Ultrafast Nonlinear Optical and Optical Limiting Properties of Phthalocyanine Thin Films Studied Using Z-Scan

We have investigated the nonlinear optical properties, optical limiting thresholds, and figures of merits for five different phthalocyanine thin films, achieved through doping in PMMA polymer, using the Z-scan technique at 800 nm with 2 ps laser pulse excitation. From the open-aperture Z-scan data we derived that these molecules exhibit strong two photon absorption (2PA) with the nonlinear coefficients in the range of 15 - 200 cm/GW. We have also estimated the sign and magnitude of real part of third order nonlinearity through the closed aperture data. Preliminary femtosecond pump-probe data suggests that the lifetimes of excited states are in the sub-100 ps regime for all the molecules in film form. Our studies provide concrete evidence that these phthalocyanines are prospective candidates for multi-photon imaging and optical limiting applications.

Z─scan方法测量介质非线性折射的研究

本文用衍射理论研究了薄介质情况下的Ｚ—ｓｃａｎ法，分析了通常所用Ｚ—ｓｃａｎ法的适用范围，研究结果对在实际测量中如何使用Ｚ—ｓｃａｎ法具有一定的指导意义，另外对介质中五阶非线性效应较强情况下及介质存在饱和非线性折射率情况下的Ｚ—ｓｃａｎ法进行了研究，给出了非线性折射率及其它非线性光学系数的测量方法。

A Study on the Cause Analysis for the Wall Thinning and Leakage in Small Bore Piping Downstream of Orifice

A number of components installed in the secondary system of nuclear power plants are exposed to aging mechanisms such as FAC (Flow-Accelerated Corrosion), Cavitation, Flashing, and LDIE (Liquid Droplet Impingement Erosion). Those aging mechanisms can lead to thinning of the components. In April 2013, one inch small bore piping branched from the main steam line experienced leakage resulting from wall thinning in a 1000 MWe Korean PWR nuclear power plant. During the normal operation, extracted steam from the main steam line goes to condenser through the small bore piping. The leak occurred in the downstream of an orifice. A control valve with vertical flow path was placed in front of the orifice. This paper deals with UT thickness data, SEM images, and numerical simulation results in order to analyze the extent of damage and the cause of leakage in the small bore piping. As a result, it is concluded that the main cause of the small bore pipe wall thinning is liquid droplet impingement erosion. Moreover, it is observed that the leak occurred at the reattachment point of the vortex flow in the downstream side of the orifice.

Monte Carlo Simulation of the Coaxial Electrons Backscattering from Thin Films

By using the Monte Carlo method, we simulated the trajectories of coaxial backscattering electrons corresponding to a new type of scanning electron microscope. From the calculated results, we obtain a universal expression, which describes with good accuracy the backscattering coefficient versus film thickness under all conditions used. By measuring the coaxial backscattering coefficient and using this universal formula, the thickness of thin films can be determined if the composition is known.

Combination of Instrumented Nanoindentation and Scanning Probe Microscopy for Adequate Mechanical Surface Testing

The elastic indentation modulus and hardness of standard bulk materials and advanced thin films were determined by using the nanoindentation technique followed by the Oliver- Pharr post-treatment. After measurements with different loading/unloading schemes on chemically polished bulk titanium a substantial decrease of both modulus and hardness vs an increasing loading time was found. Then, hard nanostructured TiBN and TiCrBN thin films deposited by magnetron sputtering （using multiphase targets） on substrates of high roughness （sintered hard metal） and low roughness （silicon） were studied. Experimental modulus and hardness characterized by using two different nanoindenter tools were within the limits of standard deviation. However, a strong effect of roughness on the spread of the experimental values was observed and it was found that hardness and elastic indentation modulus obeyed a Gaussian distribution. The experimental data were discussed together with scanning probe microscopy （SPM） images of typical imprints taken after the nanoindentation tests and the local topographyls strong correlation with the results of nanoindentation was described.

Physical Properties of Nano-Composite Silica-Phosphate Thin Film Prepared by Sol Gel Technique

A series of silica-phosphate nano-composites prepared as a host thin films Physical Properties of Nano-Composite Silica-Phosphate Thin Film Prepared by Sol Gel Technique and doped with different concentrations of Er3+ ions have been synthesized using tetraesoxysilane TEOS, triethylphosphate TEP and erbium nitrate as precursor sources of silica, phosphorus and erbium oxides. The structural properties of pure silica-phosphate thin films and doped with different concentrations of Er3+ ions were studied, using x-ray diffraction (XRD) and Fourier Transform Infrared (FTIR). The morphology of silica-phosphate was characterized by Scanning electron microscope (SEM).

