Nursing Care and Causative Analysis of Grade IV Capsular Contracture Following Breast Cancer Expander Implantation

Objective: By observing the treatment and nursing care of a patient with Grade IV capsular contracture following breast cancer expander implantation and subsequent Stage II reconstruction, we aim to analyze the reasons for the formation of capsular contracture after Stage I expander implantation and prevent its recurrence following Stage II reconstruction. Methods: In May 2020, the patient noticed an increase in the size of a breast mass. In August, she underwent AC-THP neoadjuvant chemotherapy, followed by a “right breast-conserving nipple-areolar subglandular excision + right axillary lymph node dissection + expander implantation” surgery in November 2020. Radiation therapy began in January 2021. During radiation therapy, the patient experienced severe breast hardening, distortion, tenderness, and was diagnosed with Grade IV capsular contracture. To relieve the capsular contracture, the patient underwent a “contracted capsule incision and release procedure + removal of the right breast expander + right breast implantation” surgery in July 2021. Postoperatively, measures were taken to prevent incision infection, emphasizing aseptic techniques, ensuring smooth negative pressure drainage, reducing skin flap tension, monitoring skin flap blood supply, actively preventing subcutaneous effusion and hematoma, and applying appropriate compression dressings. Results: The patient was discharged after the removal of the drainage tube. During the postoperative follow-up at 3 and 6 months, there was no recurrence of capsular contracture, and the breast appeared full, upright, and relatively soft. There were no complications such as hematoma, infection, breast implant rupture, breast sagging, or displacement. The patient had a good outcome without additional financial or surgical burdens. Conclusion: The occurrence of Grade IV capsular contracture in the patient is generally related to infection after Stage I expander implantation, improper compression dressing, excessive saline injection causing content infiltration, and radiation therapy. Therefore, it is recommended to enhance the intraoperative and postoperative prophylactic use of antibiotics after Stage I expander implantation. Intermittent saline injection after surgery, with the amount of saline gradually increasing rather than filling all at once, is advisable. This helps the breast tissue gradually adapt to expansion, reducing the risk of capsular contracture. Postoperatively, patients should be instructed to wear pressure garments and breast elastic bandages while intensifying breast monitoring during radiation therapy and increasing postoperative follow-up.

原子层制造的研究现状与科学挑战

原子层制造是指加工精度达到原子层量级的可控制造技术,包括原子层去除、添加、迁移等。针对信息、能源、航空航天等领域核心零部件超高性能构建的发展需求,通过原子层可控去除制造全频段原子级精度无损表面,并结合原子层增材制造原子级新结构,有望实现特殊功能的有效创成,保证超高性能的安全可靠。另外,后摩尔时代先进芯片的制造工艺将迈入亚纳米物理极限,原子层制造需求贯穿芯片制造工艺的全流程。本文阐述了原子层制造技术的发展需求与研究进展,围绕原子层抛光、原子层沉积/刻蚀、原子层损伤控制、原子层工艺与装备等领域,梳理了原子层制造的发展方向及研究目标,凝练了原子层制造领域未来的关键科学问题及面临的挑战,探讨了前沿研究方向和发展战略。

乳液成型制备二氧化硅/聚四氟乙烯复合薄膜及其性能优化

聚四氟乙烯(PTFE)由于优异的介电性能已成为高频通讯的重要载体,通常将其与无机填料复配以提高其力学性能。但是,受限于PTFE极低的表面能,无机填料与其界面作用极差,难以在传统车削或压延成膜的强应力作用下实现高填充复合薄膜材料的成型。因此文中尝试以尺寸更小,界面可灵活构筑的PTFE乳液为基体、二氧化硅(SiO_(2))为无机填料,通过SiO_(2)表面改性对SiO_(2)/PTFE复合膜材料性能强化,研究无机粒子表面改性对复合材料分散、界面及力学性能等的影响。研究发现,当偶联剂质量分数为5%时,SiO_(2)/PTFE复合薄膜(80μm)力学性能最优,拉伸强度由SiO_(2)改性前的4.35 MPa增加至5.33 MPa、断裂伸长率由38.2%增加至134.0%。为提高PTFE/SiO_(2)界面强度、制备高性能PTFE复合薄膜材料提供了新方法。

