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  • The nature of the Li enrichment in the most Li-rich giant star

    分类: 天文学 >> 恒星和银河系 提交时间: 2023-12-31

    摘要: About 1% of giants have anomalously high Li abundances in their atmospheres, conflicting directly with the prediction of the standard stellar evolution models. This finding makes the production and evolution of Li in the Universe intriguing, not only in the sense of Big Bang nucleosynthesis or the interstellar medium, but also for the evolution of stars. Decades of efforts have been put into explaining why such extreme objects exist, yet the origins of Lirich giants are still being debated. Here we report the discovery of the most Li-rich giant known to date, with a very high Li abundance of 4.51. This rare phenomenon was observed coincidentally with another short-term event: the star is experiencing its luminosity bump on the red giant branch. Such a high Li abundance indicates that the star might be at the very beginning of its Li-rich phase, which provides a great opportunity to investigate the origin and evolution of Li in the Galaxy. A detailed nuclear simulation is presented with up-to-date reaction rates to recreate the Li enrichment process in this star. Our results provide tight constraints on both observational and theoretical points of view, suggesting that low-mass giants can internally produce Li to a very high level through 7Be transportation during the red giant phase.

  • 紧急起始腹膜透析患者实行递增式腹透的临床疗效观察

    分类: 医学、药学 >> 临床医学 提交时间: 2023-12-30

    摘要: 目的:观察紧急起始腹膜透析(Urgent-start Peritoneal Dialysis, USPD)患者实行递增式腹膜透析(Incremental Peritoneal Dialysis)方案的可行性以及临床疗效。 方法:本研究为单中心回顾性研究,纳入2018-8-1至2021-7-31在西安交通大学第一附属医院肾内科住院行紧急起始腹膜透析的终末期肾病患者,所有患者透析前肾小球滤过率介于4~6ml/min/1.73m2。根据起始透析剂量不同,分为递增剂量组(透析剂量≤6000mL/日)和标准剂量组(透析剂量≥8000mL/日),其中递增剂量组依据患者的残余肾功能和透析充分性调整透析方案。每位患者随访时间1年,于透析1个月、3个月、6个月及1年时分别评估两组患者临床生化指标、透析剂量、透析充分性、尿量、腹透超滤量、残余肾功能以及腹膜透析相关并发症等指标。 结果:1.本研究共纳入169位患者,其中递增剂量组111人,平均年龄45.01±12.84岁;标准剂量组58人,平均年龄43.5±15.62岁。透析前两组的人口学特征、临床生化指标(血压、白蛋白、尿素氮、血肌酐、血钾、血磷、甲状旁腺素、血红蛋白)以及残余肾功能均相似,差异无统计学意义(P>0.05)。2.在整个随访期内,虽然递增剂量组的透析剂量始终低于标准剂量组,差异均有统计学意义(P<0.05),但两组的透析充分性均达标。并且在透析治疗1个月和6个月时,递增剂量组的UKt/V明显高于标准剂量组(1月:0.75±0.43 VS. 0.61±0.32,P=0.027;6月:0.68±0.53 VS. 0.50±0.29,P=0.018),差异有统计学意义。3.在随访期内,两组患者血压的控制、贫血及低钙血症纠正的情况相似,差异无统计学意义(P>0.05)。两组高磷血症的纠正情况均达标,但在透析1个月时,递增剂量组的血磷明显高于标准剂量组(1.48±0.43mmol/L VS. 1.34±0.31mmol/L,P=0.039);当透析1年时,递增剂量组的血磷明显低于标准剂量组(1.39±0.36mmol/L VS. 1.53±0.35mmol/L,P=0.030),差异均有统计学意义。4.随访期内,两组的残余肾功能相似,标准剂量组的超滤量高于递增剂量组,但差异均无统计学意义(P>0.05)。而递增剂量组的尿量均明显高于标准剂量组,尤其在透析1个月和透析6个月时差异有统计学意义(P<0.05)。5.随访期内,两组均无患者死亡,并且在腹膜透析感染相关并发症、机械并发症、技术生存率等方面相似,差异无统计学意义(P>0.05)。 结论:对于USPD患者,递增式腹膜透析的治疗效果以及并发症情况与标准剂量组相似,并且递增式腹膜透析不会导致USPD患者残余肾功能的快速下降。因此,递增性腹膜透析方式可以作为USPD患者的起始透析方式。

