved Mathematical Morphology (MM) algorithm is investigated in this paper. To evaluate the performance of our work, we calculated the energy cost of the Fourier transform (FT) and Gaussian elimination (GE) applications on the homogeneous and heterogeneous cloud computing platforms by applying the GA and MM algorithms, respectively. The results proved the MM algorithms running on the DVFS-capable heterogeneous cloud infrastructure could decrease the energy cost of the FT application and GE application respectively by 24.7% and 37.8%, if compared with the GA algorithm running on the DVFS-incapable homogeneous cloud infrastructure.

Vertical earthquake ground motion may magnify vertical dynamic responses of structures, and thus cause serious damage to bridges. As main support structures, piers and bearings play an important role in vertical seismic response analysis of girder bridges. In this study, the pier and bearing are simplified as a vertical series spring system without mass. Then, based on the assumption of small displacement, the equation of motion governing the simply-supported straight girder bridge under vertical ground motion is established including effects of vertical deformation of support structures. Considering boundary conditions, the differential quadrature method (DQM) is applied to discretize the above equation of motion into a MDOF (multi-degree-of-freedom) system. Then seismic responses of this MDOF system are calculated by a step-by-step integration method. Effects of support structures on vertical dynamic responses of girder bridges are studied under different vertical strong earthquake motions. Results indicate that support structures may remarkably increase or decrease vertical seismic responses of girder bridges. So it is of great importance to consider effects of support structures in structural seismic design of girder bridges in nearfault region. Finally, optimization of support structures to resist vertical strong earthquake motions is discussed.

A video-rate optical holographic display is achieved by using an azo-dye-doped liquid crystal as the passive, updatable recording material. The response time of this material is measured in the order of several to tens of milliseconds, depending on recording beam intensities, polarization directions, and polarization states. A holographic video at a refresh rate of 25 Hz, sourced from a spatial light modulator, is demonstrated in the experiments.

A multiplexed holographic display video has been achieved by using a passive azo-dye-doped liquid crystal (LC) cell. Holograms formed in this cell can be refreshed in the order of several milliseconds. By angular multiplexing technique, dynamically multiplexed holographic videos are realized. Moreover, the reconstructed RGB images are merged into a color image, which illustrates the possibility of a color holographic three-dimensional (3D) display by holographic multiplexing of the LC cell.

An ultrasensitive third-order optical nonlinearity measurement was theoretically proposed and experimentally demonstrated based on an extended Sagnac interferometer using weak value amplification. The predictable nonlinear refractive index coefficient (n2) of a nonlinear optical sample (nematic liquid crystals) accorded with the experimental result, which confirmed the rationality and feasibility of the proposed method. The sensitivity of the proposed method was associated with the resolution of the spectrometer and the postselection angle. By choosing a currently available spectrometer, the minimum Kerr phase of about 7.5 × 10−7 rad could be measured. Moreover, low cost and convenient operation of this method might have potential application in third-order optical nonlinearity measurements.

Weak measurement technique can provide high sensitivity for parameter estimation tasks. However in practice, time-varying errors induced by noises significantly compromise its advantages. While prolonging the measurement time can reduce the effect of short-term correlated noises (e.g. white noise), it will on the other hand increase the estimation errors in the presence of long-term correlated noises(e.g. 1/f and 1/f 2 noises). The main obstacle of compensating these kind of errors is to precisely predict the time-varying trend of error, where the disturbances that causing error are highly unpredictable. In this work, we propose a weak measurement scheme with assistance of machine learning algorithm, which can 'learn' the time-varying trend of errors from data without an explicit model. In order to verify the feasibility of this scheme, we carry out a time-delay measurement experiment and achieve the noise compensation via machine learning algorithm. Experimental results demonstrate a 6 dB reduction of mean-square error comparing to the setup without machine learning, which suggest that our scheme can effectively improve the performance of weak measurement in the presence of long-time correlated noises.

Presented is an interferometric modulator display characterized by double layers of liquid crystal (LC) Fabry–Perot filters. With this design, no polarizers and color filters are needed, and both the color and amplitude can be tuned by electrically controlling the LC's birefringence. Instead of the conventional RGB trisubpixel color scheme, a bisubpixel structure is proposed to render a super-wide color gamut. Through simulations, the device performance was numerically studied. The device was proven to be quite suitable for green-display application.

