The effect of dynamical screening on helium(e,2e) fully differential cross-sections

This paper presents the fully differential cross sections （FDCS） for 102eV electron impact single ionization of helium for both the coplanar and perpendicular plane asymmetric geometries within the framework of dynamically screened three-Coulomb-wave theory. Comparisons are made with the experimental data and those of the three-Coulomb wave function model and second-order distorted-wave Born method. The angular distribution and relative heights of the present FDCS is found to be in very good agreement with the experimental data in the perpendicular plane geometry. It is shown that dynamical screening effects are significant in this geometry. Three-body coupling is expected to be weak in the coplanar geometry, although the precise absolute value of the cross section is still sensitive to the interaction details.

Nucleus-Nucleus Effects in Fully Differential Cross Sections for Energetic C6++He Collisions with Small Momentum Transfer

The modified Coulomb-Born approximation with and without the internuclear interaction （MCB-NN and MCB） is used to calculate the fully differential cross sections （FDCS） for the single ionization of helium by lOO MeV/amu C6＋ impact. The effects of the internuclear interaction on the FDCS are examined in geometries. The results are compared with experimental data and theoretical predictions from a three-body distorted-wave （3DW） model and a time-dependent close-coupling model. It is shown that the present MCB-NN results are in good agreement with the experiments in the scattering plane and the MCB results qualitatively reproduce the experimental structure outside the scattering plane. In particular, the MCB theory predicts the ＇double-peak＇ structure in the perpendicular plane.

Interference effects on the photoionization cross sections between two neighbouring atoms:nitrogen as an example

Interference effects on the photoionization cross sections between two neighbouring atoms are considered based on the coherent scattering of the ionized electrons by the two nuclei when their separation is less than or comparable to the de Broglie wave length of the ionized electrons. As an example, the single atomic nitrogen ionization cross section and the total cross sections of two nitrogen atoms with coherently added photoionization amplitudes are calculated from the threshold to about А （1 А=0.1 nm） of the photon energy. The photoionization cross sections of atomic nitrogen are obtained by using the close-coupling R-matrix method. In the calculation 19 states are included. The ionization energy of the atomic nitrogen and the photoionization cross sections agree well with the experimental results. Based on the R-matrix results of atomic nitrogen, the interference effects between two neighbouring nitrogen atoms are obtained. It is shown that the interference effects are considerable when electrons are ionized just above the threshold, even for the separations between the two atoms are larger than two times of the bond length of N2 molecules. Therefore, in hot and dense samples, effects caused by the coherent interference between the neighbours are expected to be observable for the total photoionization cross sections.

Photoemission cross section：A critical parameter in the impurity photovoltaic effect

A numerical study has been conducted to explore the role of photoemission cross sections in the impurity photovoltaic（IPV） effect for silicon solar cells doped with indium. The photovoltaic parameters（short-circuit current density, opencircuit voltage, and conversion efficiency） of the IPV solar cell were calculated as functions of variable electron and hole photoemission cross sections. The presented results show that the electron and hole photoemission cross sections play critical roles in the IPV effect. When the electron photoemission cross section is 10^-20cm^2, the conversion efficiencyη of the IPV cell always has a negative gain（△η 0） if the IPV impurity is introduced. A large hole photoemission cross section can adversely impact IPV solar cell performance. The combination of a small hole photoemission cross section and a large electron photoemission cross section can achieve higher conversion efficiency for the IPV solar cell since a large electron photoemission cross section can enhance the necessary electron transition from the impurity level to the conduction band and a small hole photoemission cross section can reduce the needless sub-bandgap absorption. It is concluded that those impurities with small（large） hole photoemission cross section and large（small） electron photoemission cross section,whose energy levels are near the valence（or conduction） band edge, may be suitable for use in IPV solar cells. These results may help in judging whether or not an impurity is appropriate for use in IPV solar cells according to its electron and hole photoemission cross sections.

