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Numerical Simulation of Oil-Water Two-Phase Flow in Low Permeability Tight Reservoirs Based on Weighted Least Squares Meshless Method
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作者 Xin Liu Kai Yan +3 位作者 bo fang Xiaoyu Sun Daqiang Feng Li Yin 《Fluid Dynamics & Materials Processing》 EI 2024年第7期1539-1552,共14页
In response to the complex characteristics of actual low-permeability tight reservoirs,this study develops a meshless-based numerical simulation method for oil-water two-phase flow in these reservoirs,considering comp... In response to the complex characteristics of actual low-permeability tight reservoirs,this study develops a meshless-based numerical simulation method for oil-water two-phase flow in these reservoirs,considering complex boundary shapes.Utilizing radial basis function point interpolation,the method approximates shape functions for unknown functions within the nodal influence domain.The shape functions constructed by the aforementioned meshless interpolation method haveδ-function properties,which facilitate the handling of essential aspects like the controlled bottom-hole flow pressure in horizontal wells.Moreover,the meshless method offers greater flexibility and freedom compared to grid cell discretization,making it simpler to discretize complex geometries.A variational principle for the flow control equation group is introduced using a weighted least squares meshless method,and the pressure distribution is solved implicitly.Example results demonstrate that the computational outcomes of the meshless point cloud model,which has a relatively small degree of freedom,are in close agreement with those of the Discrete Fracture Model(DFM)employing refined grid partitioning,with pressure calculation accuracy exceeding 98.2%.Compared to high-resolution grid-based computational methods,the meshless method can achieve a better balance between computational efficiency and accuracy.Additionally,the impact of fracture half-length on the productivity of horizontal wells is discussed.The results indicate that increasing the fracture half-length is an effective strategy for enhancing production from the perspective of cumulative oil production. 展开更多
关键词 Weighted least squares method meshless method numerical simulation of low permeability tight reservoirs oil-water two-phase flow fracture half-length
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Focus control of wide-angle metalens based on digitally encoded metasurface
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作者 Yi Chen Simeng Zhang +7 位作者 Ying Tian Chenxia Li Wenlong Huang Yixin Liu Yongxing Jin bo fang Zhi Hong Xufeng Jing 《Opto-Electronic Advances》 SCIE EI CAS CSCD 2024年第8期26-41,共16页