We present a liquid crystal display that allows two faces of the display viewed at opposite directions to show different image/video content simultaneously. This device is characterized by a dye-doped liquid crystal, which can eliminate the need for polarizers and offer a very low crosstalk between two separated viewing angles.

The nanoscale measurement of temperature in the bulk of dielectrics initiated by a single ultrashort laser pulse was first investigated by black-body radiation. A structureless broad continuum emission has been recorded at an interval delay of 2 ns with a temporal gate of 2 ns and spectral resolution of about 0.137 nm, which provides the highest temporal and spectral precision ever. The temporally resolved emission spectrum was proved to be black-body radiation in nature, and temperature was obtained by fitting the radiation with the Planckian formula. Pulse energy was varied from 110 to 270 μJ at 600 fs and a pulse duration of 0.83 ns was also used. The temperature exhibited a small variation with an increasing pulse energy at 600 fs. However, due to the energy transfer from heated electrons to lattice, the temperature was sharply increased at pulse duration of 0.83 ns. It was estimated that heat accumulation started at 0.42–0.47 MHz for a laser pulse at 600 fs, while it was 0.25 MHz for a laser pulse at 0.83 ns.

Arrays of ferroelectric PZT nanowires with lateral size down to 200 nm were fabricated by nanoembossing technology. Structural characterization of the embossed PZT film was studied by Raman spectroscopy. Multidomain configurations of a single nanowire have been explored by vertical mode piezoresponse force microscopy (VPFM). The local electric polarization of the individual ferroelectric nanowire has also been investigated. Excellent ferroelectric and piezoelectric characteristics observed in the embossed PZT nanowires suggest nanoembossing technique proposed in this work is promising to become a useful method for ferroelectric nanowires fabrication.

A dynamic optical holographic display featuring a quantum-dot-doped liquid crystal is presented. Its response time of holographic recording is measured in the order of several to tens of milliseconds, depending on recording beam intensities, applied voltage and grating periods. The transient first-order diffraction effciency is up to 20%. A reconstructed holographic video at a refresh rate of 25 Hz is demonstrated by the experiments.

We theoretically study the light outcoupling efficiency of top-emitting organic light-emitting diode (OLED) with inverted structure and thin-film encapsulation. Thin-film optics is used to optimize the layer thickness to obtain high transmittance. Dipole mode is used to analyze the light outcoupling efficiency of the top-emitting OLED. Through this process, we can optimize the thin-film thickness with high transmittance and optimize the outcoupling efficiency of OLED. Compared with previous research, the current design method is a novel process.

The characteristics of near-fault ground motions are significantly different from far-field ground motions. There are also great differences in the damage of concrete structures caused by these two kinds of ground motions. Earthquake damage indicates that the damage of concrete frame structures subjected to near-fault ground motions is more serious and collapse mechanism is more complicated. In this paper, the traditional alternative path method (APM) in the analysis of collapse was improved. Collapse mechanism of reinforced concrete frame was studied by numerical simulation method. A typical ten-story reinforced concrete frame model was established. Three harmonic waves and three practical near-fault ground motions were selected as acceleration time history input. The results show that different damaged parts of structure caused by strong earthquake have little effect on the final collapse mode when the structure is under free vibration. The failure mode of columns subjected to different ground motions is almost the same. Simple harmonic excitation whose period is close to the predominant period of ground motion can approximately simulate the failure mode of structure caused by earthquake.

With the development of structure optimization, building materials and construction technology, the study of the P-Δ effect is becoming more and more important in the pursuit of layers, flexibility and light quality. Based on the research status of P-Δ effect at home and abroad, this paper selects thenegative property fictitious member method to calculate the P-Δ effect of the multi-layer frame structure under the combined effect of horizontal and vertical ground motion. This paper discusses the influence of the stiffness-to-weight ratio, structural damping, and the vertical acceleration response of the structure. The results show that the damping and structural acceleration responses have a significant effect on the structural P-Δ effect. Under the premise of considering both, the stiffness-to-weight ratio of the structure, that is, the frequency of the structure, has a greater influence on the P-Δ effect of the structure under earthquakes. With the increase of the stiffness-to-weight ratio, the effect of P-Δ effect on structural response is increased and decreased.

