Photodissociation Dynamics of 2-1odotoluene Investigated by Femtosecond Time-Resolved Mass Spectrometry

The photodissociation dynamics of 2-iodotoluene following excitation at 266 nm have been investigated employing femtosecond time-resolved mass spectrometry. The photofragments are detected by multiphoton ionization using an intense laser field centered at 800 nm. A dissociation time of 3804-50 fs was measured from the rising time of the co-fragments of toluene radical （C7H7） and iodine atom （I）, which is attributed to the averaged time needed for the C-I bond breaking for the simultaneously excited nσ and ππ＊ states by 266 nm pump light. In addition, a probe light centered at 298.23 nm corresponding to resonance wavelength of ground-state iodine atom is used to selectively ionize ground-state iodine atoms generated from the dissociation of initially populated hσ＊ and ππ＊ states. And a rise time of 4004-50 fs is extracted from the fitting of time-dependent I＋ transient, which is in agreement with the dissociation time obtained by multiphoton ionization with 800 nm, suggesting that the main dissociative products are ground-state iodine atoms.

Development of Technology and Equipment for Non-destructive Testing of Defects in Sewing Mandrels of a Three-roll Screw Mill 30-80

The conditions of heating and cooling of piercing mandrels made of 4X5MFS steel of a three-roll screw mill 30-80 in the production of a closed cavity of steel vessels of small volume are determined.It is established that multiple cycles of heating up to 600℃ and cooling with water up to 80℃ for about 7 seconds/1 cycle lead to the formation of ridges,shells and cracks on the surface and in the volume of the tool.The loss of structural strength of the material leads to the breakdown of the mandrel during the stitching process.The technique and equipment of magnetic powder control have been developed to establish the dynamics of the growth of internal and external defects of mandrels.An equation is obtained that allows determining the increase in the number of defects in the sewing tool of a screw rolling mill.The technology of non-destructive testing made it possible to develop a rational plan for replacing the sewing mandrels,which allows for predicting the appearance of defects leading to a complex breakdown of the deforming tool at the NPO Pribor machine-building enterprise.

Primary 4-3-oxosteroid 5β-reductase deficiency:Two cases in China

Aldo-keto reductase 1D1(AKR1D1) deficiency,a rare but life-threatening form of bile acid deficiency,has not been previously described in China.Here,we describe the first two primary 4-3-oxosteroid 5β-reductase deficiency patients in China's Mainland diagnosed by fast atom bombardment-mass spectroscopy of urinary bile acids and confirmed by genetic analysis.A high proportion of atypical 3-oxo-4-bile acids in the urine indicated a deficiency in 4-3-oxosteroid 5β-reductase.All of the coding exons and adjacent intronic sequence of the AKR1D1 gene were sequenced using peripheral lymphocyte genomic DNA of two patients and one of the patient's parents.One patient exhibited compound heterozygous mutations:c.396C>A and c.722A>T,while the other was heterozygous for the mutation c.797G>A.Based on these mutations,a diagnosis of primary 4-3-oxosteroid 5β-reductase deficiency could be confirmed.With ursodeoxycholic acid treatment and fat-soluble vitamin supplements,liver function tests normalized rapidly,and the degree of hepatomegaly was markedly reduced in both patients.

Spatial resolved temperature measurement based on absorption spectroscopy using a single tunable diode laser

A novel method based on wavelength-multiplexed line-of-sight absorption and profile fitting for nonuniform flow field measurement is reported. A wavelength scanning combing laser temperature and current modulation WMS scheme is used to implement the wavelength-multi- plexed-profile fitting method. Second harmonic （2f） signal of eight H20 transitions features near 7,170 cm^-1 are measured in one period using a single tunable diode laser. Spatial resolved temperature distribution upon a CH4/air premixed flat flame burner is obtained. The result validates the feasibility of strategy for non-uniform flow field diagnostics by means of WMS-2f TDLAS.

