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基于单片机的步进电机开环控制系统 被引量:31
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作者 房玉明 杭柏林 《电机与控制应用》 北大核心 2006年第4期61-64,共4页
通过ATMEL89C51单片机对步进电机进行控制,主要介绍了步进电机控制器、驱动电路和LED显示电路的设计,实现了步进电机的开环控制。在步进电机控制器的设计中,重点阐述了脉冲产生电路以及对速度的控制。该系统具有成本低、控制方便的特点。
关键词 单片机 步进电机 开环控制
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海上油田注水井单步法在线酸化技术 被引量:19
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作者 刘平礼 张璐 +2 位作者 潘亿勇 王天慧 赵立强 《西南石油大学学报(自然科学版)》 CAS CSCD 北大核心 2014年第5期148-154,共7页
针对常规酸化在海上油田环境、狭小空间作业时存在设备占地面积大、作业时间长、程序复杂、作业环境要求高和协调难度大,且多井次频繁酸化作业给海上油田生产带来严重影响等问题。提出并开展了新型、简易的注水井单步法在线(SSOA)酸化... 针对常规酸化在海上油田环境、狭小空间作业时存在设备占地面积大、作业时间长、程序复杂、作业环境要求高和协调难度大,且多井次频繁酸化作业给海上油田生产带来严重影响等问题。提出并开展了新型、简易的注水井单步法在线(SSOA)酸化技术的研究,研究中使用高效解堵、抑制二次沉淀能力强的单一酸液InteAcid智能复合酸代替常规酸化三段液体,显著简化配液和注液过程。采用智能注入CCS系统,将酸液按照一定比例注入注水流程管线内在线混配,由注入水携带至储层进行酸化解堵;通过实时监测注入压力和流量,模拟计算表皮系数变化判断酸化效果,进而实时调整施工参数,保证最优酸化效果。新工艺的应用大幅度节约海上油田酸化作业时间、空间、费用和人力,提高酸化施工安全性。80余井次现场应用表明,成功率和有效率高,降压增注效果显著。 展开更多
关键词 海上油田 在线 酸化 单步 注水井 实施监测
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Comparison of endoscopic stenting for malignant biliary obstruction: A single-center study 被引量:12
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作者 Ryuichi Yamamoto Masatomo Takahashi +4 位作者 Yasuyo Osafune Katsuya Chinen Shingo Kato Sumiko Nagoshi Koji Yakabi 《World Journal of Gastrointestinal Endoscopy》 CAS 2015年第9期889-894,共6页
AIM: To evaluate the efficacy and safety of single-step endoscopic placement of self-expandable metallic stents(SEMS) for treatment of obstructive jaundice.METHODS: A retrospective study was performed among 90 patient... AIM: To evaluate the efficacy and safety of single-step endoscopic placement of self-expandable metallic stents(SEMS) for treatment of obstructive jaundice.METHODS: A retrospective study was performed among 90 patients who underwent transpapillary biliary metallic stent placement for malignant biliary obstruction(MBO) between April 2005 and October 2012. The diagnosis of primary disease and MBO was based on abdominal ultrasound, computed tomography, magnetic resonance imaging, endoscopic ultrasound, endoscopic retrograde cholangiopancreatography with brush cytology, biopsy, and/or a combination of these modalities. The type of SEMS(covered or non-covered, 8 mm or 10 mm in diameter) was determined by the endoscopist. Ninety patients were divided into two groups: group 1(49 patients) who underwent a singlestep SEMS placement and group 2(41 patients) who underwent a two-step SEMS placement. The technical success rate, complication rate, stent patency, and patient survival rate were compared between the groups. In addition, to identify the clinical prognostic factors associated with patient survival, the following variables were evaluated in Cox-regression analysis: gender, age, etiology of MBO(pancreatic cancer or nonpancreatic cancer), clinical stage(Ⅳb; with distant metastases or Ⅳa >; without distant metastases), chemotherapy(with or without), patency of the stent, and the use of single-step or two-step SEMS. RESULTS: Immediate technical success was achieved in 93.9%(46/49) in group 1 and in 95.1%(39/41) in group 2, with no significant difference(P = 1.0). Similarly, there was no difference in the complication rates between the groups(group 1, 4.1% and group 2, 4.9%; P = 0.62). Stent failure was observed in 10 cases in group 1(20.4%) and in 16 cases in group 2(39.0%). The patency of stent and patient survival revealed no difference between the two groups with Kaplan-Meier analysis, with a mean patency of 111 ± 17 d in group 1 and 137 ± 19 d in group 2(P = 0.91), and a mean survival of 178 ± 35 d in group 1 展开更多
