分类： 其他 提交时间： 2024-05-10
摘要： 核素空气比释动能率常数Γa是评估剂量和屏蔽计算中非常重要的数据，Γa的计算需要用到通量到空气比释动能率的转换系数Ka/Φ以及核素衰变光子信息。2020年国际辐射与测量委员会ICRU发布了95号报告，该报告推荐了新的Ka/Φ。为了验证基础数据更新后核素 数值的变化，基于理论和蒙特卡洛方法对医学、工业、农业中常用的39种核素空气比释动能率常数进行了计算，并对不同插值方法及阈值选取做了对比分析。得到以下结论：三次样条、对数-对数拉格朗日插值、线性-对数拉格朗日插值插值方法对Γa的计算影响较小；阈值选取对Γa的计算非常重要，部分核素在不同阈值情况下计算差异较大，推荐核医学剂量估算建议使用10 keV阈值，其他情况阈值选取20 keV；理论计算和MCNP模拟计算差异较小，都可用于常数的计算。
分类： 其他 提交时间： 2024-05-07
摘要： 互补型金属氧化物半导体（Complementary Metal Oxide Semiconductor, CMOS）图像传感器有着体积小，质量轻，功耗低，高集成度等特点正逐步取代CCD图像传感器，在空间辐射环境中有着质子，重粒子，γ射线，电子等大量的高能粒子，CMOS图像传感器会受到重离子的辐射效应并对其有着永久损伤的影响。本文主要是针对CMV4000在重离子辐照下的永久损伤机制。CMV4000在经过重离子辐照过后其图像有着明显的热像素（暗电流尖峰高于其他像素暗电流尖峰数倍通常表现为该像素的灰度值是其他正常像素的数倍），在下一帧图像以及后续图像中热像素也并不会消失，因此热像素并不是暂时的。本文还将考虑 CMOS图像传感器在辐照前后各像参数的对比并揭示各项参数的退化机理。
分类： 其他 分类： 其他 提交时间： 2024-04-25
摘要： The Australia Telescope Large Area Survey (ATLAS) and the VLA survey in the XMM-LSS/VIDEO deep field provide deep ($\approx 15$ ${\mu}$Jybeam$^{-1}$) and high-resolution ($\approx$ 4.5--8 arcsec) radio coverage of the three XMM-SERVS fields (W-CDF-S, ELAIS-S1, and XMM-LSS). These data cover a total sky area of 11.3 deg$^2$ and contain $\approx 11000$ radio components. Furthermore, about 3~deg$^2$ of the XMM-LSS field also has deeper MIGHTEE data that achieve a median RMS of 5.6 ${\mu}$Jy beam$^{-1}$ and detect more than 20000 radio sources. We analyze all these radio data and find source counterparts at other wavebands utilizing deep optical and IR surveys. The nature of these radio sources is studied using radio-band properties (spectral slope and morphology), and the IR-radio correlation. %and spectral energy distribution. Radio AGNs are selected and compared with those selected using other methods (e.g. X-ray). We found 1656 new AGNs that were not selected using X-ray and/or MIR methods. We constrain the FIR-to-UV SEDs of radio AGNs using {\sc cigale} and investigate the dependence of radio AGN fraction upon galaxy stellar mass and star-formation rate.
分类： 其他 分类： 其他 提交时间： 2024-04-25
摘要： We present X-ray spectral and long-term variability analyses of an unbiased sample of 361 optically selected radio-loud quasars (RLQs) utilizing sensitive serendipitous X-ray data from the Chandra and XMM-Newton archives. The spectral and temporal properties of RLQs are compared with those of radio-quiet quasars (RQQs) matched in $L_\mathrm{2500A}$ and $z$. The median power-law photon index ($\Gamma$) of RLQs is $1.84^{+0.01}_{-0.01}$, which is close to that of matched RQQs ($1.90^{+0.02}_{-0.01}$). No significant correlations between $\Gamma$ and radio-loudness, $L_\mathrm{x}/L_\mathrm{x,rqq}$ (the X-ray luminosity over that expected from the $L_\mathrm{x}$-$L_\mathrm{uv}$ relation for RQQs), redshift, or Eddington ratio are found for our RLQs. The stacked X-ray spectra of our RLQs show strong iron-line emission and a possible Compton-reflection hump. The intrinsic X-ray variability amplitude is $\approx40$% for RLQs on timescales of months-to-years in the rest frame, which is somewhat smaller than for the matched RQQs ($\approx60$%) on similar timescales, perhaps due to the larger black-hole masses and lower Eddington ratios in our RLQ sample. The X-ray spectral and variability results for our RLQs generally support the idea that the X-ray emission of typical RLQs is dominated by the disk/corona, as is also indicated by a recent luminosity correlation study.
