钬镱掺杂波导适用型锗酸盐玻璃上转换荧光光子定量

制备了适用于钾钠离子交换波导的钬镱离子掺杂锗酸盐玻璃,采用荧光光谱绝对测试系统在975nm激光泵浦下对玻璃的上转换发光性能进行表征,解析出样品的绝对光谱功率分布,并计算了光量子数分布和荧光量子产率等绝对荧光参量.测试与计算结果表明,当Ho3+/Yb3+掺杂的锗酸盐玻璃在370℃的KNO3熔盐中热离子交换4h时,K+-Na+离子交换有效扩散系数为0.068μm2/min.锗酸盐玻璃样品中,Ho3+主要发出548nm绿光和660nm红光,其中红色上转换荧光为支配性发射.当激光激发功率密度为1 227 W/cm2时,660nm红光绝对光谱功率和净发射光量子数分别为28.03μW和9.26×1013 cps.此时,548nm绿光和660nm红光发射的荧光量子产率分别为0.17×10-5和2.41×10-5,可见区总荧光量子产率达2.61×10-5.净发射光子数与激发功率密度的双对数曲线斜率表明Ho3+/Yb3+掺杂锗酸盐玻璃的红色和绿色上转换发射均属双光子激发过程.基于波导适用型锗酸盐玻璃实施的钬离子上转换荧光发射的绝对化表征,为稀土光电功能材料的进一步研发提供了可依赖的数据参考.

铝锗酸盐玻璃中铒离子升频荧光光子定量

研究了波导适用型Er^(3+)/Yb^(3+)掺杂铝锗酸盐玻璃的绝对光谱功率分布和净发射光子数分布,实现了稀土离子升频荧光参量的绝对量化。采用积分球配以电荷耦合器件(CCD)探测器系统对Er^(3+)离子升频荧光性能进行表征,解析出绝对光谱功率分布,进一步导出升频荧光净发射光子数与量子产率等荧光参数。结果表明,Er^(3+)/Yb^(3+)掺杂铝锗酸盐玻璃在380!C的KNO_3熔盐中K^+-Na^+离子交换有效扩散速率为0.077μm^2/min。Er^(3+)经975nm抽运光照射,发射出绿光(548nm)与红光(661nm),其中红光为支配性发射。在激光功率密度为1227 W/cm^2时,红光光谱功率输出和净发射光子数分别可达47.86μW和16.03"10^(13) s^(-1)。相对于比较法给出的锗酸盐玻璃荧光量子产率量级10^(-6)~10^(-5),绝对光子定量测量能提供更精确的指标,使波导适用型铝锗酸盐玻璃中稀土升频荧光测试参数的准确性和可重复性得到显著提升。

波导适用型铝锗酸盐玻璃中铥离子上转换荧光光子输出与量子产率定量

制备了适用于钾钠离子交换波导的Tm^(3+)/Yb^(3+)掺杂铝锗酸盐玻璃,利用积分球配以光纤光谱仪在975nm激光泵浦下对玻璃的上转换荧光进行测试,解析出样品的绝对荧光特征参量。测试与计算结果显示,在380℃的KNO3熔盐中,Tm^(3+)/Yb^(3+)掺杂的铝锗酸盐玻璃的钾钠离子交换有效扩散系数为0.070μm^2/min,热离子交换过程易于控制。铝锗酸盐玻璃样品中,Tm^(3+)主要发出477 nm蓝光和806 nm近红外光,其中近红外光为支配性发射。绝对荧光参数和激发功率密度呈正相关,当功率密度达到1 482 W/cm2时,三光子上转换蓝光的绝对光谱功率、净发射光子数和量子产率分别为269μW、6.46×10^(14)/s和1.43×10^(-4),双光子近红外光上转换对应的3个参量分别为4 024μW、1.63×10^(16)/s和3.61×10^(-3)。基于波导适用型铝锗酸盐玻璃中Tm^(3+)上转换荧光的绝对化表征,为进一步研发光电子器件和激光材料提供了有益的数据参考。