蛋白酶体抑制剂致血栓性微血管病的文献分析

目的:探讨蛋白酶体抑制剂(PI)相关血栓性微血管病(TMA)的发生规律和临床特点,为临床安全用药提供参考。方法:检索中国知网、万方数据库、维普数据库、PubMed、Web of Science等数据库中收录的PI相关TMA的案例报道,检索时间为建库至2023年4月30日。对患者基本信息、用药情况、TMA的临床表现、实验室检查、治疗及预后进行汇总分析。结果:纳入文献37篇,涉及患者92例,其中男性46例(占50.00%),女性29例(占31.52%),性别不详17例(占18.48%);平均年龄为(61±13)岁。TMA的中位发病时间为64 d,临床表现以发热、乏力、恶心/呕吐、少尿/无尿为主。因1例患者出现2次TMA,则合计93例次TMA,患者血小板计数明显降低,中位值为19.5×10^(9)/L,其中0~50×10^(9)/L的患者最多(52例次,占55.91%);64例次患者(占68.82%)的血清肌酐水平升高,其中>177~445μmol/L的患者最多(32例次,占34.41%)。停药和支持治疗后(共93例次),76例次患者(占81.72%)痊愈/好转,6例次(占6.45%)有后遗症,5例次(占5.38%)死亡。PI相关TMA中,主要涉及的药物为卡非佐米(67例次,占72.04%)。结论:应重视PI所致TMA,应用PI时应考虑患者性别、药物种类等因素;根据临床表现及实验室检查结果,尽早识别不良反应,保障患者用药安全。

Multi-Objective Optimization of the Ultrasonic Scalpel Rod and Tip with Improved Performance:Vibration Frequency,Amplitude,and Service Life

Ultrasonic scalpel design for minimally invasive surgical procedures is mainly focused on optimizing cutting performance.However,an important issue is the low fatigue life of traditional ultrasonic scalpels,which affects their long-term reliability and effectiveness and creates hidden dangers for surgery.In this study,a multi-objective optimal design for the cutting performance and fatigue life of ultrasonic scalpels was proposed using finite element analysis and fatigue simulation.The optimal design parameters of resonance frequency and amplitude were determined.By setting the transition fillet and keeping the gain structure away from the node position to enable the scalpel to have a high service life with excellent cutting performance.The frequency modulation method of setting the vibration node bosses at the node position and setting the vibration antinode grooves at the antinode position was compared.Then,the mechanism of the influence of various design elements,such as tip,shank,node position,and antinode position,on the resonance frequency,amplitude,and fatigue life of the ultrasonic scalpel was analyzed,and the optimal design principles of the ultrasonic scalpel were obtained.The proposed ultrasonic scalpel design was confirmed by simulations,impedance measurements,and liver tissue cutting experiments,demonstrating its feasibility and enhanced performance.This research introduces innovative design strategies to improve the fatigue life and performance of ultrasonic scalpels to address an important issue in minimally invasive surgery.

Atomic layer deposition in advanced display technologies:from photoluminescence to encapsulation

Driven by the growing demand for next-generation displays,the development of advanced luminescent materials with exceptional photoelectric properties is rapidly accelerating,with such materials including quantum dots and phosphors,etc.Nevertheless,the primary challenge preventing the practical application of these luminescent materials lies in meeting the required durability standards.Atomic layer deposition(ALD)has,therefore,been employed to stabilize luminescent materials,and as a result,flexible display devices have been fabricated through material modification,surface and interface engineering,encapsulation,cross-scale manufacturing,and simulations.In addition,the appropriate equipment has been developed for both spatial ALD and fluidized ALD to satisfy the low-cost,high-efficiency,and high-reliability manufacturing requirements.This strategic approach establishes the groundwork for the development of ultra-stable luminescent materials,highly efficient light-emitting diodes(LEDs),and thin-film packaging.Ultimately,this significantly enhances their potential applicability in LED illumination and backlighted displays,marking a notable advancement in the display industry.

Bayesian network-based survival prediction model for patients having undergone post-transjugular intrahepatic portosystemic shunt for portal hypertension

