Study on Temperature Modulation Techniques for Micro Gas Sensors

The sensitivity and selectivity of gas sensors are related with not only sensing material,but also their operating temperatures.Applying this property,temperature modulation technique has been proposed to improve the selectivity of gas sensors.With a newly developed alumina based micro gas sensor,the sensitivity to CO and CH_4 at different operating temperatures was investigated.By modulating the temperature of the sensor at pulse and sine wave modes with different frequencies and amplitudes,the dynamic responses of the sensor were measured and processed.Results show that the modulating waveshape plays an important role in the improvement of selectivity,while the influence of frequency is small at the suitable sampling frequency in the range of 25 mHz～200 mHz.

Measurement of transient thickness between the body and graze layers of ancient porcelains using microprobe EDXRF technique

The oxide contents of TiO2, MnO, SrO and Fe2O3 in the body and graze layers of the Jiao-Tan-Xia (JTX) and Lao-Hu-Dong (LHD) porcelains in Southern Song Dynasty (1127-1279 A.D.) have been determined using an In- ternational Eagle-II μ-probe EDXRF spectrometer. The results show that the contents in the body are much different from those in the graze one. Therefore, the transient thickness (TT) between the body and graze layers can be meas- ured through determination of a distance of the drift change in the chemical contents. The TT average for the JTX porcelains is 161μm, while that for the LHD porcelains is 258μm, which are consistent with a range of 0.15-0.3mm in the Ru-Yao porcelains. The different TT is related to the variances in firing temperature and raw material for manu- facturing the respective porcelains.

Study on micro-water-collecting technique in dryland field of spring maize

This paper analyses the effect of water storage and soil moisture conservation by means of micro water collecting technique in the dryland field of spring maize. The results indicate that the rainfall infiltration depth is deeper by means of micro water collecting treatment than that of the control. In micro water collecting treatment, the amount of soil water storage within 0～200 cm of soil layers increases by 50.5 mm, 13.5～58.6 mm, and 24.5 mm respectively during seedling stage, the critical stage of water requirement and the ripening and harvesting stage compared with the control. The micro water collecting technique not only has the function of regulating and adjusting the amount and distribution of field evapotranspiration, but also can raise the water use efficiency, which results in an obvious effect of increasing crop yield, especially in the dry years.

Measurement of Ca^(2+) Flow in Cochlear Cells Using Non-Invasive Micro-Test Technique

Objective To test Calcium ion(Ca2+) flow at the head and end of outer hair cells(OHCs) in resting state and in response to Nimodipine treatment.Methods Non-invasive micro-test techniques were used to study Ca2+ in isolated OHCs in adult guinea pigs.Results Four types of Ca2+ transport were identified in OHCs on basilar membrane tissue fragments:influx at the head of with efflux at the bottom(type 1):efflux at the head of OHCs with influx at the bottom(type 2);influx at the both head and bottom(type 3);and efflux at the both head and bottom(type 4).However,only type 1 and type 3 of Ca2+ ion transport were detected in the cochlea.We propose that Ca2+ ion transport exists in adult guinea pig cochlear OHCs in resting state and is variable.Ca2 + flow in OHC can be inhibited by Nimodipine in resting state.

High-Resolution Micro-Siting Technique for Large Scale Wind Farm Outside of Japan Using LES Turbulence Model

The spatial distribution of wind speed varies greatly over steep complex terrain, thus the selection of an optimal site in such terrain for wind turbine construction requires great care. We have developed a numerical model for simulating unsteady flows called RIAM-COMPACT (Research Institute for Applied Mechanics, Kyushu University, COM putational Prediction of Airflow over Complex Terrain), which is based on the LES (Large-Eddy Simulation) technique. The computational domain of RIAM-COMPACT can be varied from several meters to several kilometers, and the model is able to predict airflow over complex terrain with high accuracy. The present paper discusses the application of RIAM-COMPACT to the micro-siting of wind turbines at sites outside Japan. The results from two case studies will be presented.