钬离子掺杂氟氧钇亚微米晶的荧光量子化表征与温度传感特性研究

采用水热合成法和高温煅烧法相结合制备了Ho^(3+)/Yb^(3+)共掺杂三方晶系的YOF亚微米晶体,该晶体具有较强的量子产率和良好的灵敏度。在977 nm激光泵浦下对晶体颗粒的上转换发光性能进行表征,利用荧光光谱测试系统绘制出样品的光谱功率分布。计算了光量子数分布和量子产率等绝对荧光参量。展示了在303~433 K温度范围内的荧光上转换发光性能并计算了灵敏度。测试结果表明,在977 nm激光激发下泵浦功率密度为73 m W/mm~2时,总光通量达到3.35 mlm,Ho^(3+)的绿光和红光的量子产率分别为2.97×10^(-5)和1.40×10^(-5),较高的量子产率确保了足够的荧光强度来实现温度反馈。在303 K时有最大相对灵敏度为0.437%K^(-1),当温度升至433 K时相对灵敏度仍能保持在0.331%K^(-1)。因此Ho^(3+)/Yb^(3+)共掺杂YOF亚微米晶体作为一种高效发光和高温度灵敏度材料为温度传感领域提供了一种潜在的选择。

定量SPECT探头系统平面灵敏度测试影响因素分析

目的比较手动测量及设备指导式测量单光子发射断层成像仪(Single Photon Emission Computed Tomography,SPECT)系统平面灵敏度的结果,分析面源与准直器距离、面源直径及面源活度在一定范围内波动对测试结果的影响,以指导定量SPECT质量控制。方法用手动测量及设备指导式测量2种方法分别按标准条件、面源与准直器的距离不同、面源直径不同、面源活度不同的条件对GE Discovery 670Pro SPECT进行系统平面灵敏度测试,记录结果及相应采集时长。采用Bland Altman分析2种方法测量结果的一致性;用单样本Wilcoxon符号秩和检验分析不同测试条件下,系统平面灵敏度测试结果及采集时长与标准条件下测试结果及采集时长的差异。结果标准条件下手动测量及设备指导式测量SPECT系统平面灵敏度结果分别为166.73、168.50 counts/min/μCi,采集时长分别为9.18、8.93 min。手动测量及设备指导式测量结果一致性良好,全部点位于95%一致性界限内。面源与准直器距离介于5~20 cm,面源直径介于3.5~20.0 cm时,2种方法测量系统平面灵敏度结果与标准条件下测试结果无显著差异(P>0.05),采集时间与标准条件下的无显著差异(P>0.05);面源活度不同时,2种方法测量系统平面灵敏度结果与标准条件下测试结果亦无显著差异(P=0.086、0.593),但采集时长较标准条件下的差异较大(P=0.046、0.039),其中面源活度介于18.5~74.0 MBq时,采集时长介于47.69~11.57 min,面源活度介于92.5~222.0 MBq时,采集时长均小于10 min,且采集时长缩短趋势平缓。结论手动测量及设备指导式测量SPECT系统平面灵敏度结果一致性良好,测试条件可参照相关要求在一定范围内波动。

^(99m)Tc-MDP SPECT/CT定量骨显像测定腰椎标准化摄取值的分析及应用

目的探讨正常腰椎^(99m)Tc-MDP SPECT/CT显像标准化摄取值(SUV)测量的稳定性、分布情况及影响因素,及其在骨密度评估中的价值。方法回顾性分析2021年5月至2023年6月行^(99m)Tc-MDP腰椎SPECT/CT显像、并于SPECT/CT显像前后1月内行DXA骨密度测定的103例[男13例、女90例;年龄(54.86±7.84)岁]患者的基本资料,测量其正常腰椎SUVmax、SUVmean、CT值及BMD;采用Bland Altman检验及Pearson相关分析不同测量者间腰椎SUV的一致性及相关性,Pearson相关分析腰椎SUV、BMD、CT值与不同指标的相关性,单因素方差分析比较不同BMD患者组间不同指标的差异,组间两两比较用LSD检验。结果不同观察者测量SUVmax、SUVmean一致性好(分别有1.3%、3.3%个点位于95%一致性界限外),相关性高(r分别为0.985,0.850;P均<0.001)。测得502个腰椎SUVmax、SUVmean分别为7.91±2.26、4.70±1.40;腰椎SUVmax、SUVmean分布趋势为L_(1)~L_(3)逐渐增高,L_(3)最高,其次为L_(5),L_(4)次之。全部患者腰椎SUVmax、SUVmean与年龄负相关(P<0.05),与体质量(P分别<0.001、0.05)、BMI(P<0.001)、CT值(P<0.05)正相关,与身高不相关;83例行同期骨密度患者L_(1)-L_(4)椎体SUVmax、SUVmean与BMD(P<0.05)正相关;全部腰椎BMD与年龄负相关(P<0.05),与CT值正相关(P<0.001);CT值与年龄负相关(P<0.001)。不同骨量患者组间SUVmax、SUVmean、BMD、CT值差异具有统计学意义(P均<0.001)。结论SPECT/CT定量骨显像测定SUV操作便捷,稳定性好;临床应用腰椎SUV可综合考虑其分布趋势及影响因素;基于SUV测定的SPECT/CT显像在骨密度评估中具有较高的价值。

