本文以5个学科的SCI期刊和论文为研究对象,取不同底数的对数对每一学科论文被引频次进行转换,计算各期刊对数矫正影响因子(IF_(log)),以各期刊IF_(log)除以所在学科所有期刊IF_(log)平均值,进行学科标准化处理,创建学科标准化影响因子(c...本文以5个学科的SCI期刊和论文为研究对象,取不同底数的对数对每一学科论文被引频次进行转换,计算各期刊对数矫正影响因子(IF_(log)),以各期刊IF_(log)除以所在学科所有期刊IF_(log)平均值,进行学科标准化处理,创建学科标准化影响因子(cnIF_(log)),探讨cnIF_(log)在学术期刊跨学科评价中的优越性。研究结果显示,5个学科期刊的IF_(log)均呈正态分布,且无论同一学科还是不同学科期刊的IF_(log1.5)、IF_(ln)、IF_(log5)、IF_(log10)之间均呈100%正相关(r=1.000,P=0.000)。与影响因子(IF2018)、平均影响因子百分位(average impact factor percentile,aJIFP)、期刊PR8指数(journal index of eight percentile rank classes,JIPR8)、IFlog和相对影响因子(relative IF2018,rIF2018)等指标相比,cnIF_(log1.5)(category normalization for IF_(log1.5))在5个学科期刊中变异程度最小、与aJIFP和JIPR8的相关度最高,具有理想的区分度和稳定性。无论同一学科还是跨学科期刊评价,cnIF_(log1.5)均是理想的评价指标。展开更多
以2015年自然科学版JCR(SCI-JCR)收录的8 778种期刊为研究对象,计算各期刊总被引频次构成中的自引率(self-citation rate for total citations,R_(SC,TC))和影响因子构成中的自引率(self-citation rate for impact factor,R_(SC,IF)),...以2015年自然科学版JCR(SCI-JCR)收录的8 778种期刊为研究对象,计算各期刊总被引频次构成中的自引率(self-citation rate for total citations,R_(SC,TC))和影响因子构成中的自引率(self-citation rate for impact factor,R_(SC,IF)),全方位比较二者差异程度,揭示不同国家和地区人为操纵期刊影响因子的倾向。结果显示:8 778种期刊集合R_(SC,TC)为0.072,集合R_(SC,IF)为0.112,R_(SC,TC)平均值为0.093,R_(SC,IF)平均值为0.132。排除17种无R_(SC,IF)者,8 761种期刊中,R_(SC,IF)>R_(SC,TC)者6 954种(79.2%),R_(SC,TC)>R_(SC,IF)者1 599种(18.2%),R_(SC,IF)=R_(SC,TC)者208种。Wilcoxon秩检验结果是,Z=59.836,P<0.001,2组差异有统计学意义。SCI来源期刊中R_(SC,IF)显著高于R_(SC,TC),捷克、印度、日本、匈牙利和加拿大等国家期刊尤为突出。R_(SC,IF)过度高于R_(SC,TC),怀疑有人为操纵的可能。展开更多
In recent years,heavy ion accelerator technology has been rapidly developing worldwide and widely applied in the fields of space radiation simulation and particle therapy.Usually,a very high uniformity in the irradiat...In recent years,heavy ion accelerator technology has been rapidly developing worldwide and widely applied in the fields of space radiation simulation and particle therapy.Usually,a very high uniformity in the irradiation area is required for the extracted ion beams,which is crucial because it directly affects the experimental precision and therapeutic effect.Specifically,ultra-large-area and high-uniformity scanning are crucial requirements for spacecraft radiation effects assessment and serve as core specification for beamline terminal design.In the 300 MeV proton and heavy ion accelerator complex at the Space Environment Simulation and Research Infrastructure(SESRI),proton and heavy ion beams will be accelerated and ultimately delivered to three irradiation terminals.In order to achieve the required large irradiation area of 320 mm×320 mm,horizontal and vertical scanning magnets are used in the extraction beam line.However,considering the various requirements for beam species and energies,the tracking accuracy of power supplies(PSs),the eddy current effect of scanning magnets,and the fluctuation of ion bunch structure will reduce the irradiation uniformity.To mitigate these effects,a beam uniformity optimization method based on the measured beam distribution was proposed and applied in the accelerator complex at SESRI.In the experiment,the uniformity is successfully optimized from 75%to over 90%after five iterations of adjustment to the PS waveforms.In this paper,the method and experimental results were introduced.展开更多
