Fast Nondestructive Identification of Endothelium Corneum Gigeriae Galli Using Visible/Near-Infrared Spectroscopy

Vis/NIR spectroscopy,in combination with partial least square(PLS)analysis and a back-propagation neural network,is investigated to identify endothelium corneum gigeriae galli(ECGG).The spectral features of ECGGs and their counterfeits are reasonably differentiated in vis/NIR region,which provides enough qualitative information to establish the relationship between the spectra and samples for identification.After pretreatment of the spectral data,cross validation is implemented for extracting the best number of principal components.Then the calibration and validation set are performed well.The PLS and back propagation neural network(BPNN)model gives the BPNN to be 0.9941 and the root mean square residual(RMSR)to be 0.0775 for the calibration set,and the multiple correlation coefficient(MCC)to 0.9874 and the RMSE to 0.1134 for the validation set.Thus the PLS and BPNN model is reliable and practicable.Through testing,a recognition accuracy of 100%is achieved.The present study could offer a new approach for fast and nondestructive discrimination of ECGG and its counterfeit.

分步连续沉淀法对锑砷污染土壤淋洗废液的回收及净化

针对高浓度Sb、As复合污染土壤的草酸淋洗废液,研究了分步连续沉淀法回收草酸并同步净化淋洗废液的处理效果。结果表明,向淋洗废液中添加钙盐进行分步连续沉淀,当pH控制在1.4时,淋洗废液中草酸回收率为35.54%,且回收的草酸对高浓度Sb、As污染土壤的淋洗效率分别为38.39%和55.54%;当pH增加至8~9时,废液中Sb、As的去除率达99%以上。净化回收过程产生的废渣中Cd、As、Sb等重金属浸出毒性均低于《危险废物鉴别标准浸出毒性鉴别》(GB 5085.3—2007)中相关限值。因此,分步连续沉淀法能在净化淋洗废液过程中同步回收淋洗剂,从而降低土壤淋洗技术的综合处理成本,减少二次污染风险,为污染土壤淋洗废液的净化处理和淋洗剂回收提供理论参考。

ZIF-8派生含氮多孔碳作为吸附剂固相萃取茶叶样品中6种痕量金属离子

以金属有机骨架化合物(ZIF-8)派生含氮纳米多孔碳(ZIF-8-NC)为固相萃取吸附剂,建立了火焰原子吸收光谱法测定茶叶样品中痕量Cu^(2+)、Pb^(2+)、Cd^(2+)、Cr^(3+)、Ni^(2+)、Co^(2+)的分析方法。ZIF-8-NC具有较大的比表面积(1239.8 m^2/g),既存在微孔又存在介孔,且材料表面存在可与金属离子配位的含氮基团,所以此材料对金属离子有很好的吸附性能。对影响金属离子富集效率的主要因素,如配位剂的种类、样品溶液pH值、样品体积、解吸剂种类、解吸剂体积等进行了优化。在优化条件下,6种金属离子的检出限为0.05~0.07μg/kg,线性相关系数在0.9988~0.9993范围内。各金属离子的加标回收率为76.8%~101%,RSD在5.9%~11.3%之间。本方法适用于复杂基质样品中金属离子的测定,具有操作简便、灵敏度高和环境友好的特点。

热加工工艺对挤压态FGH4096合金临界晶粒长大的影响

基于挤压态FGH4096合金双圆锥台试样热压缩变形及过固溶热处理试验,结合DEFORM有限元软件数值模拟,确定试样中各等效应变范围内临界晶粒长大分布规律,研究热加工工艺对挤压态FGH4096合金临界晶粒长大的影响。结果表明:在温度980~1060℃、应变速率0.003~0.03 s^−1条件下,双圆锥台试样热变形后再经过固溶热处理,合金临界晶粒长大的窗口条件从低温低应变速率向高温高应变速率转变,其中(980℃、0.03 s^−1)、(1060℃、0.003 s^−1)条件下可以避免出现临界晶粒长大,并获得均匀晶粒组织。当变形温度为980℃时,随着应变速率的增加,异常晶粒长大程度减小,且合金临界晶粒长大位置的临界等效应变数值降低;当应变速率为0.03 s^−1时,随着变形温度的升高,异常晶粒长大程度增大,且试样发生临界晶粒长大的等效应变区域扩大。

Adiabatic Enhanced Compression of Ultrashort Pulses in Fibres with Slowly Decreasing Dispersion

We investigate the adiabatic enhanced compression of ultrashort pulses from a distributed feedback laser operated at 1550 nm in fibres with slowly decreasing dispersion (FSDD). High-quality pulse compressions from 4.4 ps down to 1.1ps in a l00m FSDD and from 4.4ps down to 830fs in a 500m FSDD are obtained. The Raman self frequency shift of femtosecond pulses in the compression is observed. Theoretical analyses are in good agreement with experimental results.

Higher-Order Dispersion and Soliton Pulse Compression in the Dispersion-Decreasing Fibers

The compression results of picosecond and femtosecond soliton pulses in the dispersion-decreasing fibers are reported in this paper.We found that the high-order dispersion has a great influence on the soliton compression.The expressions of optimum compression factor and optimum fiber length are obtained numerically.