BACKGROUND Portal hypertension(PHT),primarily induced by cirrhosis,manifests severe symptoms impacting patient survival.Although transjugular intrahepatic portosystemic shunt(TIPS)is a critical intervention for managing PHT,it carries risks like hepatic encephalopathy,thus affecting patient survival prognosis.To our knowledge,existing prognostic models for post-TIPS survival in patients with PHT fail to account for the interplay among and collective impact of various prognostic factors on outcomes.Consequently,the development of an innovative modeling approach is essential to address this limitation.AIM To develop and validate a Bayesian network(BN)-based survival prediction model for patients with cirrhosis-induced PHT having undergone TIPS.METHODS The clinical data of 393 patients with cirrhosis-induced PHT who underwent TIPS surgery at the Second Affiliated Hospital of Chongqing Medical University between January 2015 and May 2022 were retrospectively analyzed.Variables were selected using Cox and least absolute shrinkage and selection operator regression methods,and a BN-based model was established and evaluated to predict survival in patients having undergone TIPS surgery for PHT.RESULTS Variable selection revealed the following as key factors impacting survival:age,ascites,hypertension,indications for TIPS,postoperative portal vein pressure(post-PVP),aspartate aminotransferase,alkaline phosphatase,total bilirubin,prealbumin,the Child-Pugh grade,and the model for end-stage liver disease(MELD)score.Based on the above-mentioned variables,a BN-based 2-year survival prognostic prediction model was constructed,which identified the following factors to be directly linked to the survival time:age,ascites,indications for TIPS,concurrent hypertension,post-PVP,the Child-Pugh grade,and the MELD score.The Bayesian information criterion was 3589.04,and 10-fold cross-validation indicated an average log-likelihood loss of 5.55 with a standard deviation of 0.16.The model’s accuracy,precision,recall,and F1 score were 0.90,0.92,0.97,and 0.95 respectively,with the area under the receiver operating characteristic curve being 0.72.CONCLUSION This study successfully developed a BN-based survival prediction model with good predictive capabilities.It offers valuable insights for treatment strategies and prognostic evaluations in patients having undergone TIPS surgery for PHT.

Estimation of speed-related car body acceleration limits with quantile regression

Purpose–This study aimed to facilitate a rapid evaluation of track service status and vehicle ride comfort based on car body acceleration.Consequently,a low-cost,data-driven approach was proposed for analyzing speed-related acceleration limits in metro systems.Design/methodology/approach–A portable sensing terminal was developed to realize easy and efficient detection of car body acceleration.Further,field measurements were performed on a 51.95-km metro line.Data from 272 metro sections were tested as a case study,and a quantile regression method was proposed to fit the control limits of the car body acceleration at different speeds using the measured data.Findings–First,the frequency statistics of the measured data in the speed-acceleration dimension indicated that the car body acceleration was primarily concentrated within the constant speed stage,particularly at speeds of 15.4,18.3,and 20.9 m/s.Second,resampling was performed according to the probability density distribution of car body acceleration for different speed domains to achieve data balance.Finally,combined with the traditional linear relationship between speed and acceleration,the statistical relationships between the speed and car body acceleration under different quantiles were determined.We concluded the lateral/vertical quantiles of 0.8989/0.9895,0.9942/0.997,and 0.9998/0.993 as being excellent,good,and qualified control limits,respectively,for the lateral and vertical acceleration of the car body.In addition,regression lines for the speedrelated acceleration limits at other quantiles(0.5,0.75,2s,and 3s)were obtained.Originality/value–The proposed method is expected to serve as a reference for further studies on speedrelated acceleration limits in rail transit systems.

The Effects of Childhood Trauma on College Students’Depressive Symptoms:The Mediation Role of Subjective Well-Being and the Moderation Role of Resilience

Background:The enduring and detrimental impact of childhood trauma on later health and well-being is now well established.However,research on the relationship between childhood trauma and depressive symptoms,along with the potential risk and protective factors,is insufficient in the context of Chinese college student population.Methods:Data on childhood trauma,depressive symptoms,resilience,and subjective well-being were collected through surveys conducted with 367 Chinese university students.The data collected in this study were analyzed using SPSS 26.0 and PROCESS 3.5.Results:The results revealed that subjective well-being mediated the relationship between childhood trauma and depressive symptoms among college students,with direct and indirect effects accounting for 59.46%and 40.54%of the total effect,respectively.The pathway process between subjective well-being and depressive symptoms was moderated by resilience,whereby an increase in resilience levels corresponded to a gradual escalation in the predictive power of subjective well-being on depressive symptoms.Conclusion:The study indicates that childhood trauma significantly and positively predicts depressive symptoms among college students,and it can also directly predict depressive symptoms through the mediating effect of subjective well-being.Elevating levels of psychological resilience and subjective well-being among college students can mitigate depression and promote psychological well-being.From the perspective of positive psychology,the present study provides a new perspective for the prevention and intervention of depressive symptoms among college students.