Based on the principle of super-symmetric lens with quadratic phase gradient transformation, combined with the principle of digital coding of metasurface, we propose a wide-angle coded metalens for focusing control in... Based on the principle of super-symmetric lens with quadratic phase gradient transformation, combined with the principle of digital coding of metasurface, we propose a wide-angle coded metalens for focusing control in two-dimensional space. This metalens achieves focus shift in the x-direction by changing the oblique incidence angle of the incident wave,and focus control in the y-direction by combining with the convolution principle of the digitally coded metasurface to achieve flexible control of light focusing in the two-dimensional plane. The metasurface unit is mainly composed of threelayer of metal structure and two layers of medium, and the transmission phase is obtained by changing the middle layer of metal structure, which in turn obtains the required phase distribution of the metalens. The design of the metalens realizes the function of the lens with a large viewing angle at the x-polarized incidence, and realizes two-dimensional focus control. Experimentally, we prepared the designed coding metalens and tested the focus control function of the wide-angle coding metalens. The experimental results are in good agreement with the design results. 展开更多
关键词 metasurface metalens WIDE-ANGLE CODING
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Mid-infrared Optical Frequency Comb-based Fourier Transform Spectrometer for Broadband Molecular Spectroscopy
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作者 Feihu Cheng Weixiong Zhao +5 位作者 bo fang Nana Yang Shuangshuang Li Weijun Zhang Lunhua Deng Weidong Chen 《Chinese Journal of Chemical Physics》 SCIE EI CAS CSCD 2024年第4期471-480,I0093,共11页
Optical frequency combbased Fourier transform spectroscopy has the features of broad spectral bandwidth,high sensitivity,andmultiplexed trace gas detection,which has valuable application potential in the fields of pre... Optical frequency combbased Fourier transform spectroscopy has the features of broad spectral bandwidth,high sensitivity,andmultiplexed trace gas detection,which has valuable application potential in the fields of precision spectroscopy and trace gas detection.Here,we report the development of a mid-infrared Fourier transform spectrometer based on an optical frequency comb combined with a Herriott-type multipass cell.Using this instrument,the broadband absorption spectra of several important molecules,including methane,acetylene,water molecules and nitrous oxide,are measured by near real-time data acquisition in the 2800-3500 cm^(-1)spectral region.The achieved minimum detectable absorption of the instrument is 4.4×10^(-8)cm^(-1)·Hz^(-1/2)per spectral element.Broadband spectra of H_(2)0 are fited using the Voigt profile multispectral fitting technique and the consistency of the concentration inversion is 1%.Our system also enables precise spectroscopic measurements,and it allows the determination of the spectral line positions and upper state constants of N_(2)O in the(0002)-(1000)band,with results in good agreement with those reported by Toth[Appl.Opt.30,5289(1991)]. 展开更多
关键词 Mid-infrared optical frequency comb Multi-pass cell Fourier transform infrared spectrometer
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Value of negative pressure sealing drainage on wound healing of Gustilo IIIB and IIIC open fractures
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作者 bo fang Yong-Sheng Wang +2 位作者 Wei Li Kai Ying Gang Zong 《World Journal of Clinical Cases》 SCIE 2024年第20期4199-4205,共7页