Radiosurgical techniques for the treatment of brain neoplasms:A short review

Radiotherapy has long been used as an adjunct to neurosurgery for the treatment of malignant and benign intracranial tumors and other intracranial lesions.Intracranial tumors can be irradiated in three different ways:Ⅰ) fractional radiotherapy, Ⅱ) stereotactic radiotherapy and Ⅲ) stereotactic radiosurgery. The third is most often by means of a gamma knife or a specially designed linear accelerator. Additionally, radiosurgery is increasingly used in combination with systemic therapy to treat metastases.

超声Micro Pure成像技术在甲状腺乳头状癌中的应用价值

目的利用超声Micro Pure成像技术对微钙化检测的灵敏性及特异性,探讨该技术在检测甲状腺乳头状癌微钙化中的应用价值。方法收集经手术病理证实的46例甲状腺乳头状癌患者,均于术前分别行常规超声及Micro Pure成像技术,观察病灶内有无微钙化及微钙化的数目及分布特点。结果 46例甲状腺乳头状癌患者中,超声Micro Pure成像技术检出42例(170枚)微钙化灶,常规灰阶检出29例(84枚)微钙化灶;在微钙化的分布上,超声Micro Pure成像技术显示微钙化呈"簇状"分布者26例,而常规灰阶超声显示"簇状"微钙化者11例。结论超声Micro Pure成像技术可清晰显示出甲状腺乳头状癌内微钙化的数目及分布形态,对提高甲状腺乳头状癌的诊断具有一定的价值。

micro-CT评价不同封闭技术的根管充填质量

目的研究micro-CT评定不同封闭技术所得到的根管充填质量。方法对2018年1月—2019年12月龙岗区人民医院口腔科和光华口腔医院颌面外科诊室收治的重度牙周病患者所拔掉的52颗下颌磨牙予以课题实验指标分析,参考随机数字表方法予以分4组干预,各个组别纳入13颗,实验1组采取冷侧压方法封闭技术,实验2组采取热牙胶方法封闭技术,实验3组采取单尖方法封闭技术,实验4组采取纯糊剂方法封闭技术,运用micro-CT对根管充填质量实施评定,分析具有气泡的横截面占据百分数、全部根管、根尖三分之一、根中三分之一、根冠三分之一位置充填材料体积占据百分数。结果实验2组具有气泡的横截面占据百分数(36.43±6.30)%小于实验1组、实验4组对应统计指标(63.40±9.10)%、(65.51±9.50)%(P<0.05),实验3组具有气泡的横截面占据百分数(37.20±6.49)%小于实验1组、实验4组对应统计指标(P<0.05),其余各个组之间具有气泡的横截面占据百分数差别较低(P>0.05);实验2组全部根管、根中三分之一、根冠三分之一位置充填材料体积占据百分数(99.50±0.41)%、(99.70±0.32)%、(99.72±0.40)%大于实验1组、实验4组对应统计指标(97.52±1.60)%、(97.12±1.30)%、(96.70±1.36)%及(98.20±0.92)%、(97.50±1.42)%、(98.03±1.64)%(P<0.05),实验3组全部根管、根中三分之一、根冠三分之一位置充填材料体积占据百分数(99.13±0.50%、(99.41±0.40)%、(99.36±0.50)%大于实验1组、实验4组对应统计指标(P<0.05),其余各个组之间全部根管、根中三分之一、根冠三分之一位置充填材料体积占据百分数差别较低(P>0.05),实验4组根尖三分之一位置充填材料体积占据百分数(98.60±0.94)%大于实验1组、实验2组、实验3组对应统计指标(97.30±0.63)%、(97.71±0.50)%、(97.43±0.60)%(P<0.05),其余各个组之间根尖三分之一位置充填材料体积占据百分数差别较低(P>0.05)。结论运用micro-CT评定根管充填质量发现,不同封闭技术均会出现气泡,单尖方法封闭技术与热牙胶方法封闭技术无大差别,都优于冷侧压方法封闭技术、纯糊剂方法封闭技术,能临床运用,提高工作效率。