Electron Microscopy Studies of Magnetron Sputtered YBa＿2Cu＿3O＿（7－δ） Thin Films

Magnetron sputtered YBa_2Cu_3O_(7-δ) superconducting thin films before and after ion implantation wereinvestigated by using high resolution electron microscopy and scanning electron microscopy. Very goodepitaxial but defect-containing, effectively single crystalline films are demonstrated. The defect density concerning (001 ) plane decreases with increasing grown thickness of the film.

Scanning Electron Microscopy Studies of YBa_2Cu_3O_(7-δ) Superconductors

Micrcostructures of bulk and thin film YBa_2Cu_3O_(7-δ) superconductors were studied by using scanning elec-tron microscopy (SEM). It was confirmed that viscous technique processed bulk YBa_2Cu_3O_(7-δ) has a homoge-neous microstructure across the pellet diameter. Concerning the thin film, it was found that 2 ￣H￣+ ion implanta-tion with a dose of 1× 10￣(12)cm￣(-2) at 50 keV does not cause microstructural change of the film at a micrometrelevel. Combined with previous studies by using high resolution transmission electron microscopy, it appearsthat the structural modification is at an atomic scale.

512层螺旋CT薄层扫描结合计算机人工神经网络对小肠病变的诊断价值研究

目的:运用图像识别和图像描述技术,研究512层螺旋CT薄层扫描结合计算机人工神经网络在小肠病变诊断上的应用价值。方法:建立基于ResNet 101、Faster R-CNN、LSTM的小肠CT图像识别描述人工神经网络模型,采用ResNet 101和Faster R-CNN联合提取图像特征信息进行ROI融合建立图像编码,采用LSTM进行图像解码输出CT图像诊断报告。设计11个病变图像特征标签,选择我院2020年1月—2022年1月行512层螺旋CT薄层扫描病例材料1572套,材料覆盖正常图像及出血、炎性息肉等9种病变类型,按7∶3随机分为训练组和测试组,对模型进行训练并展开性能测试,评价模型输出的CT诊断文字报告质量、诊断准确率及病变部位提取正确率。结果:文字报告质量评分为(4.0325±0.684)分,出现错误评估项样本占比0.8%,仅语句结合约35%存在不合理现象;各病变类型诊断准确率均在97%左右,仅腺癌存在轻微的诊断为腺瘤性息肉现象,整体病变类型诊断正确率97.17%;病变部位正确识别提取率99.43%。结论:基于ResNet 101、Faster R-CNN、LSTM建立人工神经网络模型,进行小肠512层螺旋CT扫描图像的诊断识别,可准确定位图像病变部位,根据病变部位图像特征准确进行病变类型诊断,并就11个CT图像特征进行文字化描述,输出符合医师阅读理解的图像诊断报告,并发现部分医师人工阅片遗漏错误的地方,可为医师提供更为丰富、有效、准确的CT图像诊断信息,有利于医师作出正确的诊断。

Determination of Hypoxanthine in the Presence of Copper by Adsorptive Stripping Voltammetry

A stripping method for the determination of hypoxanthine in the presence of copper at the submicromolar concentration levels is described. The method is based on controlled adsorptive accumulation of hypoxanthine-copper at the thin-film mercury electrode followed by a fast linear scan voltammetric measurement of the surface species. Optimum experimental conditions were found to be the use of 1.0 × 10﹣3 mol·L﹣1 NaOH solution as electrolyte supporting, an accumulation potential of ﹣0.50 V and a linear scan rate of 200 mV·s﹣1. The response of hypoxanthine-copper is linear over the concentration ranges of 10 - 60 ppb. For an accumulation time of 30 minutes, the detection limit was found to be 250 ppt (1.8 × 10﹣9 mol·L﹣1). Adequate conditions for measuring the hypoxanthine in the presence of metal ions, xanthine, uric acid and other nitrogenated bases were also investigated. The utility of the method is demonstrated by the presence of hypoxanthine associated in ATP or ssDNA.

Semiconductor ZnO Nano-Rods Thin Film Grown on Silver Wire for Hemoglobin Biosensor Fabrication

Wurtzite hexagonal ZnO semiconductor nano-rods (NRs) thin films were grown on silicon substrates and silver wire with diameter equal 68 nm. Sol gel (SG) and aqueous chemical growth (ACG) methods by two steps of preparation (seed layers and nano-rod growth) are used for samples preparation. The structural and morphological properties are evaluated using X-ray diffraction (XRD) and scanning electron microscope (SEM). The proposed iron ion sensor has shown good linearity for a wide concentration range from 0.078 M/L to 0.26 M/L of iron ions. The results show that the electrode is highly sensitive to iron ions with a slope around 47.8 mV/decade with a regression coefficient R2 = 0.96.

