Extraction of the key infrared radiation temperature features concerning stress and crack evolution of loaded rocks

The infrared radiation temperature(IRT)variation concerning stress and crack evolution of rocks is a critical focus in rock mechanics domain and engineering disaster warning.In this paper,a methodology to extract the key IRT features related to stress and crack evolution of loaded rocks is proposed.Specifically,the wavelet denoising and reconstruction in thermal image sequence(WDRTIS)method is employed to eliminate temporal noise in thermal image sequences.Subsequently,the adaptive partition temperature drift correction(APTDC)method is introduced to alleviate temperature drift.On this basis,the spatial noise correction method based on threshold segmentation and adaptive median filtering(OTSU-AMF)is proposed to extract the key IRT features associated with microcracks of loaded rocks.Following temperature drift correction,IRT provides an estimation of the thermoelastic factor in rocks,typically around 5.29×10^(-5) MPa^(-1) for sandstones.Results reveal that the high-temperature concentrated region in cumulative thermal images of crack evolution(TICE)can elucidate the spatiotemporal evolution of localized damage.Additionally,heat dissipation of crack evolution(HDCE)acquired from TICE quantifies the progressive failure process of rocks.The proposed methodology enhances the reliability of IRT monitoring results and provides an innovative approach for conducting research in rock mechanics and monitoring engineering disasters.

Design of a Weak Signal Detecting Circuit in the Infrared Spectrum Absorbed Type Gas Sensor

In the infrared spectrum absorbed type gas concentration sensor,voltage signal obtained from the two-channel thermopile infrared detector TPS2534 is very weak.In order to solve this problem,the authors have established the structure of the sensor and designed weak signal detecting circuit of the sensor based on infrared spectrum absorption principle,differential de-noising principle and weak signal detecting principle.The authors have made experiments using CH4 gas.The results show that the circuit can remove noise effectively and detect weak electrical signal obtained from the detector.

Ca^(2+)影响辛基异羟肟酸浮选独居石的FTIR、XPS研究

独居石浮选体系中往往有方解石、萤石、白云石等大量的伴生矿,而这些伴生矿在独居石矿中会解离出大量的Ca^(2+),而Ca^(2+)往往会影响矿浆浮选环境。为此,通过Ca^(2+)的溶液化学计算、独居石浮选试验,以及浮选条件下作用的独居石表面红外光谱分析(FTIR)和X射线光电子能谱(XPS),分析研究Ca^(2+)的影响。Ca^(2+)的溶液化学计算显示,在水溶液中,随着pH值的升高,Ca^(2+)分别以离子态、羟基络合物和氢氧化合物的形式存在,当pH值在7~8之间,优势组分为Ca^(2+)和Ca(OH)^(+)。独居石浮选结果表明,不添加Ca^(2+)时,捕收剂OHA不能充分的浮选独居石,回收率为75.37%;而在pH为8±0.5,加入3×10^(-4)mol·L^(-1)的Ca^(2+)剂量,可显著的提高OHA对独居石的浮选性能,回收率达到96.48%。由溶液化学计算可知,Ca(OH)+是活化独居石的优势组分;Ca^(2+)剂量大于3×10^(-4)mol·L^(-1)时浮选回收率下降幅度较大,说明Ca^(2+)剂量的进一步增加,反而抑制独居石浮选,只有一定剂量的Ca^(2+)有效的促进独居石浮选,这可能归因于Ca^(2+)剂量消耗了OHA的浓度,进而影响独居石的浮选。红外光谱分析表明,在Ca^(2+)的作用下,光谱中出现两个关键性的新峰,其一为1454 cm^(-1)处的N—O—H弯曲振动峰,其二为880 cm^(-1)处的O—N拉伸振动峰,而在2974和2928 cm^(-1)的有机峰—CH_(3)和—CH_(2)—峰明显增强,这些基团的出现表明发生了化学吸附且吸附强度大于纯独居石吸附OHA的效果。XPS分析表明,仅使用OHA吸附独居石,独居石表面的N元素相对含量较低,为0.61%,而Ca^(2+)处理后的独居石,OHA吸附独居石时,独居石表面的N元素相对含量较高,达到2.36,由此可以得出,Ca^(2+)会促进OHA吸附到独居石表面。从分峰拟合中可以看出,添加Ca^(2+)在独居石的解理面上氧原子与Ca(OH)^(+)反应形成O—Ca—OH基团,可以作为吸附OHA的新吸附位点,同时独居石的铈原子与OHA上的两个氧原子形成五元螯合物也作吸附位点,得出独居石表面可以有两个吸附位点,独居石表面的Ca和Ce原子的活性位点都能吸附OHA,有利于OHA在独居石表面吸附,形成更均匀更致密的OHA疏水吸附层,这就是Ca^(2+)在OHA浮选独居石的性能得到改善的原因。这项研究有助于丰富矿浆中金属离子的活化理论,也证实了有效的矿物浮选分离不仅仅依赖于捕收剂-矿物相互作用的强度,而在很大程度上依赖于浮选溶液的化学性质。利用或者控制表面反应是开发一种更高效、更经济的浮选工艺的主要技术手段。