Cloning of Brassica napus EIN3 Gene and Its Expression Induced by Sclerotinia sclerotiorum

[Objective] The study was to investigate roles of Brassica napus EINB in （ BnEIN3 ） resistance to Sclerotinia sclerotiorum. [ Methods] Genomic PCR and RT-PCR were carded out to isolate genomic DNA and cDNA sequences of BnEIN3 from oilseed rape, based on the highly conserved region of EIN3 gene from Arabidopsis thaliana and the homologous sequences of oilseed rape ESTs. Expression levels of BnEIN3 were detected in three varieties of oilseed rape inoculated with S. sclerotiorum by real-time quantitative PCR.[Results] A 1 947 bp DNA fragment was obtained from oilseed rape. The fragment shared 82% identity to A. thaliana EIIV3, encoded 614 amino acids containing an EIN3 domain, and was named as BnEIN3. Real-time PCR results showed that expression patterns of BnEIN3 were drastically different in different varieties. In highly resistant oilseed rape variety D083, BnEIN3 expression level was significantly increased 72 h after S. sclerotiorum inoculation whereas in middle resistant and susceptible varieties Zhongshuang 9 and 84039, BnEIN3 expression was suppressed. [ Conclusion ] BnEIIV3 may play an important role in oilseed rape resistance to S. sclerotiorum.

Determination of the Trace Element Contents in Plants Using Atomic Absorption Spectrophotometer

The aim of the study is to investigate the contents of trace element Se, Cd, Pb in three plants including burdock, ginkgol and garlic via graphite furnace atomic absorption and standard addition method. The results show that Se in burdock stem, skin and leaf are 32.40, 48.63, 38.10 μg/g, respectively; Cd in burdock stem, skin and leaf are 0. 160 0, 0. 300 0, 0. 140 0 μg/g, respectively; Cd in burdock stem, skin and leaf are 2. 020, 3. 960, 2. 410 μg/g, respectively. In the ginkgo and ginko leaf, Se contents are 17.63 and 16.91 μg/g, respectively ; for Cd are 0. 181 0 and 0.2020μg/g, respectively ; for Pb are 3. 572 and 4. 021 μg/g, respectively. In garlic, Se, Cd and Pb are 73. 900 0, 6. 900 0 and 0. 390 0, respectively. All the standard deviations of measured results are below 2.3%, recovery rate are from 99% to 101%.

Development of real-time PCR method for rapid detection and quantification of Heterosigma akashiwo

To rapidly detect the harmful algae H.akashiwo qualitatively and quantitatively, sequences of the 18S rDNA deduced from H.akashiwo were used for designing species-specific primers, and a RFQ-PCR (Real-time Fluorescent Quantitative Polymerase Chain Reaction) method was developed for quantitative detection of H.akashiwo. Primer H.akashiwo and TaqMan probe were designed, and the specificity of primer was checked with PCR. A calibration curve was constructed with cycle threshold value against visual counted cell number. And the value of the curve was tested with other H.akashiwo samples, which were assayed with both the RFQ-PCR method and visual count under microscope.