基于胸部薄层CT扫描的肺磨玻璃影病变“四分型法”在临床中的应用研究

目的探讨基于胸部薄层CT扫描(TSCT)的肺磨玻璃影(GGO)病变“四分型法”在临床中的应用价值。方法回顾性分析2020年1月至2022年12月于首都医科大学宣武医院接受胸腔镜手术治疗的1541例患者的临床资料,共包含肺GGO病变2005例次。采用“四分型法”对肺GGO病变进行分型:Ⅰ型,无空泡征和(或)细支气管征的纯GGO(p-GGO);Ⅱ型,有空泡征和(或)细支气管征的p-GGO;Ⅲ型,仅在肺窗可见实性成分的异质性磨玻璃影(h-GGO);Ⅳ型,在肺窗和纵隔窗均可见实性成分的部分实性磨玻璃影(ps-GGO)。分析肺GGO病变影像学特征[最大径、病变类型、发生部位、分型、肿瘤实性成分占比(CTR)等]与术后病理检查结果的关联性。结果1541例患者自发现肺GGO至接受手术治疗的时间为0.10~156.00个月,平均11.23个月,其间肺GGO病变变化不明显1255例次(62.59%),最大径增大536例次(26.73%),密度增高45例次(2.24%),最大径增大伴密度增高169例次(8.43%)。术前肺GGO最大径为(13.21±7.90)mm;主要为单发病变[1098例次(54.76%)];多分布于右肺上叶[757例次(37.76%)]。肺GGO类型:Ⅰ型248例次(12.37%),Ⅱ型682例次(34.01%),Ⅲ型862例次(42.99%),Ⅳ型213例次(10.62%)。CTR≤25%有950例次(47.38%),25%<CTR≤50%有616例次(30.72%)、50%<CTR≤75%有314例次(15.66%),CTR>75%有125例次(6.23%)。肺GGO病变中,良性病变186例次(9.28%),恶性病变1819例次(90.72%),其中包括腺体前驱病变744例次,浸润期病变1075例次。分析结果显示,肺GGO病变术后病理检查结果与GGO最大径、病变类型、发生部位、分型、CTR及随访变化情况均存在关联性(P<0.05)。对应分析结果显示,与肺GGO病变CTR相比,肺GGO病变分型散点与术后病理恶性变[不典型腺瘤样增生(AAH)、原位腺癌(AIS)、微浸润腺癌(MIA)、浸润期腺癌(IA)]散点在二维分布图中更为接近,提示基于“四分型法”的肺GGO影像学特征与术后病理恶性变有更好的对应关系。结论基于TSCT的肺GGO病变“四分型法”有助于临床医师更好地评估以GGO为主要影像学表现的早期肺癌的风险度。

Influence of Thickness on the Photosensing Properties of Chemically Synthesized Copper Sulfide Thin Films

We report here the influence of thickness on the photosensing properties of copper sulfide (CuS) thin films. The CuS films were deposited onto glass substrate by using a simple and cost effective chemical bath deposition method. The changes in film thickness as a function of time were monitored. The films were characterized using X-ray diffraction technique (XRD), field emission scanning electron microscopy (FE-SEM), optical measurement techniques and electrical measurement. X-ray diffraction results indicate that all the CuS thin films have an orthorhombic (covellite) structure with preferential orientation along (113) direction. The intensity of the diffraction peaks increases as thickness of the film increases. Uniform deposition having nanocrystalline granular morphology distributed over the entire glass substrate was observed through FE-SEM studies. The crystalline and surface properties of the CuS thin films improved with increase in the film thickness. Transmittance (except for 210 nm thick CuS film) together with band gap values was found to decrease with increase in thickness. I-V measurements under dark and illumination condition show that the CuS thin films give a good photoresponse.