Electronic structure and infrared spectrum of a W_n C^(0,±) (n = 1-6) cluster

WnC0＇± （n= 1-6） clusters are investigated by using the density functional theory （DFT） at the B3LYP/LANL2DZ level. We find that the neutral, anionic and cationic ground state structures are similar within the same size, and constituted by substituting a C atom for one W atom in the structures of Wn＋1 clusters. The natural bond orbital （NBO） charge analyses indicate that the direction of electron transfer is from the W atom to the 2p orbital of the C atom. In addition, the calculated infrared spectra of the WnC0＇± （n= 2-6） clusters manifest that the vibrational frequencies of neutral, anionic and cationic clusters are similar in a range of 80 cm-1-864 cm-1. The high frequency, strong peak modes are found to be an almost stretched deformation of the carbide atom. Finally, the polarizabilities of WnC0＇± （n= 1-6） clusters are also discussed.

新吲哚菁绿IR-820辅助的近红外荧光成像和光热及协同治疗在肿瘤诊疗中的应用进展

新吲哚菁绿IR-820因其具有强近红外(near-infrared,NIR,750~1700 nm)荧光特性、良好生物相容性、高光热转换效率及稳定性等优势,在NIR发光的有机荧光染料中脱颖而出,被广泛应用于生物医学成像、荧光标记、细胞实时监测、光热治疗等研究领域。为更好地发挥IR-820的生物医学应用价值,研究人员用不同生物化学分子修饰IR-820来增强其荧光及光热特性,制备多种类的荧光纳米粒子,在基础生物医学成像与肿瘤光热治疗方面开展了众多研究。总结了IR-820荧光纳米粒子在近红外荧光成像和通过光热机理及与其他技术协同治疗肿瘤中的应用研究,希望为进一步推进有机荧光染料IR-820在生物医学领域应用和临床转化发展提供参考。

环保绝缘介质C_(6)F_(12)O混合气体FTIR检测技术研究

环保绝缘介质C_(6)F_(12)O混合气体具有应用于中低压设备的潜力,因此C_(6)F_(12)O混合气体检测技术的研究具有非常重要的现实意义。文中基于红外吸收光谱提出了C_(6)F_(12)O混合气体定性定量检测技术。基于密度泛函理论,对C_(6)F_(12)O分子进行结构优化,仿真计算其振动频谱,与实验检测红外光谱进行对比。对体积分数标定模型的波段和特征量的选取进行了详细的研究,提出C_(6)F_(12)O混合气体相关绝缘设备的混合比和微量体积分数检测方案。结果表明,红外光谱的仿真结果与实验结果具有较好的一致性;不同体积分数的吸收峰有很好的线性关系,利用峰值作为特征值比峰面积建立的体积分数标定模型准确性和稳定性强。混合比检测时,以3 500~3 567 cm^(-1)波段的峰值作特征量建立模型的拟合度为0.999 57,检测误差在2%以内;微量检测时,以1 750~1 820 cm^(-1)波段的峰值作特征量建立模型的拟合度高达0.999 97,检测误差小于3.8%,建立的体积分数标定模型的稳定性、准确性较好。文中研究结果提供实验和仿真的C_(6)F_(12)O红外光谱信息,为C_(6)F_(12)O型气体绝缘设备提供FTIR检测技术,为C_(6)F_(12)O混合气体绝缘设备的混合比和微量体积分数检测提供了重要的理论支撑。