关键词 ENDOSCOPIC STENTING single-step Malignantbiliary OBSTRUCTION Self-expandable metallic STENTS Twostep
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一种单步法在线酸化酸液体系研究及应用 被引量:12
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作者 汪本武 刘平礼 +3 位作者 张璐 兰夕堂 赵立强 李年银 《石油与天然气化工》 CAS 北大核心 2015年第3期79-83,共5页
目前,注水井酸化主要采用常规酸化模式,但常规酸化存在酸化作业时间长、作业程序复杂、作业环境要求高、动复原复杂和协调难度大等问题。针对这些问题,提出一种单步法在线酸化技术。该技术的核心是采用一种高效酸液体系代替常规酸化三... 目前,注水井酸化主要采用常规酸化模式,但常规酸化存在酸化作业时间长、作业程序复杂、作业环境要求高、动复原复杂和协调难度大等问题。针对这些问题,提出一种单步法在线酸化技术。该技术的核心是采用一种高效酸液体系代替常规酸化三段式液体,实现"以一代三"功效。因此,开展了新一代单步法酸液体系—G智能复合酸液体系的研究,主要包括酸液体系与注入水、采出水配伍性、抑制沉淀、缓速、缓蚀性能、酸化流动效果评价及微观分析。结果表明,G-智能复合酸液能够满足单步酸液体系的性能要求,酸液体系与注入水最优混配体积比在1∶2~1∶8。微观电镜分析表明,酸液不会破坏岩石骨架。将该酸液体系应用于渤海油田B4注水井在线单步法酸化,酸化后该井的视吸水指数大幅度升高,降压增注效果显著。 展开更多
关键词 注水井 单步 酸化 酸液体系 微观分析
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电阻分压器测量高压单脉冲方法的改进 被引量:7
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作者 熊海林 陈香萍 《航空计测技术》 1995年第5期23-25,共3页
根据实验结果,对分压器测量极窄的高压单脉冲方法进行分析后,认为此方法的缺陷在于忽视了分布电容的影响。通过引入补偿电容改进了分压器。由改进后的分压器模型的时域解,得出了改进测量方法的方案。
关键词 高压单脉冲 电阻分压器 分布电容 脉冲测量
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砂岩储层酸化智能复合酸液体系研究及应用 被引量:10
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作者 刘平礼 孙庚 +2 位作者 邢希金 潘亿勇 赵立强 《西南石油大学学报(自然科学版)》 CAS CSCD 北大核心 2015年第6期138-143,共6页
常规砂岩酸化为了实现有效解堵,必须采用前置液、处理液和后置液多段液体,其作业程序复杂,研制出一套智能复合酸液体系——InteAcid。该酸液能替代常规砂岩酸化的多段酸液,实现单步酸化,显著简化作业程序,特别适合于海上酸化作业。室内... 常规砂岩酸化为了实现有效解堵,必须采用前置液、处理液和后置液多段液体,其作业程序复杂,研制出一套智能复合酸液体系——InteAcid。该酸液能替代常规砂岩酸化的多段酸液,实现单步酸化,显著简化作业程序,特别适合于海上酸化作业。室内实验表明,InteAcid在溶解砂岩矿物和解除伤害的同时,能有效抑制二次沉淀,对金属氟化物、氟硅/铝酸盐和金属氢氧化物沉淀抑制率可分别达到71.81%、70.51%和78.59%;单步岩芯流动实验后,无伤害、轻微伤害、重度伤害岩芯渗透率提高为原始渗透率的1.35倍、3.60倍和15.00倍;酸处理后孔隙结构微观分析表明,该酸液具有提高岩芯渗透率和稳定黏土作用,对岩石骨架破坏很小。该酸液现场单步酸化11口注水井,成功率100%,效果显著率达90%。 展开更多
关键词 智能酸化 单步 二次沉淀 螯合
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单步萃取-HPLC法测定人血清中卡马西平浓度 被引量:9
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作者 张国宏 潘丽春 赵婧岚 《中国医院药学杂志》 CAS CSCD 北大核心 2007年第3期341-343,共3页
目的:建立单步萃取-HPLC法测定人血清中卡马西平浓度的方法。方法:采用Nova-Pak C18柱(3.9mm×150mm,5μm)色谱柱,流动相为甲醇-2mmol·L^-1磷酸二氢钠溶液(pH3.5)(50:50),流速为0.9mL·min^-1,检测波长为2... 目的:建立单步萃取-HPLC法测定人血清中卡马西平浓度的方法。方法:采用Nova-Pak C18柱(3.9mm×150mm,5μm)色谱柱,流动相为甲醇-2mmol·L^-1磷酸二氢钠溶液(pH3.5)(50:50),流速为0.9mL·min^-1,检测波长为285nm,柱温为30℃。结果:卡马西平在1.2~32mg·L^-1范围内线性关系良好,回归方程:A=5348.61C-1891.2,r=0.9981。方法回收率为99.38%,日内、日间RSD为0.46%~2.02%,最低检测质量浓度为0.3mg·L^-1。结论:本法灵敏、准确、快速、专属性强。 展开更多
关键词 卡马西平 高效液相色谱法 单步萃取 血药质量浓度
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Single-step transepithelial photorefractive keratectomy in high myopia:qualitative and quantitative visual functions 被引量:8
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作者 Soheil Adib-Moghaddam 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2017年第3期445-452,共8页
