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This paper investigates single-period inventory management problems with uncertain market demand, where the exact possibility distribution of demand is unavailable. In this condition, it is important to order a reliable quantity which can immunize against distribution uncertainty. To model this type of single-period inventory management problem, this paper characterizes the uncertain demand by generalized interval-valued possibility distributions. We present a novel concept about an uncertain distribution set to describe distribution perturbation characterization. First, we introduce a lambda selection of the interval-valued fuzzy variable, and the uncertain distribution set is a collection of all generalized possibility distributions of lambda selection variables. According to the uncertain distribution set, a new distributionally robust fuzzy optimization method is developed for single-period inventory management problems. Under mild assumptions, the robust counterpart of the proposed fuzzy single-period inventory management model is formulated, which is an optimization program with certain linear objectives and infinitely many integral constraints. We discuss the computational issue of integral constraints and reformulate equivalently the robust counterpart as three deterministic inventory submodels under generalized interval-valued trapezoidal possibility distributions. According to the characteristics of three submodels, a domain decomposition method is designed to find the robust optimal solution that can immunize against uncertainty in our single-period inventory management problem. Finally, some computational results demonstrate the efficiency of the proposed distributionally robust fuzzy optimization method.

Background Extravillous trophoblast (EVT) cells play an essential role in the maternal-fetal interaction. Although abnormal development and function of EVT cells, including impaired migration and invasion capability, are believed to be etiologically linked to severe pregnancy disorders including pre-eclampsia (PE), the associated molecular mechanisms are not clear ascribed to the lack of an appropriate cell model in vitro. Cyclosporine A (CsA) is a macrolide immunosuppressant and is also used in clinic to improve pregnancy outcomes. However, whether CsA has any effects on the function of EVT cells has not been well investigated. Methods In this study, we induced differentiation of human induced pluripotent stem cells (hiPSCs) and human embryonic stem cells (hESCs) into EVT cells (hiPSC-EVT and hESC-EVT cells, respectively) by Y27632, NRG1, A83-01 and matrigel, and collected these derived EVT cells by flow cytometry for sorting cells positive for double HLA-G and KRT7, which are EVT markers. We then investigated the effects of CsA on the invasion and migration of these derived EVT cells. Results We found that the hiPSC-EVT and hESC-EVT cells expressed high levels of the EVT markers such as KRT7, ITGA5 and HLA-G but low levels of OCT4, a stem cell marker, and that CsA significantly promoted the invasion and migration of hiPSC-EVT and hESC-EVT cells. Conclusions We successfully generated hiPSC/hESC-derived human EVT cells, which may be applicable for investigating the remodeling process of spiral arteries remodeling and the possible mechanisms of EVT-related diseases in vitro. Furthermore, our findings provide direct evidence that CsA regulates the function of EVT cells and molecular basis by which CsA may be used to treat pregnancy complications in clinic associated with deficient EVT function.

This study considers a specific inventory management problem, where a retailer could arrange a series of sequential orders, and the next order is arranged after the yield of present stage is known. For this matter, a credibilistic dynamic programming model is formulated under uncertain supply and demand, and the mean cost convex programming model of each ordering stage is derived. The goal is to obtain the optimal order quantity at each stage under the uncertain supply and demand that are represented by fuzzy variables. By extending the analytical solutions of the optimal order quantities, the general expression of the optimal order quantity is obtained. Finally, some numerical experiments are conducted to illustrate the effectiveness of the solution, and the optimum results and sensitivity of parameters are illustrated both numerically and graphically. It showed that the effect of supply uncertainty could be mitigated by placing sequential orders in advance, and more bookings occur at the earlier stage due to the uncertainty of the next stage.

