XtalCAMP:同步辐射微衍射成像的软件开发及应用

作为一种高通量的表征手段,扫描式同步辐射劳厄微衍射成像技术在研究晶体材料的结构、晶体取向、应力/应变以及显微缺陷等领域具有广阔的应用前景。伴随着高亮度同步辐射装置的建设与高速二维探测器的应用,相应自动化定制化分析软件的开发也将成为推动该技术发展的重要力量。本文介绍一款基于同步辐射微衍射实验数据定制开发的综合分析软件XtalCAMP,并以增材制造镍基高温合金DZ125L为研究材料,阐明利用该软件进行材料多尺度微观结构可视化表征、微观缺陷密度分析、晶体取向追踪以及残余应力/应变分析的科学原理,旨在通过数据处理功能的介绍与推广展现扫描式同步辐射劳厄微衍射成像技术在材料微观研究领域的技术优势,为推动该技术软硬件开发及应用进程提供借鉴与参考。

带式输送机自动张紧液压装置的设计

本文通过简要分析带式输送机张紧装置,确定最大张紧力和张紧行程,并根据带式输送机的液压系统运行原理和特点对带式输送机的控制系统进行设计研究,根据不同的压力值的设定来控制带式输送机的运行过程。此外,充分结合不同的研究结果并采用PLC技术,使输送机的自动控制和动态监测得以实现。

峨眉山大火成岩省成都-简阳地区火山碎屑岩格架的新类别划分、成因及其油气储集效应

二叠纪峨眉山大火成岩省岩浆喷发是我国显生宙最大的岩浆喷溢事件。四川盆地中二叠世最新油气勘探成果显示,在峨眉山大火成岩省北缘成都简阳地区,发育大量以火山碎屑岩为主的全新岩性格架。本文首次对该区域岩性格架展开了详细的火山学解译。在优势储集层段中识别出熔结凝灰岩、自碎裂角砾岩和溅积集块岩三类关键岩性,分别形成于溢气爆发陆上火山碎屑流机制、溢流喷发自碎裂角砾化机制以及斯通博利夏威夷涌溅式喷发机制。这是首次对峨眉山大火成岩省中上述岩性的成因机制进行正式确认。在这些岩性中,储集空间以溶蚀孔和交代孔为主。上述岩性的喷发机制,对其储集空间的发育提供了全方位的关键制约因素:(1)有利于产生大量浆源碎屑;(2)堆积方式有利于维持大量相互连通的原生孔隙,使热液流体得以广泛接触碎屑堆积骨架;(3)堆积于火口近源区域,受异常热流值作用强,有助于维持流体的高效活性。上述三方面最终导致流体对岩石骨架进行深刻的溶蚀交代改造,为规模性储集体发育奠定前提。

纳米金刚石表面向洋葱碳转变的原位电镜研究

纳米金刚石向一种洋葱状石墨碳结构的转变对其性能改变显著,然而人们在研究这种始于表面的碳结构转变时却往往忽略了纳米金刚石表面不可避免会存在的非晶碳层的影响。本文借助原位环境球差电镜技术,利用电子束辐照和原位热氧化,获得了表面没有非晶碳层的纯净纳米金刚石颗粒,并证实了同样条件下表面含有非晶碳层的纳米金刚石更容易转变为洋葱碳,而表面结晶性好、不含非晶碳的纳米金刚石则更难转变为洋葱碳;此外,当电子束辐照耦合高温加热可以在更低的温度和更短的时间内将纳米金刚石全部转变为洋葱碳。本文的研究结果对抑制纳米金刚石表面石墨化转变提升其稳定性或促进纳米金刚石向洋葱碳转变并提升转变效率均具有一定的指导意义。