Structural, Optical and Electrical Properties of Li-doped ZnO Thin Films Influenced by Annealing Temperature

Li-doped ZnO thin films had been grown by radio frequency magnetron sputtering and then annealed under various annealing temperatures. The characteristics of ZnO films were examined by XRD, FESEM, Hall measurement and optical transmission spectra. Results showed that p type conduction was observed in Li doped ZnO films annealed at 500-600 ℃ and thep type ZnO films possessed a good crystalline with c-axis orientation, dense surface, and average transmission of about 85% in visible spectral region.

Advanced glycation end products induce neural tube defects through elevating oxidative stress in mice

Our previous study showed an association between advanced glycation end products （AGEs） and neural tube defects （NTDs）. To understand the molecular mechanisms underlying the effect of AGEs on neural tube development, C57BL/6 female mice were fed for 4 weeks with com- mercial food containing 3% advanced glycation end product bovine serum albumin （AGE-BSA） or 3% bovine serum albumin （BSA） as a control. After mating mice, oxidative stress markers including malondialdehyde and H202 were measured at embryonic day 7.5 （E7.5） of ges- tation, and the level of intracellular reactive oxygen species （ROS） in embryonic cells was determined at E8.5. In addition to evaluating NTDs, an enzyme-linked immunosorbent assay was used to determine the effect of embryonic protein administration on the N-（carboxymethyl） lysine reactivity of acid and carboxyethyl lysine antibodies at E10.5. The results showed a remarkable increase in the incidence of NTDs at El0.5 in embryos of mice fed with AGE-BSA （no hyperglycemia） compared with control mice. Moreover, embryonic protein administration resulted in a noticeable increase in the reactivity of N-（carboxymethyl） lysine and N（ε）-（carboxyethyl） lysine antibodies. Malondialdehyde and H2O2 levels in embryonic cells were increased at E7.5, followed by increased intracellular ROS levels at E8.5. Vitamin E supplementation could partially recover these phenomena. Collectively, these results suggest that AGE-BSA could induce NTDs in the absence of hyperglycemia by an underlying mechanism that is at least partially associated with its capacity to increase embryonic oxidative stress levels.

Feature Extraction of Fabric Defects Based on Complex Contourlet Transform and Principal Component Analysis

To extract features of fabric defects effectively and reduce dimension of feature space,a feature extraction method of fabric defects based on complex contourlet transform （CCT） and principal component analysis （PCA） is proposed.Firstly,training samples of fabric defect images are decomposed by CCT.Secondly,PCA is applied in the obtained low-frequency component and part of highfrequency components to get a lower dimensional feature space.Finally,components of testing samples obtained by CCT are projected onto the feature space where different types of fabric defects are distinguished by the minimum Euclidean distance method.A large number of experimental results show that,compared with PCA,the method combining wavdet low-frequency component with PCA （WLPCA）,the method combining contourlet transform with PCA （CPCA）,and the method combining wavelet low-frequency and highfrequency components with PCA （WPCA）,the proposed method can extract features of common fabric defect types effectively.The recognition rate is greatly improved while the dimension is reduced.

Characterization of Cd1-xZnxTe（0≤x≤1） Nanolayers Grown by Atomic Layer Deposition on GaSb and GaAs（001） Oriented Substrates

ZnTe, CdTe, and the ternary alloy CdZnTe are important semiconductor materials used widely for the detection of an important range of electromagnetic radiation as gamma ray and X-ray. Although, recently these materials have acquired renewed importance due to the new explored nanolayer properties of modern devices. In addition, as shown in this work they can be grown using uncomplicated synthesis techniques based on the deposition in vapour phase of the elemental precursors. This work presents the results obtained from the deposition of nanolayers of these materials using the precursor vapour on GaAs and GaSb (001) substrates. This growth technique, extensively known as atomic layer deposition (ALD), allows the layers growth with nanometric dimension. The main results presented in this work are the used growth parameters and the results of the structural characterization of the layers by the means of Raman spectroscopy measurements. Raman scattering shows the peak corresponding to longitudinal optical (LO)-ZnTe, which is weak and slightly redshift in comparison with that reported for the ZnTe bulk at 210 cm^-1. For the case of the CdTe nanolayer, Raman spectra presented the LO-CdTe peak, which is indicative of the successful growth of the layer. Its weak and slightly redshift in comparison with that reported for the CdTe bulk can be related with the nanometric characteristic of this layer. The performed high-resolution X-ray diffraction (HR-XRD) measurement allows to study some important characteristics such as the crystallinity of the grown layer. In addition, the HR-XRD measurement suggests that the crystalline quality has dependence on the growth temperature.

