The accuracy of spot centroid positioning has a significant impact on the tracking accuracy of the system and the stability of the laser link construction.In satellite laser communication systems,the use of short-wave...The accuracy of spot centroid positioning has a significant impact on the tracking accuracy of the system and the stability of the laser link construction.In satellite laser communication systems,the use of short-wave infrared wavelengths as beacon light can reduce atmospheric absorption and signal attenuation.However,there are strong non-uniformity and blind pixels in the short-wave infrared image,which makes the image distorted and leads to the decrease of spot centroid positioning accuracy.Therefore,the high-precision localization of the spot centroid of the short-wave infrared images is of great research significance.A high-precision spot centroid positioning model for short-wave infrared is proposed to correct for non-uniformity and blind pixels in short-wave infrared images and quantify the localization errors caused by the two,further model-based localization error simulations are performed,and a novel spot centroid positioning payload for satellite laser communications has been designed using the latest 640×512 planar array InGaAs shortwave infrared detector.The experimental results show that the non-uniformity of the corrected image is reduced from 7%to 0.6%,the blind pixels rejection rate reaches 100%,the frame rate can be up to 2000 Hz,and the spot centroid localization accuracy is as high as 0.1 pixel point,which realizes high-precision spot centroid localization of high-frame-frequency short-wave infrared images.展开更多
In this article, unique spectral features of short-wave infrared band of 1 μm–3 μm, and various applications related to the photodetectors and focal plane arrays in this band, are introduced briefly. In addition, t...In this article, unique spectral features of short-wave infrared band of 1 μm–3 μm, and various applications related to the photodetectors and focal plane arrays in this band, are introduced briefly. In addition, the different material systems for the devices in this band are outlined. Based on the background, the development of lattice-matched and wavelengthextended InGaAs photodetectors and focal plane arrays, including our continuous efforts in this field, are reviewed. These devices are concentrated on the applications in spectral sensing and imaging, exclusive of optical fiber communication.展开更多
The Qulong deposit in Tibet is one of the largest porphyry copper-molybdenum deposits in China.We used short-wave infrared(SWIR)spectroscopy to examine the spectral characteristics of the extensively developed chlorit...The Qulong deposit in Tibet is one of the largest porphyry copper-molybdenum deposits in China.We used short-wave infrared(SWIR)spectroscopy to examine the spectral characteristics of the extensively developed chlorite in this deposit.X-ray diffraction and electron microprobe analyses were used for phase identification and to obtain the chemical composition,ion substitution relationships,and formation environment of the chlorite.SWIR spectral parameters were applied to detect the hydrothermal centers.The results indicate that the wavelength of the absorption feature for Qulong chlorite Fe-OH(Pos2250)range from 2240 to 2268.4 nm;the chlorite substitution relationships are dominated by Mg-Fe substitution at the octahedral sites together with Al;-Si substitution at the tetrahedral sites;the chlorite formation temperatures range within the medium-low temperature hydrothermal alteration range from 164 to 281°C,with an average value of 264℃;the wavelength of the chlorite peak position for Fe-OH(2250 nm)absorption and its chemical composition are positively correlated with Al^(Ⅵ),Fe+Al^(Ⅵ),Fe/(Fe+Mg),Fe,and Fe+Al^(Ⅳ)but negatively correlated with Mg and Mg/(Fe+Mg);and the wavelength associated with the chlorite Fe-OH(2250 nm)absorption feature is positively correlated with the temperature at which the chlorite formed.These correlations indicate that more Fe and Al^(Ⅵ)ions and fewer Mg ions at the octahedral sites of chlorite lead to a longer the wavelength of the chlorite Fe-OH(2250 nm)absorption feature and a higher chlorite formation temperature.The wavelength of the Qulong chlorite Fe-OH(2250 nm)absorption feature(>2252 nm)can thus serve as an exploration indicator to guide the detection of hydrothermal centers in porphyry copper deposits.The results of the study indicate that the mineralogical and SWIR spectral characteristics of chlorite are significant indicators for locating hydrothermal centers within porphyry deposits.展开更多
