基于红外结构光三维技术的土壤表面粗糙度测量

土壤表面粗糙度是一项重要的土壤物理参数,已有的各种测量方法存在测量效率和误差难以兼顾的问题。为了在一定精度下提高野外测量工作效率,该研究基于红外结构光技术设计了一套便携的土壤表面粗糙度测量系统。该系统主要包括红外结构光扫描仪、便携式计算机、支架等,具有3.2 mm空间分辨率和3 mm的距离分辨率的性能。通过水平面板测量试验,发现本系统相对误差较小,相对误差最小区域中0.5个测量单位以内的误差(e≤1.5 mm)占87.87%,1个测量单位以内的误差(e≤3 mm)占99.58%,而大于1个测量单位的误差仅占0.42%。通过土壤表面粗糙度测量试验,发现本系统绝对误差较明显,其测量结果低于1 mm分辨率的土壤粗糙度值。通过误差分析发现:该系统的测量误差包括固有误差和随机噪声,呈特定的规律性分布;导致绝对测量误差的主要原因为该系统的性能;由于系统的随机噪声,基于水平面板距离图像的土壤表面距离图像校正存在不确定性。该研究结果为进一步降低红外结构光三维技术测量土壤表面粗糙度的误差提供了依据。

基于红外结构光的交互手势变形跟踪识别方法

针对传统手势识别方法计算过程较为复杂,识别耗时长、精准度低等问题,提出了红外结构光的交互手势跟踪识别方法。首先通过肤色像素区别将图像中人手区域单独划分,根据色度空间中特有的聚类特征性得到颜色模型和最优阈值完成对图像分割,然后采用光流跟踪方法对手势进行定位及跟踪处理,得出手势图像的特征向量,最后利用隐马尔可夫模型提取交互手势中心构建HMM模型,跟踪手势运动的轨迹,完成对交互手势的识别。结果表明,所提方法可以有效地解决计算过程复杂、耗时长问题,具有识别精准度高的优点,能够完全满足实际需求。

基于近红外结构光与可见光的三维人脸识别算法

文章综合传统的人脸识别方法,提出新的人脸识别算法。首先,建立近红外三维模型,采用傅里叶变换获取人脸三维信息。同时,建立可见光三维模型,采用3DMM技术获取三维人脸图像,然后将两种模型分别与参考系进行对比,最后进行融合,以此进行人脸识别。

基于红外结构光测量数据的道路平整度评价

道路平整度数据的采集及评价是道路管理中的重要内容。然而,采用目前最先进的激光平整度仪进行采集,会面临采集车速限制和加减速段距离限制,且无法全面采集道路三维表面。因此,基于红外结构光双目立体相机的采集作为替代方式,具有应用的潜力。研究对该方式的搭建及系统性能进行了描述,然后提出了基于该方式采集数据的三维平整度评价指标,以克服传统平整度评价指标仅考虑二维纵断面,不能全面和准确评价的问题。

基于红外结构光的三维显示用交互装置

三维显示以其直观自然的表现方式获得了广泛关注,三维交互技术也随之迅猛发展。提出了一种基于红外结构光、单摄像头的实时交互系统。红外结构光投影对空间进行编码,摄像头实时采集用户手部红外图像,经由OpenCV实现的图像处理算法比较两帧图像,获得结构光在手部移动的信息,从而实现对包括深度方向在内的三个维度的平移、缩放和旋转动作等用户交互动作的解析,并导入三维显示设备,对三维显示的虚拟物体进行实时控制。利用商用CMOS摄像头和红外LED搭建了交互样机。实验结果证明,该方案能以较低成本实现实时徒手三维交互。

基于红外编码结构光的深度测量方法

视觉深度测量是计算机视觉领域的重要问题。提出了一种基于红外编码结构光的深度测量方法。首先,设计一种新的网格图案并提出一种顺序编解码算法,准确计算参考图像与目标图像之间对应点的偏移;然后,提出一种成像系统参数线性拟合算法,建立目标深度与光斑像素偏移之间的线性关系,并修正镜头畸变;最后,基于线性关系实现深度测量,并基于Delaunay三角剖分算法实现三维重建。在实验过程中,通过多组数据进行误差评估与校正,提高测量精度,降低系统误差。多组实验数据表明,该深度测量方法准确性较高,并具有较好的实用性与鲁棒性。

