Co-enhancement of thermal conduction and radiation through morphologies controlling of graphene functional layer for chip thermal management

With the continuous advancements in electronics towards downsizing and integration,efficient thermal dissipation from chips has emerged as a critical factor affecting their lifespan and operational efficiency.The fan-less chip cooling system has two critical interfaces for thermal transport,which are the contact interface between the base and the chip dominated by thermal conduction,and the surface of the fins dominated by thermal radiation.The different thermal transfer modes of these two critical interfaces pose different requirements for thermal management materials.In the study,a novel approach was proposed by developing graphene thermal transport functional material whose morphology could be intentionally designed via reformed plasmaenhanced chemical vapor deposition(PECVD)methods to meet the diverse requirements of heat transfer properties.Specifically,graphene with multilevel branching structure of vertical graphene(BVG)was fabricated through the hydrogenassisted PECVD(H_(2)-PECVD)strategy,which contributed a high emissivity of~0.98.BVG was deposited on the fins’surface and functioned as the radiation enhanced layer to facilitate the rapid radiation of heat from the heat sinks into the surrounding air.Meanwhile,the well-oriented vertical graphene(OVG)was successfully prepared through the vertical electric field-assisted PECVD process(EF-PECVD),which showed a high directional thermal conductivity of~53.5 W·m^(-1)·K^(-1).OVG was deposited on the contact interface and functioned as the thermal conduction enhanced layer,allowing for the quick transmission of heat from the chip to the heat sink.Utilizing this design concept,the two critical interfaces in the chip cooling system can be jointly enhanced,resulting in a remarkable cooling efficiency enhancement of~30.7%,demonstrating that this novel material possessed enormous potential for enhancing the performance of cooling systems.Therefore,this research not only provided new design concepts for the cooling system of electronic devices but also opened up new avenues for the application of graphene materials in thermal management.

Management of acquired rectourethral fistulas in adults

Rectourethral fistula is an uncommon but devastating condition resulting from surgery,radiation,trauma,inflammation,or occasionally anorectal anomaly.Because of involving the urinary and the digestive system,surgical repair can be challenging.More than 40 different surgical approaches were described in the literature.However,no standardized management exists due to the rarity and complexity of the problem.Spontaneous closure of fistula is rare and most cases need reconstructive procedures.Appropriate preoperative assessment is crucial for the decision of operation time and method.Gradually accumulating evidence indicates surgeons should take fistula size,tissue health and vascularity associated with radiation or infection,urethral stricture,and bladder neck sclerosis into consideration and make a proper treatment plan according to the features of various approaches.Accurate preoperative evaluation and proper approach selection would increase success rates.Multiple surgical team corporation,including colorectal,urological and plastic surgeons,would optimize the outcomes.

Review on thermal management technologies for electronics in spacecraft environment

Due to the rapid development of the space industry,ever higher demands are being made for the optimization and improvement of spacecraft thermal management systems.Thermal control technology has become one of the key bottlenecks that restrict the level of spacecraft design.In this paper,the thermal management technologies(TMTs)for spacecraft electronics are reviewed according to the different heat transfer processes,including heat acquisition,heat transport,and heat rejection.The researches on efficient heat acquisition include the utilization of high thermal conductance materials,the development of novel package structure based on micro-/nanoelectromechanical system(MEMS/NEMS)technologies,and advanced near-junction microfluidic cooling techniques.For the heat transport process,various heat pipes and mechanical pumped fluid loops(MPFLs)are widely implemented to transport heat from heat generation components to the ultimate heat sinks.The heat pipes are divided into two categories based on their structure layout,i.e.,separated heat pipes and unseparated heat pipes.The merits and demerits of these heat pipes and MPFLs(including the single-phase MPFL and the two-phase MPFL)are discussed and summarized respectively.In terms of the heat rejection for spacecraft,thermal radiators are normally the sole option due to the unique space environment.To meet the requirements of large heat dissipation power and fluctuated thermal environment,research efforts on the radiators mainly focus on the development of deployable radiators,variable emissivity radiators,and the combination with other techniques.Due to the fluctuated characteristics of the heat power of internal electronics and the outer thermal environment,the phase change materials(PCMs)exhibit great advantages in this scenario and have attracted a lot of research attention.This review aims to serve as a reference guide for the development of thermal management system in the future spacecraft.