BACKGROUND Gustilo III fractures have a high incidence and are difficult to treat.Patients often experience difficulty in wound healing.Negative pressure drainage technology can help shorten wound healing time and has... BACKGROUND Gustilo III fractures have a high incidence and are difficult to treat.Patients often experience difficulty in wound healing.Negative pressure drainage technology can help shorten wound healing time and has positive value in improving patient prognosis.AIM To explore the clinical value of the negative pressure sealing drainage technique in wound healing of Gustilo IIIB and IIIC open fractures.METHODS Eighty patients with Gustilo IIIB and IIIC open fractures with skin and soft tissue injuries who were treated in the Second People’s Hospital of Dalian from March 2019 to December 2021 were selected as the research subjects.They were divided into a study group(n=40,healed with negative pressure closed drainage)and a control group(n=40,healed with conventional dressing changes)according to the variation in the healing they received.The efficacy of the clinical interventions,the variations in the regression indicators(time to wound healing,time to fracture healing,time to hospitalization),and the conversion and healing of bacterial wounds were compared 1-3 mo after the intervention.RESULTS The total effective rate of patients among the study group was 95.00%(38/40),which was notably higher than 75.00%(30/40)among the control group(P<0.05).The wound healing time,fracture healing time,and hospital stay of the patients in the study group was shorter than the control group(P<0.05).After the intervention,the negative bacterial culture at the wound site rate and wound healing rate of the patients among the study group increased compared to the control group(P<0.05).CONCLUSION Negative pressure sealing and drainage technology has a good therapeutic effect on patients with Gustilo IIIB and IIIC open fracture wounds with skin and soft tissue injury.It can notably enhance the wound healing rate and the negative rate of bacteria on the wound surface and help to speed up the recovery process of patients. 展开更多
关键词 Negative pressure closed drainage Gustilo type III open fracture Wound healing Clinical outcome Research value
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A Meta-Analysis of the Effect of Modified Gastric Tube Length on Enteral Nutrition in Stroke Patients
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作者 Xuehong Tang bo fang Zhenzhen Cai 《Journal of Clinical and Nursing Research》 2024年第10期147-158,共12页
Objective:To systematically evaluate the effect of modified length of gastric tube implantation in stroke patients.Methods:Randomized controlled studies on the effect of narrative therapy on negative emotions of malig... Objective:To systematically evaluate the effect of modified length of gastric tube implantation in stroke patients.Methods:Randomized controlled studies on the effect of narrative therapy on negative emotions of malignant tumor patients were published in PubMed,EMbase,Web of Science,Cochrane Library,CNKY.Wanfang Data,VIP Database and CBM disc from database establishment to May 2021.RewMan 5.2 software was used for the meta-analysis.Results:Ten articles were included,involving 1140 patients