AIM:To investigate quantitative and qualitative optical outcomes of single-step transepithelial photorefractive keratectomy(Trans PRK)in high myopia.METHODS:In a prospective interventional case-series,30 eyes with... AIM:To investigate quantitative and qualitative optical outcomes of single-step transepithelial photorefractive keratectomy(Trans PRK)in high myopia.METHODS:In a prospective interventional case-series,30 eyes with high myopia(-6.00 to-8.75 D)with(up to-3.00 D)or without astigmatism were enrolled from Bina Eye Hospital,Tehran,Iran. One-step Trans PRK was performed with aberration-free aspherical optimized profile and SCHWIND AMARIS 500 laser. One-year follow-up results for refraction,visual acuities,vector analysis,ocular wavefront(OWF)and corneal wave-front(CWF)higher order aberrations(HOA),contrast sensitivity(CS),and postoperative haze were assessed.RESULTS:After the surgery,both photopic and mesopic CSs significantly improved(both P〈0.001). We detected significant induction of OWF coma and trefoil(P〈0.001 for both)HOAs; CWF coma(P=0.002),spherical(P〈0.001),and tetrafoil(P=0.003)HOAs in 6 mm analysis diameter; and CWF trefoil(P=0.04)HOA in 4 mm analysis diameter. The range of mean induction observed for various HOAs was0.005-0.11 μm. The 86.7% of eyes reached an uncorrected distance visual acuity of 20/20 or better; 96.7% of eyes were within ±0.5 D of targeted spherical refraction. In vector analysis,mean correction index value was 1.03 and mean index of success was 0.22. By 12mo after the operation,no eye lost any number of corrected distancevisual acuity lines. We detected no corneal haze greater than 1~+ throughout the follow-up.CONCLUSION:Our findings show promising effects of single-step Trans PRK on quality of vision in high myopic eyes. It also improves refraction and visual acuity. 展开更多
关键词 single-step transepithelial photorefractive keratectomy transepithelial photorefractive keratectomy high myopia contrast sensitivity higher order aberrations vector analysis
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一种新型二维自动旋转台的研制与应用 被引量:4
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作者 叶继涛 陈儿同 +1 位作者 王芳 张华 《节能技术》 CAS 2003年第1期34-35,48,共3页
本文研制了一种自动二维旋转台 ,在此旋转台上固定的平板面能够始终与太阳光垂直。此装置可应用在太阳能发电、集热、干燥、制冷系统中 。
关键词 PSD传感器 单片机 步进电机 二维自动旋转台 太阳能
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最小曲率位场分离方法参数选择试验研究 被引量:7
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作者 纪晓琳 王万银 邱之云 《地球物理学进展》 CSCD 北大核心 2019年第4期1441-1452,共12页
位场分离是位场解释中最困难的问题之一.本文作者曾在2015年研究了单步长非原位和原位迭代两种类型最小曲率位场分离差分迭代格式,并利用Fourier频谱分析理论研究了这两种类型迭代格式的收敛性及位场分离效果,在实际应用中如何选择有关... 位场分离是位场解释中最困难的问题之一.本文作者曾在2015年研究了单步长非原位和原位迭代两种类型最小曲率位场分离差分迭代格式,并利用Fourier频谱分析理论研究了这两种类型迭代格式的收敛性及位场分离效果,在实际应用中如何选择有关参数就是本文研究的内容.首先,利用理论模型对迭代步长和迭代次数选择进行了模型试验,模型试验显示单步长原位迭代和叠加步长原位迭代均能收敛、且能获得较好的位场分离效果;迭代步长可根据位场分离目的选取,当位场异常迭代最大残差差值和原场均值平均相对误差差值趋于0时的迭代次数为最佳迭代次数;其次,三层组合模型位场分离试验再次验证了原位迭代最小曲率位场分离方法的有效性.最后,利用西非中南段加蓬盆地卫星测高重力异常数据处理试验显示了最小曲率位场分离方法的实用性. 展开更多
关键词 最小曲率 原位迭代 单步长 叠加步长 迭代步长 迭代次数 位场分离
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基于MCS-51单片机的步进电机正反转控制实现 被引量:7
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作者 何兵 《泸州职业技术学院学报》 2008年第1期56-59,共4页
介绍了步进电机正反转控制原理及其接口驱动控制电路,编制了基于MCS-51单片机的步进电机正反转控制的子程序,并应用wave软件进行了仿真。证明在并行口控制中,可以利用软件实现环行脉冲分配,实现程序较简单,同时还可以节省硬件投资。结... 介绍了步进电机正反转控制原理及其接口驱动控制电路,编制了基于MCS-51单片机的步进电机正反转控制的子程序,并应用wave软件进行了仿真。证明在并行口控制中,可以利用软件实现环行脉冲分配,实现程序较简单,同时还可以节省硬件投资。结合单片机控制步进电动机的实际工作环境,从提高控制系统运行的可靠性角度,讨论了实际应用的软件抗干扰技术。 展开更多