Due to the plane geometry of the deck of curved girder bridge, the girder of the bridge will revolve under the excitation of earthquake, leading to impacts between the curved girder and the bridge abutment. In this paper, the3D finite element model of an actual curved girder bridge is established by combining the ABAQUS finite element software with the arbitrary contact search algorithm, and the influence of the impact effect on the seismic response of the curved girder bridge is analyzed. The results show that the impact effect increases the risk of beam falling at the outer corner, and reduces the risk of the axle direction. The impact of non-coaxial contacts on the internal force of the fixed support and the pier under fixed support is greater, and the internal force of the sliding bearing and the bottom of the pier are affected by the sliding direction of the bearing.

Biphotonic holographic recording through the competition of linearly polarized laser beams with wavelengths of 532 nm and 632.8 nm was investigated in an azobenzene liquid crystal film. With the irradiation of 532 nm excitation light as a switch, holographic gratings were able to be turned on and off. It was found that diffraction behaviors of the recorded gratings were strongly dependent on not only the polarization angle between the recording light and excitation light, but also the sample temperature. Formation processes and diffraction properties of biphotonic holographic gratings were discussed based on the photoisomerization of azobenzene groups. Besides, biphotonic polarization holographic recording was also achieved by means of adjusting the polarization states of recording light and the diffraction characteristics were analyzed in terms of Jones matrices.

Under the action of near-fault ground motions, curved bridges are prone to pounding, local damage of bridge components and even unseating. A multi-scale fine finite element model of a typical three-span curved bridge is established by considering the elastic-plastic behavior of piers and pounding effect of adjacent girders. The nonlinear time-history method is used to study the seismic response of the curved bridge equipped with unseating failure control system under the action of near-fault ground motion. An in-depth analysis is carried to evaluate the control effect of the proposed unseating failure control system. The research results indicate that under the near-fault ground motion, the seismic response of the curved bridge is strong. The unseating failure control system perform effectively to reduce the pounding force of the adjacent girders and the probability of deck unseating.

Polarization modulation of two-photon excited fluorescence in a V-shaped dipicolinate-triphenylamine compound was investigated with 100 fs 800 nm laser pulses. The peak fluorescence intensity versus the input irradiance was measured to meet a square dependence, which offered evidence for two-photon excited fluorescence. The variations of the two-photon excited fluorescence intensity showed strong response to the different polarized incident lights and were tightly dependent on the linearly polarized component of the incident light. Furthermore, the polarization modulation efficiency of the two-photon excited fluorescence had an obvious concentration dependence when the concentration of solution was under 2.5×10(-4) mol/L. The enhancement of modulation efficiency was attributed to the concentration dependence of the two-photon absorption cross section.

A multiplexed holographic video has been achieved with a passive liquid crystal cell, whose response time is in the order of several milliseconds. Meanwhile, reconstructed RGB images are merged as a white color image, providing a possibility of real-time color holographic three-dimensional display. In addition, the dependence of the intensities of reconstructed images on the polarization direction of reading beam is investigated.

To improve the calculation efficiency and accuracy of numerical simulation of structure seismic damage, multi-scale finite element modeling is introduced in this paper. Two different treatment schemes of interface coupling between different-scale models by using a force equilibrium condition and a deformation compatibility condition were researched. Finally, a bridge that collapsed in the Wenchuan earthquake is used as an example to illustrate the suggested approach in this paper. A multi-scale finite element model of a bridge was established based on ABAQUS software. The seismic damage and the collapse process were simulated and compared with the actual seismic damage investigation to verify the validity of multi-scale finite element modeling. The research indicates that multi-scale finite element model can be applied to reasonably and effectively simulate the local damage and whole collapse of a complex bridge due to an earthquake, and the treatment scheme by using a force equilibrium condition can meet the stress and deformation compatibility well at the interface between different-scale models.

Nonlinear optical refraction properties of azo dye doped nematic liquid crystals were investigated with a He-Ne laser (λ = 632.8 nm) as off-resonant light irradiation using spatial self-phase modulation method. Compared with the experimental results of resonant light (λ = 532 nm), the sample irradiated by He-Ne laser exhibited lower optical threshold and the number of diffraction rings was sensitive to the laser polarization. The mechanism of nonlinear optical response of azo dye doped nematic liquid crystals at 632.8 nm could be mainly attributed to photoisomerization effect. Moreover, the diffractions of holographic gratings recorded by He-Ne laser in azo dye doped liquid crystals were consistent with the grating formation based on photoisomerization effect.