Geoengineering and the blockchain: Coordinating Carbon Dioxide Removal and Solar Radiation Management to tackle future emissions

Geoengineering is a proposed response to anthropogenic global warming (AGW). Conventionally it consists of two strands: Solar Radiation Management (SRM), which is fast-acting, incomplete but inexpensive, and Carbon Dioxide Removal (CDR), which is slower acting, more expensive, and comprehensive. Pairing SRM and CDR offers a contractually complete solution for future emissions if effectively-scaled and coordinated. SRM offsets warming, while CDR takes effect. We suggest coordination using a blockchain, i.e. smart contracts and a distributed ledger. Specifically, we integrate CDR futures with time and volume-matched SRM orders, to address emissions contractually before release. This provides an economically and environmentally proportionate solution to CO2 emissions at the wellhead, with robust contractual transparency, and minimal overhead cost. Our proposal offers a 'polluter pays' implementation of Long & Shepherds SRM 'bridge' concept. This 'polluter geoengineers' approach mandates and verifies emissionslinked payments with minimal friction, delay, or cost. Finally, we compare alternative market designs against this proposal, finding that this proposal offers several advantages. We conclude that blockchain implementation of the 'polluter geoengineers' approach is attractive and feasible for larger wellhead contracts. We also identify a handful of advantages and disadvantages that merit further study.

Effect of Nitrogen Regimes on Grain Yield,Nitrogen Utilization,Radiation Use Efficiency,and Sheath Blight Disease Intensity in Super Hybrid Rice

Poor nitrogen use efficiency in rice production is a critical issue in China. Site-specific N managements （SSNM） such as real-time N management （RTNM） and fixed-time adjustable-dose N management （FTNM） improve fertilizer-N use efficiency of irrigated rice. This study was aimed to compare the different nitrogen （N） rates and application methods （FFP, SSNM, and RTNM methods） under with- and without-fungicide application conditions on grain yield, yield components, solar radiation use efficiency （RUE）, agronomic-nitrogen use efficiency （AEN）, and sheath blight disease intensity. Field experiments were carried out at Liuyang County, Hunan Province, China, during 2006 and 2007. A super hybrid rice Liangyou 293 （LY293） was used as experimental material. The results showed that RTNM and SSNM have great potential for improving agronomic-nitrogen use efficiency without sacrificing the grain yield. There were significant differences in light interception rate, sheath blight disease incidence （DI） and the disease index （ShBI）, and total dry matter among the different nitrogen management methods. The radiation use efficiency was increased in a certain level of applied N. But, the harvest index （HI） decreased with the increase in applied N. There is a quadratic curve relationship between grain yield and applied N rates. With the same N fertilizer rate, different fertilizer-N application methods affected the RUE and grain yield. The fungicide application not only improved the canopy light interception rate, RUE, grain filling, and harvest index, but also reduced the degree of sheath blight disease. The treatment of RTNM under the SPAD threshold value 40 obtained the highest yield. While the treatment of SSNM led to the highest nitrogen agronomic efficiency and higher rice yield, and decreased the infestation of sheath blight disease dramatically as well. Nitrogen application regimes and diseases control in rice caused obvious effects on light interception rate, RUE, and HI. Optimal N rate is helpful to get higher light interception rate, RUE, and HI. Disease control with fungicide application decreased and delayed the negative effects of the high N on rice yield formation. SSNM and RTNM under the proper SPAD threshold value obtained high-yield with high efficiency and could alleviate environmental pollution in rice production.