关键词 单片机 步进电机 正反转控制 软件抗干扰
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涤棉混纺织物一浴一步法染色分散染料的选择 被引量:6
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作者 马海涛 袁琴华 +1 位作者 陈海芬 周建庆 《苏州丝绸工学院学报》 2000年第5期36-40,共5页
研究了分散 /活性染料一浴一步法染色工艺的pH值、电解质、温度等对分散染料染色性能的影响 ,结果表明 ,在匀染剂MY存在下 ,选用一些耐碱性分散染料 ,涤棉混纺织物的分散 /活性一浴一步法染色在分散染料方面是可行的。
关键词 一浴一步 分散染料 PH值 电解质 温度
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可复用微处理器片上调试功能的设计与实现 被引量:7
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作者 王琪 高瑛珂 +3 位作者 华斯亮 张铁军 王东辉 侯朝焕 《计算机辅助设计与图形学学报》 EI CSCD 北大核心 2012年第10期1369-1374,共6页
为了方便软件与应用系统的开发与调试,提出一种可复用的微处理器片上调试方法.通过设计通用的调试指令集和增加调试模块,并扩展处理器内核功能,实现了断点设置与取消、内核运行的流水级精确控制、内核资源访问、任意程序段运行中特殊事... 为了方便软件与应用系统的开发与调试,提出一种可复用的微处理器片上调试方法.通过设计通用的调试指令集和增加调试模块,并扩展处理器内核功能,实现了断点设置与取消、内核运行的流水级精确控制、内核资源访问、任意程序段运行中特殊事件的统计等片上调试功能.该方法已在自主研发的SuperV_EF01DSP上实现.在CMOS 90nm工艺下的综合结果表明,新增的片上调试功能不影响SuperV_EF01DSP的关键路径时序,而芯片总面积仅增加了3.87%. 展开更多
关键词 片上调试 可复用 数字信号处理器 单步
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基于单极倍频SPWM调制的单相Buck-Boost集成式升压逆变器研究 被引量:7
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作者 胡茂 秦岭 +2 位作者 陈瑞祥 王亚芳 候虚虚 《中国电机工程学报》 EI CSCD 北大核心 2017年第13期3863-3873,共11页
为满足低输入电压逆变场合的要求,提出了一种单相Buck-Boost集成式升压逆变器。其通过复用电压型全桥逆变器下管的体二极管以及上开关管,将两个Buck-Boost变换器和全桥逆变器集成在一起,与其他单级式升压逆变器相比,具有功率器件少、结... 为满足低输入电压逆变场合的要求,提出了一种单相Buck-Boost集成式升压逆变器。其通过复用电压型全桥逆变器下管的体二极管以及上开关管,将两个Buck-Boost变换器和全桥逆变器集成在一起,与其他单级式升压逆变器相比,具有功率器件少、结构简单、集成度高等优点。另外,其采用传统的单极倍频SPWM调制,仅通过调节调制比(M<1)就能同时实现升压和逆变,因此控制非常方便,且输出电压/电流的总谐波失真均较低。首先介绍了该逆变器的拓扑演化过程;然后分析了直流升压电感电流连续和断续两种模式下的工作原理,并结合伏秒平衡和积分变换理论,推导出电压增益、功率管电应力等稳态特性和升压电感设计准则;最后通过一台250W/10k Hz的样机进行了仿真和实验验证。 展开更多
关键词 集成式逆变器 单级 升压 BUCK-BOOST 单极倍 频SPWM
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Strong ferroelectric and luminescence properties of 0-3 type 0.8BaTiO_(3)-0.2CaTiO_(3):Pr^(3+)composite ceramics prepared by cold sintering process
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作者 Xiaocui Rao Xueling Yang +4 位作者 Renbing Sun Peng Du Hai Jiang Yao Huang Laihui Luo 《Journal of Advanced Ceramics》 SCIE EI CAS CSCD 2024年第7期1002-1010,共9页
0-3 type ferroelectric-phosphor composite ceramics cannot be prepared by the traditional solid-state sintering(SSS)method due to the strong chemical reaction between ferroelectrics and phosphors during high-temperatur... 0-3 type ferroelectric-phosphor composite ceramics cannot be prepared by the traditional solid-state sintering(SSS)method due to the strong chemical reaction between ferroelectrics and phosphors during high-temperature sintering.The cold sintering process(CSP)may solve this issue by densifying ceramics at ultralow sintering temperatures.In this work,dense 0-3 type 0.8BaTiO3-0.2CaTiO3:Pr^(3+)(0.8BT-0.2CT:Pr^(3+))binary composite ceramics were fabricated at an ultralow temperature of 225℃via CSP with the Ba(OH)2·8H2O hydrated flux.The effects of the Ba(OH)2·8H2O content,sintering temperature,and sintering time on the microstructure and densification of the ceramics were investigated.The density of the composite ceramics prepared by the optimized sintering parameters reaches 89%.Both energy-dispersive X-ray(EDX)spectroscopy and X-ray