分类: 其他 提交时间: 2025-07-13
摘要: 小型反应堆对换热设备小型化提出需求,针对某管壳式换热器的小型化需求,设计了一款适合应用增材制造技术加工的高性能矩形微通道热交换器(additive manufacaturing rectangular microchannel heat exchanger,AMRMHE)。根据金属增材制造的特点,采用激光选区熔融技术(SLM)完成不锈钢样件加工。样件具有120个通道尺寸为3.9mm的冷侧微通道和97个通道尺寸为3mm的热侧微通道,换热面紧凑度达到480m2/m3。通过搭建AMRMHE流动换热实验平台,对AMRMHE冷、热侧的流动与换热特性开展了实验研究。研究结果表明,在211mm×98mm×992mm AMRMHE实验件中最大可实现4058.1kW/m3体积换热功率,是原型管壳式换热器的5倍;AMRMHE整体换热性能与流体流量以及温度密切相关,热侧流量对换热系数影响显著高于热侧温度;AMRMHE冷、热侧压降随流量上升而增大,热侧由于管道水力直径更小,流动阻力高于冷侧。研究结果表明AMRMHE是满足小型核反应堆换热设备高效紧凑需求的有效方案。
分类: 核科学技术 >> 核科学技术其他学科 提交时间: 2025-07-12
摘要: 铅基堆堆芯上腔室的温度振荡现象是影响核电站安全稳定运行的关键因素之一,其准确描述对热脉动机制的分析具有重要意义。采用SST k-ω湍流模型对该现象进行了数值模拟研究,定量分析了模型中β1、β2、β*三个参数对温度结果的影响及其不确定区间,并进行了参数敏感度分析。研究结果表明,温度不确定性的分布特征与流体流动和混合过程有着密切的联系。喷口附近区域由于受到喷口射流的直接影响,温度不确定性较低;而冷热喷口中间区域由于流体混合作用强烈,不确定性相对较高,特别是β2和P*参数在所研究的范围内对温度结果的不确定性有较大的贡献,这些发现为后续模型改进和工程应用提供了科学指导。
分类: 核科学技术 >> 核科学技术其他学科 提交时间: 2025-07-12
摘要: 六方氮化硼具有与石墨烯类似的六元环组成的片层结构,因而呈现出优异的机械性能和导热性能,在诸多应用领域受到广泛关注。基于六方氮化硼制备工艺的高能耗问题,本文旨在提出一种更加绿色、低能耗的制备工艺。本工作使用熔盐介质法作为制备工艺方法。该方法以KCl-NaCl为熔盐体系,三聚氰胺(C3N6H6)和硼酸(H3BO3)为反应物,并且通入氮气(N2)作为反应气氛。该研究通过改变熔盐与反应物质量比、反应物中氮-硼摩尔比、保温温度、保温时间等条件,系统研究了不同条件对制备六方氮化硼产物的影响。通过对各种所得样品的表征分析,得出最优的制备条件。在该工作的系统研究下,发现熔盐与反应物质量比为2:1、氮-硼摩尔比为1:2、1000℃保温10小时为最佳制备条件。在该条件下可以制备出平均尺寸50nm大小左右的六方氮化硼纳米片。说明在最佳工艺条件下,可以制备出粒径可控、形貌一致、结晶良好的六方氮化硼纳米片。本工作提供了一种绿色低碳合成六方氮化硼纳米片的新途径。
分类: 其他 提交时间: 2025-07-10
摘要: 放射性靶向药物作为治疗恶性肿瘤的重要手段,以其精确的肿瘤定位能力和对传统治疗抵抗肿瘤的潜在疗效而备受关注。225Ac因其高细胞毒性、适宜的半衰期和独特的衰变特性,成为靶向α治疗中极具潜力的核素。本文综述了225Ac在治疗前列腺癌、神经内分泌瘤等肿瘤的临床研究进展,并讨论了靶向α药物面临的挑战和未来发展方向,旨为靶向α药物的相关研究提供借鉴。
分类: 物理学 >> 核物理学 提交时间: 2025-07-10
摘要: This paper presents a novel pixel chip readout scheme: the Region-of-Interest Readout Circuit (ROIRC), which is designed for large area, large array pixel chips and Gas Pixel Detector (GPD). This design employs a sentinel pixel detection strategy, enabling rapid identification and prioritized readout of the pixel regions containing signal events. During the scanning readout of these signal events, ROIRC employs a Block-based readout approach, effectively minimizing the readout of non-signal pixels. The functionality of ROIRC has been successfully implemented on both the ASIC and FPGA platforms. In the tests of the ROIRC, the detector is capable of detecting low-energy X-rays in the range of 2-10 keV and support multiple event readouts, and the detector can perform effective readout of effective photons with a flux of up to 15k · (cm-2 · s-1) .