MODIFICATION OF ABSORPTION SPECTRUM OF GaAs/AlGaAs QUANTUM WELL INFRARED PHOTODETECTOR BY POSTGROWTH ADJUSTMENT

Quantum well intermixing techniques modify the geometric shape of quantum wells to allow postgrowth adjustments.The tuning effect on the optical response property of a GaAs/AlGaAs quantum well infrared photodetector(QWIP) induced by the interdifussion of Al atoms was studied theoretically.By assuming an improvement of the heterointerface quality and an enhanced Al interdiffusion caused by postgrowth intermixings,the photoluminescence spectrum shows a blue-shifted,narrower and enhanced photoluminescence peak.The infrared optical absorption spectrum also shows the expected redshift of the response wavelength.However,the variation in the absorption peak intensity depends on the boundary conditions of the photo generated carriers.For high-quality QWIP samples,the mean free path of photocarriers is long so that the photocarriers are largely coherent when they transport across quantum wells.In this case,the enhanced Al interdiffusion can significantly degrade the infrared absorption property of the QWIP.Special effects are therefore needed to maintain and/or improve the optical properties of the QWIP device during postgrowth treatments.

Synthesis，Crystal Structure and Infrared Spectrum of Lanthanum Dinuclear Coordination Compound with Alanine：〔La2（ala）4（H2O）8〕·（ClO4）6

Lanthanum coordination compound with l-alanine[La2（ala）4（H2O）8]·（ClO4）6（ala=l-alanine） was synthesized by reaction of lanthanum perchlorate with l-alanine in aqueous solution and obtained in the form of single crystals.The X-ray crystal structure has been determined and the IR spectrum has been studied.The title compound Cl6La2C12H44O40N4,Mr=1375.2,crystallizes in the triclinic,space group P1 , with parameters: a= 11.227（3）,b=11.445（2）,c=11.014（3）,α=114.46（2）,β=114.51（2）,γ=78.62（2）°,V=1171.73,Z=1,Dc=1.95 g/cm￣3,F（000）=680,μ=22.9 cm￣-1（MoKα）.The final R=0.050,Rω=0.051.In the crystal,two lanthanum ions are coordinated by four alanine molecules via four carboxylate bridges to form a dinuclear coordination compound.Four water molecules are coordinated to each lanthanum ion. There is a symmetric centre between the two lanthanum ions.The IR spectrum of the coordination compound and the relationship between the IR spectrum and the structure have been studied.The mechanism of the configuration inversion of alanine has been proposed.

Evaluation of Expression Recognition Function in Autism Spectrum Disorder Using Near-Infrared Spectroscopy

One of the characteristics of Autism Spectrum Disorder (ASD) is social disorder. The specificity of facial and expression recognition for people with ASD is gathering attention as a factor of this social disorder. The study examined the hemodynamic activities in the prefrontal cortex using near-infrared spectroscopy (NIRS) when a person with ASD performed an expression recognition task. The subjects were twenty males (18 - 22 years old) with ASD and without intellectual disabilities. Forty-five healthy males matched for age and sex were included as a control group. In both groups, the degree of autistic tendencies was evaluated using the Autism-Spectrum Quotient (AQ). Using eight standard emotional expressions of Japanese people, two expression recognition tasks were set. An NIRS was used to measure the prefrontal cortex blood mobilization during the expression-processing process. The AQ was significantly higher in the ASD group, while the rate of overall correct expression response was significantly lower (p &rho;= &minus;0.40 p < 0.001). In the automatic expression-processing task, no activation in the prefrontal cortex was found in either the ASD or the control group. In the conscious expression-processing task, the activation of the left and right lateral prefrontal cortex was weaker in the ASD group compared to the control group. Unlike in the control group, a mild activation of posterior prefrontal cortex was found in the ASD group. The expression-processing process of the ASD group was found to be different from that of the control group. NIRS was effective in detecting a brain function disorder in people with ASD during an expression-processing process.