Modulation Instability of Femtosecond Optical Pulses in Long Optical Fibers with Minimum Group-Velocity Dispersion

A new region where modulation stability occurs in the fibers with minimum group-velocity was found due to the fourth-order dispersion effect.The spectral extent of the region is analyzed and found to be affected by initial input power and the dispersion parameter.

Suppression and Compensation of the Third-Order Dispersion Effect on Polarization Modes in Birefringent Fibres

The influence of the third-order dispersion (TOD) on the polarization mode dispersion (PMD) is investigated. It is found that the TOD effect destroys orthogonal polarization modes in optical birefringent fibres. A new method is proposed to compensate for the PMD by means of cascading the fibres with the positive and negative TOD. This has proven to be practicable in long transmissions.

An Extra Phase for Two-Mode Coherent States Displaced in Noncommutative Phase Space

Using deformed boson algebra,we study the property of two-mode coherent states in noncommutative phase space.When a two-mode field evolves in the noncommutative phase space,it can acquire an extra θ-dependent phase compared to the case of commutative space.This phase is detectable and may be used to test noncommutativity.

Enhanced Pulse Compression Induced by Third-Order Dispersion in Birefringent Fibre

We report on the enhanced pulse compression due to the interaction of positive third-order dispersion and cross-phase-modulation effects in birefringent fibres. Polarization soliton compression along the slow axis can be enhanced in birefringent fibres with positive third-order dispersion, and the polarization soliton compression along the fast axis can be enhanced in fibres with negative third-order dispersion. Moreover, the third-order dispersion parameter can be optimized to obtain the optimal pulse compression.

Numerical Study of the Apodization Profile Functions, Optimal Profiles and Lengths of a Linearly Chirped Fibre Bragg Grating

Starting from our definition of apodization profile functions,we discover the optimal profiles and the characteristics of defined apodization functions in sidelobe suppression.It is shown by numerical analysis that the optimal grating length is 45 mm to compensate for dispersion induced by 100 km fibres and the smoothness of the ripples in time-delay characteristics is related to the defined parameters.

Optical Information Storage in Poly [3-Methyl-4-Bis(N,N-Oxyethylene)Imino-4-Nitro-Azobenzene Sebacoyl] Film by Degenerate Four-Wave Mixing

Optical storage caused by photo-induced anisotropy in poly[3-methyl-4-bis(N,N-oxyethylene)imino-4-nitro-azobenzene sebacoyl]film is studied by degenerate four-wave mixing.Molecule orientation gratings which are stable for three months are produced.The grating in the sample can be“erased”by using circular polarized light.So an azobenzene polymer thin film can be used many times to restore optical information.

Direction-Dependent Switching in Nonlinear Chirped Gratings

Chirped gratings with uniform Kerr nonlinearity are numerically demons traced to have direction-dependent switching behavior,which is caused by the different energy storage between the two incident directions.This effect can iind useful applications such as optical diode and optical switch-isolator.

A SUPER-BROADENED STIMULATED SCATTERING IN LIQUID-FILLED WAVEGUIDE WITH LONG GAIN LENGTH

Using an intense visible laser pulse to excite the liquid-filled waveguide with a long gain length,we have observed a new stimulated-scattering with super-broadened spectral width(500cm^(-1))in addition to the sharp lines of SRS of the benzene or carbon-disulfide which is used as a filling liquid.

热改性对柱状活性炭脱硫能力的影响

在N;保护下采用不同温度对柱状活性炭进行热改性,得到了5种改性活性炭(AC-1~AC-5),将改性前后的活性炭(AC)分别置于含有SO;且有水蒸气和氧气存在的条件下进行脱硫试验,利用气体吸附仪和扫描电镜对改性前后活性炭表面的物理性质进行了表征。试验结果表明,当改性温度为700~900℃时,改性后活性炭的脱硫能力随着改性温度的升高而提升,当改性温度为900℃时,所得活性炭的脱硫能力最强,当改性温度达到1100℃时活性炭脱硫能力明显变差。气体吸附仪所得的BET分析结果和扫描电镜的结果表明,在加热过程中活性炭部分原本堵塞的孔道被打开,增大了其吸附表面积,对提升活性炭的初始脱硫率有利,但过高温度会破坏活性炭原有孔径结构,导致AC-4和AC-5样品脱硫能力变差。此外,利用程序升温脱附技术(TPD)对活性炭样品AC~AC-4的酸碱量进行了分析,结果表明,活性炭表面强碱中心的碱量与其脱硫能力存在良好的正线性相关关系,对比样品AC-2和AC-3发现,在活性炭物理性质差别不大的情况下,其脱硫能力的提升主要得益于表面化学性质的改变,尤其是碱性的增强。同时,通过Boehm滴定并结合傅里叶变换红外光谱仪(FTIR)对活性炭样品AC和AC-3的表面酸性官能团变化进行分析,发现在热改性后活性炭表面羧基、内酯基和羟基数量减少,这说明热处理能使活性炭表面的酸性官能团分解,有利于提升其脱硫能力。