The Effective Buckling Length on Numerical Study of Pipe-Sectioned Pier-Pile Integral Steel Structure

Pier-Pile integral structures provide construction works with many environmental and landscape advantages. For example, the space required to construct these structures is smaller than that of other bridges due to the footing being removed, meaning that it is not necessity to greatly change the surroundings of these bridges. While there are environmental and landscape advantages, there are also a few demerits for the overall land-scape designs, including demerits in the design of this proposed structure which consists of relatively slender parts. This proposed structure has already been constructed in areas where possibility of a severe earthquake is low. However, some problems that have yet to be examined are related to the use of this proposed structure in areas where earthquakes are frequent. Lacking detailed studies of its behavior during severe earthquakes, it is currently difficult to construct these structures in Japan. Consequently, it is necessary to investigate in detail limited performance about compression and bending moment, and earthquake- resistant performance of these structures in order to resolve these problems. In this paper, It was clarified the relationship between the rigidity of the ground and the effective buckling length by buckling analysis and elasto- plastic finite deformation analysis. Moreover, it was proposed a simplified formula using a proposed characteristic value β and several factors for analysis accuracy. A simplified formula would support to determine the effective buckling length to design the pier using the load-bearing capacity curve based on the slenderness ratio parameter.

基于节段模型测力方法的塔式起重机风荷载特性研究

塔式起重机被广泛应用于铁道工程和土木工程施工过程,属于高耸结构体系,风荷载是塔式起重机结构设计的控制性荷载。为完善《塔式起重机设计规范》(GB/T 13752—2017)和《建筑结构荷载规范》(GB 50009—2012)中的塔式起重机斜风向设计风荷载计算方法,解决风向、吊臂、平衡臂位置等因素对塔式起重机遮挡和干扰引起的设计风荷载计算问题。选取平头塔式起重机为研究对象,对塔身、吊臂、平衡臂进行多工况的节段模型测力风洞试验,研究湍流强度、节段干扰和遮挡等因素对塔式起重机节段风荷载特性的影响规律,研究不同风向下节段阻力系数分布规律,对比标准化阻力系数与当前主要规范的异同,进而探讨节段斜风向标准化阻力系数计算方法。研究结果表明湍流强度对节段阻力系数影响较小,可忽略,而平衡臂和吊臂相邻节段的干扰会减小测试节段的阻力系数;在斜风向下,由于吊臂和平衡臂之间存在相邻节段干扰,国内外规范方法的计算值均会大于干扰工况的节段风洞试验值;当前主要国家规范规定的垂直风向塔身、吊臂、平衡臂阻力系数与风洞试验测得的阻力系数值较为接近,基于风洞试验结果给出典型风向的塔式起重机各节段的风荷载系数取值可用于结构设计;基于风洞试验测试结果推导的塔式起重机斜风向风荷载计算方法具有较好的拟合效果。研究成果可推荐相关工程应用,可为相关规范的修改或补充提供参考。

植入型凶险型前置胎盘计划性剖宫产术中子宫动脉结扎阻塞及宫腔填充术的有效性和安全性

目的探究植入型凶险型前置胎盘计划性剖宫产术中采用子宫动脉结扎阻塞及宫腔填充术的有效性和安全性。方法选取2019年12月至2021年12月唐山市妇幼保健院收治的132例植入型凶险型前置胎盘计划性剖宫产术治疗患者为研究对象,按不同的血管阻断方式分为子宫动脉栓塞术联合宫腔填充治疗组(对照组)和子宫动脉结扎联合宫腔填充治疗组(观察组),观察比较两组患者的手术时间、术中出血量、术中输血量、膀胱损伤率,并观察记录两组母婴结局情况,包括新生儿1min Apgar评分、子宫切除率、凝血功能异常发生率。记录患者术后不良反应的发生情况,包括发热、慢性盆腔疼痛、伤口愈合不良、术后血栓形成、月经量降低等。结果观察组患者的手术时间、膀胱损伤率均较对照组更低(t=4.428和5.621,P<0.05),术中出血量、术中输血量未见显著差异(t=1.472和1.729,P>0.05),两组新生儿出生1min Apgar评分未见显著差异(t=0.257,P>0.05),但观察组产妇的子宫切除率、凝血功能异常发生率显著低于对照组(t=3.722和4.628,P<0.05),两组患者均未发生严重的产科并发症,其中观察组患者发热、慢性盆腔疼痛、术后血栓形成、伤口愈合不良、术后月经量降低的发生率均显著低于对照组,差异具有统计学意义(t=6.274、4.726、3.872、3.872和4.218,P<0.05)。结论子宫动脉结扎术和子宫动脉造影栓塞术对植入型凶险型前置胎盘患者具有一定的临床疗效,其中子宫动脉结扎手术时间短,术后并发症发生率低,具有较好的有效性和安全性。