Identifying Gas-Washing and Water-Washing of Oil Reservoirs by Fluorescence and Infrared Spectra of Single Oil Inclusion

Samples in the two oil fields with reported gas-washing and water-washing were collected for fluid inclusion analysis.Micro-fluorescence and Fourier infrared spectra of single oil inclusions were measured to study the different effects of gas-washing and water-washing on oil compositions.The results show that spectral parameter QF_(535)values of the oils altered by gas-washing were expanded toward decreasing and increasing,respectively.The CH_(2)/CH_(3)distribution range ratio does not expand significantly,but the peak values are averaged.And the distribution of H_(2)O/Alkanes has no change.The QF_(535)values of the oils affected by water-washing increased towards the increase direction,and the distribution ranges of both CH_(2)/CH_(3)and H_(2)O/Alkanes increase significantly.The changes of QF_(535)in light oil reservoirs altered by gas-washing and CH_(2)/CH_(3)in heavy oil reservoirs by water-washing are not obvious.Therefore,two spectral parameter distribution trend charts of light and heavy oil reservoirs are summarized to discriminate the gas-washing and water-washing processes.This study is of great practical significance to utilize fluid inclusion analysis to restructure stages and processes of petroleum accumulation.

Detection of Chlorpyrifos Residues in Akesu Red Fuji Apple based on Near Infrared Spectrum

[Objective] The paper was to explore a method for detecting chlorpyrifos residues in red Fuji apple. [Method] The original spectral data of apple samples sprayed with different volume fractions of chlorpyrifos were collected using near infrared spectrometer at the band of 4 000-10 000 cm^（-1）. The original spectra were pre-treated by a variety of methods, and partial least squares（PLS） model was established for predictive analysis. [Result] Near infrared spectrum showed sensitivity to apple samples sprayed with different volume fractions of chlorpyrifos, but had low precision on pesticide-free samples. Data of blank control group were further eliminated for modeling prediction. The results showed that the results were the best when pre-treated with first derivative（FD）： R=0.987 9; the square error of prediction（SEP） was 0.173 6; the root-mean-square error of cross-validation（RMSECV） was 0.120 5; and the precision was 0.923 4. [Conclusion] Near infrared spectrum can better predict chlorpyrifos residue, providing a new method for detecting chlorpyrifos residues in Akesu red Fuji apple.

Analysis of Thermal Infrared Anomalies for the April16,2013M_W7.8of Khash, Iran Earthquake

After using the "Time-Frequency Relative Power Spectrum"( T-F RPS) method based on the China Geostationary Meteorological Satellite( FY-2 C/FY-2 E) infrared remote sensing brightness temperature data processing,we rapidly and accurately extracted and identified pre-earthquake thermal infrared anomalies for the April 16,2013 MW7. 8 of Khash,Iran Earthquake. Spatial evolution of anomalies showed the distribution and process. The anomalies were mainly distributed in the east of Khash,Iran. The characteristics of process and distribution presented X-Type model of NE and near NS strip which relates to the geological structure of this region. The epicenter was located near the intersection region of the X-Type abnormal migration process. Besides,the results of time series of anomalies showed that,the duration was more than 40 days and the maximum amplitude was about18 times. The earthquake occurred 20 days after the abnormal maximum amplitude which appeared on March 26,2013.

Preparation of Ultrafine SiO2 Powder from Rice Husk and Properties of Its Infrared Spectrum

This paper discussed impact of temperature on the size distribution in preparing ultrafine silica from rice husk.The samples prepared were analyzed with infrared spectrum,and the relation between the particle size and intensity of characteristic absorption peak of IR at center around 1 100 cm-1 was disscussed with the baseline method.Results show that when the temperature is 650 ℃ and roasting time is 11 h,at optimal reaction conditions,the size distribution of the ultrafine silica powder prepared is relatively concentrated,and the average particle size is 199.5 nm.Moreover,the characteristic absorption band of IR is broadening gradually along with particle size decreasing.