Fructus cnidii （Chinese name shechuangzi） is the fruit produced by Cnidium monnieri （L.） Cusson （Umbelliferae）. It is a perennial herb that is used to treat skin-related diseases and gynecopathyell. Recent pharm...Fructus cnidii （Chinese name shechuangzi） is the fruit produced by Cnidium monnieri （L.） Cusson （Umbelliferae）. It is a perennial herb that is used to treat skin-related diseases and gynecopathyell. Recent pharmacological studies have revealed crude extracts or components isolated from fructus cnidii possess antiallergic, antipruritic, antidermatophytic, antibacterial, antifungal, and antiosteoporotic activities. Osthole and imperatorin are the major compounds present in shechuangzi. They are often used as standards for the evaluation of the quality of shechuangzi products.展开更多
Compared with the conventional first near-infrared(NIR-I,700900 nm)window,the short-wave infrared region(SWIR,900—1700nm)possesses the merits of the increasing tissue penetration depths and the suppression of scatter...Compared with the conventional first near-infrared(NIR-I,700900 nm)window,the short-wave infrared region(SWIR,900—1700nm)possesses the merits of the increasing tissue penetration depths and the suppression of scattering background,leading to great potential for in vivo imaging.Based on the limitations of the common spectral domain,and the superiority of the time-dimension,time-resolved imaging eliminates the auto-fuorescence in the biological tissue,thus supporting higher signal-to-noise ratio and sensitivities.The imaging technique is not affected by the difference in tissue composition or thickness and has the practical value of quan-titative in vivo detection.Almost all the relevant time-resolved imaging was carried out around lanthanide-doped upconversion nanomaterials,owing to the advantages of ultralong luminescence lifetime,excellent photostability,controllable morphology,easy surface modification and various strategies of regulating lifetime.Therefore,this review presents the research progress of SWIR time-resolved imaging technology based on nanomaterials doped with lanthanide ions as luminescence centers in recent years.展开更多
The trans-media transmission of quantum pulse is one of means of free-space transmission which can be applied in continuous-variable quantum key distribution(CVQKD)system.In traditional implementations for atmospheric...The trans-media transmission of quantum pulse is one of means of free-space transmission which can be applied in continuous-variable quantum key distribution(CVQKD)system.In traditional implementations for atmospheric channels,the 1500-to-1600-nm pulse is regarded as an ideal quantum pulse carrier.However,the underwater transmission of this pulses tends to suffer from severe attenuation,which inevitably deteriorates the security of the whole CVQKD system.In this paper,we propose an alternative scheme for implementations of CVQKD over satellite-to-submarine channels.We estimate the parameters of the trans-media channels,involving atmosphere,sea surface and seawater and find that the shortwave infrared performs well in the above channels.The 450-nm pulse is used for generations of quantum signal carriers to accomplish quantum communications through atmosphere,sea surface and seawater channels.Numerical simulations show that the proposed scheme can achieve the transmission distance of 600 km.In addition,we demonstrate that non-Gaussian operations can further lengthen its maximal transmission distance,which contributes to the establishment of practical global quantum networks.展开更多
OBJECTIVE:To analyze the distinctive pathological characteristics in the spectrums of spontaneous infrared radiation at the Taiyuan(LU 9) acupoint in patients with asthma.METHODS:A highly sensitive infrared spectrum d...OBJECTIVE:To analyze the distinctive pathological characteristics in the spectrums of spontaneous infrared radiation at the Taiyuan(LU 9) acupoint in patients with asthma.METHODS:A highly sensitive infrared spectrum detecting device was used to detect the spectrums of spontaneous infrared radiation at Taiyuan(LU 9) in 37 asthma patients and 34 healthy volunteers.RESULTS:Asthma patients had significantly lower infrared intensity than that of the healthy volunteers(P>0.01).Asthma patients had significantly lower overall infrared radiation intensity at the left Taiyuan(LU 9) than that of healthy volunteers(P>0.05),but there was no significant difference between healthy volunteers and asthma patients at the right Taiyuan(LU 9)(P>0.05).The infrared radiation intensity of 17 wavelength spots at the left Taiyuan(LU 9) and 4 wavelength spots at the right Taiyuan(LU 9) in asthma patients were significantly lower than those of healthy volunteers(P>0.05).At 2 μm,the infrared radiation intensity of asthma patients was significantly stronger than that of healthy volunteers(P>0.05).At 19 wavelength spots in the healthy volunteers and at 4 wavelength spots in the asthma patients,the left Taiyuan(LU 9) showed a significantly stronger intensity than that of the right Taiyuan(LU 9)(P>0.05).By Pearson's χ2 test,healthy volunteers had more wavelength spots that were significantly different between the left and right Taiyuan(LU 9) than the asthma patients(P>0.01).CONCLUSION:Changes in the infrared spectrum at the Taiyuan(LU 9) acupoint in asthma patients may reflect distinct pathological changes.Certain acupuncture points may be related to specific organs.展开更多
