Third-order nonlinear wavelength conversion in chalcogenide glass waveguides towards mid-infrared photonics

The increasing demand in spectroscopy and sensing calls for infrared(mid-IR)light sources.Here,we theoretically investigate nonlinear wavelength conversion of Ge_(28)Sb_(12)Se_(60)chalcogenide glass waveguide in the mid-IR spectral regime.With waveguide dispersion engineering,we predict generation of over an octave wavelength(2.8μm-5.9μm)tuning range Raman soliton self-frequency shift,over 2.5 octaves wavelength cover range supercontinuum(1.2μm-8.0μm),as well as single soliton Kerr comb generated in suspended Ge_(28)Sb_(12)Se_(60)waveguide.Our findings evidenced that Ge_(28)Sb_(12)Se_(60)chalcogenide glass waveguides can simultaneously satisfy the generation of Raman soliton self-frequency shift,supercontinuum spectrum,and Kerr frequency comb generation through dispersion engineering towards mid-IR on chip.

Frequency-modulated continuous-wave multiplexed gas sensingbased on optical frequency comb calibration

Laser absorption spectroscopy has proven to be an effective approach for gas sensing, which plays an important rolein the fields of military, industry, medicine and basic research. This paper presents a multiplexed gas sensing system basedon optical frequency comb (OFC) calibrated frequency-modulated continuous-wave (FMCW) tuning nonlinearity. Thesystem can be used for multi-parameter synchronous measurement of gas absorption spectrum and multiplexed opticalpath. Multi-channel parallel detection is realized by combining wavelength division multiplexing (WDM) and frequencydivision multiplexing (FDM) techniques. By introducing nonlinear optical crystals, broadband spectrum detection is simultaneouslyachieved over a bandwidth of hundreds of nanometers. An OFC with ultra-high frequency stability is used asthe frequency calibration source, which guarantees the measurement accuracy. The test samples involve H13C14N, C_(2)H_(2)and Rb vapor cells of varying densities and 5 parallel measurement experiments are designed. The results show that themeasurement accuracies of spectral absorption line and the optical path are 150 MHz and 20 m, respectively. The schemeoffers the advantages of multiplexed, multi-parameter, wide spectrum and high resolution detection, which can realize theidentification of multi-gas components and the high-precision inversion of absorption lines under different environments.The proposed sensor demonstrates great potential in the field of high-resolution absorption spectrum measurement for gassensing applications.

Mid-infrared Optical Frequency Comb-based Fourier Transform Spectrometer for Broadband Molecular Spectroscopy

Optical frequency combbased Fourier transform spectroscopy has the features of broad spectral bandwidth,high sensitivity,andmultiplexed trace gas detection,which has valuable application potential in the fields of precision spectroscopy and trace gas detection.Here,we report the development of a mid-infrared Fourier transform spectrometer based on an optical frequency comb combined with a Herriott-type multipass cell.Using this instrument,the broadband absorption spectra of several important molecules,including methane,acetylene,water molecules and nitrous oxide,are measured by near real-time data acquisition in the 2800-3500 cm^(-1)spectral region.The achieved minimum detectable absorption of the instrument is 4.4×10^(-8)cm^(-1)·Hz^(-1/2)per spectral element.Broadband spectra of H_(2)0 are fited using the Voigt profile multispectral fitting technique and the consistency of the concentration inversion is 1%.Our system also enables precise spectroscopic measurements,and it allows the determination of the spectral line positions and upper state constants of N_(2)O in the(0002)-(1000)band,with results in good agreement with those reported by Toth[Appl.Opt.30,5289(1991)].

Optical frequency comb technology: from ground to space

Optical frequency combs,as powerful tools for precision spectroscopy and research into optical frequency standards,have driven continuous progress and significant breakthroughs in applications such as time-frequency transfer,measurement of fundamental physical constants,and high-precision ranging,achieving a series of milestone results in ground-based environments.With the continuous maturation and evolution of femtosecond lasers and related technologies,optical frequency combs are moving from ground-based applications to astronomical and space-based applications,playing an increasingly important role in atomic clocks,exoplanet observations,gravitational wave measurements,and other areas.This paper,focusing on astronomical and space-based applications,reviews research progress on astronomical frequency combs,optical clock time-frequency networks,gravitational waves,dark matter measurement,dual-comb large-scale absolute ranging,and high-resolution atmospheric spectroscopy.With enhanced performance and their gradual application in the field of space-based research,optical frequency combs will undoubtedly provide more powerful support for astronomical science and cosmic exploration in the future.