The Paleoproterozoic Jiao-Liao-Ji Orogenic Belt is a part of the Eastern Block, North China Craton. The Shuangcha rock mass has been recently recognized in Laohe group of Jiao-Liao-Ji Orogenic Belt, and it consists of mainly porphyritic monzonitic granite and porphyritic K-feldspar granite. We present detailed studies of petrography, geochronology and geochemistry of Shuangcha rock mass to constrain the petrogenesis and tectonic evolution features of the Jiao-Liao-Ji Orogenic Belt. The mineral of the Shuangcha granite consists of K-feldspar, plagioclase, quartz and a small amount of biotite ( 350 ppm) and 10,000Ga/Al ratios (average 2.69), which are typical features of A-type granite. The Shuangcha A-type granites can be further subdivided into A2-type subgroup based on some geochemical features, such as high Y/Nb ratios (0.99~3.14, average 1.84). Petrographic and geochemical studies have shown that the Shuangcha granites were the product of partial melting of quartzo-feldspathic rocks under a high temperature (>899°C), low pressure and anhydrous environment. Based on geochemical studies of Shuangcha granites, spatial and temporal distributions of regional magmatism and metamorphism records, the Jiao-Liao-Ji Orogenic Belt was in a typical post-collision extension setting in late Paleoproterozoic period (1.82~1.88 Ga) probably triggered by the slab breaks off.

Achromatic bifunctional metasurface is of great significance in optical path miniaturization among advanced integrated optical systems. However, the reported achromatic metalenses mostly utilize a phase compensate scheme, which uses geometric phase to realize the functionality and uses transmission phase to compensate the chromatic aberration. In the phase compensation scheme, all the modulation freedoms of a nanofin are driven at the same time. This makes most of the broadband achromatic metalenses restricted to realizing single function. Also, the phase compensate scheme is always addressed with circularly polarized (CP) incidence, leading to a limitation in efficiency and optical path miniaturization. Moreover, for a bifunctional or multifunctional achromatic metalens, not all the nanofins will work at the same time. Owing to this, achromatic metalenses using a phase compensate scheme are usually of low focusing efficiencies. To this end, based on the pure transmission phase in the x-/y- axis provided by the birefringent nanofins structure, we proposed an all-dielectric polarization-modulated broadband achromatic bifunctional metalens (BABM) in the visible light. Applying two independent phases on one metalens at the same time, the proposed BABM realizes achromatism in a bifunctional metasurface. Releasing the freedom of nanofin’s angular orientation, the proposed BABM breaks the dependence on CP incidence. As an achromatic bifunctional metalens, all the nanofins on the proposed BABM can work at the same time. Simulation results show that the designed BABM is capable of achromatically focusing the incident beam to a single focal spot and an optical vortex (OV) under the illumination of x- and y-polarization, respectively. In the designed waveband 500 nm (green) to 630 nm (red), the focal planes stay unchanged at the sampled wavelengths. Simulation results prove that the proposed metalens not only realized bifunctional achromatically, but also breaks the dependence of CP incidence. The proposed metalens has a numerical aperture of 0.34 and efficiencies of 33.6% and 34.6%. The proposed metalens has advantages of being flexible, single layer, convenient in manufacturing, and optical path miniaturization friendly, and will open a new page in advanced integrated optical systems.

This paper deals with the problem of designing a two-dimensional (2D) modified repetitive-control system based on a Takagi–Sugeno (T-S) fuzzy model to achieve high tracking performance for a nonlin...

In this study, we investigate the geochronology, geochemistry, zircon Lu–Hf isotopes and Sr–Nd isotopes of mafic–intermediate intrusive rocks in the Naxiguole area of the East Kunlun Orogenic Belt ...

Self-cleaning cotton fabric with excellent amphiphobicity was fabricated by building micro-nanostructures with low surface energy on cotton fabric surface. TiO2 and SiO2 blend nanoparticles modifie...