in total.Results of meta-analysis showed that improved length of gastric tube implantation could reduce the incidence of aspiration pneumonia in stroke patients with enteral nutrition[OR=0.18,95%CI(0.10,0.31),P<0.00001],reduce gastroesophageal reflux rate[OR=0.13,95%CI(0.04,0.38),P<0.0002],the incidence of aspiration[OR=0.23,95%CI(0.11,0.38),P<0.00001],the incidence of abdominal distension and diarrhea[OR=0.13,95%CI(0.06,0.28),P<0.00001],the incidence of choking cough[OR=0.20,95%CI(0.07,0.61),P<0.005],but no difference between the two groups in terms of reducing gastric residual[OR=0.10,95%CI(2.40,2.60),P=0.94].Conclusions:The modified length of the gastric tube can replace the traditional length of the gastric tube in the application of stroke patients,can reduce the complications of enteral nutrition,is safe and feasible.However,due to the limitation of the quality and quantity of the included studies,we should be cautious about the results of this meta-analysis and expect to carry out more large-sample and high-quality randomized controlled trials for demonstration. 展开更多
关键词 STROKE Length of gastric tube Modified gastric tube META-ANALYSIS Systematic evaluation COMPLICATIONS
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上海市某初中学生使用电子产品的认识状况分析
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作者 徐蕾 卜方 +2 位作者 王洁 张佳琪 徐斌 《健康教育与健康促进》 2024年第3期287-290,共4页
目的了解初中生对电子产品使用的认知,以及管理电子产品使用行为的意愿和需求,为更好地引导青少年使用电子产品提出建议。方法采用现况研究方法,通过问卷星在手机和电脑客户端对研究对象进行问卷调查。结果有77.40%的同学认为初中学生... 目的了解初中生对电子产品使用的认知,以及管理电子产品使用行为的意愿和需求,为更好地引导青少年使用电子产品提出建议。方法采用现况研究方法,通过问卷星在手机和电脑客户端对研究对象进行问卷调查。结果有77.40%的同学认为初中学生使用电子产品是利弊各半;95.75%的同学知晓“怎样合理使用电子产品”,但在部分认知方面存在分歧;有96.44%的家长对孩子使用电子产品采取了管理措施;有41.23%的同学因使用电子产品与父母发生冲突。大多数同学希望父母能与自己约定每天使用电子产品的时间,其次是爸爸妈妈以身作则;同学们最希望学校鼓励学生制定、执行自己的电子产品使用管理计划,并可考虑纳入综合素质评价中德育活动的内容;有93.56%的同学愿意与家长、学校一起管理自己使用电子产品的行为。性别、家庭管理、亲子冲突与电子产品使用认知之间存在显著关联。结论家校合作与学生共同管理是比较适合初中生管理电子产品使用行为的方式。 展开更多
关键词 初中生 电子产品 使用状况
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1例比熊犬脾脏淋巴瘤诊断和治疗 被引量:1
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作者 陈彩琴 张玉玲 +3 位作者 薄放 侯璞 董发明 刘凤军 《现代畜牧兽医》 2023年第3期42-46,共5页
研究旨在探讨犬脾脏肿瘤的诊断流程,提高其临床治愈率。一例5岁比熊犬3个月前出现呕吐、食欲不振、颈部淋巴结肿大但未确诊。经DR和腹部彩超检查发现,脾脏明显肿大,脾下缘超过脐孔达盆腔,且有弥散性低回声暗区;血常规和血液生化检查结... 研究旨在探讨犬脾脏肿瘤的诊断流程,提高其临床治愈率。一例5岁比熊犬3个月前出现呕吐、食欲不振、颈部淋巴结肿大但未确诊。经DR和腹部彩超检查发现,脾脏明显肿大,脾下缘超过脐孔达盆腔,且有弥散性低回声暗区;血常规和血液生化检查结果显示,中性粒细胞百分比、红细胞数量和红细胞比容下降,嗜酸性粒细胞数、淋巴细胞和单核细胞剧烈升高;脂肪酶升高,天门冬氨酸氨基转移酶、乳酸脱氢酶明显升高。综合上述检查结果初判该犬脾脏肿大。经宠主同意,对患犬进行脾脏摘除术,并通过组织病理学检查确诊患犬为脾脏淋巴瘤。患犬术后短时间内食欲增加,二便正常,生活质量有一定提高,但最终于术后163 d死亡。 展开更多
关键词 脾肿大 淋巴瘤
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学术能力培养体系对物理拔尖学生培养的重要性--以南开大学物理“伯苓班”为例 被引量:6
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作者 吴强 余华 +3 位作者 薄方 刘智波 刘松芬 李川勇 《大学物理》 2018年第4期47-50,74,共5页
本文以南开大学物理"伯苓班"为例,讨论学术能力培养体系对物理拔尖人才培养的重要性.文中介绍了我们对学术能力培养体系建设的几方面认识:重视学术基础,强调学术精神,不断提高学生的学术兴趣,培养学生的团队精神和合作能力,... 本文以南开大学物理"伯苓班"为例,讨论学术能力培养体系对物理拔尖人才培养的重要性.文中介绍了我们对学术能力培养体系建设的几方面认识:重视学术基础,强调学术精神,不断提高学生的学术兴趣,培养学生的团队精神和合作能力,掌握渗透式学习方法,培养初步的科研能力;以及我们的做法:以相关课程为主干,配合相关的学术活动,形成了针对物理拔尖人才培养的学术能力培养体系.针对实施的效果,我们也对一些相关问题进行了调研和反思. 展开更多
关键词 基础学科拔尖学生培养试验计划 物拔尖学生 学术能力培养
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高中-本科-研究生辐射发展的物理学术竞赛 被引量:2
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作者 余华 李川勇 +3 位作者 吴强 薄方 刘智波 阎宝岩 《大学物理》 2018年第5期68-71,共4页