钢筋混凝土拱桥主拱圈加固方式及效果研究

目的 寻求钢筋混凝土拱桥主拱圈最佳加固方式,以改善加固效果,给同类危旧拱桥加固提供参考。方法 基于某实际加固桥例提出3种不同卸载方式的加固改造方案,采用Midas civil软件建立有限元模型,分析不同加固方式的影响规律;对原拱圈初始应力水平、施工阶段内力、成桥状态下应力、内力及挠度进行分析;利用加固层最大应力比、荷载置换率和挠度变化率对加固效果进行评价。结果 方案三的加固层最大应力比分别比方案一、二大45.12%与52.74%,荷载置换效果最显著,最大值达3.82,挠度变化率最大。结论 选择拱上建筑拆除得越多的方式进行加固,加固效果越好;对钢筋混凝土拱桥进行加固时,应基于加固方式制定加固施工方案,同时需考虑施工工期与加固成本。

Water equivalence of some 3D dosimeters:a theoretical study based on the effective atomic number and effective fast neutron removal cross section

Effective atomic numbers for photon energy absorption(ZPEA_(eff)) and their corresponding electron numbers (NPEA_(eff)), and effective macroscopic removal cross sections of fast neutrons(RR) were calculated for 27 different types of three-dimensional dosimeters, four types of phantom materials, and water. The values of ZPEA_(eff) and NPEA_(eff) were obtained using the direct method for energies ranging from 10 keV to 20 MeV. Results are presented relative to water, for direct comparison over the range of examined energies. The effect of monomers that are used in polymer gel dosimeters on the water equivalence is discussed. The relation between Σ_R and hydrogen content was studied. Micelle gel dosimeters are highly promising because our results demonstrate perfect matching between the effective atomic number, electron density number, and fast neutron attenuation coefficient of water.

Probing the medium effect and isospin dependence of the in-medium nucleon-nucleon cross section in heavy ion collisions

Probing in-medium nucleon-nucleon （NN） cross section σ1/NN（α） in heavy ion collisions has been investigated by means of the isospin-dependent quantum molecular dynamics （IQMD） with the isospin- and momentum-dependent interaction （IMDI（T））. It is found that there are the very obvious medium effect and the sensitive isospin-dependence of nuclear stopping R on the in-medium NN cross section α1/NN（α） in the nuclear reactions induced by halo-neutron projectile and the same-mass stable projectile. However, R induced by the neutron-halo projectile is obviously lower than that induced by the corresponding stable projectile. In particular, there is a very obvious dependence of R on the medium effect of σ1/NN（α） in the whole beam energy region for the above two kinds of projectiles. Therefore, the comparison between the results of R＇s in the reactions induced by the neutron-halo projectile and the corresponding same-mass stable projectile is a more favourable probe for extracting the information of σ1/NN（α） because of adding a new judgement.

不同分娩方式对盆底肌功能及产后康复效果的影响

目的探讨不同分娩方式对产妇产后盆底肌功能康复效果的影响。方法回顾性分析2022年5月至2023年5月收治的120例产妇的临床资料,根据分娩方式的不同分为顺产组和剖宫产组,各60例。两组产妇均予相同的产后康复治疗措施,检测盆底肌功能,观察其产后康复效果。结果顺产组产妇的康复总有效率为96.67%,与剖宫产组的100.00%无显著差异(P>0.05)。康复治疗前,顺产组的压力性尿失禁发生率为23.33%,盆腔器官脱垂率为13.33%,均显著高于剖宫产组产妇的3.33%和1.67%(P<0.05)。康复治疗后,顺产组的压力性尿失禁发生率为5.00%,盆腔器官脱垂率为3.33%,与剖宫产组产妇无显著差异(P>0.05)。结论顺产会造成较明显的盆底肌功能损伤,经产后康复治疗后可达到和剖宫产相当的康复效果,盆底功能障碍大幅减少。