环境透射电镜中电子束活化气体在材料表面改性方面的机理及应用研究

随着原位透射电子显微技术的不断发展与成熟,在近使役环境中对材料进行高空间与高时间分辨率下的研究得以广泛开展。而环境透射电镜(Environmental transmission electron microscope,E⁃TEM)与材料真实服役环境的一个重要区别在于所引入的环境气氛和样品材料本身都不可避免地受到电子束辐照的影响,因此多数研究都聚焦在如何降低或消除电子束辐照对研究结果的负面干扰。但实际上E⁃TEM中高能电子束可以起到较强的“催化”作用,从而激发出一些原本只有在苛刻条件下才能出现的现象或反应,助力材料改性、新材料合成及相应的微观反应机理的原位研究。本文以近几年作者所在研究团队及合作者利用E⁃TEM中电子束活化CO_(2)和H2气体分子在提升活泼金属耐蚀性、稳定性、辅助陶瓷的室温焊接及样品表面原位清洁等方面的具体应用为例,对电子束促进气固反应、改性材料表面及相关机理进行了介绍,并结合相关实验研究提出了固体表面吸附对电子束诱导气体活化过程的关键作用,更新了之前人们对电子束是通过提高游离态气体反应活性影响气-固间相互作用的认知。

Optoelectronic Synapses Based on MXene/Violet Phosphorus van der Waals Heterojunctions for Visual‑Olfactory Crossmodal Perception

The crossmodal interaction of different senses,which is an important basis for learning and memory in the human brain,is highly desired to be mimicked at the device level for developing neuromorphic crossmodal perception,but related researches are scarce.Here,we demonstrate an optoelectronic synapse for vision-olfactory crossmodal perception based on MXene/violet phosphorus(VP)van der Waals heterojunctions.Benefiting from the efficient separation and transport of photogenerated carriers facilitated by conductive MXene,the photoelectric responsivity of VP is dramatically enhanced by 7 orders of magnitude,reaching up to 7.7 A W^(−1).Excited by ultraviolet light,multiple synaptic functions,including excitatory postsynaptic currents,pairedpulse facilitation,short/long-term plasticity and“learning-experience”behavior,were demonstrated with a low power consumption.Furthermore,the proposed optoelectronic synapse exhibits distinct synaptic behaviors in different gas environments,enabling it to simulate the interaction of visual and olfactory information for crossmodal perception.This work demonstrates the great potential of VP in optoelectronics and provides a promising platform for applications such as virtual reality and neurorobotics.

Fe-N-C core-shell catalysts with single low-spin Fe(Ⅱ)-N_(4)species for oxygen reduction reaction and high-performance proton exchange membrane fuel cells

Fe-N-doped carbon materials(Fe-N-C)are promising candidates for oxygen reduction reaction(ORR)relative to Pt-based catalysts in proton exchange membrane fuel cells(PEMFCs).However,the intrinsic contributions of Fe-N_(4)moiety with different chemical/spin states(e.g.D1,D2,D3)to ORR are unclear since various states coexist inevitably.In the present work,Fe-N-C core-shell nanocatalyst with single lowspin Fe(Ⅱ)-N_(4)species(D1)is synthesized and identified with ex-situ ultralow temperature Mossbauer spectroscopy(T=1.6 K)that could essentially differentiate various Fe-N_(4)states and invisible Fe-O species.By quantifying with CO-pulse chemisorption,site density and turnover frequency of Fe-N-C catalysts reach 2.4×10^(-9)site g^(-1)and 23 e site~(-1)s^(-1)during the ORR,respectively.Half-wave potential(0.915V_(RHE))of the Fe-N-C catalyst is more positive(approximately 54 mV)than that of Pt/C.Moreover,we observe that the performance of PEMFCs on Fe-N-C almost achieves the 2025 target of the US Department of Energy by demonstrating a current density of 1.037 A cm^(-2)combined with the peak power density of 0,685 W cm^(-2),suggesting the critical role of Fe(Ⅱ)-N_(4)site(D1).After 500 h of running,PEMFCs still deliver a power density of 1.26 W cm^(-2)at 1.0 bar H_(2)-O_(2),An unexpected rate-determining step is figured out by isotopic labelling experiment and theoretical calculation.This work not only offers valuable insights regarding the intrinsic contribution of Fe-N_(4)with a single spin state to alkaline/acidic ORR,but also provides great opportunities for developing high-performance stable PEMFCs.