<i>H</i>(.,.)<i>- φ - η -</i>Accretive Operators and Generalized Variational-Like Inclusions

In this paper, we generalize H(.,.) accretive operator introduced by Zou and Huang [1] and we call it H(.,.)- φ - η - accretive operator. We define the resolvent operator associated with H(.,.)- φ - η - accretive operator and prove its Lipschitz continuity. By using these concepts an iterative algorithm is suggested to solve a generalized variational-like inclusion problem. Some examples are given to justify the definition of H(.,.)- φ - η - accretive operator.

Dramatic reduction in dark current ofβ-Ga_(2)O_(3) ultraviolet photodectors viaβ-(Al_(0.25)Ga_(0.75))_(2)O_(3) surface passivation

Solar-blind ultraviolet photodetectors with metal-semiconductor-metal structure were fabricated based onβ-(Al_(0.25)Ga_(0.75))_(2)O_(3)/β-Ga_(2)O_(3) film grown by metal-organic chemical vapor deposition.It was known that various surface states increase dark current and a large number of defects can hinder the transport of carriers,resulting in low switching ratio and low responsivity of the device.In this work,β-(Al_(0.25)Ga_(0.75))_(2)O_(3) films are used as surface passivation materials.Owning to its wide band gap,we obtain excellent light transmission and high lattice matching withβ-Ga_(2)O_(3).We explore the change and mechanism of the detection performance of theβ-Ga_(2)O_(3) detector afterβ-(Al_(0.25)Ga_(0.75))_(2)O_(3) surface passivation.It is found that under the illumination with 254 nm light at bias 5 V,theβ-(Al_(0.25)Ga_(0.75))_(2)O_(3)/β-Ga_(2)O_(3)photodetectors show dark current of just 18 pA and high current on/off ratio of 2.16×10^(5).The dark current is sharply reduced about 50 times after passivation of theβ-Ga_(2)O_(3) surface,and current on/off ratio increases by approximately 2 times.It is obvious thatβ-Ga_(2)O_(3) detectors withβ-(Al_(0.25)Ga_(0.75))_(2)O_(3) surface passivation can offer superior detector performance.

Laser-induced defects in optical multilayer coatings by the spatial resolved method

The spatial resolved method, which measures the laser-induced damage fluence by identifying the location of the damage point in the Gaussian beam three-dimensional direction, is demonstrated. The advantages and practicality of this method have been explained. Taking a triple frequency beam splitter as an example, the defect damage fluence can be accurately calculated by the spatial resolved method. The different defect damage performance of the triple frequency splitter is distinguished under irradiations of only the 355 and 532 nm lasers. The spatial resolved method provides a way to obtain precise information of optical film defect information.

Detecting the micro-defects in the GaAs materials by time resolved emissions

The GaAs material is a major semiconductor material,and it has high electron transfer rate and direct transition energy band structure.The devices and integrated circuits fabricated on the GaAs substrates have a lot of advantages such as high speed information processing.Small perturbations in the manufacturing of GaAs materials can lead to defects.The defects in the GaAs materials can degrade the performance of materials.A new method is presented in this paper for detecting the micro-defects in GaAs materials by using time resolved emissions.In this method,the micro-defects in GaAs materials are detected by making use of the photon emission features of microdefects.The strength of the emitted photons from the micro-defects is increased by applying the electric current or the periodic pulse signals to GaAs materials.The singlephoton detector is used to detect the photon emissions of the micro-defects.The time resolved photon emissions and single-photon detection are used to record and compare the amounts of the emitted photons that come from the given regions of the normal GaAs materials and the defective GaAs materials.A lot of experimental results show that the micro-defects in the GaAs materials can be detected by using the method proposed in this paper.