Security of solar radiation management geoengineering

Solar Radiation Management (SRM) geoengineering is a proposed response to anthropogenic global warming (AGW)(National Academy of Sciences, 2015). There may be profound - even violent - disagreement on preferred temperature. SRM disruption risks dangerous temperature rise (termination shock). Concentrating on aircraft-delivered Stratospheric Aerosol Injection (SAI), we appraise threats to SRM and defense methodologies. Civil protest and minor cyberattacks are almost inevitable but are manageable (unless state-sponsored). Overt military attacks are more disruptive, but unlikely - although superpowers' symbolic overt attacks may deter SRM. Unattributable attacks are likely, and mandate use of widely-available weapons. Risks from unsophisticated weapons are therefore higher. An extended supply chain is more vulnerable than a secure airbase - necessitating supply-chain hardening. Recommendations to improve SRM resilience include heterogeneous operations from diverse, secure, well-stocked bases (possibly ocean islands or aircraft carriers);and avoidance of single-point-of failure risks (e.g. balloons). A distributed, civilianoperated system offers an alternative strategy. A multilateral, consensual SRM approach reduces likely attack triggers.

Distributed governance of Solar Radiation Management geoengineering:A possible solution to SRM’s“free-driver”problem?

Geoengineering(deliberate climate modification)is a possible way to limit Anthropogenic Global Warming(AGW)(Shepherd,2009;National Research Council,2015).Solar Radiation Management geoengineering(SRM)offers relatively inexpensive,rapid temperature control.However,this low cost leads to a risk of controversial unilateral intervention—the“free-driver”problem(Weitzman,2015).Consequently,this creates a risk of counter-geoengineering(deliberate warming)(Parker et al.,2018),resulting in governance challenges(Svoboda,2017)akin to an arms race.Free-driver deployment scenarios previously considered include the rogue state,Greenfinger(Bodansky,2013),or power blocs(Ricke et al.,2013),implying disagreement and conflict.We propose a novel distributed governance model of consensually-constrained unilateralism:Countries’authority is limited to each state’s fraction of the maximum realistic intervention(e.g.,pre-industrial temperature).We suggest a division of authority based on historical emissions(Rocha et al.,2015)—noting alternatives(e.g.,population).To aid understanding,we offer an analogue:An over-heated train carriage,with passenger-controlled windows.We subsequently discuss the likely complexities,notably Coasian side-payments.Finally,we suggest further research:Algebraic,bot and human modeling;and observational studies.

Capacity Building and Transfer of Know-how in Radiation Protection. Dissemination of Enetrap Projects Results

The ENETRAP （European Network on Education and Training in RAdiological Protection） project series, since the first edition in 2005 till the current ENETRAP III, always have been the objective to maintain a high level of competence in radiation protection （RP）, assuring the continued development of suitable well-trained personnel and adequate knowledge management. This objective is crucial to ensure future safe use of ionizing radiations （IR） and the development of new technologies in a safe way. A big effort and lot of work has been done in these 11 years including the new definitions in the BSS for RP Expert （RPE）, RP Officer （RPO） and Medical Physics Expert （MPE） which are the basis for future national development and implementation and adequate the high-level education and training （E＆T） in the countries. In order to manage all the valuable results of the projects and to distribute them to the society, is required a tool, developed with this specific propose, that will be the object of this paper.

Solar Radiation Prediction Using Satin Bowerbird Optimization with Modified Deep Learning

Solar energy will be a great alternative to fossil fuels since it is clean and renewable.The photovoltaic(PV)mechanism produces sunbeams’green energy without noise or pollution.The PV mechanism seems simple,seldom malfunctioning,and easy to install.PV energy productivity significantly contributes to smart grids through many small PV mechanisms.Precise solar radiation(SR)prediction could substantially reduce the impact and cost relating to the advancement of solar energy.In recent times,several SR predictive mechanism was formulated,namely artificial neural network(ANN),autoregressive moving average,and support vector machine(SVM).Therefore,this article develops an optimal Modified Bidirectional Gated Recurrent Unit Driven Solar Radiation Prediction(OMBGRU-SRP)for energy management.The presented OMBGRU-SRP technique mainly aims to accomplish an accurate and time SR prediction process.To accomplish this,the presented OMBGRU-SRP technique performs data preprocessing to normalize the solar data.Next,the MBGRU model is derived using BGRU with an attention mechanism and skip connections.At last,the hyperparameter tuning of the MBGRU model is carried out using the satin bowerbird optimization(SBO)algorithm to attain maximum prediction with minimum error values.The SBO algorithm is an intelligent optimization algorithm that simulates the breeding behavior of an adult male Satin Bowerbird in the wild.Many experiments were conducted to demonstrate the enhanced SR prediction performance.The experimental values highlighted the supremacy of the OMBGRU-SRP algorithm over other existing models.