Beam splitters, especially those with tunable split ratios, play significant role in interferometers, spectrometers, and communication systems. To this end, we proposed a polarization-controllable beam splitter based on dielectric metasurface composed of an array of dielectric pillars. The dielectric metasurface presents phase gradients along two orthogonal directions, say, x- and y- axis, with each phase gradient applicable to one of two orthogonal linear polarizations. Due to the orthogonality of the dual phase gradients in both position and polarization, an elliptically polarized incident beam can be diffracted into two refracted beams, one lies within xoz plane and the other in yoz plane. More importantly, the split ratio of the two refracted beams is continuously tunable by changing the ellipticity of incident beam. Under extreme case, x- or y- polarized incident beam is refracted into one beam, but in different planes for different kind of linear polarization. Besides, the refracted angle of each refracted beam in respective refracted plane can be easily set by adjusting the phase difference of adjacent rows or columns of metasurface. With same method, a polarization-controllable dual-wavelength beam splitter is also achieved on the basis of phase-gradient metasurface. Such a noncoplanar beam splitter with tunable split ratios may play significant role in novel miniature optical devices and systems.

A recyclable polypyrrole (PPy)/cadmium sulfide (CdS) hollow fiber photocatalyst was innovatively fabricated for solving the loss issue of the current powder-form photocatalyst in slurry system. Core-sheath structure CdS/polyacrylonitrile (PAN) fiber was prepared via successive ionic layer adsorption and reaction (SILAR) method on the surface of PAN fiber. PPy was further deposited on the CdS/PAN fiber by vapor deposition polymerization. After the removal of interior PAN template, PPy/CdS hollow fiber was yielded. The hollow structure of PPy/CdS hollow fiber was confirmed by morphology observation. The resulting PPy/CdS hollow fiber presents low energy band gaps of 1.9 eV, which accounts for enhanced visible light photocatalytic activity after PPy deposition. PPy/CdS hollow fiber shows good dye removal efficiency of 73.06 wt% (dosage of the product as low as 5 mg·10 mL−1), and praiseworthy H2 production rate up to 269.7 μmol·g−1·h−1. PPy/CdS hollow fiber maintained high and sustainable photocatalytic activity compared to CdS/PAN fiber after 8 cycles, indicating that PPy effectively improved the stability of CdS. Here, PPy plays key synergistic role in photocatalysis of PPy/CdS hollow fiber for the promotive and protective effects based on the actual photocatalytic performance and inductively coupled plasma optical emission spectrometer (ICP-OES) results. Compared with nano-sized photocatalysts, the fiber-formed PPy/CdS hollow fiber is highly bulky and easy to recycle. PPy/CdS hollow fiber has great potential for scale-up in industrial application because of its excellent grabbing ability and degradation to contaminants, and ease of disposal.

Bus bunching could seriously damage the stability of transit system. This resultant instability always causes a dissatisfying performance of transit system. Traditional bus bunching control methods (e.g., holding control strategy) add slack to schedules or adapt cruising speed. The control methods can alleviate bus bunching in theory, but it is difficult to apply to actual operation, especially in busy traffic. The short-turning strategy only deals with spatial concentration of demand in the existing literatures. We find that the short-turning strategy is also very effective in alleviating bus bunching. In this study, based on the passenger arrival rate of each stop and the spatial-temporal running time, a short-turning model with bunching penalty is developed, and the waiting time of passengers and the operation cost are also considered. Based on data from Beijing Transportation Information Center, we take the Yuntong 111 bus line of Beijing as an example. Compared with the currently used timetable, it is found that a 46.78% reduction in bus bunching is achieved by using the optimal timetable, and there is no increase in operating costs.