分类: 心理学 >> 发展心理学 提交时间: 2025-07-10
摘要: [目的]探索基于微博文本的青少年感知社会支持评估方法,并分析其人口学差异特征。[方法]采用Python爬取全国12–18岁青少年微博文本(约30万条),构建包含四维度的感知社会支持词典,通过“文心”系统进行词频分析,并结合性别、年龄、地区等变量开展统计分析。[结果]构建词典共收录1312个词汇,具备良好效度;分析发现不同性别、年龄与地区的青少年在感知社会支持水平上存在显著差异,西部和东北部地区较低,东部和中部地区较高。[局限]数据来源为公开微博文本,可能存在群体代表性偏差;词典虽具效度,但对深层心理语义的捕捉能力有限。[结论]社交媒体文本可用于有效评估青少年感知社会支持水平,具备实践价值与预警潜力。关键词:感知社会支持,微博文本分析,词典构建,青少年
分类: 物理学 >> 核物理学 提交时间: 2025-07-10
摘要: Due to the current situation of the lack of devices and methods for measuring the internal contamination caused by radionuclides in wounds, which may be caused in spent fuel reprocessing and radioisotope production, we developed a new non-contact measurement system for radionuclide-contaminated wounds with better resolution, moderate size, and easy for clinical application by using the imaging and energy spectroscopy measurement technology to measure the amount and distribution of the contamination retained in wound. With that system,a measurement method to estimate the retention depth and activity of nuclides in the injured part was established by making use of the difference of the absorption attenuation coefficient of X/γ rays emitted by retained nuclides in the injured limb with different thicknesses , which realizes the identification of the retained nuclides in wounds, the measurement of the depth and activity of nuclides retained in different types of wounds, as well as the determination of the characteristics of the distribution of radioactive contamination in wounds. The problem of measuring the characteristics of radionuclide-contaminated wounds are solved fundamentally. This study is of great significance in upgrading the level of existing technology for radionuclide-contaminated wounds at home and abroad, improving the monitoring and evaluation system of internal irradiation, and enhancing the occupational health protection level of radiation practitioners.
分类: 物理学 >> 核物理学 提交时间: 2025-07-10
摘要: Austenitic stainless steels have been extensively utilized as key structural components in nuclear reactors, yet they exhibit a strong tendency to undergo swelling under neutron irradiation, which consequently deteriorates their mechanical performance. Hence, reliable prediction of the swelling evolution in austenitic stainless steels is essential to guarantee their operational integrity during reactor service. This research draws on a curated dataset documenting neutron irradiation-induced swelling in austenitic stainless steels, in which correlation analysis and recursive feature elimination were used to identify critical factors governing swelling behavior—namely, temperature, neutron flux, and the concentrations of Cr, Mn, Ni, Si, P, and C. Based on the 15 selected features, a multilayer perceptron (MLP) model was developed for predictive analysis of swelling, enabling precise prediction of the peak swelling temperature and the dose corresponding to the swelling incubation stage. Using the trained MLP model, a quantitative relationship was established between the swelling rate and the elemental concentrations of Cr, Mn, Ni, Si, P, and C. The analysis revealed that higher Cr content consistently promotes swelling, while increases in Si and P (above 0.02 wt.%) effectively suppress swelling. Additionally, there exist threshold concentrations for Mn (2.5 wt.%), Ni (35 wt.%), and C (0.1 wt.%), beyond which swelling is most effectively mitigated. The results of elemental interaction analysis indicate that in austenitic stainless steels containing high levels of Cr, Ni must be increased to 15–20 wt.% to achieve enhanced swelling resistance. Under conditions of low C concentration, increasing the P content appropriately can enhance the material's resistance to irradiation-induced swelling. These findings offer quantitative guidance for designing and optimizing the composition of austenitic stainless steels with improved swelling resistance under irradiation.
分类: 物理学 >> 凝聚态:电子结构、电、磁和光学性质 提交时间: 2025-07-10
摘要: Based on the general thermodynamic analysis of Polanyi adsorption potential, the adsorption potential condition for superconductors is obtained exactly by using the quantum state equation we presented. Because this adsorption potential results in changes of electron concentration, temperature and pressure in a certain volume (adsorption space) adjacent to the surface of the lattice, the composition and structure of superconductors are of course decisive for the adsorption potential. Then we calculate the molar adsorption potentials for those typical superconductors, and find that it is positively correlated to the superconductivity temperature T_c, which reveals that those high-T_c superconductors are mainly determined by the higher molar adsorption potentials. In addition, the adsorption potential at 〖T=T〗_c still works despite the disappearance of the energy gap of the BCS theory. This shows that beyond the electron-phonon interaction mechanism, the Cooper-paired electrons are mainly formed by this physical adsorption potential for high-T_c superconductors. This adsorption potential theory could explain almost all common facts about high-temperature superconductors, including many anomalies of the normal and superconducting states.