Ultrasound in Ti-Rads Classification of Thyroid Nodules at the Marie Curie Medical Clinic

Introduction: A thyroid nodule is a localized hypertrophy within the thyroid parenchyma. The aim of our study was to study the benefit of ultrasound in the Ti-rads classification of thyroid nodules. Methodology: This was a prospective study with a descriptive aim, with prospective collection, which took place over a period of 17 months at the “Marie Curie” medical clinic. The ultrasound machine used was a Voluson E8 from 2011 and the examinations were carried out by two radiologists and two experienced sonographers. The parameters studied were sociodemographic data;clinical data and ultrasound aspects of the Ti-rads classification in the management of nodules. Results: We collected 235 patients out of 738 patients referred to the service for a cervical ultrasound, i.e. a frequency of 31.84% of cases. There was a female predominance with 95.7% of cases and a sex ratio of 0.04. The average age of our patients was 50 years. We found on cervical ultrasound: Isthmo-lobar glandular hyperplasia in 99 patients, i.e. a frequency of 42.1%. The Ti-rads 3 classification was the most represented in 69.4% of cases. The benignity criterion represented 85.6% of cases in our patients and the malignancy criterion represented 14.4% of cases. Conclusion: The precise description of a thyroid nodule provided by ultrasound (Ti-rads) is essential in the management of nodules.

整合素α6靶向自组装促凋亡纳米多肽对中枢神经系统急性淋巴细胞白血病的靶向治疗

There is currently no effective targeted therapeutic strategy for the treatment of central nervous system acute lymphoblastic leukemia(CNS-ALL).Integrinα6 is considered a potential target for CNS-ALL diagnosis and therapy because of its role in promoting CNS-ALL disease progression.The targeted peptide D(RWYD)(abbreviated RD),with nanomolar affinity to integrinα6 was identified by peptide scanning techniques such as alanine scanning,truncation,and D-substitution.Herein,we developed a therapeutic nanoparticle based on the integrinα6-targeted peptide for treating CNS-ALL.The self-assembled proapoptotic nanopeptide_(D)(RWYD)-_(D)(KLAKLAK)_(2)-G_(D)(FFY)(abbreviated RD-KLA-Gffy)contains the integrinα6-targeted peptide RD,the well-known proapoptotic peptide_(D)(KLAKLAK)_(2)(abbreviated KLA),and the self-assembling tetrapeptide GD(FFY)(abbreviated Gffy).The functional mechanism of RD-KLA-Gffy is clarified using different experiments.Our results demonstrate that RD-KLA-Gffy is highly enriched in CNS-ALL lesions and induces tumor cell apoptosis,thus reducing CNS-ALL disease burden and prolonging the survival of CNS-ALL mice without obvious toxicity.Moreover,the combined use of RD-KLA-Gffy and methotrexate(MTX)shows a potent antitumor effect in treating CNS-ALL,indicating that RD-KLA-Gffy plays an important role in suppressing CNS-ALL progression either as a single agent or in combination with MTX,which shows promise for application in CNS-ALL therapy.

Blown Film Extrusion Process for Polybags: Technical Overview and Applications

The choice of extrusion process is a decisive factor that affects the finished product quality for polybag manufacturing. One important component influencing the quality of the finished product is the selection of the extrusion technique. Two popular procedures that vary in the kind of dye used and the final product’s texture are cast film and blown film. In the horizontal extrusion moulding method known as “cast film”, heated resin is injected into a flat dye and allowed to cool on chill rolls. The film produced is clear, lightweight, and appropriate for lamination;its thickness varies based on the winding speed and the film is slower to crystallize and has less clarity but more durability because the resin molecules have reoriented, facing limitation of high wastage generation. This study primarily focused on the preparation of polybag film using the blown film extrusion process, utilizing high-quality polymer resins such as polyester polyethylene (PP) and linear low-density polyethylene (LLDPE) to minimize waste generation. The novelty of the process was reflected in minimising the waste generation. The control parameters considered in this study are temperature, pressure, and air intake volume. We investigated the influence of these critical process control parameters on the gauge thickness, optical properties, and mechanical strength of the polybag film produced through blown film extrusion. Additionally, we replicated the blown film process using simulation software developed at Pennsylvania College of Technology. The simulation results confirmed the overall stability of the polybag film produced through the blown film extrusion process.

