面向双级旋流燃烧器的10kHz滤波瑞利散射测温和CH_(2)OPLIF测量研究

本文开展了常压下双级径向分层旋流燃烧器内旋流火焰的二维温度场及甲醛浓度场测量研究,发展了10kHz测量频率的滤波瑞利散射测温技术.首先,借助Hencken平面火焰炉构建了滤波瑞利散射信号与温度的校准关系.基于校准后的滤波瑞利散射系统,获得了旋流火焰的二维温度场数据:实验分析主要聚焦于甲烷-空气混合物在不同当量比(0.65至1.05)下的温度场变化.在当量比为0.85的单旋流火焰中,观察到火焰形状由V形向M形的转变,这归因于热扩散效应与空气热传导效应的相互作用.此外,在双旋流火焰中,研究发现相同运行条件下,值班火焰与主火焰在燃烧过程中发生从融合到分层的变化.本文详细描述了双旋流火焰分层现象期间的相平均温度场分布,并与瞬时CH_(2)O分布进行了对比.

Parameter Estimation of a Valve-Controlled Cylinder System Model Based on Bench Test and Operating Data Fusion

The accurate estimation of parameters is the premise for establishing a high-fidelity simulation model of a valve-controlled cylinder system.Bench test data are easily obtained,but it is challenging to emulate actual loads in the research on parameter estimation of valve-controlled cylinder system.Despite the actual load information contained in the operating data of the control valve,its acquisition remains challenging.This paper proposes a method that fuses bench test and operating data for parameter estimation to address the aforementioned problems.The proposed method is based on Bayesian theory,and its core is a pool fusion of prior information from bench test and operating data.Firstly,a system model is established,and the parameters in the model are analysed.Secondly,the bench and operating data of the system are collected.Then,the model parameters and weight coefficients are estimated using the data fusion method.Finally,the estimated effects of the data fusion method,Bayesian method,and particle swarm optimisation(PSO)algorithm on system model parameters are compared.The research shows that the weight coefficient represents the contribution of different prior information to the parameter estimation result.The effect of parameter estimation based on the data fusion method is better than that of the Bayesian method and the PSO algorithm.Increasing load complexity leads to a decrease in model accuracy,highlighting the crucial role of the data fusion method in parameter estimation studies.

Fast Estimation of Loader’s Shovel Load Volume by 3D Reconstruction of Material Piles

Fast and accurate measurement of the volume of earthmoving materials is of great signifcance for the real-time evaluation of loader operation efciency and the realization of autonomous operation. Existing methods for volume measurement, such as total station-based methods, cannot measure the volume in real time, while the bucket-based method also has the disadvantage of poor universality. In this study, a fast estimation method for a loader’s shovel load volume by 3D reconstruction of material piles is proposed. First, a dense stereo matching method (QORB–MAPM) was proposed by integrating the improved quadtree ORB algorithm (QORB) and the maximum a posteriori probability model (MAPM), which achieves fast matching of feature points and dense 3D reconstruction of material piles. Second, the 3D point cloud model of the material piles before and after shoveling was registered and segmented to obtain the 3D point cloud model of the shoveling area, and the Alpha-shape algorithm of Delaunay triangulation was used to estimate the volume of the 3D point cloud model. Finally, a shovel loading volume measurement experiment was conducted under loose-soil working conditions. The results show that the shovel loading volume estimation method (QORB–MAPM VE) proposed in this study has higher estimation accuracy and less calculation time in volume estimation and bucket fll factor estimation, and it has signifcant theoretical research and engineering application value.