ASP对胸外科围手术期抗菌药物选择和感染发病率的影响

目的评价抗菌药物管理项目(ASP)对胸外科围手术期抗菌药物选择和患者术后感染发病率的影响。方法选取2015—2016年于某院胸外科进行肺或食管手术且术前无感染的患者。2015年的患者设为对照组(干预前),2016年的患者设为试验组(干预后)。2016年开展ASP,临床药师、感染科医生对使用碳青霉烯类药物和氟喹诺酮类药物的医嘱实时干预,规范抗菌药物的使用。比较实施ASP前后胸外科围手术期抗菌药物选择的规范程度和手术部位感染发生情况。结果干预前(2015年)纳入患者953例;干预后(2016年)纳入患者1 061例。食管或肺部手术患者手术部位感染发病率干预前、干预后分别为1. 57%、1. 70%,两者比较差异无统计学意义(χ~2=0. 047,P=0. 829)。使用推荐抗菌药物(头孢呋辛或头孢美唑)预防手术部位感染的比率从干预前的37. 15%(354/953)上升至干预后的69. 75%(740/1 061),干预前后比较差异有统计学意义(χ~2=215. 025,P=0. 000)。干预前、干预后胸外科抗菌药物AUD情况比较,厄他培南的AUD下降52. 46%(8. 12 VS 3. 86);头孢呋辛(7. 49 VS14. 83)和头孢美唑(4. 98 VS 9. 72)的AUD分别增加98. 00%、95. 18%;头孢曲松的使用强度下降85. 29%(12. 03VS 1. 77)。结论实施ASP,降低了胸外科厄他培南和头孢曲松的使用量,规范了胸外科手术预防用药,且不会引起肺和食管手术手术部位感染发病率的变化。

石墨烯量子点修饰的BiOI/PAN柔性纤维的制备及其增强的光催化活性

在环境治理中,光催化氧化是去除有机污染物的一种很有前途的技术。与吸附、生物降解和化学氧化等方法相比,光催化氧化可以通过环境友好的方式,完全、方便、廉价地消除有机污染物。光催化氧化中,又以可见光光催化氧化更具优势,这是因为可见光在太阳光中的能量比例较高。碘氧化铋(BiOI)是一种很有前途的可见光光催化剂,不仅具有较窄的带隙,而且具有较低的价带(VB),其产生的光生空穴能氧化分解多种有机污染物。然而,BiOI粉末回收困难、比表面积低、载流子复合快等缺点限制了其实际应用。同时,光催化剂的柔性和分级结构有利于这些材料的操作、回收和性能改进,也是非常可取的特性。为此,本文以j静电纺丝制备的聚丙烯腈(PAN)纳米纤维为基底,通过原位反应的方法,制备了具有分级结构的柔性BiOI/PAN复合纤维。在BiOI/PAN纤维中,BiOI薄片围绕PAN纤维、垂直均匀地排列在其表面,形成独特的分级结构。在制备的过程中,PAN纤维中掺入的Bi(Ⅲ)会先形成的BiOI晶核,并成为BiOI纳米片生长的种子。这对分级结构的形成至关重要。紫外-可见漫反射光谱和光致发光发射分析显示,这种分级结构可以改善BiOI/PAN光纤的光吸收,促进光生载流子的形成。因此,BiOI/PAN纤维比BiOI粉末具有更高的光催化活性。进一步,用预先制备的石墨烯量子点(GQDs)对BiOI/PAN纤维进行修饰,可制备出GQDs修饰的BiOI/PAN纤维复合材料(GQD-BiOI/PAN)。所制备GQD-BiOI/PAN的形貌与BiOI/PAN纤维几乎是一样的。通过制备方法、光致发光发射、反应自由基测试和X射线光电子能谱(XPS)的综合分析,证实了GQDs与BiOI之间会形成梯型(S型)异质结。这种S型异质结不仅能有效地抑制光生空穴的复合,而且能保留GQDs的最低未占据分子轨道(LUMO)上还原能力更强的电子,以及BiOI的VB上氧化能力更强的空穴,用于光催化降解苯酚。在纤维分级结构和S型异质结的共同作用下,GQD-BiOI/PAN在可见光光催化氧化苯酚中,其性能明显优于BiOI粉末和BiOI/PAN纳米纤维。此外,由于粘结紧密,GQD-BIOI/PAN可以进行裁剪和徒手操作,回收利用非常方便。在循环性能测试中,没有明显的样品损失和光催化活性的降低的现象。本文的工作为制备柔性光催化剂提供了一条新的途径,并对光催化剂的增强提供了新的视野。

