采用氧合血红蛋白吸收带的漫反射光谱比率R（540）/R（575）检测浅表性膀胱癌

采用氧合血红蛋白在540和575 nm吸收带的漫反射光谱比率(R540/R575)对人浅表性膀胱癌进行了鉴别诊断,实验采用带积分球附件的分光光度计获取组织的漫反射光谱。结果表明:正常膀胱的粘膜/粘膜下层组织的漫反射光谱比率(R540/R575)在组织离体后2 h的平均值为111%,3 h的平均值为107%,4 h的平均值为104%,5 h的平均值为102%,而浅表性的膀胱癌的粘膜/粘膜下层组织的漫反射光谱比率(R540/R575)在组织离体后2 h的平均值为98.4%,3 h的平均值为95.5%,4 h的平均值为93.1%,5 h的平均值为91.6%,正常膀胱与浅表性膀胱癌的粘膜/粘膜下层组织在组织离体后2,3,4和5 h的漫反射光谱比率(R540/R575)均有显著性的差异(p<0.05),分别为12.6%,11.5%,10.9%和10.4%。这结论为快速、低成本、非入侵的浅表性膀胱癌的光活检提供了一种新的方法。     

利用高光谱植被指数监测紧凑型玉米叶绿素荧光参数F_v/F_m

为进一步评价遥感监测紧凑型玉米叶绿素荧光参数Fv/Fm的可行性,通过开展小区紧凑型玉米试验,分析紧凑型玉米整个生育期Fv/Fm与高光谱植被指数的相关关系,建立紧凑型玉米Fv/Fm高光谱监测模型。结果表明,紧凑型玉米Fv/Fm与选取的高光谱植被指数均呈极显著正相关,其中结构敏感色素指数(SIPI)与Fv/Fm的相关性最好,相关系数(r)为0.88。用SIPI建立紧凑型玉米Fv/Fm的监测模型,其决定系数(R2)为0.812 6,均方根误差(RMSE)为0.082。研究表明,利用高光谱植被指数可以有效地监测紧凑型玉米整个生育期的Fv/Fm。     

Diffuse reflectance of TiO2 pigmented paints: Spectral dependence of the average pathlength parameter and the forward scattering ratio

Diffuse reflectance spectra of paint coatings with different pigment concentrations, normally illuminated with unpolarized radiation, have been measured. A four-flux radiative transfer approach is used to model the diffuse reflectance of TiO₂ (rutile) pigmented coatings through the solar spectral range. The spectral dependence of the average pathlength parameter and of the forward scattering ratio for diffuse radiation, are explicitly incorporated into this four-flux model from two novel approximations. The size distribution of the pigments has been taken into account to obtain the averages of the four-flux parameters: scattering and absorption cross sections, forward scattering ratios for collimated and isotropic diffuse radiation, and coefficients involved in the expansion of the single particle phase function in terms of Legendre polynomials.     

Effects of the Mn/Co ratio on the magnetic transition and magnetocaloric properties of Mn1+xCo1-xGe alloys

We have investigated the magnetic transition and magnetocaloric effects of Mn 1+x Co 1 x Ge alloys by tuning the ratio of Mn/Co.With increasing Mn content,a series of first-order magnetostructural transitions from ferromagnetic to paramagnetic states with large changes of magnetization are observed at room temperature.Further increasing the content of Mn (x=0.11) gives rise to a single second-order magnetic transition.Interestingly,large low-field magnetic entropy changes with almost zero magnetic hysteresis are observed in these alloys.The effects of Mn/Co ratio on magnetic transition and magnetocaloric effects are discussed in this paper.     

Eu原子4f~76p_(3/2)ns自电离衰变分支比和弹射电子角分布

首先运用孤立实激发技术将Eu原子从基态4f~76s~(28)S_(7/2)经中间态4f~76s6p共振激发到4f~76sns Rydberg态,然后再将其进一步激发至4f~76p_(3/2)ns(n=7,8)自电离态.其次,采用速度影像技术对Eu原子自电离弹射出的电子进行探测,以便来研究自电离衰变分支比和弹射电子角分布.在研究自电离衰变分支比时,重点讨论了粒子数反转的可能性,并依据此现象可为实现自电离激光器提供有价值的信息.另外,还探讨了各向异性参数对弹射电子角分布的影响;以及在Eu原子不同自电离几率位置处,讨论了弹射电子角分布形状的变化情况.     

Effects of crystalline grain size and packing ratio of self-forming core/shell nanoparticles on magnetic properties at up to GHz bands

Self-forming core/shell nanoparticles of magnetic metal/oxide with crystalline grain size of less than 40 nm were synthesized. The nanoparticles were highly concentrated in an insulating matrix to fabricate a nanocomposite, whose magnetic properties were investigated. The crystalline grain size of the nanoparticles strongly influenced the magnetic anisotropy field, magnetic coercivity, relative permeability, and loss factor (tan δ=μ″/μ′) at high frequency. The packing ratio of the magnetic metallic phase in the nanocomposite also influenced those properties. High permeability with low tan δ of less than 1.5% at up to 1 GHz was obtained in the case of the nanoparticles with crystalline grain size of around 15 nm with large packing ratio of the nanoparticles.     