简要介绍了南开大学高中-本科-研究生各个阶段的物理学术竞赛开展情况,以及在本科教育阶段学术竞赛活动和其它创新活动的有效衔接,从而形成从高中至研究生可持续、分层次的创新教育网络.
关键词 物理学术竞赛 本科教育 创新活动 创新教育网络
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Pt纳米颗粒结合ZIF-67衍生的PtCo-NC催化剂用于醇类燃料电氧化 被引量:9
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作者 方波 冯立纲 《物理化学学报》 SCIE CAS CSCD 北大核心 2020年第7期40-46,共7页
在本工作中,通过在氮气保护下热解Pt纳米颗粒结合的ZIF-67制备了由ZIF-67原位产生的氮掺杂碳负载Pt Co合金纳米颗粒组成的Pt Co-NC复合催化剂。通过X射线衍射,扫描电子显微镜,透射电子显微镜等物理表征手段研究了催化剂的结构和形貌,并... 在本工作中,通过在氮气保护下热解Pt纳米颗粒结合的ZIF-67制备了由ZIF-67原位产生的氮掺杂碳负载Pt Co合金纳米颗粒组成的Pt Co-NC复合催化剂。通过X射线衍射,扫描电子显微镜,透射电子显微镜等物理表征手段研究了催化剂的结构和形貌,并测试了该催化剂对醇类燃料甲醇和乙醇氧化的电化学性能。与参比样Pt/C相比,Pt Co-NC催化剂的电催化活性与稳定性均得到了极大的提高,其优异的催化性能可以归因于抗一氧化碳中毒能力的提升和原位形成的Pt Co纳米颗粒和氮掺杂载体间的协同作用。 展开更多
关键词 醇类氧化反应 直接醇类燃料电池 电催化剂 铂基催化剂 氮掺杂碳
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乳腺癌患者术前、术后及化疗后外周血CD4+、CD8+和B细胞的变化及临床意义 被引量:7
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作者 隗传超 柏方 +4 位作者 刘维燕 潘高峰 史荣亮 葛梅馨 吴克瑾 《海军医学杂志》 2018年第1期33-37,共5页
目的探讨乳腺癌患者术前、术后及化疗后外周血CD4+、CD8+和B细胞的变化及其与临床预后的关系。方法选取2015年7月至2017年3月上海市闵行区中心医院普外科收治的乳腺癌患者79例。应用流式细胞术分析乳腺癌患者和良性乳腺肿瘤患者外周血C... 目的探讨乳腺癌患者术前、术后及化疗后外周血CD4+、CD8+和B细胞的变化及其与临床预后的关系。方法选取2015年7月至2017年3月上海市闵行区中心医院普外科收治的乳腺癌患者79例。应用流式细胞术分析乳腺癌患者和良性乳腺肿瘤患者外周血CD4+、CD8+和B细胞水平的差异,以及乳腺癌患者术前、术后及化疗后T细胞亚群和B细胞水平及与乳腺癌患者不同TNM分期和分子分型之间的相关性。结果在TNM不同分期CD4+细胞水平存在差异(均P<0.05),在良恶性肿瘤之间、化疗前后及不同年龄分层,CD8+细胞水平的差异均有统计学意义(均P<0.05),化疗后在不同的TNM分期(P=0.001)及分子分型存在差异(P=0.011);在良恶性肿瘤之间、化疗前后及不同年龄分层之间B细胞水平差异有统计学意义(均P<0.05),术后在不同的TNM分期之间及分子分型之间差异有统计学意义(P=0.026,P=0.022);CD8+、B细胞可能成为患者的预后因素,但CD8+与B细胞水平并非乳腺癌治疗后生存的独立预后因素。结论外周血B细胞、CD4+和CD8+淋巴细胞水平对于乳腺癌的诊断和预后有一定价值,值得进行深入探讨并将其应用于临床。 展开更多
关键词 乳腺癌 CD4+细胞 CD8+细胞 B细胞 TNM分期 分子分型
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下颌骨前突患者下颌管走行及临床价值探讨
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作者 叶丽娟 薄芳 +1 位作者 刘晶 王跃平 《上海口腔医学》 CAS CSCD 北大核心 2020年第5期524-527,共4页
目的:运用锥形束CT(cone-beam CT,CBCT)分析正常人群和下颌骨前突患者下颌神经管轨迹,为临床手术方案的制订和操作时避开重要神经血管提供帮助。方法:选取28例骨性Ⅲ类下颌骨前突患者(男10例,女18例)、20例正常对照组患者(男12例,女8例)... 目的:运用锥形束CT(cone-beam CT,CBCT)分析正常人群和下颌骨前突患者下颌神经管轨迹,为临床手术方案的制订和操作时避开重要神经血管提供帮助。方法:选取28例骨性Ⅲ类下颌骨前突患者(男10例,女18例)、20例正常对照组患者(男12例,女8例),使用CBCT拍摄下颌管影像,从下颌孔至第一磨牙区分为5个平面,在每个层面分别测量下颌管内外径、下颌骨厚度、下颌管至颊舌侧骨皮质及下颌骨下缘的距离。采用SPSS 17.0软件包对测量结果进行统计学分析。结果:下颌骨前突患者自下颌支到下颌角前部逐渐增厚,继续至下颌第一磨牙区逐渐变薄。下颌神经管的内外径自下颌支到下颌体部逐渐变细。颊侧骨皮质厚度自下颌支区域逐渐增厚,到下颌体部继续变薄。下颌骨前突患者与对照组患者下颌管的对比分析显示,骨髓腔宽度与下颌支厚度有显著差异,且具有显著相关性。结论:CBCT能够精确显示下颌神经管的走行及与周边结构的关系,下颌骨前突患者与对照组患者下颌支厚度的差异主要由颊侧骨髓腔宽度造成。 展开更多
关键词 下颌神经管 锥形束CT 下颌骨前突
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The roles of microRNAs in spinal cord ischemia-reperfusion injury 被引量:2
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作者 Feng-Shou Chen Xiang-Yi Tong +3 位作者 bo fang Dan Wang Xiao-Qian Li Zai-Li Zhang 《Neural Regeneration Research》 SCIE CAS CSCD 2022年第12期2593-2599,共7页