  • 认知建模中模型比较的方法

    分类: 心理学 >> 认知心理学 分类: 心理学 >> 心理统计 提交时间: 2023-12-30

    摘要: 认知建模近年来在科学心理学获得广泛应用,而模型比较是认知建模中关键的一环:研究者需要通过模型比较来选择出最优模型,才能进行后续的假设检验或潜变量推断。模型比较不仅要考虑模型对数据的拟合(平衡过拟合与欠拟合),也需要考虑参数数据和数学形式的复杂度。然而,模型比较指标众多,纷繁复杂。将认知建模常用的模型比较的指标分为三大类,并介绍了其计算方法及优劣,包括拟合优度指标(包括平均平方误差、决定系数、RUC曲线等)、基于交叉验证的指标(包括AIC、DIC等)和基于边际似然的指标。结合正交Go /No-Go范式下的数据,展示各指标在R语言中如何实现。在此基础上,探讨各指标的适用情境,介绍模型平均等模型比较的新思路。

     

  • Measurement of the high energy γ-rays from heavy ion reactions using ˇ Cerenkov detector

    分类: 物理学 >> 核物理学 提交时间: 2023-12-29

    摘要: The energetic bremsstrahlung photons up to 100 MeV produced in heavy ion collisions can be used as a
    sensitive probe to the short range correlation in atomic nuclei. The energy of the γ-rays can be measured
    by collecting theˇCerenkov light in medium induced by the fast electrons generated in Compton scattering or
    electromagnetic shower of the incident γ ray. Two types of detectors, based on pure water and lead glass as
    the sensitive material respectively, are designed for the above purpose. The γ response and optical photon
    propagation in detectors have been simulated based on the electromagnetic and optical processes in Geant4.
    The inherent energy resolution of 0.022(4) + 0.51(2)/Eγ 1/2 for water and 0.0026(3) + 0.446(3)/Eγ 1/2 for
    lead glass are obtained. The geometry size of lead glass and water are optimized at 30 × 30 × 30 cm3 and
    60 × 60 × 120 cm3 , respectively, for detecting high energy γ-rays at 160 MeV. Hough transform method has
    been applied to reconstruct the direction of the incident γ-rays, giving the ability to distinguish experimentally
    the high-energy γ rays produced in the reactions on the target from the random background cosmic ray muons.

  • 女性社会创业:身份认同策略、合法性获取及绩效影响研究

    分类: 心理学 >> 心理学其他学科 分类: 管理学 >> 管理学其他学科 提交时间: 2023-12-29

    摘要: 身份认同作为女性社会创业者创业行为和结果的起点,对于解决她们所面临的关键问题——获取合法性和提升创业绩效,具有重要意义。然而, 目前对于女性社会创业者身份认同策略与合法性获取之间的关系,以及身份认同整合如何提升社会创业绩效的内在机理的研究仍然匮乏。因此,本研究遵循“身份认同策略—合法性获取—绩效影响”的递进逻辑,开展三项子研究:首先,基于认同理论,通过联合分析实验探讨身份认同策略对女性社会创业决策的影响;其次,基于制度逻辑视角,利用模糊集定性比较分析(fsQCA)探究身份认同策略对合法性获取的组态影响;最后,基于认同理论,构建女性社会创业者身份认同整合影响社会创业绩效的理论模型,揭示合法性的中介作用以及社会拼凑的调节作用。相关研究成果有助于指导女性社会创业者形成清晰的自我认知并做出合理的创业决策,成功获取合法性,进而提升社会创业绩效。