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 th...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.展开更多
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(Q...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.展开更多
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...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 ρ= −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.展开更多
[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 co...[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.展开更多
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...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.展开更多
InP quantum dots(QDs)have been a major building block of modern display technology due to their high photoluminescence quantum yield(PLQY)in the visible spectrum,superior stability,and eco-friendly composition.However...InP quantum dots(QDs)have been a major building block of modern display technology due to their high photoluminescence quantum yield(PLQY)in the visible spectrum,superior stability,and eco-friendly composition.However,their applications at short-wave infrared(SWIR)have been hindered by their low efficiency.Here,we report the synthesis of efficient and SWIR-emitting InP QDs by precisely controlling the InP core nucleation using a low-cost ammonia phosphorus precursor,while avoiding size-limiting ZnCl_(2) for effective copper doping.Subsequent epitaxial growth of a lattice-matched ZnSe/ZnS multishell enhanced the QD sphericity and surface smoothness and yielded a record PLQY of 66% with an emission peak at 960 nm.When QDs were integrated as the high-refractive-index luminescent core of a liquid waveguide-based luminescent solar concentrator(LSC),the device achieved an optical efficiency of 7.36%.This performance arises from their high PLQY,spectral alignment with the responsivity peak of silicon solar cells,and the optimized core/cladding waveguide structure.These results highlight the potential of InP QDs as a promising nanomaterial for SWIR emission and applications.展开更多
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 resu...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.展开更多
Nanofibrous pyrolusite （β-MnO2） was synthesized. The particle shape changes from nanofibers to nanoparticles after grinding, and the phase structure does not change. The local environment around the central mangane...Nanofibrous pyrolusite （β-MnO2） was synthesized. The particle shape changes from nanofibers to nanoparticles after grinding, and the phase structure does not change. The local environment around the central manganese ion has a slight change in nanoparticles related to nanofibers. Fourier transform infrared （FTIR） spectra showed that A2u mode frequency shifts from 514 cm-1 to 574 cm-1 to 617 cm-1 gradually while the particle shape and size change from long nanofibers to short fibers and to nanoparticles. The extra vibrational band that is unpredicted by factor group analysis originates from the contribution of A2u mode of the particles with different sizes and shapes in the studied sample. On the basis of Rietveld refinement analysis of XRD profiles and the FTIR spectra, we think that two kinds of MnO6 octahedral geometries, i.e., 4 long＋2 short and 4 short＋2 long, could exist in pyrolusites synthesized by different route. The maximum vibrational frequency in the FTIR spectra of pyrolusites is sensitive to these micro-structures. Assignment of four vibrational bands in the middle and far infrared region has been made.展开更多
An experimental study on infrared radiation from the hot jet by means of model test is presented. The infrared detection system of the universal infrared instruments. the testing method and experimental results of inf...An experimental study on infrared radiation from the hot jet by means of model test is presented. The infrared detection system of the universal infrared instruments. the testing method and experimental results of infrared radiation from the hot jet are introduced. The space distribution of infaed radiant energy. the spectrum of infrared radiation from the hot jet. the distribution of the radiant energy of the hot jet against the wavebands and the characteristic difference of the hot jet radiaton between the 2-D jet tube and the circular jet tube are obtained. It is indicated that the testing system and the method are valid and the results are in accord with the theoretical analysis.展开更多