Effect of Fe/Pb molar ratio on the structure,magnetic and dielectric properties of PbFe12O19 nanoparticles

In this paper, lead hexaferrite (PbFe₁₂O₁₉) nanoparticles were synthesized by sol-gel method. In order to prepare PbFe₁₂O₁₉ nanoparticles, the metal nitrates with Fe/Pb?=?8, 10, 11, 12, 14 ratios and citric acid were used. The structure, morphology, magnetic, and dielectric properties of PbFe₁₂O₁₉ nanoparticles were characterized by X-ray diffraction (XRD), field emission scanning electron microscope (FESEM), vibrating sample magnetometer (VSM) and LCR meter. XRD results revealed that the samples with Fe/Pb?≤?10 and Fe/Pb?>?10 have single-phase hexaferrite and hematite (α- Fe₂O₃) structures, respectively. As a result, the sample with Fe/Pb?=?10 is single-phase and shows the highest values of the saturation magnetization and remanence magnetization. We found that the values of dielectric constant (ε′) and dielectric loss (ε″) increase with an increase in the Fe/Pb molar ratio from 8 to 12 and then decreases with an increase of Fe/Pb molar ratio to 14. The variation of ac conductivity (σ_ac) with frequency ranging from 1?kHz to 200?kHz showed that electrical conductivity in these ferrites is mainly due to the electron hopping mechanism.     

Branching ratio and angular distribution of ejected electrons from Eu 4f~76p_(1/2)nd auto-ionizing states

The branching ratios of ions and the angular distributions of electrons ejected from the Eu 4f~76p_(1/2)nd auto-ionizing states are investigated with the velocity-map-imaging technique.To populate the above auto-ionizing states,the relevant bound Rydberg states have to be detected first.Two new bound Rydberg states are identified in the region between41150 cm~(-1)and 44580 cm~(-1),from which auto-ionization spectra of the Eu 4f~76p_(1/2)nd states are observed with isolated core excitation method.With all preparations above,the branching ratios from the above auto-ionizing states to different final ionic states and the angular distributions of electrons ejected from these processes are measured systematically.Energy dependence of branching ratios and anisotropy parameters within the auto-ionization spectra are carefully analyzed,followed by a qualitative interpretation.     

多针-网电极离子风激励器推力与推功比的实验研究

本文搭建了一种无摩擦气垫悬浮测试平台测量了19针和31针-网电极离子风激励器产生的推力特性, 为多针-网电极离子风激励器作为新型动力源提供动力控制方法. 通过研究多针-网间隙、针-针间距、针尖曲率半径和电晕电压电流对离子风激励器推力特性的影响, 提出了在低功耗下产生较大推力的方法, 改善离子风激励器对低功耗与大推力的需求不能同时满足的现状. 关键词： 多针-网电极 离子风 推力 推功比     

In situ radiation measurement and estimation of U/Th ratio to reflect on the uranium bearing potential zone in metamorphic rocks of Mahendragarh district, Haryana

Gross gamma radiation survey was carried out using Nal(Tl) scintillator based portable gamma ray spectrometer (PGRS) around areas of Gaonri, Dholera, Pachnota and Meghot in Mahendragarh district, Haryana. Geologically the area forms part of north Delhi fold belt comprising calc-silicate, quartz biotite schist, impure marble, quartzite and pegmatite rocks. Equivalent uranium (eU₃O₈) concentration in ppm was estimated in situ on a regular grid pattern of 500 m (E-W) × 1000 m (N-S) and grab samples were collected at grid locations for analyzing in the laboratory for estimating the contents of eU₃O_s Ra_eq, ThO₂ and %K. A comparison with the laboratory analysed grab samples for eU₃0₈ data and in situ radiation measurements shows a good match of the two sets of data. The in situ measurements indicate higher concentration of eU₃O₈ in Chapra Bibipur in northeastern most corners, Maghot area in central part, Gaonri in western part and Pachnota in southwestern part of the study area. As index to uranium favorability, U(Ra_eq)-Th contour map (prepared using Surfer software with Krieging interpolation method for this grid size) based on the data on grab samples was generated which show three major clusters of relatively high U-Th ratio. The blocks delineated are enriched in sodic mineral albite which support albite hosted uranium mineralization potential in metamorphic rocks in Haryana.      

Remnant magmatic activity in the Coastal Range of East Taiwan after arc–continent collision: fission-track data and He/He ratio evidence

The magma activity of the North Luzon Arc is considered to have ceased, due to collision with the Asian continental margin, since late Miocene. New fission track dates of zircons taken from dike swarms in the central Coastal Range of East Taiwan show very young ages of 0.5 Ma. Furthermore, the high ³He/⁴He ratios (2.5 R_A; R_A is the air ratio) of hot spring gases near the same area indicate that more than 30% of a mantle-derived source component is necessary to account for the helium composition. These results suggest the existence of later remnant magmatic activity (more than 4 Ma) in the central Coastal Range. Therefore, arc magmatism may survive longer than the previously expected after collision.     