  • A High-Mass Young Star-forming Core Escaping from Its Parental Filament

    分类: 天文学 >> 天体物理学 提交时间: 2023-12-29

    摘要: We studied the unique kinematic properties in massive filament G352.63-1.07 at 1000-AU spatial scale with the dense molecular tracers observed with the Atacama Large Millimeter/submillimeter Array (ALMA). We find the central massive core M1 (12 Msun) being separated from the surrounding filament with a velocity difference of v-v_sys=-2 km/s and a transverse separation within 3 arcsec. Meanwhile, as shown in multiple dense-gas tracers, M1 has a spatial extension closely aligned with the main filament and is connected to the filament towards its both ends. M1 thus represents a very beginning state for a massive young star-forming core escaping from the parental filament, within a time scale of ~4000 years. Based on its kinetic energy (3.5x10^44 erg), the core escape is unlikely solely due to the original filament motion or magnetic field, but requires more energetic events such as a rapid intense anisotropic collapse. The released energy also seems to noticeably increase the environmental turbulence. This may help the filament to become stabilized again.

  • 《齐民要术》中的南方因素

    分类: 农、林、牧、渔 >> 农业史 提交时间: 2023-12-29

    摘要: 北魏贾思勰撰著的《齐民要术》是中国传统农学经典中的经典,也是研究中国古代史的重要史料。该书共十卷,除第十卷标题为“五谷、果蓏、菜茹非中国物产者”外,言下之意,前九卷所载之内容,当属北魏统治下的所谓“中国”之物产。因而,《齐民要术》也被认为是反映中国古代黄河流域农业的农学著作,即北方农书。但细检书中内容,却发现书中包含有许多非典型性北方因素,如,稻、鱼、竹、橘、莼、莲、芡、芰、菰、菘、姜、杬、越瓜、山石榴(杜鹃花)、水牛等。这些因素除了当时北方环境提供了某种可能的存在外,从地名、稻作技术和鱼类分布等方面都显示出某种南方因素的介入与存在。本文从物产和技术入手,揭示其中的南方农业因素,探讨其进入北方的途径,包括人员往来和文本传播,藉以展示前此相关研究未曾注意的一面,即中国南、北方农业文化交流与技术传播。

  • 中国社区卫生服务发展的挑战与优化路径

    分类: 医学、药学 >> 临床医学 提交时间: 2023-12-29 合作期刊: 《中国全科医学》

    摘要:  新时代居民健康需求不断提升,社区卫生服务如何顺应时代需要进行全方位转变亟须得到解答。文章梳理了我国社区卫生服务的发展历程,认为存在功能缺位的问题;归纳了我国社区卫生服务发展所面临的挑战,指出当前人群健康需要正发生结构性改变;最后从转变工作重心、提高签约医生价值感和居民获得感、构建协同互补的社区卫生服务网络、建立以需求为导向的健康信息平台等方面提出了我国社区卫生服务的发展路径。

  • 儿童青少年家庭功能障碍与心理健康关系的三水平元分析

    分类: 心理学 >> 发展心理学 提交时间: 2023-12-29

    摘要: 当家庭无法完成相应任务或家庭不具备良好的特征时,即为家庭功能障碍。家庭功能障碍是影响儿童青少年心理健康的重要因素,但两者关系存在争议。为了较为全面地理解家庭功能障碍(主观与客观)与儿童青少年心理健康(积极与消极)的关系,基于家庭系统理论和心理健康双因素模型,采用三水平元分析对两者关系进行探讨。检索和筛选2022年3月1日以前发表的文献,最终纳入97项研究,包括173个效应量和130227名被试。主效应检验发现,单亲通过损害积极心理健康状态、加剧消极心理健康状态影响儿童青少年,父母离异、父母服刑、父母物质滥用、父母患精神疾病、主观家庭功能障碍通过加剧消极心理健康状态影响儿童青少年。调节效应检验发现,单亲对男生心理健康的消极影响更大;集体主义背景下,父母服刑对儿童青少年心理健康的消极影响更大。研究结果不仅支持家庭系统理论,还提示需要给予家庭功能障碍儿童青少年的积极心理健康状态更多关注,并在关注文化背景的同时,根据性别差异进行精准干预。