A large number of Eocene–Oligocene alkaline/alkali-rich igneous rocks were developed in the Tuotuohe region of the Qinghai-Tibetan Plateau. In this study, we present zircon U–Pb ages, Hf isotope data, and major and trace element compositions of the Cenozoic alkaline rocks from the Tuotuohe region in order to constraint the petrogenesis and tectonic evolution history of Qiangtang Block. Zircon U–Pb ages were measured via LA–ICP–MS to be 39.6, 37.6 and 32.0 Ma. The 39.6 Ma trachyte was characterized by low SiO2 and high K2O and MgO contents. The 37.6 and 32.0 Ma orthophyres show enrichment in SiO2 and K2O, but deficient in MgO. All of the samples belong to the alkaline rocks. These rocks display enrichment in REE, LREE, and LILE, depletion in HFSE, and no obvious Eu anomalies. Geological and geochemical features suggest that there were two possible mechanisms for the origin of the alkaline rocks in the Tuotuohe region: (1) the removed mafic lower crust dropped into the asthenosphere, forming the mix magma (Nariniya trachyte); (2) the upwelling asthenosphere triggered the crustal melting (Nariniya and Zamaqu orthophyre). The Eocene–Oligocene alkaline rocks in the study and adjacent areas are likely to be the result of the same tectonic–magmatic event of deep lithospheric evolution that is the crustal material melting triggered by lithospheric delamination. This conclusion extends the influence scope of lithospheric delamination eastward to the Tuotuohe region (~ 92°E) from Banda Co (~ 82°E).

Perfect vortex (PV) beam has seen significant advances in fields like particle manipulation, optical tweezers, and particle trapping, due to the fact that its ring radius is independent of the topological charge. Although geometric-phase metasurfaces have been proposed to generate PV beams, it always relies on circularly or elliptically polarized incident light, which hinders the miniaturization of compact optical devices. Here, using orthogonal decomposition of polarization vectors (ODPV), we proposed a geometric-phase metasurface, which breaks the dependence of circular polarization, to generate PV beam. In the design of the metasurface, we introduced PV phase profiles corresponding to the left-handed circularly polarized (LCP) component and the right-handed circularly polarized (RCP) component into the metasurface based on the principle of ODPV. We further determined the rotation angle of each nanostructure of the metasurface by calculating the argument of the composite vector of LCP and RCP in the transmission field. Simulation results show that the proposed geometric-phase metasurface can generate the PV beam upon the illumination of a linearly polarized incident. Moreover, the PV beam with polarization-rotated functionality is achieved by setting the polarization rotation angle. Furthermore, dual PV beams with orthogonal polarization states is realized at the same time by superimposing two sets of phase profiles on a single metasurface. It is also demonstrated that the PV beam parameters, such as ring radius and/or topological charge, can be set on demand in the metasurface design. The proposed metasurface has the exceptional advantage of high fabrication tolerance and is optical path miniaturization friendly, and will open a new avenue in advanced compact and integrated optical systems.

This paper concerns the design and optimisation of two-dimensional (2D) repetitive control of nonlinear systems based on the Takagi-Sugeno (T-S) fuzzy model. First, a continuous-discrete 2D model of nonlinear repetitive-control systems based on T-S fuzzy model is constructed by utilizing the 2D characteristics of continuous control and discrete learning actions in the repetitive-control process. Next, a fuzzy Lyapunov-Krasovskii functional derives the linear-matrix-inequality-based stability condition with a low conservatism. Two positive and two nonzero parameters in the fuzzy Lyapunov-Krasovskii functional tune the control and learning actions. Then the particle swarm optimisation algorithm based on a 2D performance index searches for the best parameter combination, resulting in the optimal 2D controller gains. A numerical example is given to demonstrate the effectiveness of the method.

In this paper, the issue of disturbance rejection of nonlinear repetitive control system (RCS) based on a continuous-discrete two-dimensional (2D) model is studied. Since a RCS involves continuous control and discrete learning, higher tracking performance may be realizable by taking into account these two different actions in system design. This paper construct a fuzzy RCS based on T-S model at first. Then, an improved fuzzy-equivalent-input-disturbance (IFEID)-based 2D RCS is presented to achieve both high tracking precision of periodic input and satisfactory rejection of aperiodic disturbances. Stability conditions of two subsystems are derived by exploiting separation theorem to ease the solution of state-feedback and observer gains. A design algorithm is presented via the concept of parallel distributed compensation. A simulation and a comparison demonstrate the availability and advantage of the IFEID-based 2D RCS approach.