石蜡与低熔点合金双级联相变材料强化板翅式散热器换热性能的数值模拟

相变散热技术可以通过相变材料的物态变化,有效吸收或释放热量,从而实现被动式热管理。本文建立了一种板翅式相变散热器的结构模型,研究级联相变技术的相变传热过程及优化传热性能的措施,重点分析了相变材料(PCM)的组合方式、翅片结构以及不同的PCM体积比工况对相变散热器传热性能的影响。研究结果表明,改变PCM的组合方式对相变材料传热过程有显著影响,对于采用双PCM的级联相变散热器,PCM1和PCM2呈相变温度递减排列具备更优的热管理性能;当翅片数为16时,具备更低的工作温度,并且相比于四翅片结构的相变散热单元,两种级联PCM组合的相变散热单元的凝固时间分别缩短了25.3%和22.5%。因此,当翅片数为16及翅片厚度为0.5 mm时,热管理性能较优;采用石蜡和低熔点合金材料,当PCM体积比为1∶2时,两个临界温度下的热管理时间分别延长了17.2%和15%,温升速率也随着低熔点合金所占体积增多而逐渐减小,综合考虑热管理时间和温升速率,可知PCM体积比为1∶2时级联相变散热器的热管理性能较优。

放射防护教育的重要性及针对不同专业医务人员的培训策略

目前越来越先进的医学影像及电离辐射应用于临床诊断和治疗,在众多被提出用于辐射暴露管理的策略中,教育和培训对辐射防护和剂量减少尤为重要。然而研究显示医务人员普遍出现缺乏基本放射防护方面的知识。因此,如何进行放射防护的教育和培训,是当前大型综合性医院需探讨实践的重要问题。文章通过分析电离辐射暴露造成的医务人员或患者的伤害,进而阐述了医务人员进行教育培训的必要性,医务人员应进行辐射物理学、放射生物学、放射防护以及辐射相关的国家法律法规的知识培训。另外,除了以上主题,放射防护的教育培训计划也必须考虑到每个医学专业的需求和要求,因此文章也详细分析了各专业医务人员应具备的辐射相关知识及教育培训内容,这将对临床上如何更好地做好放射防护具有积极重要的意义。

放射影像设备的质控管理及维修分析

临床对放射影像设备进行质控管理的预期目标是在符合行业的标准要求下,采用适当的影像检查技术条件为临床提供优质的图像信息。我院1.5T MRI设备于2015年10月开始使用,虽然该设备已使用了8年,经过持续而严格的质控,使该设备的各项技术指标依然保持在较好状态,不但满足了正常的工作需求,而且保持了较低的故障率。设备的良好运转、医务人员准确的技术应用,以及患者的最佳配合才能得到优质的影像图像。对于放射影像设备的质量控制,其覆盖了设备的整个使用周期,且质量控制的过程也是设备在整个使用周期中的运行流程。只有通过科学的手段,强化和优化放射影像设备的质量控制,提升设备的使用效率,才能为临床诊断提供有效的技术支持。同时及时的维修和独立的解决问题既能保证诊疗的正常进行,还能给医院节省资金。因此,优秀的技术能力加上严格规范的质控管理是我院影像设备安全运行的最好保证。

基于区块链技术的辐射事故应急管理系统设计

放射性设备的应用发展导致辐射事故增多,对环境和公众健康产生威胁,需建立高效可靠的辐射事故应急管理体系。传统辐射事故应急管理系统存在数据孤岛、信息不透明等问题,而基于区块链技术的辐射事故应急管理系统具有去中心化、数据不可篡改、高度安全等特性,可实现应急响应流程自动化和智能化,提高响应速度和效果。区块链技术在辐射事故应急管理系统中的应用可有效解决传统管理系统存在的问题,提高管理效率和效果,为保障环境和公众健康提供技术支持。