Study of the Application of PPG-5-CETETH-20 in Personal Care Rinse-off Product

PPG-5-Ceteth-20 is a multifunction raw material.PPG-5-Ceteth-20 has a wide range of application in skin care and hair care products.The purpose of this study was to evaluate the performance of PPG-5-Ceteth-20.The results shown that PPG-5-Ceteth-20 can improve hair combing,softness and smoothing in the hair care product.In additional,it can improve foam stability and compactness,and it doesn’t affect the transparency of the hair care product.

Wavelength switchable mode-locked fiber laser with a few-mode fiber filter

We have proposed and constructed a few-mode fiber(FMF)-based comb filter realized by dislocation splicing a fewmode long-period fiber grating(FM-LPFG) with a single-mode fiber(SMF). From an all-fiber laser with a FMF-based comb filter, the generation of switchable single-, dual-, triple-, and quadruple-wavelength continuous light has been achieved.Moreover, wavelength switchable mode-locked pulses have been obtained with the increased pump power. In the experiment, the output wavelength of the mode-locked fiber laser was changed from 1567.72 nm to 1571.04 nm, while the signal-to-noise(SNR) ratio was maintained above 61 d B. The switchable multiwavelength continuous wave(CW) and mode-locked all-fiber lasers have potentially important applications for fiber sensing, wavelength-division multiplexing(WDM) and signal processing.

SM9中高次幂运算的快速实现方法

国密SM9算法是基于双线性对的标识密码算法,其运行过程需进行多次十二次扩域的高次幂运算,其计算性能对SM9算法体制的应用至关重要。SM9签名运算中的高次幂可以预存点,在运算过程中通过查表减少运算时间。由于验签运算中高次幂的底数不确定,无法通过查表进行运算,因此分别使用Comb固定基和NAF算法在算法模型上降低高次幂中十二次扩域乘法运算量。为提高十二次扩域乘法的计算效率,根据R-ate对的特殊性质提出基于分圆子群的快速平方算法,降低扩域乘法所需的基域运算开销,并将其应用于高次幂的运算中。硬件架构创新性地采用基于自定义RISC指令集的ASIP微码控制方式实现,该架构的灵活性有利于在有限的硬件资源下实现复杂的SM9算法逻辑,其中可修改的指令集可以更好地与底层硬件适配。在Xilinx Artix-7系列的FPGA平台上的实验结果表明,在167 MHz的时钟频率条件下,不增加额外的硬件资源开销,该方法完成一次SM9签名的时间仅为0.244 ms。

Phase-coherence dynamics of frequency-comb emission via high-order harmonic generation in few-cycle pulse trains

Frequency-comb emission via high-order harmonic generation(HHG)provides an alternative method for the coherent vacuum ultraviolet(VUV)and extreme ultraviolet(XUV)radiation at ultrahigh repetition rates.In particular,the temporal and spectral features of the HHG were shown to carry profound insight into frequency-comb emission dynamics.Here we present an ab initio investigation of the temporal and spectral coherence of the frequency comb emitted in HHG of He atom driven by few-cycle pulse trains.We find that the emission of frequency combs features a destructive and constructive coherences caused by the phase interference of HHG,leading to suppression and enhancement of frequency-comb emission.The results reveal intriguing and substantially different nonlinear optical response behaviors for frequency-comb emission via HHG.The dynamical origin of frequency-comb emission is clarified by analyzing the phase coherence in HHG processes in detail.Our results provide fresh insight into the experimental realization of selective enhancement of frequency comb in the VUV–XUV regimes.

Two New Species of Fire-Bellied Newts (Caudata, Salamandridae, Cynops) from Southeastern China

The fire-bellied newt genus Cynops contains ten known species distributed in China and Japan in East Asia.In this work,two new Cynops species are described,namely Cynops jiaoren sp.nov.distributed in northern Guangdong and Cynops maguae sp.nov.distributed in eastern Jiangxi.The two new species can be distinctly distinguished from their congeners by the independent phylogenetic placements and a combination of morphological characteristics.The discovery of these two new species in the Southeast Chinese Hilly Area,where half of congeners occur,increases the known diversity of Cynops,and indicates unresolved relationships among the species in southeastern China.Further discussions on the taxonomic status of Cynops cyanurus are also provided.