Study on the Authenticity of Identification Methods in White Spirit by Infrared Spectrometer

This experiment studies on the used infrared spectroscopy to establish technology methods for liquor identification methods, as well as offers the science data for establishment of the fingerprint in white spirit. The results have shown that using near-infrared spectroscopy analysis of liquor has the obvious features such as strong specificity, good reproducibility, simple operation, and finally confirmed that it is an authentic and ideal method for identification in white spirit.

ATR-FTIR方法判断PA6/PA66共混物中两组分相对含量

尼龙(PA)66与PA6都是应用极其广泛的工程塑料,在面对不同的性能要求、加工要求、成本要求时往往会将PA6与PA66共混后使用。共混后的材料后续的回收改性有一定困难,需要找到一个相对简便的方法快速对PA共混物中的共混比例进行分析。采用衰减全反射傅里叶变换红外光谱(ATR-FTIR)分析了不同比例PA6/PA66共混物的峰位与峰形的差异。试验结果表明,不同比例共混物的红外光谱图在1300~4000 cm^(-1)范围内的峰位和峰形与共混物共混比例相关性不大,而在1169~1180 cm^(-1)处吸收峰峰位置随共混比例变化相关性较大,可作为成分分析判据。将1169~1180 cm^(-1)处吸收峰峰位置和共混物中PA6含量进行作图拟合,拟合结果发现,峰位随着PA6含量增加的变化相关性函数一开始变化程度平缓,在1172 cm^(-1)到1178 cm^(-1)位置处发生突变,后续变化又变小,相关系数达0.98076。后续用预处理试样进行测试,发现测试与实际共混比例相差在5%左右,可作为半定量分析。使用该方法可快速对未知PA6/PA66共混物样品进行红外光谱分析确定PA6和PA66的相对比例。

檀香木与非洲螺穗木的构造及GC-MS和FT-IR辨析

为了解决不良商家常以非洲螺穗木冒充檀香木的市场乱象,从构造特征、气相色谱-质谱联用(GC-MS)及傅里叶红外光谱(FT-IR)特征三方面对檀香木和非洲螺穗木进行了辨析。从木材构造特征角度详细阐述了檀香木和非洲螺穗木的主要辨别要点:檀香木心材为黄褐色,非洲螺穗木心材呈褐色且有黑色条纹;檀香木几乎全部为单管孔,管孔内未见树胶,而非洲螺穗木管孔除单管孔外,还具有径列复管孔和少数管孔团,且心材管孔具有树胶;檀香木的木射线宽1~2列,主为2列,木射线组织类型多为异Ⅱ型,而非洲螺穗木木射线以单列为主,木射线组织类型为同形及异Ⅲ型;檀香木的轴向薄壁组织以星散状为主,而非洲螺穗木的轴向薄壁组织呈不规则、断续的切线状或星散聚合。用95%乙醇超声提取1 h檀香木与螺穗木木粉,GC-MS研究显示:檀香木与非洲螺穗木总离子流图存在一定区别,檀香木出峰时间主要集中在23~27 min,非洲螺穗木出峰时间主要集中在31~34 min;檀香木主要化学成分为α-檀香醇、β-檀香醇、反式-α-檀香醇、月桂酸乙酯和黏蒿三烯,其中相对含量最高的是α-檀香醇,而非洲螺穗木提取出的主要化学成分为2-莰烯、1H-环戊烯并[b]喹啉-9-胺,2,3,5,6,7,8-六氢化-、维生素A和雄烯二酮,维生素A的相对含量最高。通过FT-IR研究发现,檀香木和非洲螺穗木在600~1 000 cm-1范围内差异显著,檀香木的891~899和663~669 cm-1吸收峰均不明显,而非洲螺穗木在这两处均有明显的吸收峰,在748 cm-1处檀香木未出现代表纤维素的一个峰值,而非洲螺穗木在此处具有一个小的波峰。