赋能管理模式在^(125)I粒子植入术后放射防护中的效果研究

目的探讨赋能管理模式在^(125)I粒子植入术后放射防护中的作用。方法选择医院2020年10月至2022年10月首次进行^(125)I粒子植入的患者66例,随机分为对照组和实验组,对照组(n=33)实施传统健康教育;实验组(n=33)在传统健康教育的基础上实施赋能管理模式,评价两组患者在自我效能感、健康教育效果及防护依从性等方面的差异。结果实验组患者在自我效能感、健康教育效果及防护依从性等方面均高于对照组,差异有统计学意义(P<0.05)。结论运用赋能管理模式实施健康教育,能够提高^(125)I粒子植入术后健康教育效果,从而让患者更正确地认识^(125)I粒子治疗,使自我效能感加强,有利于提高术后防护依从性,保护周围人群的安全,值得临床推广。

标准化皮肤管理对乳腺癌放疗患者放射性皮炎的预防效果

目的:观察标准化皮肤管理对乳腺癌放疗患者放射性皮炎的预防效果。方法:回顾性分析2021年1月至2022年9月该院收治的80例乳腺癌患者的临床资料,按照护理方法不同将其分为对照组和观察组各40例。两组均接受放疗治疗,对照组采用常规护理,观察组在对照组基础上给予标准化皮肤管理,比较两组护理后皮肤损伤严重程度[放射性皮肤损伤评估量表(RISRAS)]评分与健康状况[Karnofsky功能状态(KPS)]评分、放射性皮炎首次发生时间和持续时间、护理前后心理状态[简式心境状态量表(POMS)]评分和病耻感[慢性病病耻感量表(SSCI)]评分。结果:护理后,观察组RISRAS评分低于对照组,KPS评分高于对照组,差异均有统计学意义(P<0.05);观察组放射性皮炎首次发生时间晚于对照组,持续时间短于对照组,差异均有统计学意义(P<0.05);护理后,两组紧张、愤怒、疲劳、抑郁、慌乱等POMS评分均低于护理前,且观察组低于对照组,两组精力、与自我有关的情绪等POMS评分均高于护理前,且观察组高于对照组,差异有统计学意义(P<0.05);两组外在病耻感、内在病耻感评分均低于护理前,且观察组低于对照组,差异有统计学意义(P<0.05)。结论:标准化皮肤管理用于预防乳腺癌放疗患者放射性皮炎,可减轻皮肤损伤程度,延缓皮肤损伤发生时间,减少皮肤损伤持续时间,改善患者心理状态和健康状态,降低病耻感,效果优于单纯常规护理。

4R危机管理理论在乳腺癌放疗期患者放射性皮炎管理中的应用

目的 探讨4R危机管理理论在乳腺癌放疗期患者放射性皮炎管理中的应用。方法 该研究为回顾性队列研究。采用整群抽样法,抽取2021年3月至2022年2月在该院肿瘤放射中心接受术后放射治疗(放疗)的52例乳腺癌患者为对照组,抽取2022年3月至2023年2月在该院肿瘤放射中心接受术后放疗的57例乳腺癌患者为观察组。对照组采用常规护理管理模式进行干预,观察组运用4R危机管理理论进行管理。比较2组患者放射性皮炎的发生率、严重程度、舒适度和整体满意度。结果 观察组放射性皮炎发生率[40.35%(23/57)]低于对照组[69.23%(36/52)],差异有统计学意义(χ^(2)=9.134,P=0.003);观察组放射性皮炎的严重程度较对照组明显减轻,差异有统计学意义(Z=-3.445,P=0.001)。观察组治疗期间的舒适度和整体满意度均高于对照组,差异均有统计学意义(Z=-2.553,P=0.011;Z=-2.332,P=0.020)。结论 4R危机管理理论在乳腺癌放疗期患者放射性皮炎管理中的应用能够显著降低患者放射性皮炎的发生率,减轻其严重程度,提高患者治疗期间的舒适度和整体满意度。