Citrate-stabilized CdSe/CdS quantum dots as fluorescence probe for protein determination

A rapid, ultrasensitive and convenient fluorescence measurement technology based on the enhancement of the fluorescence intensity resulting from the interaction of functionalized CdSe/CdS quantum dots （QDs） with bov/ne serum albumin （BSA） was proposed. The citrate-stabilized CdSe/CdS （QDs） were synthesized by using Se powder and Na2S as precursors instead of any pyrophoric organometallic precursors. The modified CdSe/CdS QDs are brighter and more stable against photobleaching in comparison with organic fluorophores. At pH 7.0, the fluorescence signal of CdSe/CdS is enhanced by increasing the concentration of BSA in the range of 0.1-10 μg/mL, and the low detection limit is 0.06 μg/mL. A linear relationship between the enhanced fluorescence peak intensity （△F） and BSA concentration （c） is established using equation △F=50.7c＋16.4 （R=0.996 36）. Results of determination for BSA in three synthetic samples are identical with the true values, and the recovery （98.9%-102.4%） and relative standard deviation （RSD, 1.8%-2.5%） are satisfactory.

One and Two Photon Excitation of Radiofrequency Trapped Ca

Radiofrequency （rf） trapped ions are versatile candidates for a large panel of applications ranging from quantum information to the creation of cold molecules. Sample size can range from a single to 10^6 ions, and the internal and external energy states of the atoms can be controlled with high precision. In the experiment, we focus on different protocols related to frequency metrology using rf trapped Ca.

Interferences in Photodetachment of a Negative Molecular Ion

The photodetachment of a negative molecular ion is studied theoretically using a two-center model. The detached electron wave function is obtained as a superposition of two coherent waves originating from each center. The photo-detached electron flux is evaluated on a screen placed at a large distance from the negative molecular ion. The electron flux on the screen displays strong interferences, the peak positions are related to the distance between the two centers in the negative molecular ion. We a/so obtained a simple analytical formula for the total photodetachment cross section. It approaches one and two times of the cross section for the one-center system in the high and lowphoton energy limits respectively.

Dynamics of Optically Driven Exciton and Quantum Decoherence

By using the normal ordering method, we study the state evolution of an optically driven excitons in a quantum well immersed in a leaky cavity, which was introduced by Yu-Xi Liu et al. [Phys. Rev. A 63 (2001) 033816]. The influence of the external laser field on the quantum decoherence of a mesoscopically superposed state of the excitons is investigated. Our result shows that, the classical field can compensate the energy dissipation of the excitons. Although the decoherence rate of the excitonic Schr?dinger cat state does not depend on the external field, the phase of the decoherence factor can be well controlled by adjusting the amplitude of the external field as well as the detuning between the field and the transition frequency of the atom.

Structural Description of Polyaromatic Nucleus in Residue

The proton nuclear magnetic resonance spectroscopy （1H-NMR）, the synchronous fluorescence spectrometry （SFS） and the ruthenium ions catalyzed oxidation （RICO） method were used to determine the chemical structure of polyaromatic nucleus in Oman residue fractions. The results of 1H-NMR analyses showed that the average numbers of aromatic rings in the aromatics, resins and asphaltenes units were 3.2, 5.6 and 8.2, respectively. SFS was used to investigate the distribution of aromatic rings in residue fractions, the main distribution range of aromatic rings in aromatics, resins and asphaltenes were 3 4 rings, 3--5 rings and more than 5 rings, respectively. The aromatic network in residue fractions was oxidized to produce numerous carboxylic acids. The types and content of benzenepolycarboxylic acids, such as phthalic acid, benzenetricarboxylic acids, benzenetetracarboxylic acids, benzenepentacarboxylic acid and benzenehexacarboxylic acid disclosed the condensed types of aromatic nuclei in the core. The biphenyl fraction （BIPH）, the cata-condensed fraction （CATA）, the peri-condensed fraction （PERI） and the condensed index （BCI） were calculated based on the benzenepolycarboxylic acids formed. The results implied that there was less biphenyl type structures in all residue fractions. The aromatics fraction was almost composed of the cata-condensed type system, and the asphaltenes fraction was wholly composed of the peri-condensed type system, while in the resins fraction co-existed the two types, herein the peri-con- densed type was predominant over the cata-condensed type. Based on the analytical results obtained in the study, the components --aromatics, resins and asphaltenes -- were given the likely structural models.