春季中国东部海域气旋急流在气旋发展中的作用研究

对2008—2014年中国东部海域春季海上发展气旋进行了统计与诊断分析。结果表明:1)这类气旋属于较浅薄的低值系统,垂直伸展高度多在600 h Pa以下,水平尺度多在1 500 km以内。伴随的强天气为大风、大浪与强降水,落区主要位于气旋东南部。2)气旋环流各层的大风急流区构成了气旋的东南部位,称为气旋急流。从高层到低层,气旋急流轴在垂直方向上呈逆时针旋转,形成气旋上大下小的漏斗形状。3)气旋急流左侧的气旋式切变有利于气旋中心强度的维持,上层气旋急流左侧对应下层气旋急流前部流速辐合区,有利于气旋式动力抽吸及在气旋东南部形成强的垂直上升运动区。各层气旋急流配置导致气旋的非对称结构,以及气旋要素的非对称分布。气旋急流向气旋中输入螺旋度以及充足的水汽,并在东南部强烈抬升,增强了凝结潜热释放,从热力和动力两方面促进气旋发展及强天气落区。4)春季下垫面温度分布(锋区)有利于气旋急流的增强,并通过西北部非绝热冷却和东南部非绝热加热,增强气旋斜压性。高空环境西风急流位于气旋右侧,形成了整层偏差风辐合,有效增强低层气旋急流。同时高空动量下传位于气旋西侧,首先增强气旋西北部的弱流部分(即气旋螺旋结构的下沉支),进而增强整个气旋的螺旋环流,促使气旋急流也从下层开始增强。

基于Bresenham算法的四步画直线算法

通过分析计算机图形学中的画直线的Bresenham算法,以及由此改进的"对称算法"、"二步法",提出将"对称算法"和"二步法"结合形成"4-点画线算法".与Bresenham算法相比,该算法可以将画线效率提高近2倍.

中国式现代化背景下我国构建新发展格局的主要标志与对策研究

构建新发展格局是我国应对百年变局、开拓发展新局的主动调整,也是重塑我国参与国际合作和竞争新优势,加快实现中国式现代化的战略选择,是事关全局的系统性、深层次变革,是贯彻新发展理念的重大举措。从加快实现中国式现代化的要求来看,构建新发展格局是一个统一的整体,其关键在于经济循环的畅通无阻、本质特征是实现高水平的自立自强,重要途径是构建强大国内市场和推动国内国际双循环相互促进。目前,我国国内循环占比明显上升,但国内大循环仍存在不少“卡点”和“堵点”,经济循环效率下降;向自主创新模式转换加快,但“卡脖子”瓶颈突出,实现高水平自立自强任重道远;强大国内市场加快建设,“大”而不“强”的问题突出;对外开放水平明显提升,但国内国际双循环相互促进有待提升。要全面、完整、准确把握新发展格局的内涵特征、主要标志和战略重点,找准制约新发展格局构建的难点和痛点,进一步深化供给侧结构性改革,强化创新驱动,注重质量提升,扩大高水平对外开放,提升居民收入和消费水平,尽快打通制约国内大循环的“卡点”“堵点”,努力实现高水平自立自强。

要素市场化配置改革研究

我国改革开放40年来,开创了前所未有的经济奇迹,其最主要的发展动力源于市场化改革。目前产品市场已基本实现由供需关系来决定产品价格,要素市场化改革在市场体系建设、要素参与分配、要素价格形成等方面也取得了较大进展,但要素市场化改革还远未完成。要素市场配置结构失衡问题日益显现,带来经济结构及产业结构失衡现象逐渐扩大,在产权保护、价格形成、行政和市场垄断、市场规则等方面还存在重大制度短板。要素市场差异化性强,市场发育程度不平衡,只有深入剖析其结构性矛盾和背后深层次的体制弊端,破除制约经济社会发展的制度性障碍,才能全面推动以要素市场化配置改革为重点的经济体制改革,为我国经济高质量发展和健全现代化经济体系奠定重要基础。

A Whole-Course and Multidisciplinary Nutrition Management Model for Breast Cancer: A Typical Case Report

Breast cancer patients face different nutritional problems at each stage. However, the nutrition of breast cancer patients has not been taken seriously. As a result, some patients cannot tolerate treatment due to poor nutrition, thus affecting the prognosis. This study aims to introduce a typical case to explore the whole-course (started at admission and ended 5 years after surgery) and Multidisciplinary Teams (MDTs) (comprising physician, primary nurse, case manager, nutrition liaison and nutrition specialist nurse) nutritional management mode of breast cancer patients. The patient successfully completed the scheduled treatment by implementing the whole-course and multidisciplinary nutrition management. The mode can prospectively and dynamically estimate the changes in patients’ nutritional status, and provide timely nutritional intervention to promote patient outcomes.