Resolution of racemic R.S-α-arylethylamine by a new resolving agent (R)thiazolidine-2-thione-4-carboxylic acid

Racemic R.S-α-arylethylamine was resolved by R (-) thiazolidine-2-thione-4-carboxylic acid, a new resolving agent abbreviated as [R (-) TTCA], by which R (-) TTCA.S(-) arylethylamine salts2a-2e, [α] D 20 =-47.24° — 64.40° and optically active R(+)-a-arylethylamines3a – 3e, 74. 54%-94. 45% e, e., were obtained. Optically active S (-) -α-arylethylamines4a-4e, 72.84%-90.36% e.e., were obtained by the decomposition of2a-2e in basic solutions. The influence of substitutive group of the benzene ring on the basicity of the amino group was studied by semiempirical PM3 method. The structures of the R (-) TTCA.S (-) -α-phenylethylamine salt (2a(R-S) configuration) and R (-) TTCA-R(+)-a-phenylethylamine salt (2a(R-R) configuration) have been established by means of X-ray diffraction. They crystallize in a monoclinic system. Space group isP21. The cell constants of2a(R-S) configuration were obtained as follows: α = 1.387 8(2), b = 0.664 05(101,c = 1.580 O(2) nm; β = 90.844(10)° Z = 4; those obtained for2a(R-R) configuration were α = 1.080 6(2),b = 0.584 80(12),c = 1.2188(2) nm, β= 110.38(3)dg, V = 0.7220nm3,Z = 2. There are intermolecular hydrogen bonds in the crystals of the two kinds of configurations of the amine salt. The hydrogen bond number in the unit cell of R (-) TTCA.S (-)-α-phenylethylamine salt is twice as much as that of R (-) TTCA.R(+)-a-phenylethylamine salt.

高压交联聚乙烯电缆附件局部放电特性分析

构建了110 kV电缆中间接头内部4种典型绝缘缺陷物理模型,通过建立电缆附件局部放电(partial discharge,PD)试验研究平台,获取不同绝缘缺陷模型下的放电数据,并构造了三维放电图谱,分析了单次脉冲的时频域特征及放电统计特性。试验结果显示,在起始放电阶段各缺陷下的放电脉冲波形比较稳定,时频特性有明显差异,其随机性主要表现为脉冲峰值的波动,而放电区间、放电重复率等统计特征也有很大不同,这些特征可用作放电类型识别的依据。

高压交联电缆接头局部放电的电容耦合法检测及分析

为研究110kV交联电缆接内部绝缘缺陷的局部放电(partial discharge,PD)特性,设计并构造了5种典型绝缘缺陷,通过建立电缆接头局放试验研究平台,采用电容耦合法获取不同绝缘缺陷下的放电信号,构造出三维PRPD(phase resolved partial discharge)谱图表征缺陷放电状态,并采用单次放电脉冲时域波形的3、4阶特征参量萃取放电特性进行分析。研究试验结果显示,电容耦合法检测法可有效检测出电缆接头内部缺陷引起的局放,且不影响电缆接头及本体的绝缘性能;所构建的5种典型缺陷在工频电压激励下,放电脉冲序列在放电区间、放电重复率等统计特征有很大的不同,用时域波形的3、4阶特征参量所描述的放电特性也存在很大差异。这些特征可用作放电类型识别的依据。