CT三维重建及薄层扫描在特发性脊柱侧弯矫正手术中的应用

目的:探讨CT三维重建及薄层扫描在特发性脊柱侧弯矫正手术中的应用。方法:本研究为回顾性研究,选取2020年6月至2023年6月在本院收治的112例行择期矫正术的特发性脊柱侧弯患者作为本研究观察对象,根据手术方式分为徒手置钉组(n=42),接受常规解剖标志法结合C型臂透视定位指导,和CT三维辅导组(n=70),接受CT三维重建配合薄层扫描指导。对比两组置钉准确率、术中透视次数、出血量、手术时间和术后住院时间;记录并比较两组患者手术前后视觉疼痛目测类比评分(visual analogue scale,VAS)、日本骨科协会(Japanese Orthopaedic Association,JOA)评分和cobb角变化;观察两组并发症。结果:CT三维辅导组共置入1192枚螺钉,徒手置钉组共置入673枚螺钉。其中CT三维辅导组置钉准确率达95.71%(1141/1192),高于徒手置钉组的91.08%(613/673)(P<0.05)。CT三维辅导组术中透视次数少于徒手置钉组,术中出血量低于徒手置钉组,手术时间短于徒手置钉组(P<0.05)。两组术后住院时间比较差异无统计学意义(P>0.05)。较术前比较,两组术后VAS均下降、JOA评分均上升,主弯cobb角均降低(P<0.05),且CT三维辅导组JOA上升程度和主弯cobb角下降程度均高于徒手置钉组(P<0.05),两组VAS改善程度比较差异无统计学意义(P>0.05)。两组患者均未发生严重并发症,仅有1例患者出现切口愈合不良。结论:CT三维重建及薄层扫描可有效指导特发性脊柱侧弯术,提高手术质量,减少术中X线暴露,缩短手术时间,降低出血量,促进术后恢复。

螺旋CT薄层扫描对胃部良恶性肿瘤性质的鉴别诊断价值及影像学特征分析

目的:探讨螺旋电子计算机断层扫描(CT)薄层扫描对胃部良恶性肿瘤性质的鉴别诊断价值,为胃癌诊治提供科学参考。方法:回顾性分析2021年1月—2022年1月河南科技大学第一附属医院收治的106例胃部肿瘤患者的临床资料,所有患者均接受X线钡餐与CT薄层扫描检查,根据患者胃镜活检或手术病理检查结果,将65例良性肿瘤患者分为良性组,将41例恶性肿瘤患者分为恶性组。比较胃部良恶性肿瘤的影像学特征,主要包括肿块直径、病灶边缘状态、恶性龛影、黏膜侵犯、肌层侵犯等特征。以胃镜活检或手术病理检查为金标准,分析X线钡餐、CT、X线钡餐+CT诊断胃部良恶性肿瘤的效能。结果:恶性组肿块直径≥5 cm、病灶边缘欠清、恶性龛影、黏膜侵犯、肌层侵犯等影像学特征检出率高于良性组,差异有统计学意义(χ^(2)=13.974、15.851、19.755、15.306、7.949,P<0.05)。X线钡餐+CT薄层扫描诊断胃部良恶性肿瘤的符合率、灵敏度、特异度、阳性预测值、阴性预测值,均高于X线钡餐、CT薄层扫描单一诊断方式,差异有统计学意义(χ^(2)=20.673、13.529、8.159、10.332、11.248,P<0.05);X线钡餐诊断胃部良恶性肿瘤的AUC为0.685,CT薄层扫描诊断胃部良恶性肿瘤的AUC为0.762,X线钡餐+CT薄层扫描诊断胃部良恶性肿瘤的AUC为0.898。结论:CT薄层扫描能够为胃部肿瘤的良恶性诊断与病情评估提供科学参考依据,操作简单且敏感性好。

阵列式柔性薄膜传感器的快速扫描实现

柔性薄膜传感器由于具有极高的柔韧性和可拓展性,可生产出不同大小的面积形状,通过阵列式排布,可以设计出大尺寸、多样化与数据实时特点的集成传感器模块。但对于大尺寸阵列式柔性薄膜的数据实时采集的方法仍存在挑战,本文基于STM32单片机以及一块4×4(可拓展)的阵列式柔性薄膜,经STM32控制,实现阵列式快速扫描,实时快速地定位出信号来源并反馈出在该薄膜单元的压力变化值。

电子计算机X射线断层成像薄层扫描及动态增强检查在周围型小肺癌诊断中的应用

目的评估电子计算机X射线断层成像(CT)薄层扫描及动态增强检查在周围型小肺癌诊断中的应用价值,以期为临床早期诊疗提供依据。方法选取焦作市疾病预防控制中心2020年3月至2022年12月期间收治的疑似周围型小肺癌患者204例作为研究对象,依据病理结果分成肺癌组(135例)与肺炎组(69例),统计对比两组CT影像特征,分析CT薄层扫描以及动态增强的诊断价值。结果肺癌组不规则形病灶、边界模糊、毛刺状边界、空泡、强化、血管侵犯占比均高于肺炎组(P<0.05);CT薄层平扫、动态增强联合诊断的敏感度、准确度均高于单一CT薄层平扫、动态增强(P<0.05);CT薄层扫描平扫、动态增强联合诊断分期结果和病理结果kappa值为0.916,高于单一检查方式(P<0.05)。结论CT薄层扫描联合动态增强检查应用于周围型小肺癌临床诊断中,具有较高诊断效能,并能为临床分期鉴别提供可参考依据,便于临床早期制定针对性治疗措施。