The manganite perovskite polycrystal samples of （La1-xDyx）2/3Sr1/3MnO3 （x = 0, 0.1, 0.2, 0.35, and 0.5） doped with Dy were prepared by solid state reaction in atmosphere to measure their X-ray diffraction （XRD） ...The manganite perovskite polycrystal samples of （La1-xDyx）2/3Sr1/3MnO3 （x = 0, 0.1, 0.2, 0.35, and 0.5） doped with Dy were prepared by solid state reaction in atmosphere to measure their X-ray diffraction （XRD） patterns, scanning electric microscope （SEM） images, infrared absorption spectra, and microwave electromagnetic properties. The displacement of the XRD peaks of the samples was found, and the 2θ increases from 0.05o to 0.5o. The grains of undoped La2/3Sr1/3MnO3 not only have the greatest size, but also the most regular shape. The size of the grains decreases as the Dy doping content increases from 0 to 0.5. The infrared absorption spectra of all samples were measured at room temperature. An absorption peak corresponding to the stretching vibration mode of Mn-O bonds appears within the range of 591-629 cm-1. The absorption peak shifts from a higher frequency to a lower one with the decrease of the average ionic radius of A-site. The frequency de- pendence of microwave-absorbing properties, imaginary components of the complex magnetic permeability μ＂ and dielectric permeability ε＂ for all samples was measured at room temperature from 8 to 13 GHz. The results show that the loss of microwave absorption can be attrib- uted to both the magnetic and electric losses. The increase of Dy content not only enhances the microwave absorption but also causes the displacement of the absorption peaks.展开更多
In this study the effects of microwaves on the secondary structure of three typical proteins have been investigated. A set of samples of lysozyme, bovine serum albumin and myoglobin in D2O solutions were exposed for 8...In this study the effects of microwaves on the secondary structure of three typical proteins have been investigated. A set of samples of lysozyme, bovine serum albumin and myoglobin in D2O solutions were exposed for 8 hours to mobile phone microwaves at 900 MHz at a magnetic field intensity around 16 mA/m. The relative effects on the secondary structure of the proteins were studied by means of Fourier Transform Infrared Spectroscopy. An increase of the amide I band intensity in the secondary structure of the proteins was observed after the microwaves exposure. Furthermore, a weak shift of the amide I mode of bovine serum albumin and a heavier shift of the amide I of myoglobin occurred after the exposure. In addition, a clear increasing of the β-sheet components with respect to the α-helix content was observed in the spectra of bovine serum albumin and myoglobin after the exposure, suggesting the hypothesis of the formation of aggregates.展开更多
This paper deals with the radiation effects of different kinds ofradiant carriers used in making far infrared textile materials.From two radiation experiments,methods of testing radiation ef-fects of carriers have bee...This paper deals with the radiation effects of different kinds ofradiant carriers used in making far infrared textile materials.From two radiation experiments,methods of testing radiation ef-fects of carriers have been found,results of the experiments arediscussed.Finally,some conclusions for choosing appropriateradiant carrier are drawn.展开更多
The complete experimental IR spectra and vibrational analysis of the title complex Co(mnt)(dmbpy) were reported in this paper. The results show that the complex molecule has a planar geometry belonging to point group ...The complete experimental IR spectra and vibrational analysis of the title complex Co(mnt)(dmbpy) were reported in this paper. The results show that the complex molecule has a planar geometry belonging to point group C 2v and ground electronic state with spin quartet. A new method for analyzing vibrational spectra of complicated molecule is established. The essential of this method is to point out main fixed points and pivotal vibrational units in assignment for each fundamental band. Two new symbols η (heaving along the specified direction) and M (midpoint of a bond or unit) were defined for describing the vibrational modes accurately.展开更多
基金Supported by the Short-wave Infrared Camera Systems(B025F40622024)。