分类： 其他 分类： 其他 提交时间： 2024-04-25
摘要： Radio-loud quasars (RLQs) are known to produce excess X-ray emission, compared to radio-quiet quasars (RQQs) of the same luminosity, commonly attributed to jet-related emission. Recently, we found that the HeII EW and $\alpha_{\rm{ox}}$ in RQQs are strongly correlated, which suggests that their extreme-ultraviolet (EUV) and X-ray emission mechanisms are tightly related. Using 48 RLQs, we show that steep-spectrum radio quasars (SSRQs) and low radio-luminosity ($L_{\rm R}$) flat-spectrum radio quasars (FSRQs) follow the $\alpha_{\rm ox}$--HeII EW relation of RQQs. This suggests that the X-ray and EUV emission mechanisms in these types of RLQs is the same as in RQQs, and is not jet related. High-$L_{\rm R}$ FSRQs show excess X-ray emission given their HeII EW by a factor of $\approx$ 3.5, which suggests that only in this type of RLQ is the X-ray production likely jet related.
分类： 其他 分类： 其他 提交时间： 2024-04-25
摘要： Radio-loud quasars (RLQs) are more X-ray luminous than predicted by the X-ray-optical/UV relation (i.e. $L_\mathrm{x}\propto L_\mathrm{uv}^\gamma$) for radio-quiet quasars (RQQs). The excess X-ray emission depends on the radio-loudness parameter ($R$) and radio spectral slope ($\alpha_\mathrm{r}$). We construct a uniform sample of 729 optically selected RLQs with high fractions of X-ray detections and $\alpha_\mathrm{r}$ measurements.We find that steep-spectrum radio quasars (SSRQs; $\alpha_\mathrm{r}\le-0.5$) follow a quantitatively similar $L_\mathrm{x}\propto L_\mathrm{uv}^\gamma$ relation as that for RQQs, suggesting a common coronal origin for the X-ray emission of both SSRQs and RQQs. However, the corresponding intercept of SSRQs is larger than that for RQQs and increases with $R$, suggesting a connection between the radio jets and the configuration of the accretion flow. Flat-spectrum radio quasars (FSRQs; $\alpha_\mathrm{r}>-0.5$) are generally more X-ray luminous than SSRQs at given $L_\mathrm{uv}$ and $R$, likely involving more physical processes. The emergent picture is different from that commonly assumed where the excess X-ray emission of RLQs is attributed to the jets. We thus perform model selection to comparecritically these different interpretations, which prefers the coronal scenario with a corona-jet connection. A distinct jet component is likely important for only a small portion of FSRQs.The corona-jet, disk-corona, and disk-jet connections of RLQs are likely driven by independent physical processes. Furthermore, the corona-jet connection implies that small-scale processesin the vicinity of SMBHs, probably associated with the magnetic flux/topology instead of black-hole spin, are controlling the radio-loudness of quasars.
分类： 其他 提交时间： 2024-04-25
摘要： We have investigated the jet-linked \mbox{X-ray} emission from highly radio-loud quasars (HRLQs; $\log R>2.5$) at high redshift. We studied the X-ray properties of 15 HRLQs at $z>4$, using new {\it Chandra} observations for six objects and archival {\it XMM-Newton} and {\it Swift} observations for the other nine. We focused on testing the apparent enhancement of jet-linked \mbox{X-ray} emission from HRLQs at $z>4$. Utilizing an enlarged (24 objects) optically flux-limited sample with complete X-ray coverage, we confirmed that HRLQs at $z>4$ have enhanced X-ray emission relative to that of HRLQs at $z\approx$ 1--2 with matched UV/optical and radio luminosity, at a \mbox{4.0--4.6}~$\sigma$ level; the X-ray enhancements are confirmed considering both two-point spectral indices and inspection of broad-band spectral energy distributions. The typical factor of enhancement is revised to $1.9^{+0.5}_{-0.4}$, which is smaller than but consistent with previous results. A fractional IC/CMB model can still explain our results at high redshift, which puts tighter constraints on the fraction of IC/CMB X-rays at lower redshifts, assuming the physical properties of quasar jets do not have a strong redshift dependence. A dominant IC/CMB model is inconsistent with our data.