分类: 心理学 >> 教育心理学 提交时间: 2025-07-09
摘要: 认知脱离综合征(Cognitive Disengagement Syndrome,CDS),又称认知节奏迟缓(Sluggish Cognitive Tempo,SCT),是一组涉及注意脱离、对外界信息加工迟滞及行为活动低下等因神经发育不良导致的持续行为或症状。该综合征在注意缺陷多动障碍(ADHD)的研究中逐渐受到关注,并成为新兴的独立研究领域。研究发现,CDS/SCT群体在心智游移、学业问题、内化问题、睡眠问题等方面存在有别于注意缺陷多动障碍、焦虑障碍、抑郁障碍等相关障碍的损伤特征,CDS功能损伤可能与背侧注意网络和默认模式网络异常相关。越来越多的证据显示CDS是一种独立的心理疾病。未来除了明确CDS 作为一种独立障碍、关注CDS特征的毕生发展历程、探讨CDS的整体结构与子维度的关系外,还需丰富CDS的研究方法。
分类: 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间: 2025-07-09
摘要: As to matter wave, an interesting question is whether a particle can behave as a wave in the frame tied toitself. If the answer is negative, it is possible to establish a self-reference frame to cancel the particle’swaveform, and even develop a metric field equation to describe wave-particle duality as a geodesic effect.Meanwhile, it also shows that in addition to on-site verification, another efficacy of physicalmeasurement is to systematically reset the quantum geodesic curve of measured object. This retroactivereset not only prunes a randomly selectable history into a causal course with specific trend, but alsomakes the verified a historical inevitability dominated by geodesic geometry. The procedure adopted herewill provide a conceptually different explanation for irreversible quantum collapse and entanglement.
分类: 计算机科学 >> 自然语言理解与机器翻译 提交时间: 2025-07-09
摘要: 科技的进步和互联网的发展让大规模非结构化数据(如音频,视频,自然语言文本)的存储和分发成为可能。然而任何存储和分发数据的行为都会产生一定的成本,因此人们很自然地会思考高效利用大规模非结构化数据的方式。自然语言处理(NaturalLanguageProcessing,NLP)就是一门研究如何分析这些非结构化数据的计算机科学和人工智能学科。简单来说,自然语言处理的核心任务就是将非结构化数据以计算机可以理解的方式进行表示,让计算机用自已擅长的方式对处理过的非结构化数据进行处理,并将计算机处理结果“翻译”回人类可以理解的语言。自然语言处理的发展依赖许多不同的学科,比如语言学和计算机科学。语言学提供了语言结构的定义和意义理论,而计算机科学则提供处理和实现这些语言学理论和定义的技术与算法,二者相辅相成,共同支持计算机实现自然语言的自动化理解与生成。在工业界,自然语言处理被广泛应用于情感分析,文本分类,基于上下文的文本提取,文档摘要和机器翻译等任务。本篇综述报告的目的就是对自然语言处理及其核心技术进行有深度的探究,并对自然语言处理相关前沿技术和前沿模型进行讨论。
分类: 物理学 >> 核物理学 提交时间: 2025-07-09
摘要: Within the framework of the isospin-dependent quantum molecular dynamics model, the fusion cross section and fusion mechanism of neutron-deficient Pu isotopes in the reactions 24,26,30Si+196Hg were investigated. We found that the fusion cross sections are higher in the reaction with a more neutron-rich beam owing to the lower dynamical barrier. The dynamic barrier decreases with decreasing incident energy, which explains the fusion enhancement at the sub-barrier energy. The peak value of N/Z ratio in the neck region was the highest in reaction 30Si+196Hg, indirectly leading to the lowest dynamic barrier. Compared with the proton density distribution, the neck region for neutrons is larger, indicating that neutrons transfer more quickly than protons, leading to a high N/Z ratio in the neck. The time distribution of the appearance of dynamical barriers was wider at lower incident energies, indicating that the fusion process took longer to exchange nucleons. The single-particle potential barrier decreases with time evolution and finally disappears at a lower impact parameter, which is favorable for fusion events.
分类: 物理学 >> 核物理学 提交时间: 2025-07-09
摘要: To overcome the difficulty and expensive cost for some specific isotopic targets, a substitution method was proposed to measure the cross section of (γ, n) reactions. Considering that the natural copper element (natCu) only has 63Cu and 65Cu isotopes, the 65Cu(γ, n)64Cu reaction was taken as an example to test the substitution method. Using quasi-monoenergetic γ beams provided by the Shanghai Laser Electron Gamma Source (SLEGS) of the Shanghai Synchrotron Radiation Facility (SSRF), the natCu(γ, n) was measured from Eγ= 11.09 to 17.87 MeV. Furthermore, based on the 63Cu(γ, n) reaction measured using the same experimental setup at SLEGS, the 65Cu(γ, n)64Cu was extracted using the substitution method. The abundance variation of natural copper, showing a significant influence in the cross section, is also investigated. The results were compared to the existing experimental data measured by bremsstrahlung and positron annihilation in-flight sources, and the TALYS 2.0 predictions. The γ strength function (γSF) of 65Cu is obtained from the 65Cu(γ, n) data, and the reaction cross section of 64Cu(n, γ) was further calculated.