Correlating the Interfacial Polar-Phase Structure to the Local Chemistry in Ferroelectric Polymer Nanocomposites by Combined Scanning Probe Microscopy

Ferroelectric polymer nanocomposites possess exceptional electric properties with respect to the two otherwise uniform phases,which is commonly attributed to the critical role of the matrix-particle interfacial region.However,the structure-property correlation of the interface remains unestablished,and thus,the design of ferroelectric polymer nanocompos-ite has largely relied on the trial-and-error method.Here,a strategy that combines multi-mode scanning probe microscopy-based electrical charac-terization and nano-infrared spectroscopy is developed to unveil the local structure-property correlation of the interface in ferroelectric polymer nano-composites.The results show that the type of surface modifiers decorated on the nanoparticles can significantly influence the local polar-phase content and the piezoelectric effect of the polymer matrix surrounding the nano-particles.The strongly coupled polar-phase content and piezoelectric effect measured directly in the interfacial region as well as the computed bonding energy suggest that the property enhancement originates from the formation of hydrogen bond between the surface modifiers and the ferroelectric polymer.It is also directly detected that the local domain size of the ferroelectric polymer can impact the energy level and distribution of charge traps in the interfacial region and eventually influence the local dielectric strength.

BITS: an efficient transport solver based on a collocation method with B-spline basis

A B-spline Interpolation Transport Solver(BITS) based on a collocation method is developed. It solves transport equations as a generalized interpolation problem, taking the first-order accuracy in time and the second-order accuracy in space along with a predictor–corrector or under-relaxation iteration method. Numerical tests show that BITS can solve one-dimensional transport equations for tokamak plasma more accurately without additional computation cost, compared to the finite difference method transport solver which is widely used in existing tokamak transport codes.

Absolute quantitative detection of genetically modified soybean MON87708×MON89788 with stacked traits by digital polymerase chain reaction

The main advantage of digital PCR(dPCR) is that it facilitates absolute quantification of the target without reference to the standard/calibration curve.Crystal droplet dPCR has a three-color staining detection function,which enables multiplex PCR reaction.In this study,this technique was used to establish triple dPCR detection for the genetically modified soybean MON87708 × MON89788 with stacked traits.Specific absolute quantitative detection was accomplished for the genomic DNA extracted from the homogenized seeds of GM stack MON87708× MON89788 soybean.Our results can serve as a reference for the absolute quantitative detection of stacked events of genetically modified crops.

Development of a UPLC–MS/MS method for determination of pimavanserin tartrate in rat plasma: Application to a pharmacokinetic study

A simple, rapid and sensitive method based on an ultra-performance liquid chromatography tandem mass spectrometry （UPLC-MS/MS） has been developed and validated for the determination of pimavanserin in rat plasma. The analyte was extracted by protein precipitation with methanol and separated on an ACQUITY BEH C18 column （100 mm × 2.1 mm, 1.7μm; Waters, USA）, with an isocratic elution of acetonitrile-water containing 10 mM ammonium acetate （70：30, v/v）, at a flow rate of 0.2 mL/min for 2.5 rain. The analyte and clarithromyein （the internal standard） were detected and quantified in positive ion mode using multiple reaction monitoring transitions at m/z 428.2 - 223.0 for pimavanserin and m/z 748.5 - 589.5 for clarithromycin. Relative coefficient （r） for the calibration curve was more than 0.9980. The intra-day and inter-day precisions （relative standard deviation, RSD%） were less than 13.3% and 10.5%, respectively, and the accuracy （relative error, RE%） was within ± 11.5%. The analytical method was successfully applied to a routine pharmacokinetic study of pimavanserin in rats after oral administration at the dose of 10 mg/kg.

Implementation of field-aligned coordinates in a semi-Lagrangian gyrokinetic code for tokamak turbulence simulation

Field-aligned coordinates have been implemented in the gyrokinetic semi-Lagrangian code NLT, Ye et al （2016 J. Comput. Phys. 316 180）, to improve the computational efficiency for the numerical simulations of tokamak turbulence and transport. 4D B-spline interpolation in field- aligned coordinates is applied to solve the gyrokinetic Vlasov equation. A fast iterative algorithm is proposed for efficiently solving the quasi-neutrality equation. A pseudo transform method is used for the numerical integration of the gyro-average operator for perturbations with a high toroidal mode number. The new method is shown to result in an improved code performance for reaching a given accuracy. Some numerical tests are presented to illustrate the new methods.