头颈癌放疗患者家庭肠内营养支持管理的最佳证据总结

目的总结头颈癌放疗患者家庭肠内营养管理的最佳证据,为临床决策和管理提供循证依据。方法检索国内外数据库及网站中自建库至2023年12月关于头颈癌放疗患者家庭肠内营养的临床决策、指南、证据总结、专家共识、系统评价、随机对照试验等,对各类研究进行文献质量评价后提取证据。结果共纳入17篇文献,总结包括家庭肠内营养的评估与启动、家庭肠内营养的实施、患者自我管理、组织管理、营养监测与随访5个方面共30条证据。结论总结的头颈癌放疗患者家庭肠内营养最佳证据,可为开展家庭肠内营养实践提供指引。

An Integrated Simulation System Based on Digital Human Phantom for 4D Radiation Therapy of Lung Cancer

Purpose: To develop and test an integrated simulation system based on the digital Extended Cardio Torso (XCAT) phantom for 4-dimensional (4D) radiation therapy of lung cancer. Methods: A computer program was developed to facilitate the characterization and implementation of the XCAT phantom for 4D radiation therapy applications. To verify that patient-specific motion trajectories are reproducible with the XCAT phantom, motion trajectories of the diaphragm and chest were extracted from previously acquired MRI scans of five subjects and were imported into the XCAT phantom. The input versus the measured trajectories was compared. Simulation methods of 4D-CT and 4D-cone-beam CT (CBCT) based on the XCAT phantom were developed and tested for regular and irregular respiratory patterns. Simulation of 4D dose delivery was illustrated in a simulated lung stereotactic-body radiation therapy (SBRT) case based on the XCAT phantom. Dosimetric comparison was performed between the planned dose and simulated delivered dose. Result: The overall mean (±standard deviation) difference in motion amplitude between the input and measured trajectories was 1.19 (±0.79) mm for the XCAT phantoms with voxel size of 2 mm. 4D-CT and 4D-CBCT images simulated based on the XCAT phantom were validated using regular respiratory patterns and tested for irregular respiratory patterns. Comparison between simulated 4D dose delivery and planned dose for the lung SBRT case showed comparable results in all dosimetric matrices: the relative differences were 0.3%, 4.0%, 0%, and 2.8%, respectively, for max cord dose, max esophagus dose, mean heart dose, and V20Gy of the lungs. 97.5% of planning target volume (PTV) received prescription dose in the simulated 4D delivery, as compared to 95% of PTV received prescription dose in the plan. Conclusion: We developed an integrated simulation system based on the XCAT digital phantom and illustrated its utility in 4D radiation therapy of lung cancer. This simulation system is potentially a useful tool for quality control and development of imaging and treatment techniques for 4D radiation therapy of lung cancer.

辐射环境监测与紧急响应管理

文章旨在探讨辐射环境监测与紧急响应管理,从而有效地应对辐射环境污染事件。文章简要分析了紧急响应管理的基本原则,详细分析了辐射环境监测相关技术,如辐射监测设备与仪器、辐射环境样品采集等。在此基础上,重点探讨了辐射环境污染事件的紧急响应管理方案,包括事故报告与启动紧急响应、人员疏散与安全防护、应急资源调配与协调等。通过文章的研究可知,辐射环境监测与紧急响应管理十分重要,可为相关领域的研究者和从业人员提供有效的参考。

基于飞发一体化的滑油系统热性能仿真

航空发动机滑油系统与飞机、发动机的关联参数有限。为准确表达变工况滑油系统的热性能,通过研究发动机轴承腔热性能与转子转速及主流路温度参数的拟合关系,将主机温度、燃滑油参数作为输入,对发动机滑油系统在飞行剖面上典型飞行状态点的热性能参数进行了迭代计算;针对管壳式燃滑油散热器结构及运行特性,计算了散热器换热性能。建立轴承腔和散热器的数学模型;基于系统流动仿真平台,利用内部的二次开发环境编写出C#语言代码,开发出了适用于发动机的轴承生热模型和散热器模型,实现发动机滑油系统与发动机燃油系统及飞机热管理系统的联合计算;在航空发动机、飞机变工况输入条件下,进行滑油系统、发动机整机及飞发一体化的变工况热性能迭代计算,并与试验数据进行对比。结果表明:该计算方法误差小于5%,可较准确地反映变工况条件下的热管理相关参数,为飞发一体化热管理联合仿真分析提供可靠的数据来源。