Supramolecular flow chemistry: Construction of multiscale supramolecular assemblies by micro/nanofluidic techniques

The rapid and precise fabrication of multiscale supramolecular assemblies using micro/nanofluidic techniques has emerged as a dynamic area of research in supramolecular chemistry, materials chemistry, and organic chemistry. This review summarizes the application of micro/nanofluidic techniques in constructing supramolecular assemblies, including nanoscale supramolecular assemblies such as macrocycles and cages, microscale supramolecular assemblies such as metal organic frameworks (MOFs) and covalent organic frameworks (COFs), and macroscale supramolecular assemblies such as supramolecular hydrogels. Compared to conventional synthesis methods, micro/nanofluidic techniques for the production of supramolecular assemblies have significant advantages, including enhanced safety, high reaction rates, improved selectivity/yield, and scalability. Additionally, micro/nanofluidic systems facilitate the creation of precisely controllable micro/nanoconfined environments, allowing for a unique flow behavior that improves our understanding of the supramolecular self-assembly process. Such systems may also lead to the development of novel supramolecular assemblies that differ from those generated via traditional methods.

Mini/Micro LED巨量转移技术研究与发展现状

对巨量转移(Mass Transfer, MT)方案和运动定位平台(Motion Positioning Platform, MPP)的研究现状及其未来发展进行了详细阐述。根据芯片转移方式,将MT方案分为精准拾取-释放技术、自组装技术、滚轴转印技术、激光剥离技术,结合芯片转移效率和良率,论述了国内外MT方案的发展过程。在此基础上,从平台支撑方式,详细介绍了机械构型、气浮构型、磁浮构型和混合构型的MPP结构及工作原理,考虑运动行程、运动定位精度等因素,比较了MPP性能的优劣。展望了MT方案和MPP技术的未来发展方向,指出基于微孔液气双态介质的激光剥离MT和具备周向小角度修正以及轴向微高度调节能力的“机械+磁浮”混合构型MPP是Mini/Micro LED芯片转移技术的研究重点。

基于低密度粒子图像叠加的Micro-PIV速度场测量

提出了一种基于低密度粒子图像的微流体粒子图像全场测速技术。经过背景噪声去除、阈值过滤、图像增强等图像预处理过程,获得了高质量的低密度荧光示踪粒子图像。对100对图像进行图像叠加处理,得到了满足互相关算法求解二维速度场的高密度叠加粒子图像。针对宽度为250μm,深60μm的长直微通道开展了覆盖全场不同流体层平面的二维速度测量,并利用多个流体平面的二维速度场实现了微通道内全场速度的构建。研究结果表明:由于图像叠加法去除了像径大但灰度低的背景粒子图像,采用互相关分析能够准确获得分层二维速度场,所构建的全场速度场正确反映了长直微通道内流流场特征。

Micro-LED蓝宝石衬底AlN上GaN激光剥离研究

为了比较分析纳秒激光和皮秒激光剥离微型发光二极管(micro-LED)时AlN上GaN的热传导效果,采用了改进的实时紫外光吸收和热传导的激光剥离理论模型进行计算分析的方法,取得了在不同的激光波长、激光脉冲宽度、激光能量密度下的紫外波段光辐照时和停止辐照后GaN材料热场分布等数据,并获得了适合micro-LED器件剥离的所用纳秒激光和皮秒激光的阈值条件。结果表明,激光脉宽、激光波长、激光能量密度是实现激光剥离工艺的关键因素;较适合的激光波长为209 nm~365 nm的紫外波段;皮秒激光的剥离效果优于纳米激光,且激光的脉冲宽度越短,激光的波长越短,剥离所需激光脉冲阈值能量也越低,则对LED芯片区域的热影响也越小。该研究可为开发新型激光剥离设备和相关工艺应用提供重要参考。