分类: 数字出版 >> 互联网期刊 提交时间: 2025-07-09 合作期刊: 《中国传媒科技》
摘要: 【目的】 6G 技术超高速的传输速率和极低的延迟,目的在于极大地提升融媒体内容的传播效率和质量。借助 6G 技术强大的连接能力和大数据处理能力,融媒体可以实现个性化的内容推荐和精准营销。6G 网络能够实时收集用户的行为数据、兴趣爱好等信息,并进行深度分析。【方法】6G技术在融媒体产业运营方面的创新方法 ,6G 技术可以通过智能算法优化融媒体产业的资源分配。6G 网络能够实时监测各个业务环节的数据,6G 的高速率和低延迟可以支持更多高附加值的融媒体服务。【结果】6G 技术在融媒体领域的创新结果 ,内容创作的智能化与高效化 ,在传播效果上,6G 技术带来了显著的提升。【结论】6G 技术在融媒体领域的创新结论,6G 技术与融媒体实现了深度融合并带来了创新变革。6G 技术促使融媒体的业务模式得到拓展和重塑。
分类: 数字出版 >> 互联网期刊 提交时间: 2025-07-09 合作期刊: 《中国传媒科技》
摘要: 【目的】随着人工智能技术的快速发展,教辅数字化出版领域正经历深刻变革。【方法】智能技术在教辅数字化出版中的应用涉及内容生产、资源整合、个性化推荐等多个环节。通过引入自然语言处理、机器学习、知识图谱等技术,教辅数字化出版实现了内容智能分析、精准化推送和交互式学习体验。【结果】智能技术的应用不仅提升了教辅出版的效率和质量,也为学习者提供了更加个性化、智能化的学习支持。【结论】深入探讨智能技术在教辅数字化出版中的具体应用场景和实施策略,对推动教育资源的智能化建设具有重要意义。
分类: 数字出版 >> 互联网期刊 提交时间: 2025-07-09 合作期刊: 《中国传媒科技》
摘要: 【目的】探究中波广播发射机电路设计中的关键技术问题,优化信号处理方案,提升系统性能和频谱利用效率。【方法】基于数字信号处理技术对发射机电路进行优化设计,采用分布式监测方案对发射信号质量进行测量,通过大功率假负载测试系统验证系统性能指标。【结果】改进设计的中波发射机在频谱控制、调制深度和杂散发射抑制等方面均显示出显著的性能提升。输出槽路的双调谐结构有效改善了频谱特性,分布式监测系统保证了设备运行稳定性。【结论】优化后的数字电路设计方案显著提升了发射机整体性能,具有良好的工程应用价值,为中波广播发射设备的技术革新提供了实用解决方案。
分类: 数字出版 >> 互联网期刊 提交时间: 2025-07-09 合作期刊: 《中国传媒科技》
摘要: 【目的】剖析人工智能技术嵌入新闻采编业务的融合实践,探索智能化转型路径。【方法】采用文献分析法,结合主流媒体实践案例,系统梳理智能技术在采编业务中的应用模式与发展趋势。【结果】人工智能技术重构采编流程,实现多模态内容生产;深度伪造、算法偏差等风险凸显;采编岗位转型压力加大。【结论】构建“算法 + 人工”双重把关机制,完善智能化采编体系,强化采编人员数字技能培训,是推进深度融合发展的关键着力点。
分类: 数字出版 >> 互联网期刊 提交时间: 2025-07-09 合作期刊: 《中国传媒科技》
摘要: 【目的】探讨人工智能(AI)对在提高传播效果、推动文化交流、促进舆论管理和重构传播范式等方面的作用。【方法】采用案例分析和文献综述法,分析 AI 如何通过数据分析和机器学习优化传播策略,增强信息可见性,以及如何利用 VR 和AR提供沉浸式体验,加深文化理解和交流。【结果】研究发现,AI 的应用显著提高了新闻传播的效率,促进了不同文化间的相互理解与尊重。此外,AI还推动了传播范式的创新,具体表现为传播主体多元化、场域改变及传播秩序重构。【结论】AI为新闻传播领域带来了革命性的变化,不仅提升了信息传递的速度和广度,还加强了跨文化沟通,未来应继续探索 AI 的潜力,为更加开放和包容的全球对话奠基。