Structure and Vibrational Spectroscopy of 2-Methylallyl Alcohol

The intramolecular O−H…πhydrogen bond has garnered significant research interest in recent decades.In this work,we utilized the infrared(IR)-vacuum-ultraviolet(VUV)nonresonant ionization detected IR spectroscopy(NRID-IR)method to study the molecular structure of neutral and cationic 2-methylallyl alcohol(MAA,CH_(2)=C(CH_(3))−CH_(2)−OH).Density functional theory calculations revealed five stable neutral and three stable cationic MAA conformers,respectively.Two neutral MAA conformers are expected to have an O−H…πintramolecular hydrogen bond interaction,based on the structural characterization that the OH group is directed toward the C=C double bond.The IR spectra of both neutral(2700−3700 cm^(−1))and cationic MAA(2500−7200 cm^(−1))were measured,and the anharmonic IR spectra were calculated at the B3LYP-D3(BJ)/def2-TZVPP level.The OH stretching vibration frequency of neutral MAA was observed at 3656 cm−1,slightly lower than those of methanol and ethanol.In contrast,the OH stretching vibration of cationic MAA was red-shifted by about 140 cm^(−1)compared to neutral MAA.The interaction region indicator and natural bond orbital analysis suggest that the O−H…πinteraction in neutral MAA is weak,and may not play a major role in stabilizing the neutral MAA.

GaAs远红外探测器中的辐射复合特性研究

借助光致发光技术对ｎ－ＧａＡｓ同质结内发射远红外探测器结构进行了详细的辐射复合特性研究．根据发光特性和高密度理论计算,观察和确认了来自探测器发射层中的光致发光信号．提出了光生载流子转移模型,很好地解释了发射层中光致发光信号与温度和激发功率的依赖关系．根据得到的辐射复合特性,提出了进一步提高探测器工作温度的方案．

复杂光照条件下矿石三维视觉实时筛选方法

矿石自动筛选是提高矿产资源加工效率的关键环节之一。针对矿石开采现场光照复杂多变,传送带矿石难以实时自动检测等问题,提出了一种基于红外线结构光的现场矿石3D视觉实时筛选方法。为了解决复杂光照条件下太阳辐射对矿石表面结构光成像干扰的问题,提出采用800 nm附近红外线结构光作为成像主动光源,在各种光照条件下获取稳定的矿石表面结构光图像;提出邻域累积差分特征分析方法,通过快速定位光条边界点来提取结构光光条中心,实时获取矿石3D坐标数据。对复杂光照条件下的大量现场矿石表面结构光图像采用多线程进行处理,实验结果表明,与现有方法相比,文中方法速度更快,稳定性更强,能适应线结构光形态和方向变化。对每幅矿石结构光图像筛选的时间为13.2 ms,满足现场矿石3D实时筛选需求。

Influence of thermal history on conversion of aluminate species in sodium aluminate solution

It is necessary to clarify the influence of thermal history on the conversion of aluminate species in sodium aluminate solution in order to optimize Bayer alumina production. The interconversion of various solution species in the systems was investigated by measuring the infrared spectra of sodium aluminate solution with different compositions after separate heat treatment, dilution and concentration. The results show that increasing temperature or prolonging holding time favors the transformation of Al2O（OH）2- to Al—OH vibration（condensed Al O4 tetrahedral aluminate ion） at about 880 cm-1 and Al（OH）-4. A12O（OH）2-66 and Al—OH tetrahedral dimer ions convert rapidly to Al（OH）-4 during the dilution process; however, the back transformation of Al（OH）-4 to the Al—OH tetrahedral dimer ions can occur in diluted sodium aluminate solution. As for the concentration process, the transformation of Al（OH）-4 to A12O（OH）2-6 and Al—OH tetrahedral dimer ions can take place, while it is relatively difficult to transform to A12O（OH）2-6.

基于曲面重建的带式输送机堆煤识别方法

针对现有带式输送机堆煤识别方法存在的易发生误触发报警、成本高等问题,提出一种采用红外结构光技术快速重建煤流曲面的带式输送机堆煤识别方法。首先,利用红外结构光技术获取堆煤的深度图;其次,将深度图映射为点云图,用点云数据构建凸四边形网,通过近似德劳内剖分法对凸四边形网进行三角剖分,完成堆煤曲面重建;最后,根据三角形顶点到相机的距离及顶点距离小于阈值的三角形面积占总面积的比例,判定是否出现堆煤事故。近似德劳内剖分法用遍历过程代替插入排序过程,存在小概率不满足德劳内性质的情况,但算法复杂度低,可大幅提升三角剖分速度,从而提高堆煤识别的实时性。实验结果表明:红外结构光技术有效地提高了算法对光照的鲁棒性;近似德劳内剖分法的成功率为99.4661%,同等条件下近似德劳内剖分法和经典德劳内剖分法的曲面重建时间分别为1.28,134.93 ms,近似德劳内剖分法在精度满足应用要求的前提下,极大地提高了运算速度;设定恰当的阈值,得出漏检数和误检数均为0;对大量图像处理时间进行统计,得出每帧处理时间小于20 ms,满足实时性要求。