diffraction(XRD)confirm the existence of BT and CT:Pr^(3+)phases in the prepared ceramics.A strong ferroelectric performance is obtained,and the luminescent properties of CT:Pr^(3+)are preserved for the ceramics.Furthermore,the 0.8BT-0.2CT:Pr^(3+)composite ceramics prepared by CSP have stronger photoluminescence and photo-stimulated luminescence than their counterparts prepared by cold sintering assistance(CSA)and SSS methods.Therefore,CSP is a promising method for combining luminescent and ferroelectric properties into 0-3 type composite ceramics. 展开更多
关键词 single-step densification cold sintering composite ceramics FERROELECTRIC LUMINESCENCE
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A compact bimorph rotary piezoelectric actuator with customized small power supply
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作者 DENG Jie LIU DaQing +1 位作者 WANG WeiYi LIU YingXiang 《Science China(Technological Sciences)》 SCIE EI CAS CSCD 2024年第4期1185-1195,共11页
Inertial piezoelectric actuators are widely applied in precision devices with simple structure and accurate movement.However,existing inertial piezoelectric actuators still face the challenges of rollback motion and b... Inertial piezoelectric actuators are widely applied in precision devices with simple structure and accurate movement.However,existing inertial piezoelectric actuators still face the challenges of rollback motion and bulky power supply.In this work,an alternate excitation strategy and a customized small power supply for a bimorph rotary piezoelectric actuator(BRPA)are proposed to solve the problems.The BRPA prototype is designed with a bipedal symmetrical structure,measuring 35 mm in height and 32 mm in diameter,which has a maximum rotation velocity of 0.247 rad/s and a resolution of 0.66μrad.Thanks to the bipedal symmetrical structure,the friction directions between the driving feet and the rotor can be coordinated to suppress the rollback.The rollback ratio is almost zero when the phase difference of the exciting signal is set as 180°.The customized power supply is designed and manufactured,whose size is 58 mm×56 mm×46 mm.It can output signals for the single step mode and the continuous mode,and they are adopted to excite BRPA to achieve a small stroke with one single step and a large stroke with continuous step,respectively.Then,an experimental system for optical fiber alignment is developed based on the BRPA and the customized small power supply,the experiment has verified the practicability of this work in the precision fields,especially in the miniaturized precision systems. 展开更多
关键词 inertial piezoelectric actuator customized small power supply single step mode continuous mode rollback suppression miniaturized precision system
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Phenotype-Directed DNA Nanomachine for in Situ Analysis of Stem Cell-like Subpopulation in Breast Cancer
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作者 Ya Cao Huiru Mao +4 位作者 Lingjun Sha Qi Liu Bing Han Jing Zhao Genxi Li 《CCS Chemistry》 CSCD 2024年第4期1034-1046,共13页