Tunable topological polaritons by dispersion tailoring of an active metasurface

Hyperbolic polaritons are known to exist in materials with extreme anisotropy,exhibiting exotic optical properties that enable a plethora of unusual phenomena in the fields of polaritonics and photonics.However,achieving simultaneous low-dimensionality,high-speed controllability,and on-demand reconfigurability of the polaritons remains unexplored despite their excellent potential in light-matter interactions,photonic integrated circuits,and optoelectronic devices.Here,we propose a metasurface approach to integrating artificially engineered electromagnetic anisotropy with fast-controllable electronic elements,offering a new route to realize active topological polaritons.Experiments showcase the proposed reconfigurable metasurface can support real-time transitions of designer polaritons from elliptical to flat,and then to hyperbolic and circular isofrequency contours.Correspondingly,the in-plane surface wavefront undergoes the transitions from convex to collimating,concave,and eventually back to convex.By exploiting the topological variations in polariton dispersions,we observe intriguing phenomena of controllable field canalization and tunable planar focusing.Furthermore,we report the concept of a planar reconfigurable integrated polariton circuit by spatially tailoring the distributions of polariton isofrequency contours,unveiling rich dispersion engineering possibilities and active control capabilities.We may provide an inspiring platform for developing planar active plasmonic devices with potential applications in subdiffraction-resolution imaging,sensing,and information processing.

Simplistic framework of single-pixelprogrammable metasurfaces integrated with a capsuled LED array

Coding metasurfaces can manipulate electromagnetic wave in real time with high degree of freedom,the fascinating properties of which enrich the metasurface design with a wide range of application prospects.However,most of the coding metasurfaces are designed based on external excitation framework with the wired electrical or wireless light control devices,thus inevitably causing the interference with electromagnetic wave transmission and increasing the complexity of the metasurface design.In this work,a simplistic framework of single-pixel-programmable metasurfaces integrated with a capsuled LED array is proposed to dynamically control electromagnetic wave.The framework fully embeds the photoresistor in the meta-atom,controlling the LED array to directly illuminate the photoresistor to modulate the phase response.With this manner,the complex biasing network is transformed to the universal LED array,which means the physical control framework can be transformed to a software framework,and thus the functions of the metasurface can be freely manipulated by encoding the capsuled LED array avoiding mutual coupling of adjacent meta-atoms in real time.All the results verify that the far-field scattering pattern can be customized with this singlepixel-programmable metasurface.Encouragingly,this work provides a universal framework for coding metasurface design,which lays the foundation for metasurface intelligent perception and adaptive modulation.

Metabolic flux simulation of microbial systems based on optimal planning algorithms

The genomic scale metabolic networks of the microorganisms can be constructed based on their genome se-quences,functional annotations,and biochemical reactions,reflecting almost all of the metabolic functions.Mathematical simulations of metabolic fluxes could make these functions be visualized,thereby providing guidance for rational engineering design and experimental operations.This review summarized recently devel-oped flux simulation algorithms of microbial systems.For the single microbial systems,the optimal planning algorithm has low complexity because there is no interaction between microorganisms,and it can quickly simulate the stable metabolic states through the pseudo-steady hypothesis.Besides,the experimental conditions of single microbial systems are easier to reach or close to the optimal states of simulation,compared with pol-ymicrobial systems.The polymicrobial culture systems could outcompete the single microbial systems as they could relieve metabolic pressure through metabolic division,resource exchange,and complex substrate co-utilization.Besides,they provide varieties of intracellular production environments,which render them the po-tential to achieve efficient bioproduct synthesis.However,due to the quasi-steady hypothesis that restricts the simulation of the dynamic processes of microbial interactions and the algorithm complexity,there are few re-searches on simulation algorithms of polymicrobial metabolic fluxes.Therefore,this review also analyzed and combed the microbial interactions based on the commonly used hypothesis of maximizing growth rates,and studied the strategies of coupling interactions with optimal planning simulations for metabolism.Finally,this review provided new insights into the genomic scale metabolic flux simulations of polymicrobial systems.