A Low-Power 12-Bit SAR ADC for Analog Convolutional Kernel of Mixed-Signal CNN Accelerator

As deep learning techniques such as Convolutional Neural Networks(CNNs)are widely adopted,the complexity of CNNs is rapidly increasing due to the growing demand for CNN accelerator system-on-chip(SoC).Although conventional CNN accelerators can reduce the computational time of learning and inference tasks,they tend to occupy large chip areas due to many multiply-and-accumulate(MAC)operators when implemented in complex digital circuits,incurring excessive power consumption.To overcome these drawbacks,this work implements an analog convolutional filter consisting of an analog multiply-and-accumulate arithmetic circuit along with an analog-to-digital converter(ADC).This paper introduces the architecture of an analog convolutional kernel comprised of low-power ultra-small circuits for neural network accelerator chips.ADC is an essential component of the analog convolutional kernel used to convert the analog convolutional result to digital values to be stored in memory.This work presents the implementation of a highly low-power and area-efficient 12-bit Successive Approximation Register(SAR)ADC.Unlink most other SAR-ADCs with differential structure;the proposed ADC employs a single-ended capacitor array to support the preceding single-ended max-pooling circuit along with minimal power consumption.The SARADCimplementation also introduces a unique circuit that reduces kick-back noise to increase performance.It was implemented in a test chip using a 55 nm CMOS process.It demonstrates that the proposed ADC reduces Kick-back noise by 40%and consequently improves the ADC’s resolution by about 10%while providing a near rail-to-rail dynamic rangewith significantly lower power consumption than conventional ADCs.The ADC test chip shows a chip size of 4600μm^(2)with a power consumption of 6.6μW while providing an signal-to-noise-and-distortion ratio(SNDR)of 68.45 dB,corresponding to an effective number of bits(ENOB)of 11.07 bits.

Management of Immediate Postpartum Hemorrhage at the University Hospital Center of the Sino-Central African Friendship

Introduction: Immediate postpartum hemorrhages constitute a frequent maternal complication and remain at the forefront of maternal death in our countries. Objective: Contribute to improving the management of immediate postpartum hemorrhage in our context with a view to reducing maternal mortality. Patients and Methods: We conducted a retrospective descriptive and analytical study over a period of 12 months from January 1st to December 31st 2020. Results: We collected a total of 109 files on a total of 4360 deliveries. The frequency of postpartum haemorrhages was of the order of 2.5%. The most represented age group was between 20 and 24 years old. Pauciparas represented the majority of our study population. 64.5% of patients were uneducated. These hemorrhages occurred in patients who often gave birth outside the department with 63.8%. The main causes of postpartum hemorrhage were cervical tears (51.2%) and partial placental retention (30.7%). The majority of these deliveries (48.8%) were carried out by midwives followed by assistant midwives (33.2%). Active management of the third period of delivery was systematic and immediate followed by the valve examination completed by the infusion of oxytocin in case of uterine atony, tranexamic acid ans misoprostol intrarectally. In the event of persistent hemorrhage, suture of the cervical lesions, ligation of the cervical vessels or even laparotomy either for the selective ligation of the blood vessels or for the hysterectomy for hemostasis were practiced. We do not have a Nalador, nor a Bakry balloon, nor an Interventional Radiology service for embolization of the uterine arteries. We deplore 1.3% of deaths from afibrinogenemia. Conclusion: The frequency of immediate postpartum hemorrhages is lower in our health facility. This is due to the rapid handling of cases. Improving the quality of services offered to women during childbirth can further help reduce the frequency of these hemorrhages.

开展自然教育实践活动流程——以陕西省红河谷森林公园为例

在绿色生态教育理念指导下,秦岭北麓经过多年的健康发展建设,各级森林公园不计其数,逐渐也从以发展森林旅游经营定位转变为以开展自然生态教育实践的主题基地。该研究通过作者多年工作实践经验总结出在森林公园开展自然教育活动流程,具有较强的专业和实践指导作用。

Otorhinolaryngology Diseases in HIV-Positive Patients: 208 Cases at the Donka National Hospital