  • Atypical radio pulsations from magnetar SGR 1935+2154

    分类: 天文学 >> 天文学 提交时间: 2023-12-29

    摘要: Magnetars are neutron stars with extremely strong magnetic fields, frequently powering high-energy activity in X-rays. Pulsed radio emission following some X-ray outbursts have been detected, albeit its physical origin is unclear. It has long been speculated that the origin of magnetars' radio signals is different from those from canonical pulsars, although convincing evidence is still lacking. Five months after magnetar SGR 1935+2154's X-ray outburst and its associated Fast Radio Burst (FRB) 20200428, a radio pulsar phase was discovered. Here we report the discovery of X-ray spectral hardening associated with the emergence of periodic radio pulsations from SGR 1935+2154 and a detailed analysis of the properties of the radio pulses. The complex radio pulse morphology, which contains both narrow-band emission and frequency drifts, has not been seen before in other magnetars, but is similar to those of repeating FRBs - even though the luminosities are many orders of magnitude different. The observations suggest that radio emission originates from the outer magnetosphere of the magnetar, and the surface heating due to the bombardment of inward-going particles from the radio emission region is responsible for the observed X-ray spectral hardening.

  • Search for Ronin Pulsars in Globular Clusters Using FAST: Discovery of Two New Slow Pulsars in M15

    分类: 天文学 >> 天文学 提交时间: 2023-12-29

    摘要: Globular clusters harbor numerous millisecond pulsars; however, the detection of long-period pulsars within these clusters has been notably scarce. The search for long-period pulsars encounters significant challenges due to pronounced red noise interference, necessitating the crucial step of red noise removal in the data preprocessing. In this study, we use running median filtering to mitigate red noise in multiple globular cluster datasets obtained through observations with the Five-hundred-meter Aperture Spherical radio Telescope (FAST). Additionally, we estimated the minimum detectable flux density of pulsars ($S_{ rm min}$) considering this processing step, resulting in a function depicting how $S_{ rm min}$ varies with different duty cycles and periods. Subsequently, a systematic search for long-period pulsars was conducted on the globular cluster datasets after red noise elimination. Ultimately, two isolated long-period pulsars were discovered in the M15 globular cluster, with periods of approximately 1.928451 seconds and 3.960716 seconds, both exhibiting remarkably low pulse duty cycles of around 1 %. Using archived data, we obtained timing solutions for these pulsars. Based on the timing results, their positions are found to be close to the center of the M15 cluster. On the $P- dot{P}$ diagram, they both lie below the spin-up line, suggesting that their recycling process was likely interrupted, leading them to become isolated pulsars. Moreover, in our current search, these very faint long-period pulsars are exclusively identified in M15, and one possible reason for this could be the relatively close proximity and extremely high stellar formation rate of M15. As observational data accumulate and search algorithms undergo iterative enhancements, the prospect of discovering additional long-period pulsars within globular clusters, such as M15, becomes increasingly promising.

  • Milestone progress of the HEPS booster commissioning

    分类: 物理学 >> 核物理学 提交时间: 2023-12-28

    摘要: The High Energy Photon Source (HEPS) is the first fourth-generation synchrotron light source building in China. Its injector consists of a Linac and a full energy booster. The booster captures the electron beam from the Linac and further increases its energy to the same as that required by the storage ring. The full-energy beam could be injected to the storage ring directly or after “high-energy accumulation”. On November 17, 2023, it was demonstrated that key parameters of the booster successfully reached corresponding target values. These milestone results were accomplished based on many contributions, including nearly a decade of physics design, years of development and installation of equipment, as well as months of beam commissioning. As measured at the extraction energy of 6 GeV, the averaged beam current and emittance reached 8.57 mA with 5 bunches and 30.37 nm.rad with a single-bunch charge of 5.58 nC, compared with the corresponding target values of 6.6 mA and 35 nm.rad, respectively. This paper presents the physics design, equipment development and installation, and commissioning process of the HEPS booster.