Metasurfaces provide a remarkable platform to manipulate over phase, amplitude, and polarization flexibly and precisely. Bifocal metalens draws great research interest due to its ability of converging wavefronts to different focal positions horizontally and longitudinally. However, as wavelength of incident light changes, chromatic aberration will cause the focal lengths reliance on the incident wavelength, which will affect the performance of metasurface, especially for longitudinal bifocal metalens. In this work, a broadband achromatic longitudinal bifocal metalens (BALBM) based on single nanofin unit cell is demonstrated. Pancharatnam-Berry (PB) phase is used to converge the incident light. Cross commixed sequence distribution (CCSD) is introduced to control the positions of focal points FLand FRwhen left-handed circularly polarized (LCP) and right-handed circularly polarized (RCP) incident. Propagation phase is used to compensate the phase difference caused by chromatic aberration. Simulation results show that in the continuous wavelength range from 500 nm to 700 nm, the focal point shifts caused by chromatic dispersion are reduced 81% for FL and 83% for FR, respectively. The focal length variations are stabilized to 6.21% for FLand 4.8% for FRcomparing with the focal lengths at the initial wavelength 500 nm. The proposed BALBM brings advances to bifocal metasurfaces in versatile application areas including machine vision, optical computed tomography and microimaging.

By patterning the metasurface of two phase gradients that are both space-orthogonal and polarization-orthogonal, we derived the three-dimensional (3D) Snell-like formula and the Fresnel-like formula of the proposed metasurface. Theoretically, the dual-phase-gradient metasurface resembles biaxial-like birefringence, i.e., decomposing any homogeneously polarized incident beam into two anomalously refracted beams whose polarizations vary as the incident beam. According to the Fresnel-like formula, the relative intensity between the two anomalously refracted beams not only depends on the incidence angle and the polarization ellipticity of the incident beam being similar to the biaxial crystals, but it also depends on the polarization ellipticity orientation even for a given incident polarization, which is an unique property absent in the biaxial crystals. All the theoretical analyses were numerically demonstrated. The 3D Snell-like and Fresnel-like formulas will make the design of functional devices based on the dual-phase-gradient metasurface much easier.

The Wuxing deposit in Northeast China, tectonically located in the Jiamusi–Khanka Block, is a Pt–Pd-rich Cu-Ni sulfide deposit related to mafic–ultramafic rocks. The zircon U–Pb ages of pyroxenites , gabbros , porphyritic granites , and leucogranits in the mining area are 516.7 ± 2.6, 513.8 ± 2.0, 505.4 ± 2.3 and 499.5 ± 2.9 Ma, respectively, indicating that the diagenesis and metallogenesis of the Wuxing deposit occurred during the Cambrian. The ore-forming complex is cut by quartz diorite porphyritic and plagiogranite porphyry dikes. Zircon U–Pb ages of the quartz diorite porphyrite and plagiogranite porphyry are 206.6 ± 2.1 and 201.6 ± 1.3 Ma, respectively. The U–Pb ages indicate the metallogenic age constraint of 516.7 ± 2.6 Ma for the Wuxing deposit, rather than Cambrian and Triassic magmatic activities. The Hf isotopic composition e Hf(t) of zircons in the pyroxenites and gabbros are −11.5 to −7.7 and −5.8 to −2.5, with the two–stage model ages (tDM2 ) of 2198–1958 and 1841–1633 Ma, respectively. Geochemically, the mafic–ultramafic complexes are enriched in light rare earth elements (LREE) and large ion lithophile elements (LILE), and depleted in high-field strength elements (HFSE), indicating these rocks originated from the enriched mantle. The porphyritic granites are high-K calc-alkaline rocks (Rittman index δ = 1.92–2.00), and the leucogranites are low-K alkaline rocks ( δ = 4.76–4.86) with eHf(t) and tDM2 of −9.2 to +0.8 and 2037–1411 Ma, respectively. The porphyritic granites and leucogranites are characterized by low A/CNK values (0.91–1.05), 10,000 Ga/Al values (1.76–2.36), and Zr saturation temperature (731–823 ℃) similar to those of I-type granites. Along with contemporaneous intrusions, the Wuxing deposit is inferred to have formed in a post-collisional extension environment. Consequently, the origin of the Wuxing deposit is likely related to the evolution of enriched mantle magma during the Cambrian post-collision extensional setting of the Jiamusi–Khanka Block.