Introduction: Otorhinolaryngology (ENT) diseases in patients living with Human Immunodeficiency Virus/Acquired Immunodeficiency Syndrome (HIV/ AIDS) are relatively common and of concern to ENT specialists and other health professionals. Aim: It was to describe the epidemiological and diagnostic aspects of ENT and cervicofacial diseases in patients living with HIV/ AIDS. Material and Methods: This was a descriptive study with prospective data collection, conducted over a period of six months (September 16, 2019 to March 16, 2020), carried out at the ENT and Infectious Diseases Departments of the Donka National Hospital. Results: Of 522 HIV-positive patients, 208 (39.8%) presented with ENT diseases. Women represented 62.5% with a sex ratio of 0.6. The mean age was 42.21 years with extremes of 16 and 64 years. Housewives were the most represented (29.8%). Married people were the most affected (76.4%). Cervical involvement was present in 7.7% of patients. Otologic involvement accounted for 43.7%. Oral cavity and pharyngolaryngeal involvement accounted for 50.9%. Nasosinus involvement accounted for 55.7%. HIV type I was the most common (99.5%). Conclusion: Otorhinolaryngology diseases were frequent in HIV positive patients. They may constitute the first reason for consultation. However, these ENT diseases remain in appendix of the opportunistic diseases of HIV/AIDS taking the front stage.

多普勒全向信标的故障与应对措施分析

阐述THALES DVOR432全向信标案例,THALES DVOR432结构及全向信标的基本原理和功能,探讨多普勒全向信标常见故障及维修处理措施,包括供电板件、远端遥控器的故障及维修方法。

NCEP、ECMWF及CMC全球集合预报业务系统发展综述

总结了目前最具代表性的3个全球集合预报系统(global ensemble forecast system,GEFS)——美国国家环境预报中心(National Centers for Environmental Prediction,NCEP)、欧洲中期天气预报中心(European Centre for Medium-Range Weather Forecasts,ECMWF)和加拿大气象中心(Canadian Meteoro-logical Centre,CMC)建成至今的发展概况。由于计算资源的不断扩展,各中心集合预报系统的模式分辨率、集合成员数也随之增加。同时各中心都在不断地致力于发展和完善初始和模式扰动方法,来更好地估计与初值和模式有关的不确定性,促进预报技巧的提高。其中初始扰动方法从最初的奇异向量法(ECMWF)、增殖向量法(NCEP)和观测扰动法(CMC)更新为现在的集合资料同化—奇异向量法(ECMWF)、重新尺度化集合转换法(NCEP)和集合卡尔曼滤波(CMC)。在估计模式不确定性方面,ECMWF和CMC都修订了各自的随机参数化方案和多参数化方案,NCEP最近也在模式中加入了随机全倾向扰动。为提高全球高影响天气预报的准确率,TIGGE计划(the THORPEX interactive grand global ensemble)的提出增进了国际间对多模式、多中心集合预报的合作研究,北美集合预报系统(North American ensemble forecast system,NAEFS)为建立全球多模式集合预报系统提供了业务框架,这都将有助于未来全球交互式业务预报系统的构建。

超声引导胸椎旁神经阻滞对于肋骨骨折患者术后镇痛效果的影响

目的观察超声引导胸椎旁神经阻滞(TPVB)对于肋骨骨折患者术后镇痛效果的影响。方法 40例择期行肋骨骨折切开复位内固定术的患者,随机分为全麻组(GA组,n=20)和全麻联合胸椎旁神经阻滞组(GA+TPVB组,n=20)。GA组接受标准的全身麻醉。在GA+TPVB组,全麻诱导后以0.5%罗哌卡因行患侧超声引导胸椎旁神经阻滞。所有患者在麻醉后恢复室(PACU)开始接受含有舒芬太尼的静脉镇痛泵,术后前3d应用注射用帕瑞昔布钠(特耐)40mg静脉推注,每日2次。记录两组患者术中切皮前后5min平均动脉压(MAP)及心率(HR)变化,术中舒芬太尼的用量;于术后1、12、24、48和72h对患者进行静息和活动下(深呼吸、咳嗽时)疼痛评估,主要预后指标为所有视觉模拟评分法(VAS);记录患者满意度;同时观察术后有无血肿、恶心、呕吐、呼吸抑制等不良反应的发生。结果与GA组比较,GA+TPVB组切皮前后MAP、HR波动明显减小(P<0.05),术中舒芬太尼用量明显减少(P<0.05);两组患者术后1、12、24、48h的VAS有显著差异,与GA组比较,GA+TPVB组VAS明显降低(P<0.05);GA组和GA+TPVB组术后呕吐发生率分别为15%和0,差异有统计学意义(P<0.05)。术后两组患者均未见血肿、呼吸抑制等不良反应发生。结论超声引导胸椎旁神经阻滞定位准确,操作成功率高,明显减少围手术期镇痛药物用量,提供有效的术后镇痛。