  • α decay in extreme laser fields within a deformed Gamow-like model

    分类: 物理学 >> 核物理学 提交时间: 2023-12-28

    摘要: In this study, the effect of extreme laser fields on the α decay process of ground-state even–even nuclei was investigated. Using the deformed Gamow-like model, we found that state-of-the-art lasers can cause a slight change in the α decay penetration probability of most nuclei. In addition, we studied the correlation between the rate of change of the α decay penetration probability and angle between the directions of the laser electric field and α particle emission for different nuclei. Based on this correlation, the average effect of extreme laser fields on the half-life of many nuclei with arbitrary α particle emission angles was calculated. The calculations show that the laser suppression and promotion effects on the α decay penetration probability of the nuclei population with completely random α particle-emission directions are not completely canceled. The remainder led to a change in the average penetration probability of the nuclei. Furthermore, the possibility of achieving a higher average rate of change by altering the spatial shape of the laser is explored. We conclude that circularly polarized lasers may be helpful in future experiments to achieve a more significant average rate of change of the α decay half-life of the nuclei population.

  • 北京市失能老人上门医疗服务质量评价指标体系的构建研究

    分类: 医学、药学 >> 预防医学与公共卫生学 提交时间: 2023-12-28 合作期刊: 《中国全科医学》

    摘要: 背景  随着我国老龄化程度不断加深,失能老人对上门医疗服务的需求日益增加,而对其服务质量的评价是服务高质量实施的有力保证。目的  基于德尔菲法制定北京市失能老人上门医疗服务质量指标体系,为社区卫生服务机构向失能老人提供上门医疗服务的质量评价提供客观标准。方法  根据文献研究和定性研究初步形成指标体系条目池,并设计专家函询表。在北京市地区选择在上门医疗服务和老年综合评估领域富有经验的社区护理、全科医学及管理研究专家21名,在2021年6-10月以邮件形式发出专家函询表,进行三轮德尔菲专家函询,并统计专家的个人信息及权威程度相关指标,建立北京市失能老人上门医疗服务质量指标体系。结果  三轮专家函询表均全部收回且全部有效,专家积极系数为100%,21位专家权威程度在0.700~1.000,平均为0.927,达到可接受标准。第一轮专家函询的指标重要性、可行性协调系数分别为0.170和0.140(均P<0.001),第二轮分别为0.147和0.175(P<0.001),第三轮分别为0.231和0.208(均P<0.001),专家意见趋于一致,函询结果可靠。最终构建的失能老人上门医疗服务质量指标体系包括服务条件、服务过程和服务结果共3项一级指标及9项二级指标和34项三级指标。结论  本研究构建的指标体系适于评价单次上门医疗服务的实施质量,为社区卫生服务机构制定相关制度与工作方案提供参考。

  • 我国基层中医药服务现状及发展路径探讨

    分类: 医学、药学 >> 预防医学与公共卫生学 提交时间: 2023-12-28 合作期刊: 《中国全科医学》

    摘要: 背景  我国对基层中医药卫生服务的关注度持续提升,但是目前基层中医药卫生服务体系仍存在问题,制约了我国中医药事业的发展。目的  分析我国基层中医药卫生服务体系现状,探索持续提升基层中医药服务能力的策略。方法  于2022年12月,检索《中国卫生健康统计年鉴》《全国中医药统计编摘》及国家疾病预防控制局和国家心血管病中心官方网站获取数据,从卫生投入、服务产出、健康需要3个层面构建指标体系,结合秩和比法和WHO卫生系统绩效模块框架对基层中医药服务现状进行综合评价。结果  卫生投入方面:2017—2021年,除乡镇卫生院外,其他能够提供中医药服务的基层医疗卫生机构数量均有所增加;社区卫生服务中心(站)、乡镇卫生院、门诊部中医类临床科室床位数呈现上升趋势,但门诊部中医类临床科室床位数占门诊部总床位数的比例有所下降;社区卫生服务中心(站)、乡镇卫生院、诊所中医类执业(助理)医师占比明显上升,而村卫生室的中医类执业(助理)医师占比保持稳定,门诊部的中医类执业(助理)医师占比逐年递减;近5年,基层医疗卫生机构财政投入的绝对数值稳步提高,而中医机构财政拨款波动减少。服务产出方面:尽管各类机构中医诊疗人次占机构总诊疗人次的比例按照一定增幅稳步增长(除中医类门诊部外),但仅村卫生室的中医诊疗量占比始终保持在30.0%以上;除乡镇卫生院外,其他基层医疗卫生机构的中医类执业(助理)医师人均担负年诊疗人次总体上呈下降趋势。根据综合评价结果,2017、2018、2021年处于资源分配适宜状态,而2019、2020年处于资源分配不均衡状态。结论  目前,我国基层中医药卫生服务体系建设得到有效落实,但在有序推进的过程中也存在一些不足。基层中医药资源不足、服务与利用不均衡、中医药优势未充分发挥、人才培养机制不健全、财政投入少等问题制约中医药事业的发展。为推动基层医疗卫生机构持续提高中医药卫生服务能力,需要夯实政府职能,进一步弘扬中医药文化,建立激励机制以优化人才培养模式,加强中医药服务与医保政策紧密结合,建设以“信息一体化”为支撑的中医医联体。