基于短视频平台的个人医疗健康认证账号现状研究

目的了解商业平台个人医疗健康账号开展健康科普现状,为规范基于商业平台开展的健康传播活动提供参考。方法以第三方数据公司提供的抖音平台数据为数据来源,选取粉丝量在1万以上的个人医疗健康账号为研究对象,通过提取账号认证信息,分析账号分布特征及传播效果。结果共随机选取符合研究条件的个人医疗健康账号3985个。公开性别信息的账号有624个,占全部研究账号的15.65%,其中,男性443个,占70.99%,女性181个,占29.01%。3960个(99.37%)创作者任职于三级甲等医院,主任医师1716个(43.07%),副主任医师1375个(34.50%),主治医师有880个(22.08%),医师有14个(0.35%)。账号数量排名前5位的领域有外科1174个(29.46%),内科662个(16.61%),中医科445个(11.17%),妇产科332个(8.33%),皮肤性病科270个(6.78%)。东部地区2656个(66.66%),中部地区823个(20.66%),西部地区505个(12.68%)。账号数量排前5位的省份依次为北京1238个(31.07%),广东382个(9.59%),河南330个(8.28%),上海265个(6.65%),四川211个(5.30%)。账号总粉丝量平均24.43万,中位数8.03(P25=3.11,P75=22.92)万;账号总获赞平均144.13万,中位数41.91(P25=16.16,P75=110.10)万;账号总作品数平均为410个,中位数347(P25=200,P75=544)个;30 d新增作品数平均43个,中位数30(P25=13,P75=58)个,30 d点赞量平均12.53万,中位数0.79(P25=0.18,P75=4.21)万;30 d评论量平均0.85万,中位数0.08(P25=0.01,P75=0.37)万;30 d分享数平均6.51万,中位数0.16(P25=0.02,P75=1.61)万。结论商业平台医疗健康账号主要来自三级甲等医院,职称上主任医师账号数量最多,数量上以东部地区占优,专业上外科、内科、中医、妇产和皮肤性病占优,粉丝量、作品数、传播指标等方面存在较大的不均衡性。

艾司氯胺酮联合舒芬太尼在剖宫产术后静脉自控镇痛患者中的应用效果

目的:观察艾司氯胺酮联合舒芬太尼在剖宫产术后静脉自控镇痛(PCIA)患者中的应用效果。方法:选取2021年3月至2022年8月该院收治的80例剖宫产术后患者进行前瞻性研究,按照随机数字表法分为观察组与对照组各40例。对照组术后PCIA采用枸橼酸舒芬太尼注射液治疗,观察组术后PCIA在对照组基础上联合盐酸艾司氯胺酮注射液治疗,比较两组视觉模拟评分法(VAS)评分、PCIA按压次数、爱丁堡产后抑郁量表(EPDS)评分和不良反应发生率。结果:术后2、6、12、24、48 h,观察组VAS评分均低于对照组,差异有统计学意义(P<0.05);观察组PCIA按压次数明显少于对照组,差异有统计学意义(P<0.05);术后3 d,两组EPDS评分均高于术前,但观察组低于对照组,差异有统计学意义(P<0.05);两组术后PCIA期间不良反应发生率比较,差异无统计学意义(P>0.05)。结论:艾司氯胺酮联合舒芬太尼应用于剖宫产术后PCIA患者可降低术后VAS评分和EPDS评分,减少PCIA按压次数,效果优于单纯应用舒芬太尼。

国有股权参股与小微企业融资约束——基于制度逻辑与效率逻辑的双重视角

基于制度逻辑与效率逻辑,本文使用CMES数据实证研究国有股权参股对缓解小微企业融资约束的作用机制。研究发现,政府股权介入增强了政企利益的关联程度,有助于小微企业降低代理成本和信息不对称,并获得资源保障,而小微企业较少受到双重代理问题的影响,通过与政府建立股权联系可以更有效地将信贷资源投入转化为投资项目产出,具有更显著的制度收益效应。因此,国有股权参股是缓解小微企业融资约束的有效政策工具。