文摘The accuracy of spot centroid positioning has a significant impact on the tracking accuracy of the system and the stability of the laser link construction.In satellite laser communication systems,the use of short-wave infrared wavelengths as beacon light can reduce atmospheric absorption and signal attenuation.However,there are strong non-uniformity and blind pixels in the short-wave infrared image,which makes the image distorted and leads to the decrease of spot centroid positioning accuracy.Therefore,the high-precision localization of the spot centroid of the short-wave infrared images is of great research significance.A high-precision spot centroid positioning model for short-wave infrared is proposed to correct for non-uniformity and blind pixels in short-wave infrared images and quantify the localization errors caused by the two,further model-based localization error simulations are performed,and a novel spot centroid positioning payload for satellite laser communications has been designed using the latest 640×512 planar array InGaAs shortwave infrared detector.The experimental results show that the non-uniformity of the corrected image is reduced from 7%to 0.6%,the blind pixels rejection rate reaches 100%,the frame rate can be up to 2000 Hz,and the spot centroid localization accuracy is as high as 0.1 pixel point,which realizes high-precision spot centroid localization of high-frame-frequency short-wave infrared images.
基金Project supported by the National Key Research and Development Program of China(Grant No.2016YFB0402400)the National Natural Science Foundation of China(Grant Nos.61675225,61605232,and 61775228)the Shanghai Rising-Star Program,China(Grant No.17QA1404900)
文摘In this article, unique spectral features of short-wave infrared band of 1 μm–3 μm, and various applications related to the photodetectors and focal plane arrays in this band, are introduced briefly. In addition, the different material systems for the devices in this band are outlined. Based on the background, the development of lattice-matched and wavelengthextended InGaAs photodetectors and focal plane arrays, including our continuous efforts in this field, are reviewed. These devices are concentrated on the applications in spectral sensing and imaging, exclusive of optical fiber communication.
基金funded by Science and Technology Project of Tibet Autonomous Region(Grant Nos.XZ201801-GB-01XZ202102YD0024C)+2 种基金The Second Round of Comprehensive Investigation and Research on the Qinghai-Tibet Plateau(Grant No.2019QZKK0806)National Natural Science Foundation of China(Grant No.42002097)Demonstration Research on Alteration Mapping using Short-wave Infrared and Thermal Infrared Hyperspectral Technologies(Grant No.KK2102)。
文摘The Qulong deposit in Tibet is one of the largest porphyry copper-molybdenum deposits in China.We used short-wave infrared(SWIR)spectroscopy to examine the spectral characteristics of the extensively developed chlorite in this deposit.X-ray diffraction and electron microprobe analyses were used for phase identification and to obtain the chemical composition,ion substitution relationships,and formation environment of the chlorite.SWIR spectral parameters were applied to detect the hydrothermal centers.The results indicate that the wavelength of the absorption feature for Qulong chlorite Fe-OH(Pos2250)range from 2240 to 2268.4 nm;the chlorite substitution relationships are dominated by Mg-Fe substitution at the octahedral sites together with Al;-Si substitution at the tetrahedral sites;the chlorite formation temperatures range within the medium-low temperature hydrothermal alteration range from 164 to 281°C,with an average value of 264℃;the wavelength of the chlorite peak position for Fe-OH(2250 nm)absorption and its chemical composition are positively correlated with Al^(Ⅵ),Fe+Al^(Ⅵ),Fe/(Fe+Mg),Fe,and Fe+Al^(Ⅳ)but negatively correlated with Mg and Mg/(Fe+Mg);and the wavelength associated with the chlorite Fe-OH(2250 nm)absorption feature is positively correlated with the temperature at which the chlorite formed.These correlations indicate that more Fe and Al^(Ⅵ)ions and fewer Mg ions at the octahedral sites of chlorite lead to a longer the wavelength of the chlorite Fe-OH(2250 nm)absorption feature and a higher chlorite formation temperature.The wavelength of the Qulong chlorite Fe-OH(2250 nm)absorption feature(>2252 nm)can thus serve as an exploration indicator to guide the detection of hydrothermal centers in porphyry copper deposits.The results of the study indicate that the mineralogical and SWIR spectral characteristics of chlorite are significant indicators for locating hydrothermal centers within porphyry deposits.