分类： 其他 提交时间： 2024-04-25
摘要： Rapid flares from blazars in very high energy (VHE) $\gamma$-rays challenge the common understanding of jets of active galactic nuclei (AGNs). The same population of ultra-relativistic electrons is often thought to be responsible for both X-ray and VHE emission. We thus systematically searched for X-ray flares at sub-hour timescales of TeV blazars in the entire Rossi X-ray Timing Explorer archival database. We found rapid flares from PKS 2005-489 and S5 0716+714, and a candidate rapid flare from 1ES 1101-232. In particular, the characteristic rise timescale of PKS 2005-489 is less than half a minute, which, to our knowledge, is the shortest among known AGN flares at any wavelengths. The timescales of these rapid flares indicate that the size of the central supermassive black hole is not a hard lower limit on the physical size of the emission region of the flare. PKS 2005-489 shows possible hard lags in its flare, which could be attributed to particle acceleration (injection), its flaring component has the hardest spectrum when it first appears. For all flares, the flaring components show similar hard spectra with $\Gamma=1.7-1.9$, and we estimate the magnetic field strength $B\sim$ 0.1--1.0 G by assuming synchrotron cooling. These flares could be caused by inhomogeneity of the jets. Models that can only produce rapid $\gamma$-ray flares but little synchrotron activity are less favorable.
分类： 其他 分类： 其他 分类： 其他 提交时间： 2024-04-25
摘要： Fluxes emitted at different wavebands from active galactic nuclei (AGNs) fluctuate at both long and short timescales. The variation can typically be characterized by a broadband power spectrum, which exhibits a red-noise process at high frequencies. The standard method of estimating power spectral density (PSD) of AGN variability is easily affected by systematic biases such as red-noise leakage and aliasing, in particular, when the observation spans a relatively short period and is gapped. Focusing on the high-frequency PSD that is strongly distorted due to red-noise leakage and usually not significantly affected by aliasing, we develop a novel and observable normalized leakage spectrum (NLS), which describes sensitively the effects of leaked red-noise power on the PSD at different temporal frequencies. Using Monte Carlo simulations, we demonstrate how an AGN underlying PSD sensitively determines the NLS when there is severe red-noise leakage and thereby how the NLS can be used to effectively constrain the underlying PSD.
分类： 其他 提交时间： 2024-04-25
摘要： 观察耳穴贴压联合耳尖放血治疗一例外感咳嗽病患者的疗效。选取1例外感咳嗽患者，通过耳穴贴压对针对性穴位进行按摩，结合耳尖放血的治疗手法，达到有效改善平衡阴阳、调整脏腑、疏通经络、扶正祛邪、活血止痛，有效缓解患者咳嗽咳痰症状，从而缓解病情，促进康复，临床效果良好，无明显不良反应。
分类： 其他 提交时间： 2024-04-07