Spinal cord ischemia/reperfusion injury is a devastating medical disorder with poor prognosis that is associated with several pathophysiological conditions.However,multiple stimuli can trigger SCII,so the underlying m... Spinal cord ischemia/reperfusion injury is a devastating medical disorder with poor prognosis that is associated with several pathophysiological conditions.However,multiple stimuli can trigger SCII,so the underlying mechanism of this pathology has not yet been fully established.MicroRNAs(miRNAs)are a class of non-coding RNAs that mediate a variety of nervous system diseases and regulate numerous physiological functions,including apoptosis,autophagy,inflammation,and blood-spinal cord barrier damage.miRNA expression profiles are known to be altered after spinal cord ischemia/reperfusion injury.Therefore,gaining a better understanding of the significant roles that miRNAs play in spinal cord ischemia/reperfusion injury could help develop potential preventive and therapeutic strategies for spinal cord ischemia/reperfusion injury.This review summarizes the current state of our knowledge about the relationship between miRNAs and spinal cord ischemia/reperfusion injury,as well as potential miRNAs that could be targeted to treat spinal cord ischemia/reperfusion injury. 展开更多
关键词 APOPTOSIS AUTOPHAGY blood-spinal cord barrier INFLAMMATION MICRORNAS PATHOPHYSIOLOGY review spinal cord ischemia-reperfusion injury
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铌酸锂晶体的光折变效应 被引量:2
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作者 郑大怀 张宇琦 +5 位作者 王烁琳 刘宏德 刘士国 孔勇发 薄方 许京军 《人工晶体学报》 CAS 北大核心 2022年第9期1626-1642,共17页
铌酸锂(LiNbO_(3),LN)是一种多功能多用途的人工晶体,被称为“光学硅”。近期以铌酸锂薄膜(LNOI)为平台的集成光子学发展迅速,有将“光学硅”变为现实的趋势。高集成意味着高局域高光强密度,使铌酸锂晶体的光折变效应变得不容忽视。光... 铌酸锂(LiNbO_(3),LN)是一种多功能多用途的人工晶体,被称为“光学硅”。近期以铌酸锂薄膜(LNOI)为平台的集成光子学发展迅速,有将“光学硅”变为现实的趋势。高集成意味着高局域高光强密度,使铌酸锂晶体的光折变效应变得不容忽视。光折变效应是光致折射率变化的简称,是非线性光学的重要组成部分。本文回顾了铌酸锂晶体光折变效应的发现和机理、不同掺杂及掺杂组合对光折变效应的调控,重点介绍了铋镁双掺铌酸锂晶体的光折变性能及相关理论和实验结果,概述了铌酸锂光折变波导和孤子,及基于LNOI的集成光子学器件中的光折变效应,并对未来的研究趋势进行了展望。期待我国发挥铌酸锂光折变研究及LNOI产业化的优势,在光子学芯片的竞争中占据主导地位。 展开更多
关键词 铌酸锂晶体 光折变效应 机制 掺杂 全息存储及显示 集成光子学
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Detection of Nitric Oxide with Faraday Rotation Spectroscopy at 5.33μm 被引量:2
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作者 bo fang Na-na Yang +4 位作者 Chun-hui Wang Wei-xiong Zhao Xue-zhe Xu Yang Zhang Wei-jun Zhang 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2020年第1期37-42,共6页
We report the development of a static magnetic eld Faraday rotation spectrometer for NO detection.A 5.33μm continuous-wave quantum cascade laser was used as the probing laser.Line absorption at 1875.81 cm^−1(2Π3=2Q(... We report the development of a static magnetic eld Faraday rotation spectrometer for NO detection.A 5.33μm continuous-wave quantum cascade laser was used as the probing laser.Line absorption at 1875.81 cm^−1(2Π3=2Q(3/2),v=1←0)was chosen for the detection.By using a Chernin type multipass cell,a detection precision of 1.15 ppbv(1σ,1s)was achieved with an absorption pathlength of 108 m.This value was reduced to 0.43 ppbv by increasing the data-acquisition time to 15 s. 展开更多
关键词 Faraday rotation spectroscopy MID-INFRARED Laser spectroscopy Nitric oxide
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铌酸锂薄膜微腔激光器研究进展(特邀) 被引量:2
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作者 罗强 薄方 +2 位作者 孔勇发 张国权 许京军 《红外与激光工程》 EI CSCD 北大核心 2021年第11期43-55,共13页
绝缘体上铌酸锂薄膜凭借铌酸锂晶体优异的光学性能和薄膜器件的易加工和可集成特性,被视为理想的集成光学平台。除了波导、调制器等传输、控制器件方面的研究之外,最近铌酸锂薄膜激光器的研究也取得了显著的进展。文中将对最近迅速发展... 绝缘体上铌酸锂薄膜凭借铌酸锂晶体优异的光学性能和薄膜器件的易加工和可集成特性,被视为理想的集成光学平台。除了波导、调制器等传输、控制器件方面的研究之外,最近铌酸锂薄膜激光器的研究也取得了显著的进展。文中将对最近迅速发展的铌酸锂薄膜微腔激光器的研究现状进行综述。首先,介绍铌酸锂晶体和铌酸锂薄膜稀土离子掺杂的主要技术方案,以及近期有关于稀土离子掺杂铌酸锂薄膜微纳光学器件制备方面的探索;其次,总结近年来掺铒铌酸锂薄膜微盘腔、微环腔激光器方面的研究进展;然后,阐述微腔激光器体系几种常见的实现单模激光器方法的工作机理,介绍研究者们利用"游标效应"调制模式损耗等方式实现掺铒铌酸锂薄膜单模激光器的研究进展;最后,基于目前报导的铌酸锂薄膜激光器研究成果,对目前研究存在的局限性以及未来的研究方向进行了探讨。 展开更多