Evaluation of photon beam dose calculation accuracy of treatment planning systems using in vivo dosimetry

Objective The treatment planning system currently represents one of the basics of radiation therapy,because it is the only method to estimate patient dose delivery fast forward and accurately represent estimated tumor location of the tumor with the possibility of estimating densities in the tissue surrounding the tumor to overcome dose calculation defects but radial estimated the patient.Despite the flaws associated with the systems and calculates the dose of your programs in all programs currently existing in the world.Than necessary,to the existence of a review of the accuracy of accounts and how to confirm the radiation dose to the patient programs.Methods A total of 35 cancer patients were considered for this study,with 245 field measurements made with low-and high-energy diode detectors for brain and prostate cases.The treatments for all patients were planned using Eclipse Treatment Planning System version 13.6.Results Of the 105 field measurements made for the prostate cancer patients,16 included discrepancies outside the ±5% action level.Of the 145 measurements taken of the brain cases,there were four outside the ±5% action level.The results indicated a higher degree of accuracy.The study revealed that,for the prostate measurements,the higher discrepancy in the doses for the particular fields(exceeding the action level) may have been due to the isocenter being very close to the jaws and multi-leaf collimator of the linear accelerator machine.As a result,scatter from the jaws and the multi-leaf collimator could have contributed to the high dose delivered to the diode;hence,a probable higher discrepancy of the dose in more brain cases due highest quality of VMAT technique and fixation system.Conclusion A greater percentage of the observed discrepancies were well within the set tolerance level.However,it is recommended that the positioning of the diode on the patient's skin and the angular sensitivity of the diodes be reconsidered.It is also recommended that a more accurate calculation of expected diode values be performed,especially for fields that pass through the table.These efforts would achieve action levels of ±5%.

Inhibiting effect of[HOEmim][BF_4]and[Amim]Cl ionic liquids on the cross-linking reaction of bituminous coal

In order to reduce the hazard of coal spontaneous combustion,the cross-linking reaction between O-containing functional groups of coal should be inhibited.So the inhibitory effect of an ionic liquid(IL) on the cross-linking reaction was studied.The O-containing functional groups change the weight loss and H_2O,CO_2,CO yields of bituminous coal before and after[H0Emim][BF_4]and[Amim]Cl pre-treatment and were detected by Fourier Transform Infrared spectroscopy(FT1R) and Thermo Gravimetric(TC) analysis.The results show that | AmimjCI has a weaker ability to inhibit the cross-linking reaction of bituminous coal compared to[HOEmim][BF_4].Besides,based on Quantum Chemistry calculation,it was found that the different inhibiting effects of |H0Emim][BF_4]and[Amim]Cl are greatly related to their anions and the H linked with C2 atom on the imidazole ring.The H-donor ability of coal will be enhanced by[HOEmim][BF_4]leading to a weaker cross-linking reaction of coal.

The Use of Multiwalled Carbon Nanotubes Mini Column for Preconcentration of Trace Metal Ions in Tap Water of Khartoum City and Their Determination by Flame Atomic Absorption Spectrometry （FAAS）

The adsorption behavior of multiwalled carbon nanotubes （MWNTs） toward heavy elements has been investigated systemically, and a new method has been developed for the determination of trace elements in water samples based on preconcentration with mini-column packed with MWNTs prior to its determination by flame atomic absorption spectrometry （FAAS） The recommended parameters of proposed method influencing the preconcentration of the analytes, such as pH of the sample, sample flow rate and volume, elute solution and interfering ions, have been used. Under the optimized conditions, the calibration graphs were linear with the correlation coefficient range 0.9981-0.9995. According to the results, the metals were found 0.019-0.051, 0.011-0.031, 0.00-0.081, 0.00-0.0002, 0.007-0.0925, 0.00-0.0104 μg/L in water samples for Pb, Mn, Zn, Cd, Fe, Cu respectively. The percentage relative standard deviation （%RSD） for five replicate samples were 〈 5% in all cases. The method has been successfully applied to the determination of trace elements in some environmental samples with satisfactory results.