The cancer stem cell hypothesis provides a basis for prediction of the recurrence and risk of metastasis in breast cancer.However,the unique expression pattern of stemness markers and the presence of nonstem-like canc... The cancer stem cell hypothesis provides a basis for prediction of the recurrence and risk of metastasis in breast cancer.However,the unique expression pattern of stemness markers and the presence of nonstem-like cancer cells with varied phenotypes have brought great challenges to the characterization of breast cancer stem cells.To address these challenges,a phenotype-directed DNA nanomachine has been designed for high-accuracy labeling and in situ analysis of the stem cell-like subpopulation in breast cancer.The key for the design is to use cell surfaceanchored inputs to activate the nanomachine,which undergoes different branch migration pathways such that the signal strand can only be brought onto the cancer cells having the stem cell-like phenotype.Highly sensitive determination and single-step isolation of the stem cell-like subpopulation were achieved by incorporating functional groups into the signal strand such that the nanomachine was successfully applied in a tumor-bearing mouse model.Overall,the approach provides for a substantial improvement in capability for the analysis of the breast cancer stem cell-like subpopulation,and it is expected that the new approach will advance the use of DNA nanomachines in cancer-related studies. 展开更多
关键词 breast cancer DNA nanomachine stem cell-like subpopulation electrochemical determination single-step isolation phenotypic analysis
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Single-Step Combined Laparoscopic Management of Hepatocellular Carcinoma with Simultaneous Radio Frequency Ablation and Trans-Arterial Embolization in Unresactable Lesions 被引量:3
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作者 Lukman Cheraghvandi Michael Silva +4 位作者 Charlie Cheng Mauro Montalbano Ali Shirafkan Cristiana Rastellini Luca Cicalese 《Journal of Cancer Therapy》 2016年第13期979-985,共8页
Hepatocellular carcinoma (HCC) is a cancer with increasing incidence in the USA and high mortality rate. HCC is often difficult to treat due to underlying comorbidities such as cirrhosis. However, the application of l... Hepatocellular carcinoma (HCC) is a cancer with increasing incidence in the USA and high mortality rate. HCC is often difficult to treat due to underlying comorbidities such as cirrhosis. However, the application of loco-regional thermal ablation using radio frequency (RF) and trans-arterial embolization with chemotherapy (TACE) or without (TAE) has shown promising results in the treatment of patients not amenable to surgical resection or liver transplantation. Conventionally, RF and TAE are performed in two separated sessions or two steps and often RF ablation is performed percutaneously. However, no consensus has been reached regarding the ideal interval between the two treatments. In this article, we discuss the feasibility and benefits of a single-step TAE in combination with laparoscopic RF ablation in one operative session. We also present a case where this procedure has been successfully performed demonstrating its feasibility. We suggest that the use of laparoscopic RF ablation in the same surgical session as TAE is feasible and potentially offers several advantages over the two-step process that is usually performed with embolization followed by percutaneous RF with a long time interval. In this article we discuss such advantages. 展开更多