血清CRP/PA、TFPI-1及血RBP在颅脑外伤患者病情评估及预后预测中的价值

目的研究血清C反应蛋白(CRP)/前白蛋白(PA)、组织因子途径抑制物-1(TFPI-1)及血视黄醇结合蛋白(RBP)在颅脑外伤患者病情评估及预后预测中的价值。方法98例颅脑外伤患者按入院后的格拉斯哥昏迷量表(GCS)评分,将其分为轻型组(42例)、中型组(38例)、重型组(18例)。检测患者入院1、3、7 d时的血清CRP、PA、TFPI-1及血RBP水平,计算CRP/PA值。在患者住院14 d时,采用格拉斯哥预后量表(GOS)评分评判患者的预后,GOS评分1~3分者为预后不良组(69例),GOS评分4~5分为预后良好组(29例)。用受试者工作特征曲线(ROC)分析血清CRP/PA、TFPI-1、血RBP及3项指标联合在预测颅脑外伤患者预后中的价值。结果重型组患者的GCS评分显著高于轻型组和中型组;中型组GCS评分显著高于轻型组(均P<0.001)。3组患者随着入院1、3、7 d血清CRP/PA均逐步下降,TFPI-1和RBP逐步上升。重型组患者入院后1、3、7 d的血清CRP/PA明显高于轻型组和中型组,TFPI-1和RBP水平明显低于轻型组和中型组;中型组患者入院后1、3、7 d的血清CRP/Pa水平明显高于轻型组,TFPI-1和RBP水平明显低于轻型组;差异均有统计学意义(均P<0.05)。预后不良组患者入院后7 d后的血清CRP/PA显著低于预后良好组,TFPI-1、血RBP水平显著高于预后良好组(均P<0.001)。相比于血清CRP/PA、TFPI-1及血RBPP各项单一指标检测,3种指标联合检测的灵敏度(89.7%)和曲线下面积(AUC)(0.861)显著更高。结论血清CRP/PA、TFPI-1及血RBP能够评估颅脑外伤患者的病情程度;同时3种指标联合检测对于颅脑外伤患者预后预测价值较高。

利用多源遥感卫星数据研究南海内波的时空分布特征

利用1995～2005年300多幅ERS-1／2，Radarsat-1，ENVISAT、SPOT、Landsat、IRS和NOAA AVHRR图像统计了南海北部海洋内波的时间分布特征，并绘制了内波空间分布图，利用KdV方程和Levitus历史跃层资料反演了内波的振幅和波速等参数。研究结果表明，南海北部海洋内波出现的区域主要有3块：吕宋海峡，东沙岛和海南东北部。内波传播方向以西向为主。在吕宋海峡，相速度达3m／s，内波振幅超过100m。在东沙岛附近，相速度在1-5～2m／s左右，振幅在20～80m左右；东沙岛西面和北面，相速度在1～1．5m／s左右，振幅在5～20m左右。海南东北部，相速度在0．4～0．8m／s左右，振幅在2～4m左右。内波的时间分布特征为：内波以4～9月为高峰期，1～3月和11～12月为低峰期；在每个月里以16～19日为高峰期。

北京地区尖锐湿疣患者皮损中人乳头瘤病毒的检测和分型

目的分析北京地区尖锐湿疣患者人乳头瘤病毒的型别和发病特点,比较普通患者和抵抗力弱的患者的发病差异。方法采用PCR和RFLP方法分析HPV型别,对于难以通过酶切鉴定的PCR产物,构建重组测序质粒,检索GenBank进一步分型鉴定。结果普通患者HPV6型为主要感染型别,其次是HPV11型。HPV6型患者年龄较HPV11和HPV6+HPV11型更低;而高龄患者和免疫抑制患者则以HPV11+HPV6的混合感染和HPV11感染为主。部分患者还检测出HPV16和HPV53感染。结论HPV6是尖锐湿疣的主要致病型别,但患者年龄比其他型别更低,而抵抗力弱的患者则多与HPV11的感染有关。一般存在于正常生殖道组织的HPV53也可致尖锐湿疣的发生。