关键词 铌酸锂薄膜 微腔激光器 集成光学
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Population Change of OH and H2O in Water Vapor Glow Discharge Measured Using Concentration Modulation Spectroscopy 被引量:1
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作者 Bao Li Li Wang +3 位作者 bo fang Wei-xiong Zhao Lun-hua Deng Huai-liang Xu 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2020年第4期411-416,I0001,共7页
A distributed feedback laser with a wavelength of 2.8μm was used to measure the species produced by water vapor glow discharge.Only the absorption spectra of OH radicals and transient H2O molecules were observed usin... A distributed feedback laser with a wavelength of 2.8μm was used to measure the species produced by water vapor glow discharge.Only the absorption spectra of OH radicals and transient H2O molecules were observed using concentration modulation(CM)spectroscopy.The intensities and orientations of the absorption peaks change with the demodulation phase,but the direction of one absorption peak of H2O is always opposite to the other peaks.The different spectral orientations of OH and H2O reflect the increase or the decrease of the number of particles in the energy levels.If more transient species can be detected in the discharge process,the dynamics of excitation,ionization,and decomposition of H2O can be better studied.This study shows that the demodulation phase relationship of CM spectrum can be used to study the population change of molecular energy levels. 展开更多
关键词 Glow discharge OH radical Concentration modulation spectroscopy Population change
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阴离子交换树脂对典型及新型全氟/多氟烷基酸的吸附去除
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作者 李霞 曹溢 +3 位作者 方博 张连营 陈浩 孙红文 《科学通报》 EI CAS CSCD 北大核心 2024年第14期1934-1944,共11页
全氟/多氟烷基酸类物质(PFAAs)作为一类优良的表面活性剂被广泛应用于纺织、半导体和航天等多种商业和工业领域,造成了水体中PFAAs的严重污染.常规饮用水处理工艺如絮凝、高级氧化等不能有效去除PFAAs,而离子交换树脂仅能去除传统的长链... 全氟/多氟烷基酸类物质(PFAAs)作为一类优良的表面活性剂被广泛应用于纺织、半导体和航天等多种商业和工业领域,造成了水体中PFAAs的严重污染.常规饮用水处理工艺如絮凝、高级氧化等不能有效去除PFAAs,而离子交换树脂仅能去除传统的长链PFAAs,对于短链替代物C4 PFAAs和全/多氟醚羧酸的去除效果仍然未知.因此,本研究选取不同链长和官能团的PFAAs,探究不同结构PFAAs的吸附动力学特征,以及树脂性质和水化学条件(溶液pH、共存污染物、无机盐离子)对阴离子交换树脂(AERs)吸附去除不同结构PFAAs的影响特征及关键控制因素.结果表明, PFAAs在大孔AERs(A860)上的吸附速率更快,而凝胶型高憎水性的聚苯乙烯基树脂(A600)对PFAAs的吸附容量和去除率更高. PFAAs链长及官能团的电负性对其吸附速率和去除率均有较大影响:相同碳链长度下,全氟磺酸(PFSAs)>全氟羧酸(PFCAs).对于含有相同官能团的PFAAs,短链PFAAs的吸附速率高于长链PFAAs.溶液pH对PFAAs在树脂上的吸附影响较小.短链PFAAs在AERs上的吸附主要受离子交换作用控制,易受无机盐离子干扰.憎水性较强的PFAAs在树脂上的吸附除静电作用外,主要受憎水性分配的控制.常规的AERs难以有效去除水体中亲水性较强的短链PFCAs(C<4)和全氟醚羧酸(如GenX),因此这些新型PFAAs替代物给未来的水处理工作带来了极大挑战. 展开更多
关键词 全氟/多氟烷基酸 短链全氟烷基酸 离子交换树脂 竞争吸附
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Photorheologically reversible micelle composed of polymerizable cationic surfactant and 4-phenylazo benzoic acid
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作者 Jie Chen bo fang +5 位作者 Hao Jin Licheng Yu Meng Tian Kejing Li Leiping Jin Mo Yang 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2016年第2期289-292,共4页