In the present work, oil adsorption, desorption, and resorption of poly(lauryl methacrylate-co-hydroxyethyl methacrylate) P(LMA-co-HEMA) were evaluated with different oils by a gravimetric method. Adsorption kinetics were modeled using pseudo-first-order and pseudo-second-order equations. Polymer network parameters of P(LMA-co-HEMA) regarding average molecular weight (Mc) between two crosslink piontss can be calculated by oil absorbency at equilibrium (Q e ), the solubility parameter (δ) and polymer-solvent interaction parameter (χ) with Flory-Huggins relation. The results showed pseudo-second-order model has a better fit to the oil adsorption kinetic data The desorption can be analyzed by fitting a prediction of exponential-like decay to the deswelling curves. A typical oil desorption exhibited two stages: a burst release driven by concentration gradient, and a slow release controlled by diffusion and the elastic recovery of polymer networks. For reusability, the resorption behavior of P(LMA-co-HEMA) was also investigated. It was worth noting that oil resorption was faster than the first adsorption due to potential passages. Moreover, the adsorption capacity was not significantly changed after regeneration.

In multiproduct single-period inventory management problem (MSIMP), the optimal order quantity often depends on the distributions of uncertain parameters. However, the distribution information about uncertain parameters is usually partially available. To model this situation, a MSIMP is studied by credibilistic optimization method, where the uncertain demand and carbon emission are characterized by variable possibility distributions. First, the uncertain demand and carbon emission are characterized by generalized parametric interval-valued (PIV) fuzzy variables, and the analytical expressions about the mean values and second-order moments of selection variables are established. Taking second-order moment as a risk measure, a new credibilistic multiproduct single-period inventory management model is developed under mean-moment optimization criterion. Furthermore, the proposed model is converted to its equivalent deterministic model. Taking advantage of the structural characteristics of the deterministic model, a domain decomposition method is designed to find the optimal order quantities. Finally, a numerical example is provided to illustrate the efficiency of the proposed mean-moment credibilistic optimization method. The computational results demonstrate that a small perturbation of the possibility distribution can make the nominal optimal solution infeasible. In this case, the decision makers should employ the proposed credibilistic optimization method to find the optimal order quantities.

A number of erratums are presented to correct the inadvertent typing mistakes in our paper.

This paper concerns robust stabilization for a class of nonlinear systems with uncertainties and disturbaces. The equivalent-input-disturbance (EID) approach is utilized to estimate the influence of nonlinearities and exogenous disturbances on the output of the system. A robust stability condition is derived in terms of linear matrix inequalities. Moreover, two parameters are used to tune the robustness of the system. Simulation results show that it is more effective to stabilize the system using the developed method than using the sliding-mode control (SMC) method.

Metalens recently attracts enormous attention due to its microscale figure and versatile functionalities. With the combination of geometric phase and propagation phase, we first wrote the phase equation of bifocal metalens that can high efficiently focus incidence into one or two foci in tandem along longitudinal direction, depending on the polarization of incidence. More importantly, the relative intensity of the two foci can be modulated conveniently by changing the ellipticity of incidence, which is different from previous bifocal metalenses need to be repatterned for each kind of relative intensity [Opt. Express23, 29855 (2015)]. Besides, the focusing efficiency of the proposed metalens is as high as 72%, and the separate distance between those two foci can be designed at will, which may find itself significant applications in optical tomography technique, optical data storage, and so on.