右美复合纳布啡对剖宫产术后镇痛及血清CRP、NO影响

目的:探究右美托咪定复合纳布啡对剖宫产患者镇痛及血清C反应蛋白(CRP)、一氧化氮(NO)影响。方法:随机数字表法将2022年3月~2023年12月我院收治的102例剖宫产产妇均分,对照组行纳布啡+阿扎司琼,观察组行右美托咪定+纳布啡+阿扎司琼,比较两组镇痛效果、血清学指标、抑郁评分和不良反应。结果:观察组术后静息痛和运动痛评分下降更快;CRP水平更低,NO水平更高;EPDS评分更低;不良反应发生率5.88%更低,且与对照组相比均具有统计学意义(P<0.05)。结论:右美托咪定复合纳布啡可缓解剖宫产术后产妇疼痛,改善血清CRP和NO水平。

自由体位联合无痛暗示对足月无痛分娩产妇的效果及睡眠质量的影响

目的:探究足月无痛分娩产妇于护理期间联合应用自由体位、无痛暗示护理的干预价值。方法:选取2022年6月至2023年1月福建省立医院南院收治的足月无痛分娩产妇86例作为研究对象,按照随机数字表法分为对照组和观察组,每组43例。对照组实施常规护理,观察组予以自由体位联合无痛暗示护理,对比2组护理效果,评估指标包含产程时间、顺转剖宫产率及睡眠质量。结果:测定2组产妇产程,所得结果均显示为观察组第一、二、三产程以及总产程时间偏短,与对照组比较,差异均有统计学意义(均P<0.05);相较于对照组,观察组顺转剖宫产等风险事件发生率较低,差异有统计学意义(P<0.05);术后,评估2组产妇睡眠质量,观察组各项指标数值均偏低于对照组,差异均有统计学意义(均P<0.05)。结论:足月无痛分娩的产妇予以其自由体位、无痛暗示护理在缩短产程的同时可以提高产妇睡眠质量,降低了顺转剖宫产率以及风险事件发生率。

子宫内膜异位症患者疾病认知调查及中医慢病管理的效果评价

目的了解子宫内膜异位症(EMs)患者对疾病的认知水平、治疗意愿,评价中医慢病管理对EMs患者的效果。方法通过横断面调查对2020年10月-2021年12月就诊于全国19个省、自治区、直辖市的省/市/县/区级医院的1895例EMs患者的疾病认知水平及治疗意愿进行分析;通过自身前后对照评价中医慢病管理对北京市6家三级甲等医院的801例EMs患者认知效果。结果EMs患者对于疾病的认知水平整体上随学历的增加而提高。患者普遍认为EMs属于慢性疾病,需要定期复查、长期管理。高中及以下、专科、本科及以上学历患者知晓EMs有恶变可能的比例较少,分别为32.3%、41.6%和47.7%。高中及以下学历患者对于EMs保守手术治疗后可能复发的知晓率为46.9%,低于专科(66.8%)和本科及以上学历(72.7%)患者。在饮食禁忌中,高中及以下、专科、本科及以上学历患者知晓忌食雪蛤油的比例较少,分别为20.7%、30.3%和32.9%。在生活调摄方面,患者认知度普遍较高。EMs患者主要通过与妇科医生的面对面交流认知疾病。高中及以下学历患者通过微信公众号、APP等新媒体了解EMs的比例为34.4%,低于专科(48.6%)和本科及以上学历(55.4%)患者。EMs患者普遍倾向于在综合性大医院治疗,中医药治疗接受度高,以中药汤剂为主,中医适宜技术接受度偏低。经中医慢病管理1年后,EMs患者的疾病认知度整体上较管理前显著提升,差异有统计学意义(P<0.05)。结论不同教育背景的EMs患者对疾病的认知不一致,各有侧重,应针对其知识盲点进行宣教、科普。中医慢病管理可提高EMs患者的疾病认知水平。