基于人脸识别的防疫系统研究

为了满足新冠病毒疫情下人员密集场所防疫工作的要求,本文研发了基于三维人脸识别的防疫系统。传统的二维人脸识别技术,识别效率较低,不能用于疫情期间对佩戴口罩人员进行识别,本文所设计的防疫系统利用非接触式红外条纹结构光技术,实现对佩戴口罩人员的快速精准识别,并且识别率高达90%,基于三维图像识别技术可有效鉴别用照片、视频、3D人皮面具以及硬质面具的仿冒,具有很强的防伪能力。此外,该系统还具有红外测温功能,通过非接触式红外感应测温,将体温超标人员信息上传到云端后台。该防疫系统的使用有效提升了人员密集场所的防疫安全性,降低了人员感染的风险。

Computational Exploration of Conformations of Glycine-Arginine and a Deduced Model on Global Minimum Configurations of Dipeptides in Gas Phase

An extensive computational study on the conformations of gaseous dipeptide glycine- arginine, GlyArg, has been performed. A large number of trail structures were generated by systematically sampling the potential energy surface （PES） of OlyArg. The trial structures were successively optimized with the methods of PM3, HF/3-21G＊, BHandHLYP/6-31G＊ and BHandHLYP/6-311＋＋G＊＊ in order to reliably find the low energy conformations. The eonformational energies were finally determined with the methods of BHandHLYP, cam- B3LYP, B97D, and MP2 using the basis set of 6-311＋＋G（3df,3pd）. The results establish firmly that gaseous GlyArg exists primarily in its canonical form, in sharp contrast with ArgGly that adopts the zwitterionic form. Important data such as the rotational constants, dipole moments, vertical ionization energies, temperature distributions and IR spectra of the low energy conformers are represented for the understanding of the future experiments. Moreover, considering the global minima of all amino acids and many dipeptides, combined with the hydrophobicities of amino acids, a model predicting whether the global minimum configuration of a dipeptide is canonical or zwitterionic is developed.

The relationship between IR characteristic peak and microstructure of the glass used as optical fiber

Based on the harmonic vibration equation, the relationship between IR characteristic peak of fiberglass and Si-O-Si bond angle was deduced, and 1 100 cm^-1 characteristic peak was specifically studied. It is found that 1 100 cm^-1 characteristic peak shifts to higher wave number when Si-O-Si bond angle increases. Taking fused biconical taper （FBT） coupler as an example, the microstructures of the fiber coupler manufactured at different draw- ing speeds were tested with micro infrared spectrum. According to the test results, it is found that the bond angle at the taper region is the largest, the one at the fused region is the second largest, and the one of bare fiber is the smal- lest. The characteristic peaks of fused-taper region shift to higher wave number when drawing speed increases.

FTIR Characterization of the Secondary Structure of Insulin Encapsulated within Liposome

Aim To determine the secondary structure of insulin encapsulated withinliposome. Methods The secondary structure of native insulin, mixture of insulin with liposome(sample Ⅰ) and insulin encapsulated within liposome( sample Ⅱ) were determined by FTIR (FourierTransform Infrared) spectroscopy. Results The secondary structure of insulin encapsulated withinliposome(Ⅱ) are similar with the secondary structure of native insulin. The difference existed inthe amount of α-helices (from 36% of insulin to 31% of sample Ⅱ) and β-sheet(from 48% of insulinto 51% of sample Ⅱ). The content of α-helices and β-sheet of insulin in sample Ⅰ was found to bevery close to that of sample Ⅱ. The results revealed that the insulin encapsulated within liposomepossibly spread on the surface of liposome, without inserting into the liposome membrane.Conclusion The secondary structure of insulin encapsulated within liposome is similar with thenative insulin.

Conformations and Metal Ion Affinities of Glutamine Binding with Alkali and Alkaline Earth Metal Cations： an ab initio Study

Conformations and reaction energetics are important for understanding the interactions be- tween biomolecules and metal ions. In this work, we report a systematic ab initio study on the conformations and metal ion affinities of glutamine （Gln） binding with alkali and alkaline earth metal ions. An efficient and reliable method of searching low energy conformations of metalated Gln is proposed and applied to the complexes of Gln.Gln.M^＋/＋＋（M＋/＋＋=Li^＋、Na^＋、K^＋、Rb^＋、Cs^＋、Be^＋＋、Mg^＋＋、Ca^＋＋、Sr^＋＋ and Ba^＋＋）.. In addition to all conformers known in literatures, many new important conformations are located, demonstrating the power of the new method and the necessity of the conformational search performed here. The metal coordination modes, relative energies, dipole moments, and equilibrium distributions of all important conformations of Gln.M^＋/＋＋ are calculated by the methods of B3LYP, BHandHLYP, and MP2. IR spectra and metalation enthalpies and free energies are also presented and compared with the available experiments. The results form an extensive database for systematic examination of the metalation properties of Gln.