A rapid micro-magnetic resonance imaging scanning for three-dimensional reconstruction of peripheral nerve fascicles

The most common methods for three-dimensional reconstruction of peripheral nerve fascicles include histological and radiology techniques. Histological techniques have many drawbacks including an enormous manual workload and poor image registration. Micro-magnetic resonance imaging（Micro-MRI）, an emerging radiology technique, has been used to report results in the brain, liver and tumor tissues. However, micro-MRI usage for obtaining intraneural structures has not been reported. The aim of this study was to present a new imaging method for three-dimensional reconstruction of peripheral nerve fascicles by ~1T micro-MRI. Freshly harvested sciatic nerve samples from an amputated limb were divided into four groups. Two different scanning conditions（Mannerist Solution/GD-DTPA contrast agent, distilled water） were selected, and both T1 and T2 phases programmed for each scanning condition. Three clinical surgeons evaluated the quality of the images via a standardized scale. Moreover, to analyze deformation of the two-dimensional image, the nerve diameter and total area of the micro-MRI images were compared after hematoxylin-eosin staining. The results show that rapid micro-MRI imaging method can be used for three-dimensional reconstruction of the fascicle structure. Nerve sample immersed in contrast agent（Mannerist Solution/GD-DTPA） and scanned in the T1 phase was the best. Moreover, the nerve sample was scanned freshly and can be recycled for other procedures. MRI images show better stability and smaller deformation compared with histological images. In conclusion, micro-MRI provides a feasible and rapid method for three-dimensional reconstruction of peripheral nerve fascicles, which can clearly show the internal structure of the peripheral nerve.

Compound Ceramic Coatings Grown by Micro-plasma Oxidation on Ti-6Al-4V Alloy

Compound ceramics coatings on the Ti-6Al-4V alloy were prepared by the direct current micro-plasma oxidation （MPO） in NaAlO2 solution. The composition and morphology of the coatings were studied with the X-ray diffraction （XRD） and the scanning electron microscopy （SEM）, respectively. Inductively coupled plasma atomic emission spectrometer technique was used to analyze the solution features of Ti-6Al-4V alloy in the process of preparation. The results reveal that Al2TiO5 forms in the coatings at the initial stages of MPO reaction, and its content changes rapidly with the reaction continuing： after 20 min, the ceramics coatings are composed of α-Al2O3, 7-Al2O3 and Al2TiO5, but after 40 min, its main composition is of α-Al2O3. The content of Ti in the solution will increase when the MPO time extends, and as will Al in the anode area until, after 30 min, it reaches the maximum and keeps constant from then on. Both substrata of Ti and Al in the electrolyte join the MPO reaction at the initial stage, where the formation of Al2TiO5 happens; but as the MPO reaction prolongs, more and more Al in the electrolyte will take part in the reaction, leading to the appearance of a large amount ofAl2O3.

空化现象对水导激光微水束稳定性的影响研究

为了探寻空化现象对水导激光微水束稳定性影响,利用计算流体动力学的方法,分别在不考虑空化和考虑空化的情况下,对从典型喷嘴出射的水射流进行了数值模拟分析,研究了空化现象的产生机理及对微水束稳定性的影响。结果表明,在入口直径为0.1 mm、圆柱段长径比为1、上边缘锐利的喷嘴结构下,随着入口压力从0.2 MPa增大到16 MPa,水射流与喷嘴壁面分离后再次附着的长度逐渐增大,并且空化会导致该长度延长;在入口压力小于6 MPa的情况下,不考虑空化的水射流在稳定后会贴着喷嘴壁面流下,而添加空化模型使得水束形成翻转流。该研究对设计满足水导激光工艺的喷嘴结构有着重要的参考价值。