A photorheologically reversible micelle composed of polymerizable cationic surfactant n-cetyl dimethylallyl am- monium chloride (CDAAC) and trans-4-phenylazo benzoic acid (trans-ACA) was prepared. The effects of m... A photorheologically reversible micelle composed of polymerizable cationic surfactant n-cetyl dimethylallyl am- monium chloride (CDAAC) and trans-4-phenylazo benzoic acid (trans-ACA) was prepared. The effects of molar ratio of CDAAC/trans-ACA, time of UV and visible light irradiation and temperature on the rheological properties of micellar system were investigated. The results show that before UV irradiation the system with an optimum CDAAC/trans-ACA molar ratio of 1.4 forms viscoelastic micelles at 45 ℃. After 365 nm UV irradiation, the viscos- ities of micelle systems with different concentrations at fixed molar ratio of 1.4 are decreased by 85%-95%. The CDAAC/trans-ACA (14 mmol. L- 1/10 mmol. L- 1 ) micelle system exhibits shear thinning property and its viscos- ity is decreased obviously with the increases of UV irradiation time less than I h. The rheological process during LIV irradiation for CDAAC/trans-ACA (14 mmol- L- 1/10 mmol. L 1) micelle proves that viscosity, elastic modulus G' and viscous modulus G" will reduce quickly with the UV light. Furthermore, the micelle system after 1 h UV- irradiation is able to revert to its initial high viscosity with 460 nm visible light irradiation for 4 h, and the micelle can be cycled between low and high viscosity states by repetitive UV and visible light irradiations. The LIV-Vis spectra of CDAAC/trans-ACA micelle indicate that its photosensitive theological properties are related closely to photoisomerization of trans-ACA to c/s-ACA. 展开更多
关键词 Photorheological micelle Polymerizable cationic surfactant4-Phenylazo benzoic acid Rheological properties
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Vibration analysis of fluid-conveying nanotubes embedded in an elastic medium considering surface effects
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作者 Yuhang Li bo fang +1 位作者 Jiazhong Zhang Jizhou Song 《Theoretical & Applied Mechanics Letters》 CAS 2012年第3期41-44,共4页
An analytical model is developed to study the surface effects on the vibration behavior including the natural frequency and the critical flow velocity of fluid-conveying nanotubes embedded in an elastic medium.The eff... An analytical model is developed to study the surface effects on the vibration behavior including the natural frequency and the critical flow velocity of fluid-conveying nanotubes embedded in an elastic medium.The effects of surface elasticity and residual surface stress are accounted through the surface elasticity model and the Young-Laplace equation.A Winkler-type foundation is employed to model the interaction of nanotubes and the surrounding medium.The results show that the surface effects have more prominent influences on the nature frequency with smaller nanotube thickness,larger aspect ratio and larger elastic medium constants.Both surface layers and the elastic medium enhance the stability of nanotubes.This study might be helpful for designing the fluid-conveying nanotube devices in NEMS and MEMS systems. 展开更多
关键词 surface effect fluid-conveying nanotube vibration stability
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