Rare case of lupus enteritis presenting as colorectum involvement:A case report and review of literature

BACKGROUND Systemic lupus erythematosus(SLE)is a multisystem autoimmune disease that can affect the gastrointestinal tract.Most cases of lupus enteritis(LE)involve the small intestine,while the involvement of the whole colon and rectum without the small intestine being affected is extremely rare.CASE SUMMARY A 35-year-old woman was diagnosed with colorectal LE after initially presenting with intermittent abdominal pain and vomiting for two months.She had a regular medication history for five years following the diagnosis of SLE but had been irregular in taking medications,which may have contributed to the onset of LE and led to her current hospital admission.According to the 2019 Classification criteria for SLE of the European League Against Rheumatism/American College of Rheumatology,this case scored 14.Additionally,abdominal computed tomography revealed significant wall edema of the colon and rectum,ischemia and hyperemia of the ascending colon intestinal wall,mesenteric vessel engorgement,increased mesangial fat attenuation,ascites,and bilateral ureter-hydronephrosis,all indicative of colon and rectum LE.Laboratory tests also showed lower levels of complement C3 and C4,with an antinuclear antibody titer of 1:100.Overall,it was clear that this case involved the colon and rectum without affecting the small intestine,representing a rare manifestation of SLE.The patient received treatment with 10 mg of methylprednisolone sodium succinate,100 mL of 0.9%sodium chloride,hydroxychloroquine(100 mg),and nutrition support.After one week of methylprednisolone and hydroxychloroquine therapy,her SLE symptoms and disease activity improved significantly.CONCLUSION Although colorectal LE without small intestine involvement is very rare,early diagnosis and excellent management with corticosteroids prevented the need for surgical intervention.Physicians should be aware of colorectal LE without small intestine involvement as a manifestation of lupus flare.

Comb-Based Filter Design Using Sharpening Technique and Certain Palindromic Polynomial

This paper presents a novel approach to improve aliasing rejection in comb-based decimation filters. The method is established on certain palindromic polynomials with all zeros on the unit circle and the sharpening technique. As a result, aliasing rejection and the passband characteristic are improved. The method is illustrated with various examples and compared with the methods from the literature. .

基于Frobenius映射的快速标量乘算法

标量乘法的效率决定着椭圆曲线密码体制的性能，而Koblitz曲线上的快速标量乘算法是标量乘法研究的重要课题，在标量k的TNAF约简基础上，给出了一种基于Frobenius映射的上层运算：Comb算法．在预计算阶段，该算法利用Frobenius映射对宽度为r的序列计算其对应椭圆曲线上的点，从而建立预计算表，在累加赋值阶段结合约简后的TNAF（k）和预计算表来提高效率．Comb算法基于高效的Frobenius映射无须进行倍点运算，经过Comb矩阵的组合，其所需点加量是传统算法的1／5～1／4，当行数r任意时，其效率在任意坐标下比传统Comb算法提高至少67％．

A Discovery of Anomozamites with Reproductive Organs

Anomozamites haifanggouensis (Kimura et al.) Zheng et Zhang comb. nov. is a characteristic Bennettitalean plant in Middle Jurassic flora. Only one specimen was collected from Haifanggou Formation (Middle Jurassic) in Daohugou village, Shantou town, Ningcheng County, Nei Mongol Autonomous Region, China. The stem of plant is slender and repeatedly branches as a dichasial system with a fertile shoot in the fork, forming equal and widely divergent branches, on the branches born with the fronds of Anomozamites type. Its reproductive organs consists of some microsporophylls and a few of the bracteoid small leaves (or receptacular leaves). Some scattered bracteoid leaves and microsporophylls were formerly considered by Pan as dicots. Since then, they were proposed to be a non-committal genus Pankuangia and described them as P. haifanggouensis by Kimura et al. In this study, we discover that these bracteoid small leaves and microsporophylls should be of Anomozamites. This discovery provides strong evidence for the 'Pankuangia' determination of the taxonomical position.

一种改进的Fixed-base Comb安全快速算法

本文从分析椭圆曲线上Fixed-baseComb算法出发,根据其特点,利用牺牲乘法操作以降低求逆操作的方法,分别用2kP、2P+Q的快速算法对Fixed-baseComb算法的预计算阶段和赋值阶段进行改进,极大地提高了计算效率:在素数域上预计算阶段提高70%～80%,而赋值阶段提高38%～43%,同时,改进算法通过对k的预处理,使得算法能够抵抗边际信道攻击.