基于扰动状态概念的软岩蠕变本构模型与试验验证

软岩材料的蠕变过程从初始加载阶段开始即容易产生塑性变形,这与硬岩存在较大差异,而传统的元件模型仅在应力超过某一阈值后才开始描述其粘塑性行为.通过分析岩石加卸载时效变形过程中弹塑性状态的演变规律,以扰动状态理论为基础,确定了以塑性变形为变量的扰动因子函数,并通过塑性变形随时间的变化特征进一步建立了以时间为自变量的蠕变扰动因子演化方程.在此基础上,针对泥质页岩的蠕变变形过程,选取Burgers和Bingham模型分别描述扰动状态理论中的相对完整状态和完全调整状态,并选取蠕变扰动因子为权重函数建立了基于扰动状态理论的蠕变本构模型.通过泥质页岩的室内蠕变特性试验对模型进行有效性检验表明,理论曲线与实测曲线的逼近程度较高,蠕变扰动函数能随时间的发展持续调整相对完整状态向完全调整状态转换的过程,较高应力状态下软岩进入完全调整状态的速率较快,相对传统模型该模型具有更好的非线性及阶段协调性,可较好地描述软岩的初始、稳定和加速蠕变阶段.

Deterministic Approach to Achieve Full-Polarization Cloak

Achieving full-polarization(σ)invisibility on an arbitrary three-dimensional(3D)platform is a long-held knotty issue yet extremely promising in real-world stealth applications.However,state-of-the-art invisibility cloaks typically work under a specific polarization because the anisotropy and orientation-selective resonant nature of artificial materials made theσ-immune operation elusive and terribly challenging.Here,we report a deterministic approach to engineer a metasurface skin cloak working under an arbitrary polarization state by theoretically synergizing two cloaking phase patterns required,respectively,at spin-up(σ+)and spin-down(σ−)states.Therein,the wavefront of any light impinging on the cloak can be well preserved since it is a superposition ofσ+andσ−wave.To demonstrate the effectiveness and applicability,several proof-of-concept metasurface cloaks are designed to wrap over a 3D triangle platform at microwave frequency.Results show that our cloaks are essentially capable of restoring the amplitude and phase of reflected beams as if light was incident on a flat mirror or an arbitrarily predesigned shape under full polarization states with a desirable bandwidth of~17.9%,conceiving or deceiving an arbitrary object placed inside.Our approach,deterministic and robust in terms of accurate theoretical design,reconciles the milestone dilemma in stealth discipline and opens up an avenue for the extreme capability of ultrathin 3D cloaking of an arbitrary shape,paving up the road for real-world applications.

Polarization-insensitive 3D conformal-skin metasurface cloak

Electromagnetic metasurface cloaks provide an alternative paradigm toward rendering arbitrarily shaped scatterers invisible.Most transformation-optics(TO)cloaks intrinsically need wavelength-scale volume/thickness,such that the incoming waves could have enough long paths to interact with structured meta-atoms in the cloak region and consequently restore the wavefront.Other challenges of TO cloaks include the polarization-dependent operation to avoid singular parameters of composite cloaking materials and limitations of canonical geometries,e.g.,circular,elliptical,trapezoidal,and triangular shapes.Here,we report for the first time a conformal-skin metasurface carpet cloak,enabling to work under arbitrary states of polarization(SOP)at Poincarésphere for the incident light and arbitrary conformal platform of the object to be cloaked.By exploiting the foundry three-dimensional(3D)printing techniques to fabricate judiciously designed meta-atoms on the external surface of a conformal object,the spatial distributions of intensity and polarization of its scattered lights can be reconstructed exactly the same as if the scattering wavefront were deflected from a flat ground at any SOP,concealing targets under polarization-scanning detections.Two conformal-skin carpet cloaks working for partial-and full-azimuth plane operation are respectively fabricated on trapezoid and pyramid platforms via 3D printing.Experimental results are in good agreement with numerical simulations and both demonstrate the polarization-insensitive cloaking within a desirable bandwidth.Our approach paves a deterministic and robust step forward to the realization of interfacial,free-form,and full-polarization cloaking for a realistic arbitrary-shape target in real-world applications.