基金Supported by the Talented Young Pressional Foundation of Jilin Province(No 2005123)
文摘Fructus cnidii （Chinese name shechuangzi） is the fruit produced by Cnidium monnieri （L.） Cusson （Umbelliferae）. It is a perennial herb that is used to treat skin-related diseases and gynecopathyell. Recent pharmacological studies have revealed crude extracts or components isolated from fructus cnidii possess antiallergic, antipruritic, antidermatophytic, antibacterial, antifungal, and antiosteoporotic activities. Osthole and imperatorin are the major compounds present in shechuangzi. They are often used as standards for the evaluation of the quality of shechuangzi products.
基金the National Natural Science Foundation of China(No.81971704)the National Key ResearchandDevelopment Program of China(No.2017YFA0205304)the Translational Medicine Research Fund of National Facility for Translational Medicine(Shanghai)(No.TMSK-2021-117)。
文摘Compared with the conventional first near-infrared(NIR-I,700900 nm)window,the short-wave infrared region(SWIR,900—1700nm)possesses the merits of the increasing tissue penetration depths and the suppression of scattering background,leading to great potential for in vivo imaging.Based on the limitations of the common spectral domain,and the superiority of the time-dimension,time-resolved imaging eliminates the auto-fuorescence in the biological tissue,thus supporting higher signal-to-noise ratio and sensitivities.The imaging technique is not affected by the difference in tissue composition or thickness and has the practical value of quan-titative in vivo detection.Almost all the relevant time-resolved imaging was carried out around lanthanide-doped upconversion nanomaterials,owing to the advantages of ultralong luminescence lifetime,excellent photostability,controllable morphology,easy surface modification and various strategies of regulating lifetime.Therefore,this review presents the research progress of SWIR time-resolved imaging technology based on nanomaterials doped with lanthanide ions as luminescence centers in recent years.
基金supported by the National Natural Science Foundation of China(Grant Nos.62101180 and 61871407)the Key R&D Program of Hunan Province(Grant No.2022GK2016)+1 种基金the State Key Laboratory of High Performance Computing,National University of Defense Technology(Grant No.202101-25)the Fundamental Research Funds for the Central Universities(Grant No.531118010371)。
文摘The trans-media transmission of quantum pulse is one of means of free-space transmission which can be applied in continuous-variable quantum key distribution(CVQKD)system.In traditional implementations for atmospheric channels,the 1500-to-1600-nm pulse is regarded as an ideal quantum pulse carrier.However,the underwater transmission of this pulses tends to suffer from severe attenuation,which inevitably deteriorates the security of the whole CVQKD system.In this paper,we propose an alternative scheme for implementations of CVQKD over satellite-to-submarine channels.We estimate the parameters of the trans-media channels,involving atmosphere,sea surface and seawater and find that the shortwave infrared performs well in the above channels.The 450-nm pulse is used for generations of quantum signal carriers to accomplish quantum communications through atmosphere,sea surface and seawater channels.Numerical simulations show that the proposed scheme can achieve the transmission distance of 600 km.In addition,we demonstrate that non-Gaussian operations can further lengthen its maximal transmission distance,which contributes to the establishment of practical global quantum networks.