血清SCML2在胃肠胰神经内分泌肿瘤中的表达及临床意义

目的探讨血清SCML2蛋白在胃肠胰神经内分泌肿瘤(GEP-NENs)中的表达及临床意义。方法收集南通大学附属医院2009年1月至2014年1月GEP-NENs组织和血清标本64例,另外收集同时期胃、肠、胰腺癌(均为腺癌)和胃肠息肉手术患者各30例组织和血清标本。采用TRFIA法检测血清SCML2水平,采用免疫组化法检测组织中SCML2蛋白表达。分析血清SCML2表达与GEP-NENs临床病理特征及预后的关系。结果GEP-NENs患者血清SCML2蛋白表达量[(62.50±34.0)ng/ml]明显高于腺癌患者[(24.89±15.32)ng/ml]、胃肠息肉患者[(21.83±16.49)ng/ml],差异具有统计学意义(P<0.05);且血清SCML2蛋白表达与病理类型、病理分级、浸润深度、TNM分期有关(P<0.05)。GEP-NENs患者血清SCML2水平与血清CgA水平(r=0.649,P<0.05)、组织SCML2蛋白表达(r=0.814,P<0.05)呈正相关。ROC曲线分析,血清SCML2诊断GEP-NENs的效能高于血清CgA[0.871(95%CI:0.812~0.930)vs.0.714(95%CI:0.624~0.804)]。GEP-NENs患者随访时间为2~125个月,中位生存时间(OS)为48.0个月(37.6~58.4个月),其中血清SCML2低表达患者中位OS为89.0个月(29.2~148.8个月),高于血清SCML2高表达患者中位OS为42.0个月(28.2~55.9个月),差异有统计学差异(χ^2=9.442,P=0.002)。结论血清SCML2在GEP-NENs患者中的表达量明显升高,与病理类型、病理分级、浸润深度、TNM分期、预后不良有关。

针对椭圆曲线点乘算法的代数故障攻击

首先通过分析固定梳(comb)点乘算法和窗口非相邻型(NAF)点乘算法,提出了一种代数故障攻击算法,可以恢复椭圆曲线密码算法的全部私钥。代数故障攻击算法在执行过程中不会被检测出来,遇到全零块也不会使攻击失效。然后通过软件仿真分别实现了对两种点乘算法的攻击,攻击的参考椭圆曲线为商用密码SM2算法提供的素数域曲线。攻击comb点乘算法需要13min,攻击窗口NAF点乘算法需要18min,并且都恢复了256比特长的私钥。而差分故障攻击方法不能攻击comb点乘算法,也容易遭受"故障检测"和"零块失效"的威胁,使得攻击失败。实验结果表明,代数故障攻击可以对有预计算的点乘算法实现高效攻击,健壮性强。

Numerical well test for well with finite conductivity vertical fracture in coalbed

A new well test model is developed for the hydraulic fractured well in coalbed by considering the following aspects： methane desorption phenomena, finite conductivity vertical fractures, and asymmetry of the fracture about the well. A new parameter is introduced to describe the storage of the fracture, which is named as a combined fracture storage. Another new concept called the fracture asymmetry coefficient is used to define the asymmetry of the fracture about the well. Finite element method （FEM） is used to solve the new mathematical model. The well test type curves and pressure fields are obtained and analyzed. The effects of the combined fracture storage, desorption factor, fracture conductivity, and fracture asymmetry coefficient on the well test type curves are discussed in detail. In order to verify the new model, a set of field well test data is analyzed.

Ultrasonic Sound Hot Extract—Ultraviolet Spectrophotometric Determination of Total Flavone in Comb Honey

[Objective] The aim was to establish a rapid method for the determination of the content of total flavonoids in the honey comb. [Method] The content of total flavonoids weas determined based on samples including comb honey, propolis, royal jelly, linden tree honey, with a polyamide column chromatography by spectrophotometry at 360 nm wavelength. [Result] The recovery rate of the method was above 90%, and the variation coefficient was lower than 2%. Compared with the traditional method, this method has less reagent consumption, simple operation and so on.[Conclusion] The content of total flavonoids in comb honey was 14.97 mg/100 g, although is only 0.87% of the total flavone content in propolis. The contained total flavonoids at least doubled than that of others and comb honey is more valuable in the content of flavonoids.

Laterally Electrostatically Driven Poly 3C-SiC Folded-Beam Resonant Microstructures

Micromachined comb-drive electrostatic resonators with folded-cantilever beams were designed and fabricated. A combination of Rayleigh＇s method and finite-element analysis was used to calculate the resonant frequency drift as we adjusted the device geometry and material parameters. Three micromachined lateral resonant resonators with different beam widths were fabricated. Their resonant frequencies were experimentally measured to be 64.5,147.2, and 255.5kHz, respectively, which are in good agreement with the simulated resonant frequency. It is shown that an improved frequency performance could be obtained on the poly 3C-SiC based device structural material systems with high Young＇s modulus.

标量乘法底层域快速算法研究

从椭圆曲线加法公式出发,在Comb算法中,运用以折半运算为基础的Comb标量乘算法,减少赋值和预计算期间的运算量,使得椭圆曲线标量乘法的运算效率大幅提高.