古籍“蝴蝶装”视觉符号中的道家模仿观

阐述中国文化背景下,中国古籍“蝴蝶装”视觉符号中的独特模仿观。结合老子提出的“道法自然”命题中“人、地、天、道”之间的层次关系,分析并总结出“道”是蝴蝶装装帧设计中的终极模仿对象,“自然”是蝴蝶装装帧设计的模仿原则,“道复归根”是蝴蝶装装帧设计的模仿意图。中国古代书籍装帧设计中的“蝴蝶装”,是中国古代设计者模仿观的体现,也是“道法自然”思想的直观表达。总之,道家“道法自然”的思想贯穿于“蝴蝶装”的整体设计中,决定了这一艺术形式的符号价值和文化底蕴。

电阻钎焊过程的动态电阻特征分析

采用电阻钎焊进行了1060铝板与T2铜板的搭接试验,通过设计复合电极头和选用阻抗较大的工艺垫片实现热补偿的作用,可在较低电流水平下实现铜铝异种材料的焊接。设定不同的焊接工艺参数,利用实时传感技术实时采集电阻钎焊动态过程的温度、电极电压和电极电流信号,并以温度为依据初步确定焊接工艺参数的范围,然后通过计算和处理检测信号得到动态电阻曲线。实验结果表明:焊接电流、焊接时间的变化导致提供的焊接能量不同,电阻钎焊过程中出现不同的动态电阻变化,并形成不同的焊接接头质量特征,从而为焊接接头质量的非破坏性评估提供了可能。

Malakoplakia: Rare Disorder with No Significant Racial Prevalence

Introduction: Malakoplakia is a rare acquired granulomatous inflammatory condition. Microscopically it is characterized by sheets of histiocytes with abundant eosinophilic granular cytoplasm (known as von Hansemann cells) with intracytoplasmic rounded concentric basophilic inclusions (Michelis-Guttmann bodies). We reviewed all cases of malakoplakia diagnosed at our institution in the past 15 years, including clinical, macroscopic, and microscopic features as well as treatment and prognosis. Methods: Gross and microscopic features of cases diagnosed as malakoplakia from 2005 to 2019 at our institution were reviewed. Clinical history, including sites of involvement, clinical presentation, imaging, past medical history, treatment, follow-up and prognosis, as well as demographic characteristics were obtained. Results: Eighteen surgical pathology cases of malakoplakia were identified. Most cases occurred in female (14/18, 77.8%) and all in adults (median age 48.5 years;range 31 - 87). Half of the patients were Caucasian, 44% African American and 6% were reported as “other” race. One third (6/18) of patients presented with a mass-like lesion on imaging or endoscopic studies. As to site of lesion, 61.1% (11/18) involved GU tract, 27.8% (5/18) gastrointestinal (GI) tract, 5.6% (1/18) liver, and 5.6% (1/18) vagina. 38.9% of patients (7/18) had antibiotics treatment upon diagnosis. Conclusion: Malakoplakia is a rare disorder occurring in a wide age range, more commonly in females, with no significant racial prevalence. While the GU and GI tracts are the most common sites, other anatomic locations can be involved. Accurate diagnosis and appropriate treatment are important to avoid recurrence.

聚三氟氯乙烯结晶形态调控对其高频介电性能的影响

通过调控聚三氟氯乙烯(PCTFE)的结晶及形态结构,研究其对PCTFE高频介电性能的影响。采用淬火处理、175℃和185℃等温热处理方式制备了不同结晶形态和结晶度的PCTFE,通过差示扫描量热分析和偏光显微镜表征不同热处理工艺下PCTFE的结晶形态结构,并采用带状线谐振法研究了不同结晶行为的PCTFE在高频交变电场下的介电性能。结果表明,淬火处理使PCTFE结晶不完善,仅生成细小的晶粒;而在175℃及以上进行等温热处理时,PCTFE链端更易排列进入晶格,生成球晶。等温温度越高,球晶尺寸越大,185℃等温1h后球晶尺寸达到36~42μm。高频电场下,淬火方式制备的低结晶度和较小结晶尺寸的PCTFE具有最低的介电常数和介电损耗,满足高频信号传输需求。