基金Supported by the National Basic Research Program of China(2009CB522901)Key Project of State Administration of Traditional Chinese Medicine of ChinaShanghai Municipal Science Foundation(11DZ1973300,11ZR1436700, 10QA1406400)
文摘OBJECTIVE:To analyze the distinctive pathological characteristics in the spectrums of spontaneous infrared radiation at the Taiyuan(LU 9) acupoint in patients with asthma.METHODS:A highly sensitive infrared spectrum detecting device was used to detect the spectrums of spontaneous infrared radiation at Taiyuan(LU 9) in 37 asthma patients and 34 healthy volunteers.RESULTS:Asthma patients had significantly lower infrared intensity than that of the healthy volunteers(P>0.01).Asthma patients had significantly lower overall infrared radiation intensity at the left Taiyuan(LU 9) than that of healthy volunteers(P>0.05),but there was no significant difference between healthy volunteers and asthma patients at the right Taiyuan(LU 9)(P>0.05).The infrared radiation intensity of 17 wavelength spots at the left Taiyuan(LU 9) and 4 wavelength spots at the right Taiyuan(LU 9) in asthma patients were significantly lower than those of healthy volunteers(P>0.05).At 2 μm,the infrared radiation intensity of asthma patients was significantly stronger than that of healthy volunteers(P>0.05).At 19 wavelength spots in the healthy volunteers and at 4 wavelength spots in the asthma patients,the left Taiyuan(LU 9) showed a significantly stronger intensity than that of the right Taiyuan(LU 9)(P>0.05).By Pearson's χ2 test,healthy volunteers had more wavelength spots that were significantly different between the left and right Taiyuan(LU 9) than the asthma patients(P>0.01).CONCLUSION:Changes in the infrared spectrum at the Taiyuan(LU 9) acupoint in asthma patients may reflect distinct pathological changes.Certain acupuncture points may be related to specific organs.
基金supported by the National Natural Science Foundation of China (Grant No. 51072072)
文摘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.
文摘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.
文摘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 ρ= −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.
基金Supported by Emergency Management Project of National Natural Science Foundation of China(61640413)Open Project of South Xinjiang Agricultural Information Research Center of Agricultural Information Institute,CAAS(ZX2015005)Key Laboratory Project of Crop Water Use and Regulation,Ministry of Agriculture(FIRI2018-05-03)
文摘[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.
文摘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.
文摘InP quantum dots(QDs)have been a major building block of modern display technology due to their high photoluminescence quantum yield(PLQY)in the visible spectrum,superior stability,and eco-friendly composition.However,their applications at short-wave infrared(SWIR)have been hindered by their low efficiency.Here,we report the synthesis of efficient and SWIR-emitting InP QDs by precisely controlling the InP core nucleation using a low-cost ammonia phosphorus precursor,while avoiding size-limiting ZnCl_(2) for effective copper doping.Subsequent epitaxial growth of a lattice-matched ZnSe/ZnS multishell enhanced the QD sphericity and surface smoothness and yielded a record PLQY of 66% with an emission peak at 960 nm.When QDs were integrated as the high-refractive-index luminescent core of a liquid waveguide-based luminescent solar concentrator(LSC),the device achieved an optical efficiency of 7.36%.This performance arises from their high PLQY,spectral alignment with the responsivity peak of silicon solar cells,and the optimized core/cladding waveguide structure.These results highlight the potential of InP QDs as a promising nanomaterial for SWIR emission and applications.
基金supported by the National Natural Science Foundation of China (Grant No.11074025)the National Basic Research Program of China (Grant No.2011CB922200)a grant from the China Academy of Engineering Physics
文摘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.
文摘Nanofibrous pyrolusite （β-MnO2） was synthesized. The particle shape changes from nanofibers to nanoparticles after grinding, and the phase structure does not change. The local environment around the central manganese ion has a slight change in nanoparticles related to nanofibers. Fourier transform infrared （FTIR） spectra showed that A2u mode frequency shifts from 514 cm-1 to 574 cm-1 to 617 cm-1 gradually while the particle shape and size change from long nanofibers to short fibers and to nanoparticles. The extra vibrational band that is unpredicted by factor group analysis originates from the contribution of A2u mode of the particles with different sizes and shapes in the studied sample. On the basis of Rietveld refinement analysis of XRD profiles and the FTIR spectra, we think that two kinds of MnO6 octahedral geometries, i.e., 4 long＋2 short and 4 short＋2 long, could exist in pyrolusites synthesized by different route. The maximum vibrational frequency in the FTIR spectra of pyrolusites is sensitive to these micro-structures. Assignment of four vibrational bands in the middle and far infrared region has been made.