  • 基于社区居民健康程度评估表的汉化及其在老年患者中的信效度检验

    分类: 医学、药学 >> 预防医学与公共卫生学 提交时间: 2023-12-28 合作期刊: 《中国全科医学》

    摘要: 背景  在国家大力推进为高龄、慢病和失能患者开展居家医疗服务的背景下,采用能够有效评估居家环境中患者健康程度及满足医疗护理服务需求的专业评估工具,是精准对接患者居家医疗护理需求的重要保障。目的  汉化社区居民健康程度评估表(CHIRS),并评价该量表在社区老年慢病患者人群中的信度和效度。方法  在征得原作者授权后,遵循Brislin模型的翻译、回译、文化调适过程,形成中文版CHIRS。于2021年3~6月采用便利抽样法抽选成都市某社区卫生服务中心(站)管理的老年患者为研究对象。采用专家咨询评价量表的内容效度,采用内部一致性系数检验量表的信度,验证其实用性。结果  共调查并完成244例患者的入户问卷调查,有效回收率100%。专家咨询结果显示,中文版CHIRS的S-CVI/ave为0.98,I-CVI在0.71~1.00之间;总体Cronbach'α系数为0.884,四个维度Cronbach'α系数范围在0.593~0.787之间,预测效度结果显示社区居民健康程度评估表评级结果分别与患者自评健康状况、自评居家医疗护理服务需求程度的Spearman相关系数为-0.611(P<0.001)和0.584(P<0.001)。结论  经汉化及本土化修改后,中文版CHIRS具有较好的信效度和参考价值,可用于社区老年慢病患者健康状况及居家医疗护理服务需求程度的评估。

  • 基于Selenium框架的文献传递机器人的开发与应用

    分类: 图书馆学、情报学 >> 图书馆学 提交时间: 2023-12-28

    摘要: 目的/意义 笔者在江苏省工程文献信息中心平台承担文献传递工作,其中机械重复的操作占比很大,严重侵占了工作时间。而且文献需求是24小时的,作为值班馆员只能在有限的时间来进行传递,传递时效性难以得到保证。所以,笔者尝试开发一个文献传递机器人,自动化实现完成文献传递工作。 方法/过程]论文以江苏省工程文献信息中心平台为例,基于Selenium框架,设计开发文献传递机器人,实现登录、签到,获取订单、检索、下载、上传,完成文献传递后再继续等待派单的全过程。 结果/结论]通过一个月的运行分析,文献传递机器人虽然不能完全取代人工传递,但却可以有效解决文献传递过程中的占比很大的机械重复的工作,提高了传递效率,同时,又拓展了服务时间,让传递馆员有更多的精力解决特殊文献等难查找的文献。最后,文献传递机器人对文献传递领域和其他相关场景也有借鉴意义。

  • 核物质和中子星物质的相对论第一性原理研究

    分类: 物理学 >> 核物理学 分类: 天文学 >> 天体物理学 提交时间: 2023-12-28

    摘要: 相对论 Brueckner-Hartree-Fock (RBHF) 理论是相对论框架下重要的第一性原理方法,仅包含两体力即可以满意描述核物质的饱和性质。在完备的 Dirac 空间中自洽求解核物质 RBHF 方程,唯一确定了单粒子势的标量和矢量分量,避免了已有工作中由于忽略负能态所导致的不确定性,解决了 40 多年来 RBHF 计算中不能唯一确定单粒子势的问题。文章简要回顾 RBHF 理论的发展历史,阐述包含负能态做 RBHF 计算的必要性,介绍利用完备 Dirac 空间的 RBHF 理论,研究核物质性质和中子星物质性质的最新进展,包括有效质量、纯中子物质的每核子结合能、对称和纯中子物质的压强、中子星物质的粒子分数和状态方程、中子星的质量—半径关系和潮汐形变等。文章还展望了完备 Dirac 空间的RBHF 理论在确定密度泛函理论参数、描述核子—原子核弹性散射和研究中子星内部强子—夸克相变等方面的可能应用。