摘要： 本文总结1例面肌痉挛患者行火龙罐综合灸治疗的效果观察及护理经验。基于中医辨证施护理论基础上，给予火龙罐综合灸治疗并进行动态观察，同时配合情志护理、生活起居护理等常规护理措施，有效改善了患者的临床症状，缓解患者焦虑，提高了患者的舒适度及生活质量。
分类： 其他 分类： 其他 提交时间： 2024-03-11
摘要： 目的 通过随机对照试验评估中西医结合护理路径对呆病患者效果。方法 选取90名符合入选标准的患者，随机分为试验组（接受中西医结合护理）和对照组（接受常规护理）。在基线、干预第四周和出院后第四周测量MMSE、PSQI、ADL、MNA，进行组间比较。结果 ①MMSE：试验组在干预第四周和随访第四周明显提高（P＜0.05），且显著优于对照组（P＜0.05）。②PSQI：试验组在干预第四周和随访第四周明显下降（P＜0.05），对照组在干预第四周也下降（P＜0.05），试验组明显更佳（P＜0.05）。③ADL：两组无显著差异（P＞0.05）。④MNA：干预第四周两组无显著差异（P＞0.05），试验组随访第四周明显改善（P＜0.05）。结论 中西医结合护理路径对呆病患者病情干预效果较常规护理明显更佳。
分类： 其他 分类： 其他 提交时间： 2024-02-12
摘要： The technical evolution of domestic multi-functional electricity meter is deeply discussed. With the rapid development of the domestic power market and the continuous innovation of technology, the domestic multi-functional electricity meters have experienced the transformation from simple billing to complex multi-functional, from a single application to a wide range of fields. This transformation has not only driven the rapid development of electricity meter technology, but also met the increasing power demand and management requirements. This paper expounds the concept of multi-function meter, the working principle and algorithm of digital multiplier, the initiation and evolution of multi-function electricity meter standard, and the initiation and evolution of domestic multi-function electricity meter products. Although the domestic independent production of multi-functional meter has made great achievements in performance, but in the reliability and key process technology still need to be improved. In addition, the development of communication technology also provides a new opportunity for the progress of electricity meter technology. The application of the new technology provides a more convenient and efficient way for the data transmission and remote management of electricity meters. Domestic multi-functional electricity meters have made remarkable achievements in technology evolution and application and expansion, but they still face some challenges and opportunities. In the future, with the continuous development of the power market and the promotion of smart grid construction, domestic multi-functional electricity meters need to continue to strengthen technological innovation and product research and development, improve the reliability and competitiveness of products, in order to meet higher application needs and market requirements.
分类： 其他 提交时间： 2024-01-23
摘要： 本文总结手指点穴联合艾条灸中医特色技术治疗了一例顽固性呃逆患者的护理体会，在中西医结合治疗基础上辅以中医外治法，通过辨证论治，辨证施护，根据病症选取特殊穴位、采用特殊手法，在整体治疗中起到顺气解郁，和胃降逆的重要作用，其疗效显著，患者呃逆症状消失，创伤小，安全无副作用，为临床提供借鉴。
分类： 其他 分类： 其他 提交时间： 2024-01-22
摘要： 本文总结1例中药水罐疗法治疗气滞血瘀型腰痛患者疼痛的临床疗效。根据该例患者住院期间出现的腰部疼痛症状，通过采用中医护理特色水罐治疗技术，治疗患者腰部疼痛的症状疗效显著，从而提高了患者的生活质量。