316L不锈钢粉末激光熔覆薄壁件成形工艺研究

在316L不锈钢薄壁墙和方形薄壁试件的激光熔覆过程中,薄壁墙出现塌陷、表面不平整的缺陷,方形薄壁试件出现翘曲、过堆和裂纹等问题,对其成形过程进行了分析,提出措施解决了成形问题。并分析了方形薄壁件的硬度分布。结果表明:熔覆头急停急走,送粉量不均匀,造成熔覆成形缺陷。通过实时观察成形形貌,采用均匀送粉,得到规则形状的薄壁墙。对于方形薄壁件,不仅采用均匀送粉量,还采用“路径随机”方法,即以四层为一个周期,其中每周期第一、二、三、四层的起点依次为正方形的四个随机点进行熔覆,成形件层间均匀、表面平整,成形质量得到有效改善。

CT三维重建及薄层扫描联合磁共振ADC定量诊断良、恶性脊柱骨折的价值分析

目的:探讨CT三维重建及薄层扫描联合磁共振ADC定量诊断良、恶性脊柱骨折的价值。方法:选取该院2021年2月-2023年2月收治的80例脊柱骨折患者为研究对象,所有患者均使用CT三维重建及薄层扫描、磁共振表观扩散系数定量诊断,并且以病理诊断作为金标准,对比3种诊断方式的诊断价值、诊断效能、影像学特征及ADC数值。结果:经病理诊断80例脊柱骨折患者中良性52例,恶性28例。CT三维重建及薄层扫描、磁共振表观扩散系数定量诊断、联合检查良性检出数分别为41例、47例、51例,其中联合检查阳性检出数更高,与病理检查结果具有一致性,差异有统计学意义(P<0.05)。联合检查阳性检出率、灵敏度、特异度、阳性预测值、阴性预测值、诊断符合率均高于磁共振表观扩散系数定量诊断、CT三维重建及薄层扫描,组间差异有统计学意义(P<0.05)。CT影像特征显示,良性脊柱骨折患者有80.77%呈现T2WI高信号,恶性脊柱骨折89.29%存在T2WI高信号,差异无统计学意义(P>0.05)。良性椎体骨折椎体形态楔形为90.30%,高于恶性脊柱骨折的64.29%,恶性脊柱骨折椎体后缘膨隆概率为42.86%,高于良性的7.69%,恶性脊柱骨折椎旁软组织结节肿块检出为32.14%,良性脊柱骨折未检出结节肿块;良性脊柱骨折ADC均值为(2.14±0.70)×10^(3)mm^(2)/s,恶性脊柱骨折ADC均值为(1.24±0.41)×10^(3)mm^(2)/s,组间差异有统计学意义(P<0.05)。结论:脊柱骨折患者疾病诊断过程中使用CT三维重建及薄层扫描联合磁共振表观扩散系数定量诊断能够实现疾病的良性恶性区分,对于疾病治疗方案制订有重要指导价值。

CT薄层增强扫描及图像后处理技术诊断肾肿瘤的价值研究

目的探究CT薄层增强扫描及图像后处理技术诊断肾肿瘤的价值。方法回顾性分析本院2022年1月至2024年1月经病理证实的60例肾肿瘤患者临床资料,术前均已接受CT薄层增强扫描及图像后处理技术处理图像,以手术病理检查结果为“金标准”,计算CT对肾肿瘤患者TNM分期准确性。结果60例肾肿瘤患者经病理检查证实均为肾癌,其中肾透明细胞癌54例、乳头状肾细胞癌3例、肾嫌色细胞癌3例;病理T分期结果:T1a期16例、T1b期9例、T2a期10例、T2b期7例、T3a期8例、T3b期4例、T3c期3例、T4期3例;CT薄层增强扫描及图像后处理技术诊断T1a期16例、T1b期7例、T2a期11例、T2b期7例、T3a期8例、T3b期5例、T3c期3例、T4期3例,与病理结果的符合率为85%(51/60),Kappa值=0.821(P<0.05)提示两者一致性好。结论CT薄层增强扫描及图像后处理技术能够较准确地诊断肾肿瘤T分期,有助于指导手术治疗。