Microstructure and microwave dielectric properties of CaO-B_2O_3-SiO_2 glass ceramics with various B_2O_3 contents

The effects of B2O3 addition on both the sintering behavior and microwave dielectric properties of CaO-B2O3-SiO2 （CBS） glass ceramics were investigated by Fourier transform infrared spectroscopy （FTIR）, X-ray diffractometry （XRD） and scanning electron microscopy （SEM）. The results show that the increasing amount of B203 causes the increase of the contents of [BO3], [BO4] and [SiO4], which deduces the increase of CaB204 and a-SiO2 and the decrease of CaSiO3 correspondingly. No new phase is observed throughout the entire experiments. A bulk density of 2.54 g/cm3, a thermal expansion coefficient value of 11.95× 10-6 ℃-1 （20-500℃）, a dielectric constant er value of 6.42 and a dielectric loss tanδ value of 0.000 9 （measured at 9.7 GHz） are obtained for CBS glass ceramics containing 35%-B203 （mass fraction） sintered at 850 ℃ for 15 min.

Infrared Photodissociation Spectroscopic and Theoretical Study of [Co（CO2）n]+ Clusters

The mass-selected infrared photodissociation (IRPD) spectroscopy was utilized to investigate the interactions of cationic cobalt with carbon dioxide molecules. Quantum chemical calculations were performed on the [Co(CO2)n]^+ clusters to identify the structures of the low-lying isomers and to assign the observed spectral features. All the [Co(CO2)n]^+(n=2-6) clusters studied here show resonances near the CO2 asymmetric stretch of free CO2 molecule. Experimental and calculated results indicate that the CO2 molecules are weakly bound to the Co+ cations in an end-on con guration via a charge-quadrupole electrostatic interaction. The present IRPD spectra of [Co(CO2)n]^+ clusters have been compared to those of Ar-tagged species ([Co(CO2)n]^+-Ar), which would provide insights into the tagging effect of rare gas on the weakly-bounded clusters.

Preparation and Characterization of Tungsten-substituted Molybdophosphoric Acids and Catalytic Cyclodehydration of 1,4-Butanediol to Tetrahydrofuran

A series of tungsten-substituted molybdophosphoric acids(H3PMo12-nWnO40·xH2O) were synthesized and characterized by inductive coupled plasma atomic emission spectroscopy(ICPAES),thermal gravimetry and differential scanning calorimetry(TG-DSC),Fourier transform infrared spectroscopy(FTIR),X-ray diffraction(XRD),and FTIR pyridine adsorption.The as-prepared heteropoly acids have a Keggin type structure.The synthesis of tetrahydrofuran by reactive distillation and cyclodehydration of 1,4-butanediol was studied using the tungsten-substituted molybdophosphoric acids as catalysts.The results of catalytic test indicated that the catalytic activity increased with the increase in the substitution number(n) of tungsten atom in H3PMo12-nWnO40·xH2O and was constant as the substitution number(n) was more than 8.The catalytic activity increased with the increase in the catalyst loading and the selectivity of tetrahydrofuran was nearly 100%.

Solid State Synthesis and Structural Characterization of Binuclear Cu(I) SbPh 3 Complex 〔Cu(SbPh 3) 2I〕 2

Dimeric complex 〔Cu(SbPh 3) 2I〕 2 has been synthesized by a solid state reaction at a low heating temperature and its crystal structure has been analyzed by X ray crystallography. The crystal is monoclinic, space group P2 1/a (#14), a = 20 436(5), b=14.125(3), c=24.683(3) , β=110.67(1)°, Z=4, V =6666(2) 3; C 72 H 60 Sb 4I 2Cu 2, M r = 1792, D c = 1.787 g·cm -3 , μ (Mo Kα ) = 31.88 cm -1 , F(000)=3440, R= 0.038 and R w= 0.043 for 5632 observed reflections ( I≥3.0σ(I) ) and 361 refined parameters. The result reveals the copper and the bridging iodide atoms form an approximately planar rhomboid array. Effects of the bulkiness of the ligands upon the structures of the analogous complexes are discussed.\;