Long-term fertilization and residue return affect soil stoichiometry characteristics and labile soil organic matter fractions

Ecological stoichiometry provides the possibility for linking microbial dynamics with soil carbon(C),nitrogen(N),and phosphorus(P)metabolisms in response to agricultural nutrient management.To determine the roles of fertilization and residue return with respect to ecological stoichiometry,we collected soil samples from a 30-year field experiment on residue return(maize straw)at rates of 0,2.5,and 5.0 Mg ha^-1 in combination with 8 fertilization treatments:no fertilizer(F0),N fertilizer,P fertilizer,potassium(K)fertilizer,N and P(NP)fertilizers,N and K(NK)fertilizers,P and K(PK)fertilizers,and N,P,and K(NPK)fertilizers.We measured soil organic C(SOC),total N and P,microbial biomass C,N,and P,water-soluble organic C and N,KMnO4-oxidizabIe C(KMnO4-C),and carbon management index(CMI).Compared with the control(F0 treatment without residue return),fertilization and residue return significantly increased the KMn〇4-C content and CMI.Furthermore,compared with the control,residue return significantly increased the SOC content.Moreover,the NPK treatment with residue return at 5.0 Mg ha^-1 significantly enhanced the C:N,C:P,and N:P ratios in the soil,whereas it significantly decreased the C:N and C:P ratios in soil microbial biomass.Therefore,NPK fertilizer application combined with residue return at 5.0 Mg ha^-1 could enhance the SOC content through the stoichiometric plasticity of microorganisms.Residue return and fertilization increased the soil C pools by directly modifying the microbial stoichiometry of the biomass that was C limited.

Optimization and modeling of biohydrogen production by mixed bacterial cultures from raw cassava starch

The production of bio-hydrogen from raw cassava starch via a mixed-culture dark fermentation process was investigated. The production yield of H2 was optimized by adjusting the substrate concentration and the microorganism mixture ratio. A maximum H2 yield of 1.72 mol H2/mol glucose was obtained with a cassava starch concentration of 10 g/L to give a 90% utilization rate. The kinetics of the substrate utilization and of the generation of both hydrogen and volatile fatty acids were also investigated. The substrate utilization follows pseudo first order reaction kinetics, whereas the production of both H2 and the VFAs correlate with the Gompertz equation. These results show that cassava is a good candidate for the production of biohydrogen.

国际肩关节镜技术文献计量学研究

内窥镜技术自1918年由Kenji首次应用于关节,此后关节镜技术在骨科的应用日益成熟并于80年代初引入我国[1],如今已取得蓬勃发展并涉及膝、肩、髋、踝、肘等多个领域。随着影像学特别是核磁的发展,肩关节镜技术已广泛应用于肩袖撕裂/损伤、肩关节不稳、盂唇病变、肩峰撞击等各种肩部疾病的诊疗,开展了镜下清创术、肩袖修复术、Bankart修复术、Latarjet手术、肱二头肌长头腱切开/固定术等诸多术式[2],并取得了诸多研究成果。

Stimuli-responsive cyclometalated platinum complex bearing bent molecular geometry for highly efficient solution-processable OLEDs