日立7080生化分析仪的缺陷及其解决办法

报告了日立7080生化分析仪的结构缺陷及由此缺陷引发的种种故障,并提出了对此缺陷的解决办法。

益气活血法联合西医常规治疗用于气虚血瘀型急性缺血性脑卒中患者的临床疗效及安全性研究

目的:探讨益气活血法联合西医常规治疗用于气虚血瘀型急性缺血性脑卒中患者的临床疗效及安全性。方法:选取2020年12月至2021年2月石家庄市中医院脑病科收治的急性缺血性脑卒中患者100例,借助SAS统计分析系统随机分为观察组、对照组,每组50例。对照组患者根据医学指南诊疗规范给予西医常规治疗,观察组患者在对照组的基础上给予益气活血化瘀开窍方。观察两组患者的临床疗效、相关指标及不良反应发生情况。结果:观察组患者的总有效率为88.00%(44/50),明显高于对照组的72.00%(36/50),差异有统计学意义(P<0.05)。两组患者美国国立卫生院卒中神经功能缺损评分量表评分,血清总胆固醇、甘油三酯、低密度脂蛋白胆固醇和纤维蛋白原水平,血浆黏度、全血低切黏度、全血中切黏度和全血高切黏度,C反应蛋白和同型半胱氨酸水平在治疗后均较治疗前明显降低;且观察组患者上述指标水平在治疗后较对照组明显更低,差异均有统计学意义(P<0.05)。两组患者高密度脂蛋白胆固醇水平在治疗后较治疗前明显升高,血浆凝血酶时间、血浆凝血酶原时间和活化部分凝血活酶时间在治疗后较治疗前明显延长,且观察组患者上述指标水平在治疗后明显优于对照组,差异均有统计学意义(P<0.05)。两组患者均无不良反应发生。结论:益气活血法联合西医常规治疗对气虚血瘀型急性缺血性脑卒中患者的临床疗效显著,可促进患者神经功能的恢复,调节脂质代谢,改善凝血功能及血液流变学,降低C反应蛋白、同型半胱氨酸水平,安全高效。

Down’s综合征及胎儿某些严重缺陷的产前筛查

[目的 ] 进行DS及胎儿某些严重缺陷产前筛查 ,提高DS检出率 ,减少产前诊断的盲目性。 [方法 ] 用时间分辨荧光免疫分析法及AFP/freeβ -hCG药盒测定孕中期妇女血清AFP、游离 β -hCG ,并结合孕妇年龄、孕周、体重等 ,用MulticalcDown’s软件分析 ,得到该名孕妇怀DS风险率。对于筛查阳性孕妇作遗传咨询或确诊实验。 [结果 ] 85 95名孕妇中检得DS 5例 ,阳性病例检出率为 83.3% ,假阳性率 6 .0 %。其他胎儿异常 ,包括 18-三体 2例 ,18-环状 ,45 ,XO ,多倍体 ,无脑儿及胎儿腹壁缺损各 1例及 2 3例胚胎坏死。 [结论 ] 孕妇血清标记物检测作为筛查DS及胎儿某些严重缺陷具有实效 ,对提高我国人口素质有积极意义。

连续挤压铜银合金异型排充不满缺陷的研究

连续挤压技术作为一种先进成形技术已成功地应用于换向器用无氧铜银合金异型排的生产,并且取得了良好的经济效益和社会效益。但是用连续挤压技术生产的无氧铜银合金异型排还存在一些缺陷,充不满缺陷是其最主要的缺陷之一。本文对充不满缺陷进行了研究,找出其产生原因,并提出了具体解决措施。

益气活血化痰通络汤对急性脑梗死的治疗效果分析

目的分析研究益气活血化痰通络汤对急性脑梗死的治疗效果。方法选取76例急性心肌梗死患者,比较采用西医基础治疗与西医基础治疗+益气活血化瘀通络汤治疗效果。结果观察组患者治疗后神经功能缺损评分、有效率与对照组相比有差异,P<0.05。结论采用中西医联合治疗益气活血化瘀通络汤治疗,疗效显著。