It is popularly believed that when the focal spot is shifted far away from the optical axis of optical system with the pupil filter, it will be significantly aberrated. Therefore, the pupil filter is usually only used to adjust the distribution of the focal spot at the optical axis of optical system. In this paper, the special combination of the phase pupil filter shifting the focal spot and the high-pass filter eliminating the aberration of the focal spot is designed so that the focal spot can be shifted dynamically at the focal plane. By utilizing the Debye vector diffractive theory, the shifting behaviours of the focal spot are investigated in detail. The proof-of-principle experiment demonstrates the validation of the method for dynamically controlling the position of focal spot. This work is helpful to realize dynamically shifting the focal spot with the pupil filter and may find valuable applications in particle trapping, microscopes, optical engineering, and so on.

Aiming at the problems of slow recognition, low efficiency and degree of automation in handwritten letter recognition system at present, a handwritten letter recognition system based on extreme learning machine is designed in this paper. The system is implemented by mixed programming with MATLAB and visual studio, it can reads, normalize, binarize and extract the handwritten letter images. The real-time interactive recognition of handwritten letters can be realized on the basis of training the simple pictures by using the identification model of the extreme learning machine algorithm. The experimental results show that the handwriting recognition system based on extreme learning machine designed in this paper can recognize 98.82% of handwritten letters and greatly reduce learning and testing time. Compared with BP neural network and other recognition algorithms, its training times have been reduced by hundreds or even thousands of times. At the same time, there is no manual intervention in the entire learning and testing process, which improves the automation of handwriting recognition.

By investigating the surface wave of photonic crystal, we put forward two sets of rules: the right-handed screw rule, judging the transverse spin angular momentum (SAM) directions according to the propagation direction of the surface wave; and the left-handed rule, judging the excitation direction of the surface wave in accordance to the SAM direction of incident circularly polarized light and the relative position of the dipole-like scatterer with respect to the interface where the surface wave propagates. Both right- and left-handed rules apply to the interface consisting of opposite-sign-permittivity materials. With the help of these two sets of rules, it is convenient to judge the direction of the transverse SAM and the excited surface wave, which facilitate the application involving transverse SAM of the surface wave.

The discovery of transverse spin angular momentum (SAM) of evanescent and guided modes presents a novel spin-orbit interaction (SOI), i.e., transverse SOI, to affect and control the intensity distribution and propagation path of light. In this Letter, we first theoretically verify the transverse SAM property of the surface wave of a photonic crystal (PhC) slab. Then we realize the polarization-controllable unidirectional excitation of such (forward) surface wave by means of transverse SOI. Furthermore, taking advantage of dispersion engineering of PhC, we design another PhC slab capable of sustaining a backward surface wave and find that, compared to a forward surface wave, the backward surface wave is related to inverse unidirectional excitation with incident of a circularly polarized beam. In other words, dispersion engineering of PhC provides another route to control the excitation direction of surface modes. The combination of dispersion engineering and transverse SOI will facilitate the design of functional devices based on PhC in the field of nanophotonics and nanoplasmonics.

Murine norovirus (MNV) was first found as a surrogate for human norovirus study. However, MNV infection was mostly prevalent in laboratory mice, and its immunomodulatory properties may affect the outcome of animal experiments. MNV surveillance had been performed in Europe, North America and some other countries, but not in China. Nowadays, the complete MNV virions had been used as antigen in MNV serological detection. However, the complexity in the preparation of virions might affect the antigen stability, and the virulence recovery of virion antigen had also been detected. In this study, the caspid VP1 protein was proved to be the mostly predominant antigen in MNV virions. An ELISA method using the recombination VP1 as antigen was developed (rVP1 ELISA). The rVP1 ELISA is more sensitive and less specific than the MNV virion-derived IFA method. To address the prevalence of MNV in China, a totally 600 mouse serum samples from Beijing area were tested by rVP1 ELISA and confirmed by IFA and WB. The MNV infection rate was 11.67%, but most of the MNV-positive samples were from experimental facilities (MNV rate=30.94%), not from commercial vendors (MNV rate=0.27%). Collectively, a sensitive rVP1 ELISA was developed in the current study, and the MNV investigation by rVP1 ELISA showed that MNV infection was mostly prevalent in the laboratory mice, especially the mice from experimental facilities in Beijing area in China.