Smart materials,such as stimuli-responsive luminescence,have attracted much attentions due to their potential application in semiconductor filed.In this context,platinum complexes of(dfppy-DC)Pt(acac) and(dfppy-O-DC)Pt(acac) were prepared and characterized,in which(2-(4',6'-difluorophenyl)pyridinato-N,C2')(2,4-pentanedionato-0,0)Pt(Ⅱ) was used as the planar emission core and 9-(4-(phenylsulfonyl)phenyl)-9 H-carbazole(DC) was regard as the bent pendent.Both platinum complexes showed bright emission in solution and solid state,concomitant with charming external-stimuli-responsive emission under mechanical grinding,organic solvent vapors and pressure.The change emission color spanned from yellow to near-infrared region.Using the platinum complexes as the dopant,solution processable organic light-emitting diodes(OLEDs) were fabricated and a maximum external quantum efficiency of ~18% was achieved,which is the highest value among the reported solution-processable OLEDs based on externalstimuli-responsive luminescence.This research demonstrated that platinum complex can show promising stimuli responsive emission via ingenious molecular design,indicating a novel way for developing the smart materials in semiconductor filed.

Adaptable Invisibility Management Using Kirigami-Inspired Transformable Metamaterials

Many real-world applications,including adaptive radar scanning and smart stealth,require reconfigurable multifunctional devices to simultaneously manipulate multiple degrees of freedom of electromagnetic(EM)waves in an on-demand manner.Recently,kirigami technique,affording versatile and unconventional structural transformation,has been introduced to endow metamaterials with the capability of controlling EM waves in a reconfigurable manner.Here,we report for a kirigami-inspired sparse meta-architecture,with structural density of 1.5%in terms of the occupation space,for adaptive invisibility based on independent operations of frequency,bandwidth,and amplitude.Based on the general principle of dipolar management via structural reconstruction of kirigami-inspired meta-architectures,we demonstrate reconfigurable invisibility management with abundant EM functions and a wide tuning range using three enantiomers(A,B,and C)of different geometries characterized by the folding angleβ.Our strategy circumvents issues of limited abilities,narrow tuning range,extreme condition,and high cost raised by available reconfigurable metamaterials,providing a new avenue toward multifunctional smart devices.

Xingshentongqiao Decoction Mediates Proliferation, Apoptosis, Orexin-A Receptor and Orexin-B Receptor Messenger Ribonucleic Acid Expression and Represses Mitogen-activated Protein Kinase Signaling

Background：Hypocretin （HCRT） signaling plays an important role in the pathogenesis of narcolepsy and can be significantly influenced by Chinese herbal therapy.Our previous study showed that xingshentongqiao decoction （XSTQ） is clinically effective for the treatment of narcolepsy.To determine whether XSTQ improves narcolepsy by modulating HCRT signaling,we investigated its effects on SH-SY5Y cell proliferation,apoptosis,and HCRT receptor 1/2 （orexin receptor 1 [OXl R] and orexin receptor 2 [OX2R]） expression.The signaling pathways involved in these processes were also assessed.Methods：The effects of XSTQ on proliferation and apoptosis in SH-SY5Y cells were assessed using cell counting kit-8 and annexin V-fluorescein isothiocyanate assays.OX1R and OX2R expression was assessed by quantitative real-time polymerase chain reaction analysis.Western blotting for mitogen-activated protein kinase （MAPK） pathway activation was performed to further assess the signaling mechanism of XSTQ.Results：XSTQ reduced the proliferation and induced apoptosis of SH-SY5Y cells.This effect was accompanied by the upregulation of OX 1R and OX2R expression and the reduced phosphorylation of extracellular signal-regulated kinase （Erk） 1/2,p38 MAPK and c-Jun N-terminal kinase （JNK）.Conclusions：XSTQ inhibits proliferation and induces apoptosis in SH-SY5Y cells.XSTQ also promotes OX1R and OX2R expression.These effects are associated with the repression of the Erkl/2,p38 MAPK,and JNK signaling pathways.These results define a molecular mechanism for XSTQ in regulating HCRT and MAPK activation,which may explain its ability to treat narcolepsy.