文摘An experimental study on infrared radiation from the hot jet by means of model test is presented. The infrared detection system of the universal infrared instruments. the testing method and experimental results of infrared radiation from the hot jet are introduced. The space distribution of infaed radiant energy. the spectrum of infrared radiation from the hot jet. the distribution of the radiant energy of the hot jet against the wavebands and the characteristic difference of the hot jet radiaton between the 2-D jet tube and the circular jet tube are obtained. It is indicated that the testing system and the method are valid and the results are in accord with the theoretical analysis.
基金supported by the National Natural Science Foundation of China (No. 60561001)the Natural Science Foundation of Inner Mongolia Autonomous Region, China (No. 200408020105)+1 种基金the Program for New Century Excellent Talents in Universities (No. NCET-05-0272)College Science and Technology Re-search Project of Inner Mongolia Autonomous Region, China (No. NJ04094)
文摘The manganite perovskite polycrystal samples of （La1-xDyx）2/3Sr1/3MnO3 （x = 0, 0.1, 0.2, 0.35, and 0.5） doped with Dy were prepared by solid state reaction in atmosphere to measure their X-ray diffraction （XRD） patterns, scanning electric microscope （SEM） images, infrared absorption spectra, and microwave electromagnetic properties. The displacement of the XRD peaks of the samples was found, and the 2θ increases from 0.05o to 0.5o. The grains of undoped La2/3Sr1/3MnO3 not only have the greatest size, but also the most regular shape. The size of the grains decreases as the Dy doping content increases from 0 to 0.5. The infrared absorption spectra of all samples were measured at room temperature. An absorption peak corresponding to the stretching vibration mode of Mn-O bonds appears within the range of 591-629 cm-1. The absorption peak shifts from a higher frequency to a lower one with the decrease of the average ionic radius of A-site. The frequency de- pendence of microwave-absorbing properties, imaginary components of the complex magnetic permeability μ＂ and dielectric permeability ε＂ for all samples was measured at room temperature from 8 to 13 GHz. The results show that the loss of microwave absorption can be attrib- uted to both the magnetic and electric losses. The increase of Dy content not only enhances the microwave absorption but also causes the displacement of the absorption peaks.
文摘In this study the effects of microwaves on the secondary structure of three typical proteins have been investigated. A set of samples of lysozyme, bovine serum albumin and myoglobin in D2O solutions were exposed for 8 hours to mobile phone microwaves at 900 MHz at a magnetic field intensity around 16 mA/m. The relative effects on the secondary structure of the proteins were studied by means of Fourier Transform Infrared Spectroscopy. An increase of the amide I band intensity in the secondary structure of the proteins was observed after the microwaves exposure. Furthermore, a weak shift of the amide I mode of bovine serum albumin and a heavier shift of the amide I of myoglobin occurred after the exposure. In addition, a clear increasing of the β-sheet components with respect to the α-helix content was observed in the spectra of bovine serum albumin and myoglobin after the exposure, suggesting the hypothesis of the formation of aggregates.
文摘This paper deals with the radiation effects of different kinds ofradiant carriers used in making far infrared textile materials.From two radiation experiments,methods of testing radiation ef-fects of carriers have been found,results of the experiments arediscussed.Finally,some conclusions for choosing appropriateradiant carrier are drawn.
基金Supported by the National Natural Science F oundation of China( No. 2 97710 2 5 )
文摘The complete experimental IR spectra and vibrational analysis of the title complex Co(mnt)(dmbpy) were reported in this paper. The results show that the complex molecule has a planar geometry belonging to point group C 2v and ground electronic state with spin quartet. A new method for analyzing vibrational spectra of complicated molecule is established. The essential of this method is to point out main fixed points and pivotal vibrational units in assignment for each fundamental band. Two new symbols η (heaving along the specified direction) and M (midpoint of a bond or unit) were defined for describing the vibrational modes accurately.