  • Conceptual Design of a 714-MHz RFQ for Compact Proton Injectors and Development of a New Tuning Algorithm on its Aluminium Prototype

    分类: 物理学 >> 核物理学 提交时间: 2023-12-28

    摘要: Radio frequency quadrupoles (RFQs), which are crucial components of proton injectors, significantly affect the performance of proton accelerator facilities. An RFQ with a high frequency of 714 MHz dedicated to compact proton injectors for medical applications is designed in this study. The RFQ is designed to accelerate proton beams from 50 keV to 4 MeV within a short length of 2 m and can be matched closely with the downstream drift tube linac to capture more particles through a preliminary optimization. To develop an advanced RFQ, challenging techniques, including fabrication and tuning method, must be evaluated and verified using a prototype. An aluminium prototype is derived from the conceptual design of the RFQ and then redesigned to confirm the radio frequency performance, fabrication procedure, and feasibility of the tuning algorithm. Eventually, a new tuning algorithm based on the response matrix and least-squares method is developed, which yields favorable results based on the prototype, i.e., the errors of the dipole and quadrupole components reduced to a low level after several tuning iterations. Benefiting from the conceptual design and techniques obtained from the prototype, the formal mechanical design of the 2-m RFQ is ready for the next manufacturing step.
     

  • 约克郡新冠康复量表改良版(C19-YRSm)的汉化及信效度检验研究

    分类: 医学、药学 >> 预防医学与公共卫生学 提交时间: 2023-12-28 合作期刊: 《中国全科医学》

    摘要: 背景  约克郡新冠康复量表改良版(C19-YRSm)已在发达国家被证明可用于评估和监测新型冠状病毒感染后症状,但其在中国人群中应用的信效度尚不清楚。目的  汉化C19-YRSm,并对中文版C19-YRSm进行信效度检验。方法  研究团队在获得英国利兹大学MANOJ SIVAN团队的C19-YRSm汉化及使用授权后,参照翻译与跨文化调适流程对C19-YRSm进行汉化,经过翻译、回译、跨文化调适形成中文版C19-YRSm。于2023-05-01—07,通过简单随机抽样的方法抽取“问卷星”平台样本库中的新型冠状病毒感染康复者作为研究对象,使用一般资料调查表、中文版C19-YRSm进行调查,并邀请13位专家对量表进行内容效度评价。对中文版C19-YRSm进行条目分析、信度检验和效度检验。结果  共发放问卷512份,回收有效问卷370份,有效问卷回收率为72.3%。条目分析结果显示,各条目的|CR值|为6.589~22.725(P<0.001),与量表总分的|r值|为0.547~0.806(P<0.001)。信度方面,中文版C19-YRSm的Cronbach'sα系数为0.881,Guttman折半系数为0.837,重测信度为0.816。内容效度方面,中文版C19-YRSm各条目的内容效度指数(I-CVI)为0.692~1.000,量表水平的内容效度指数(S-CVI)为0.914。验证性因子分析(CFA)结果显示,初始模型拟合结果不理想。根据提示增加误差变量e12和e13之间的相关关系后,除调整拟合优度指数(AGFI)外,修正模型的其余各项拟合指标均在可接受的范围内。判别效度分析结果显示,不同慢性病患病情况、累积感染次数调查对象中文版C19-YRSm4个子量表得分比较,差异均有统计学意义(P<0.05)。新型冠状病毒感染前后除其他症状外的其他3个子量表得分比较,差异有统计学意义(P<0.05)。结论  中文版C19-YRSm具有良好的信度和效度,在中国人群中的适用性较好,可用于中国新型冠状病毒感染后患者康复状况的评估与监测。