红色微电影中的“微”技巧

红色微电影是微电影的一个子类,其本质仍是电影,微电影是新媒体时代不断发展的必然产物,因此红色微电影也具备了媒体属性。红色微电影与传统红色电影相比最突出的特点是微小,表现为时间短、制作成本较低、场景少等。根据微电影及红色微电影的概念和特点,结合传统电影创作的方法和理论,以广受好评的红色微电影作品为主要分析案例,分析和探讨了红色微电影创作的“微”技巧:红色微电影吸引观者的技巧、红色微电影的叙事技巧等。

难治性癫痫的外科治疗进展

在癫痫患者中,药物难治性癫痫一直占据相当比例。这部分患者在经过精确的评估后或可通过外科治疗的手段达到发作缓解。本文阐述了难治性癫痫的术前神经电生理和影像评估方法,并结合最新临床研究进展,针对不同类型癫痫总结手术治疗方案,补充阐述了无创治疗方法,且在此基础上探讨了癫痫外科治疗未来发展趋势。

吉林省西岔金银矿床多阶段石英原位组成及地质意义

西岔金银矿床为早白垩世中温热液脉型,主要产金,伴生银。成矿过程先后经历了热液成矿期和表生成矿期。其中,热液成矿期可划分为3个成矿阶段,每个成矿阶段都发育热液石英。利用LA-ICP-MS原位微区分析技术,对不同成矿阶段石英开展了微量元素组成分析。结果显示,第二阶段为主成矿阶段,矿化最为强烈,是金的主要生成阶段。载金矿物以硫化物为主,但第二阶段Sb、Bi含量显著升高,Au、Ag与Cu、Pb、Zn等金属元素具有正相关关系,说明主成矿阶段的载金矿物可能还有碲化物和铋化物,以微颗粒形式包裹于石英中。基于热液石英Ti含量构建的石英Ti地质温度计显示,热液成矿期成矿温度逐渐降低。石英中Al、Ti、Li含量的规律性变化,表明成矿流体pH逐渐升高,由最初的酸性逐渐向中性、弱碱性演化。

使用晶圆级键合技术制备金属微结构

使用金属材料的晶圆级键合技术可以制备半封闭结构的金属矩形微同轴线。基于柔性金属衬底的晶圆级键合技术,制备了金属矩形微同轴结构。通过选择合适的对准标记和键合工艺,实现了≤10 μm的对准误差。通过多个金属矩形微同轴线的微组装,初步展示了使用单层金属矩形微同轴线构建射频开关矩阵单元的能力。

低离子聚凝胺技术与卡式微柱凝胶技术在溶血病患儿输血前检验中的应用

目的比较低离子聚凝胺技术和卡式微柱凝胶技术在溶血病患儿输血前检验中的应用效果。方法前瞻性选取2020年4月至2023年4月间当地各医院待输血治疗的80例溶血病患儿,于信阳市中心血站进行输血前检验。对所有患儿使用低离子聚凝胺技术与卡式微柱凝胶技术进行输血前检验。比较两种检验技术的配血成功率、检验时间、一次性正反定型检验正确率,并统计患儿检验后不良反应发生率和满意率。结果卡式微柱凝胶试验技术配血成功率为90.00%,明显高于低离子聚凝胺技术的77.50%,检测时间为(17.32±1.21)min,明显长于低离子聚凝胺技术的(16.29±.08)min,差异均有统计学意义(P<0.05);卡式微柱凝胶技术正定型的检验正确率为96.25%,明显高于低离子聚凝胺技术的87.50%,反定型的检验正确率为91.25%,明显高于低离子聚凝胺技术的86.25%,差异均有统计学意义(P<0.05);卡式微柱凝胶技术检测的不良反应发生率为18.75%,明显低于低离子聚凝胺技术的36.25%,检测的满意率为97.50%,明显高于低离子聚凝胺技术的88.75%,差异均有统计学意义(P<0.05)。结论卡式微柱凝胶技术在溶血病患儿输血前检验中表现出更高的检测准确率与满意率,更低的不良反应发生率,是一种更为有效的检测方法。在选择适合的输血前检验技术时,需要综合考虑检测效率、准确性以及成本效益,以确保患儿输血的安全和效率。