分类： 其他 提交时间： 2024-01-07
摘要： 目的 探讨改良固定法在难固定部位自制负压引流中的应用。方法 选取我科2020年4月-2021年5月收治腋肩部、骶尾部、臀部、会阴部、腘窝等难固定部位行自制负压治疗的慢性创面患者34例，为对照组；选取我科2021年7月-2022年8月收治腋肩部、骶尾部、臀部、会阴部、腘窝等难固定部位行自制负压治疗的慢性创面患者34例，为观察组。对照组：自制负压中采用传统透明贴膜固定；观察组：自制负压中采用改良固定法固定。比较两组患者贴膜卷边发生率、负压渗漏发生率、负压更换频次、周围皮肤张力性损伤发生率。结果 观察组贴膜卷边发生率、负压渗漏发生率、负压更换频次、周围皮肤张力性损伤发生率均低于对照组，差异有统计学意义（P＜0.05）。结论 在难固定部位自制负压引流技术中,改良固定法较传统固定更稳妥、有效降低周围皮肤张力性损伤发生率，保证负压的有效性，减少负压的更换频次及治疗费用，减轻病人因换药带来的疼痛，提高患者的满意度。
分类： 其他 提交时间： 2023-11-20
摘要： 目的 本研究将Orem自护理论运用在中药保留灌肠治疗溃疡性结肠炎中，并用该方案对患者临床症状和炎症反应的影响进行分析。方法 选取2020年2月至2023年2月期间我院住院接受治疗的84例溃疡性结肠炎患者作为研究对象，依照信封法将其分为实验组和对照组，各42例。两组患者均采用保留灌肠治疗，在此基础上，对照组患者采用常规护理干预，实验组在常规护理上采用Orem自护理论干预，对比两组患者临床症状、炎性反应和生存质量。结果 干预后两组患者UCDAI指数中的便血、腹泻、内镜表现、医师评定的评分相较于干预前均有降低（P＜0.05），其中实验组低于对照组；干预后两组患者的TNF-α、IL-6、IL-8的水平相较于干预前均有降低（P＜0.05），其中实验组低于对照组； 干预后两组患者IBDQ评分中的肠道症状、全身症状、情感功能及社会功能的评分相较于干预前均有降低（P＜0.05），其中实验组低于对照组。结论 Orem自护理论运用在中药保留灌肠治疗溃疡性结肠炎中，能够有效改善患者的各项临床症状和炎性反应，提高患者的生活质量。
分类： 其他 分类： 其他 分类： 其他 提交时间： 2023-11-07
摘要： 目的 观察辨证饮水联合艾灸与大黄贴敷神阙穴对气虚秘的治疗效果。方法 选取2020年3月至2021年12月到本院肛肠科门诊就医的气虚秘患者180例为研究对象，随机分为A、B、C三组，每组60例。A组：不限定饮水,B组：卯时饮温开水300ml，C组：卯时饮黄芪水300ml。三组患者均要进行4个疗程的艾灸及大黄贴敷神阙穴的治疗。观察、记录并比较三组患者大便排便时间、大便性状、次数、量及患者一般情况。结果 治疗效果比较：B组优于A组，C组优于B组，3组治疗效果C>B>A，差异具有统计学意义（P＜0.05）。结论 辨证饮水联合艾灸与大黄贴敷神阙穴对气虚秘有良好的治疗效果，且具有调理肠胃、强身健体、无创伤及不良体验，值得临床推广应用。
分类： 其他 提交时间： 2023-10-31
Chengbo Li
Qungang Wen
Yuanyong Fu
Jing Zhou
Shuhua Zhou
Qiuying Meng
C. Spitaleri
A. Tumino
R. G. Pizzone
L. Lamia
摘要： The study of d(d,p)t reaction is very important for the nucleosynthesis in both standard Big Bang and stellar evolution, as well as for the future fusion reactors planning of energy production. The d(d,p)t bare nucleus astrophysical S(E) factor has been measured indirectly at energies from about 400 keV down to several keV by means of the Trojan horse method applied to the quasi-free process 2H(6Li, pt)4He induced at a lithium beam energy of 9.5 MeV, which is closer to the zero quasi-free energy point. An accurate analysis leads to the determination of the Sbare(0) = 56.72.0keVb and of the corresponding electron screening potential Ue = 13.2 4.3eV. In addition, this work gives an updated test for the Trojan horse nucleus invariance comparing with previous indirect investigations using 3He = (d + p) breakup.
分类： 其他 提交时间： 2023-02-24
摘要： 随着近几年来大量高压直流输电工程接入交流系统，给交直流混联电网带来重要影响，直流系统的运行状况，尤其是其控制保护系统的性能，已成为影响交直流混联电网安全稳定的重要因素。系统故障引发平波电抗器瓦斯保护误动作是导致直流系统闭锁的重要非电气量因素之一，本论文详细研究分析了平抗瓦斯的设备原理和特点，采用Gaussian回归算法对平抗瓦斯机械振动与冲击电流的非线性耦合特性进行精细化模拟和解耦，且与电磁暂态算法相兼容，并基于国网仿真中心华东电网ADPSS纯电磁暂态实际工程控保算例进行交直流电网纯电磁仿真，可以详细描述交直流电网故障冲击电流等电气量动态变化对平抗瓦斯机械振动加速度非电气量的非线性快速响应动态特性，为实际工程中多次发生的平抗瓦斯误动导致直流闭锁的事故分析和故障重演、预防以及设备改进提供关键技术手段，对于进一步提高直流实用化工程仿真的多维度精度具有重要现实意义，并为其他非线性电气相关设备的详细建模提供思路。
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