Signature of symmetry of laterally coupled quantum dots in far-infrared spectrum

We study the effect of structure asymmetry on the energy spectrum and the far-infrared spectrum （FIR） of a lateral coupled quantum dot. The calculated spectrum shows that the parity break of coupled quantum dot results in more coherent superpositions in the low-lying states and exhibits unique anti-crossing in the two-electron FIR spectrum modulated by a magnetic field. We also find that the Coulomb correlation effect can make the FIR spectrum of coupled quantum dot without strict parity deviate greatly from Kohn theorem, which is just contrary to the symmetric case. Our results therefore suggest that FIR spectrum may be used to determine the symmetry of coupled quantum dot and to evaluate the degree of Coulomb interaction.

基于NDIR技术的微量环保绝缘气体C_(4)F_(7)N检测

C_(4)F_(7)N混合气体由于其优异的绝缘性能和更低的温室效应被认为是一种优异的替代SF_(6)的环保绝缘气体,C_(4)F_(7)N/CO_(2)混合气体绝缘设备已被逐渐推广和使用。由于混合气体的绝缘性能与C_(4)F_(7)N的体积分数有关,通过对混合气体中微量C_(4)F_(7)N的检测,可以对C_(4)F_(7)N/CO_(2)混合气体电气设备的绝缘状态进行有效评估。文中通过红外光谱平台,确定了C_(4)F_(7)N的红外光谱信息通过对C_(4)F_(7)N体积分数为100~2 000μL/L的C_(4)F_(7)N/CO_(2)混合气体检测,确定了微量C_(4)F_(7)N的最佳检测波段。搭建了基于NDIR技术的微量C_(4)F_(7)N检测平台,测量通道滤光片为7.9μm,实现了对12.6~52.5μL/L的微量C_(4)F_(7)N定量检测,C_(4)F_(7)N气体体积分数与反演信号值的线性拟合系数R^(2)为0.989,最大绝对误差为0.107。研究成果为C_(4)F_(7)N/CO_(2)混合气体绝缘设备的绝缘状态评估提供了一种可行方案。

Airborne Shortwave Infrared Spectral Remote Sensing as a Direct Prospecting Method for Oil and Gas Resources

The spectral characters of hydrocarbons in some oil-bearing strata and soil layers over oil and gas reservoirs in the Junggar Basin and northern Tarim Basin in Xinjiang are compared with those of chemically pure hydrocarbons. The hydrocarbons are characterized by the bi-absorption at 2310nm and 2350nm. Hydrocarbon and radioactive anomalies in oil and gas terrains are found much more widespread than carbonate altcrations. Based on the spectra of heavy hydrocarbons related to oil between 2270nm and 2460nm and refined data treatme nt, remote sensing may hold encouraging promise as a directly prospecting technique for oil and gas resources.

Classification and spectrum optimization method of grease based on infrared spectrum

The infrared(IR)absorption spectral data of 63 kinds of lubricating greases containing six different types of thickeners were obtained using the IR spectroscopy.The Kohonen neural network algorithm was used to identify the type of the lubricating grease.The results show that this machine learning method can effectively eliminate the interference fringes in the IR spectrum,and complete the feature selection and dimensionality reduction of the high-dimensional spectral data.The 63 kinds of greases exhibit spatial clustering under certain IR spectrum recognition spectral bands,which are linked to characteristic peaks of lubricating greases and improve the recognition accuracy of these greases.The model achieved recognition accuracy of 100.00%,96.08%,94.87%,100.00%,and 87.50%for polyurea grease,calcium sulfonate composite grease,aluminum(Al)-based grease,bentonite grease,and lithium-based grease,respectively.Based on the different IR absorption spectrum bands produced by each kind of lubricating grease,the three-dimensional spatial distribution map of the lubricating grease drawn also verifies the accuracy of classification while recognizing the accuracy.This paper demonstrates fast recognition speed and high accuracy,proving that the Kohonen neural network algorithm has an efficient recognition ability for identifying the types of the lubricating grease.