The difference between multi-drug resistant cell line A549/Gem and its parental cell A549

Objective:To discuss the difference between multi-drug resistant cell line A549/Gem and its parental cell A549 on the basis of establishment of human gemcitabine-resistant cell line A549/Gem so as to elaborate the possible mechanisms of gemcitabine resistance.Methods:Human gemcitabine-resistant non-small cell lung cancer cell line A549/Gem was estab-lished by the method of repeated clinical serous peak concentration plus gradually increasing concentration of gemcitabine from its parental cell human lung adenocarcinoma cell line A549 which was sensitive to gemcitabine.During the course of inducement,we had monitored their morphology,checked their resistance indexes and resistant pedigree by MTT method,gathered their growth curves and calculated their doubling time,examined their DNA contents and cell cycles by FCM;at the same time,we had measured their expressions of P53,EGFR,Cerb-B-2,PTEN,PCNA,c-myc,VEGF,MDR-1,Bcl-2,nm23,MMP-9,TIMP-1,and CD44v6 proteins via immunocytochemistry staining,RRM1 and ERCC1 mRNA by real-time fluorescent quantitative-PCR.Results:The resistance index of A549/Gem' cells(the deputy of cells in the process of inducement) to gemcitabine was 163.228,and the cell line also exhibited cross-resistance to vinorelbine,taxotere,fluorouraci,etoposide and cisplatin,but kept sensitivity to paclitaxol and oxaliplatin.The doubling time of A549/Gem' was shorter and figures in G0-G1 phases were increased than A549 cells.Compared with A549 cells,A549/Gem' cells achieved EGFR and c-myc proteins expressions,nm23 protein expression enhanced,P53,Cerb-B-2 and Bcl-2 proteins expressions reduced,PTEN,PCNA and MDR-1 proteins expressions vanished,but those of MMP-9,VEGF,CD44v6 and TIMP-1 proteins changed trivially.Meanwhile,expressions of RRM1 and ERCC1 mRNA were augmented markedly.The resistance index of A549/Gem cells to gemcitabine was 129.783,and the cell line also held cross-resistance to vinorelbine,taxotere,etoposide,cisplatin and sensitivity to paclitaxol.But the resistance to fluorouracil and sensitivity to oxaliplatin vanished.And the expression of RRM1 and ERCC1 mRNA decreased visibly.The doubling time of A549/Gem cells was longer and figures in G0-G1 phases were decreased than A549/Gem' cells.In A549/Gem cells,expressions of P53,EGFR,PCNA and MDR-1 proteins was same to those of A549/Gem' cells.A549/Gem cells achieved TIMP-1 and PTEN proteins expressions,Cerb-B-2,MMP-9,c-myc and Bcl-2 proteins expressions enhanced,nm23 protein expressions vanished,but the expressions of VEGF and CD44v6 proteins changed trivially.Furthermore,Compared with its parental cell A549,A549/Gem cell was mixed with giant cells of different sizes and was larger and more irregular.Conclusion:The human gemcitabine-resistant non-small cell lung cancer cell line A549/Gem had achieved multi-drug resistance and great changes of biological characters compared with its parental cells A549.And these changes possibly participated in the formation of multidrug resistance.

Determination of Ultra Trace Level of Uranium in Electronic Materials by Fluorescence Spectrometry

Using ultra high purity NaF-NaKCO3 in the Fluorescence spectrometry, determination of sub ppb levels of Uranium in the electronic materials has been achieved. The method could be applied to determination of Uranium in any electronic materials.

STUDY ON THE DETERMINATION OF TRACE BISMUTH(III) BY THIN-LAYER RESIN PHASE SPECTROPHOTOMETRY

In this paper, a new thin-layer ion-exchange resin phase analytical method is introduced. It is based on that, the bismuthous cation can associate with iodic anions, so as to formed an anion complex [BiI4-] in a strong acidic environments. This anion complex can also exchanges with a weaker anions on the surface active site of anion exchange resin, so that a [R+] [BiI4-] solid phase binary associational system is produced. Owing to the solid system is a great many dispersive particulates, it can be pressed to a thin-layer by press tools of the so called 搕hin-layer resin phase?or 搑esin phase? and using this solid association system spectrophotometry for the determination of trace metals. So it can increase the analytical sensitivity. This association system exhibits maximum absorbance at 460nm, and obeys Beer抯 law over the concentration range 0.01ug/ml^1.20ug/ml of bismuthous(III). It has a molar absorptivity of 7.1×105 [L/mol穋m]. It indicated the resin phase spectrophotometry is a sensitive analytical method for trace bismuthous. It is 18 times higher than routine aqueous spectrophotometry. The relative standard deviations is 1.82% (n=6) for the measurements of 0.5ug/ml Bi(III). The detection limit of Bismuthous(III) is 1.4×10-8mol/L. The method has applied to the analysis Bi(III) in environmental water samples.