Theoretical insight into the influence of molecular ratio on the binding energy and mechanical property of HMX/2-picoline-N-oxide cocrystal,cooperativity effect and surface electrostatic potential

Molecular dynamics method was employed to study the binding energies and mechanical properties of the selected crystal planes of the energetic/nonenergetic 1,3,5,7-tetranitro-1,3,5,7-tetrazacyclooctane (HMX)/2-picoline-N-oxide cocrystal in different molecular ratios. The solvent effect in HMX:2-picoline-N-oxide (1:1) was calculated, and the cooperativity effect was discussed in HMX···HF/CH₄···2-picoline-N-oxide by using the M06-2X and MP2(full) methods at the 6-311++G^** basis set. The density, oxygen balance and detonation velocity were calculated. The results indicate that HMX/2-picoline-N-oxide prefers cocrystalising in the 1:1, 2:1 and 3:1 molar ratios, in which the cocrystals own the highest binding energy and best ductility. The cooperativity effect is present in the cyclic complex with CH₄, while the anti-cooperativity effect is found in the HF complex. Thus, in order to obtain stable HMX/2-picoline-N-oxide cocrystal, the solvent with low dielectric constant should be chosen, as is in accordance with the result from solvent effect. The reduced density gradient (RDG) and surface electrostatic potential analysis confirms the cooperativity effect and reveals the nature of decreased sensitivity in complex (or cocrystal). The cocrystals in the molar ratios of 5:1–10:1 could be satisfactory in view of explosive properties.     

转反义ACS基因番茄和普通番茄果实中锌含量和钠钾比与抗病性的关系研究

植物激素与矿质元素吸收以及与植物抗性的关系研究是近年来人们关注的热点。实验采用电感耦合等离子体原子发射光谱法(ICP-AES)测定转反义ACS基因耐贮番茄(乙烯的生物合成被抑制)及同品种普通番茄果实(对照)中Zn,Na,K元素的含量及Na/K比例的差异,并对其与果实抗病原菌侵染能力的关系进行讨论。结果表明：乙烯生物合成受阻的转反义ACS番茄果实抗病原菌侵染的能力高于对照果实,其Zn元素的含量是普通番茄果实的1.5倍;K元素含量在两种果实中无明显差异,但Na元素含量显著高于对照,Na/K比值是对照的2.0倍。说明Zn元素含量和Na和K元素的比例关系可能在转反义ACS番茄果实抗病原菌侵染的过程中起到一定作用。     

Laser spectroscopic monitoring of gas emission and measurements of the C/C isotope ratio in CO2 from a wood-based combustion

We report on the application of a compact and field-deployable instrument, based on a continuous-wave fiber-coupled Telecom external cavity diode laser, to measure the ¹³C/¹²C isotope ratio in CO₂ from a wood-based combustion. Carbon dioxide, the most important greenhouse gas, is a major product of combustion. The measurements of the ¹³C/¹²C isotopic ratio in CO₂ from combustion emission permit one to identify the CO₂ source and to study the temporal and spatial variations of pollution in the atmosphere. The average value of the ¹³CO₂/¹²CO₂ ratio is found to be (1.1011±0.0024)%. The corresponding δ-value relative to PDB standard is (−20.17±2.14)‰, which is in good agreement with the typical value of (−25±2)‰ for wood. Simultaneous monitoring of multiple species from gas emission has been performed using direct-absorption spectroscopy. The concentrations of C₂H₂, CO, CO₂ and H₂O were determined on the basis of integrated absorbance measured by least-squares fitting a Voigt lineshape to experimental absorption spectra.     

Recovery of the depolarization ratio of single lines from overlapping isotropic and anisotropic Raman profiles and assignment of molecular vibrations,with special reference to toluene and toluene‐d8

If a Raman line consists of several overlapping components, any attempt to perform a quantitative analysis of the wavenumber‐dependent depolarization ratio ρ(ν) fails, since ρ(ν) of a composite line is not an additive function of ρ(ν) of its constituents, and for a composite line representing an envelope of i single lines, ρ_comp(ν) ≠ ∑ρ_i(ν). This situation causes significant difficulties in the analysis of Raman spectra, especially in the case of weak lines (overtones, combination bands, etc.) situated in the close vicinity of strong fundamentals. In this paper, a specific algorithm is employed to recover isotropic and anisotropic Raman profiles. Using toluene and toluene‐d₈ as examples, it is shown that the ρ(ν) spectra of all components of a composite spectrum can be easily restored, facilitating the assignment of overtones, hot bands, and combination bands. Copyright © 2006 John Wiley & Sons, Ltd.