关键词 single step single Session Hepatocellular Carcinoma Laparoscopic Radiofrequency Ablation Trans-Arterial Embolization
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硅晶圆分层划片工艺试验研究 被引量:5
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作者 尹韶辉 杨宏亮 +2 位作者 陈逢军 耿军晓 张俊杰 《表面技术》 EI CAS CSCD 北大核心 2018年第7期1-7,共7页
目的优化硅晶圆划片工艺参数,提高划片质量。方法提出一种硅晶圆分层划片工艺方法,利用自主研发的精密全自动划片机,通过全因素试验,研究了主轴转速、进给速度和切削深度等工艺参数对分层划片与传统单次划片的工艺性能的影响,检测了崩... 目的优化硅晶圆划片工艺参数,提高划片质量。方法提出一种硅晶圆分层划片工艺方法,利用自主研发的精密全自动划片机,通过全因素试验,研究了主轴转速、进给速度和切削深度等工艺参数对分层划片与传统单次划片的工艺性能的影响,检测了崩边宽度、相对缝宽、切缝表面粗糙度,通过检测划片过程中主轴电流大小来间接反映切削力的大小。最后对分层划片工艺进行优化试验,得出最佳工艺参数组合。结果随着划片深度的增加,主轴电流增大,进给速度对主轴电流的影响较小,分层划片可以有效减少划片过程产生的切削力,提高划切效果。分层划片试验发现,随主轴转速的增加,相对缝宽增大;随进给速度增大,相对缝宽先减小后增大。进给速度为15 mm/s,转速为10 000 r/min时,相对缝宽最小,为1.048。随着主轴转速的增加,崩边宽度减小;随着进给速度的增大,崩边宽度增大。进给速度为1 mm/s,转速为25 000 r/min时,崩边宽度最小,为5.31μm。结论与传统单次划片方式相比,分层划片工艺能够得到更好的划片效果,可一定程度上降低崩边宽度,减小相对缝宽值,减少微裂纹,提高划切质量。 展开更多
关键词 硅晶圆 单次划片 分层划片 崩边 相对缝宽 切削力 划切质量
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Fabrication of coconut shell-derived porous carbons for CO_(2) adsorption application 被引量:1
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作者 Jiali Bai Jiamei Huang +5 位作者 Qiyun Yu Muslum Demir Eda Akgul Bilge Nazli Altay Xin Hu Linlin Wang 《Frontiers of Chemical Science and Engineering》 SCIE EI CSCD 2023年第8期1122-1130,共9页
Biomass-derived porous carbons have been considered as the most potential candidate for effective CO_(2) adsorbent thanks to being widely-available precursor and having highly porous structure and stable chemical/phys... Biomass-derived porous carbons have been considered as the most potential candidate for effective CO_(2) adsorbent thanks to being widely-available precursor and having highly porous structure and stable chemical/physical features.However,the biomass-derived porous carbons still suffer from the poor optimization process in terms of the synthesis conditions.Herein,we have successfully fabricated coconut shell-derived porous carbon by a simple one-step synthesis process.The as-prepared carbon exhibits advanced textual activity together with well-designed micropore morphology and possesses oxygen-containing functional groups(reached 18.81 wt%)within the carbon matrix.Depending on the different activating temperatures(from 700 to 800℃)and KOH/biomass mass ratios(from 0.3 to 1),the 750℃ and 0.5 mass ratio were found to be enabling the highest CO_(2) capture performance.The optimal adsorbent was achieved a high CO_(2) uptake capacity of 5.92 and 4.15 mmol·g^(−1) at 0 and 25℃(1 bar),respectively.More importantly,as-prepared carbon adsorbent exhibited moderate isosteric heat of adsorption and high CO_(2)/N_(2) selectivity.The results were revealed not only the textural feature but also the surface functional groups critically determine the CO_(2) capture performance,indicating coconut shell-derived porous carbon has a considerable potential as a solid-state adsorbent for the CO_(2) capture. 展开更多
关键词 porous carbons CO_(2)adsorption KOH activation single step reaction BIOMASS
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