The electron cooler was installed in one of the straight sections of CSRe which is used to provide high-qualitybeams for experiments. Longitudinally the dynamics of the cooling process have been studied for a series o...The electron cooler was installed in one of the straight sections of CSRe which is used to provide high-qualitybeams for experiments. Longitudinally the dynamics of the cooling process have been studied for a series of electronbeam parameters and the friction force was measured with the aid of an RF-buncher for C6+ (122 MeV/u) and O8+(122 MeV/u) ions. The cooling time at different electron beam state have been measured, too.展开更多
[目的]从SSCI论文角度分析我国哲学社会科学2008—2017年国际化进程状况,并将结果与G7国家和有代表性的新兴国家作对比。研究结果有利于相关人员从宏观上了解我国哲学社会科学近10年国际化进程状况,也为后续研究提供数据资料。[方法]基...[目的]从SSCI论文角度分析我国哲学社会科学2008—2017年国际化进程状况,并将结果与G7国家和有代表性的新兴国家作对比。研究结果有利于相关人员从宏观上了解我国哲学社会科学近10年国际化进程状况,也为后续研究提供数据资料。[方法]基于2008—2017年Web of Science,获得我国和美国、英国、德国、法国、日本、意大利、加拿大、印度、韩国、俄罗斯共11国的SSCI论文量(论文均特指Article和Review,且不限于第一作者),并作对比。[结果]2008—2017年我国SSCI论文量逐年显著增长,至2017年已超越德国和加拿大,但与美国和英国相比仍有较大差距,我国SSCI论文量的环比增长速度位居11国中第1位,平均为22.77%。[结论]我国哲学社会科学相对较低的国际话语权应引起相关政策制定者的注意。展开更多
Over the past years,experimentalists have launched an expedition to explore the predicted,centered near the double-magic Z=114,N=184 nucleus.With their remarkable e orts,elements from hydrogen up to element 118 at pre...Over the past years,experimentalists have launched an expedition to explore the predicted,centered near the double-magic Z=114,N=184 nucleus.With their remarkable e orts,elements from hydrogen up to element 118 at present.The discovery of the superheavy elements o ers the possibilities to study properties of nuclei under extremely strong Coulomb elds and to explore the limits of existence of nuclei.The fusion evaporation reactions induced by low-energy heavy ions are employed for synthesis and study of superheavy isotopes,and the gas-lled recoil separator technique is always used to e ectively separate the produced evaporation residues from projectile-like and target-like products.展开更多
The super ferric superconducting dipoles are in development for the High Intensity high Energy FRagment Separator(HFRS)of the Heavy-ion Accelerator Facility(HIAF).The dipole magnets of the separator will have a deflec...The super ferric superconducting dipoles are in development for the High Intensity high Energy FRagment Separator(HFRS)of the Heavy-ion Accelerator Facility(HIAF).The dipole magnets of the separator will have a deflection radius of 15.7 m,a field up to 1.6 T with a 320 mm wide good field region and an effective length of 2.74 m.In the HIAF-HFRS,there will be a total of 11 super ferric dipoles.The dipole consists of two superconducting coils,a coil box,a cryostat,and a warm iron warm laminated iron,as shown in Fig.1.The superconducting coils are protected by the active quench protection.展开更多
The High Energy Fragment Separator(HFRS)within the Heavy-ion Accelerator Facility(HIAF)features a beamline comprised of 11 sets of superconducting dipoles and 39 sets of combined multipoles,spanning a length of approx...The High Energy Fragment Separator(HFRS)within the Heavy-ion Accelerator Facility(HIAF)features a beamline comprised of 11 sets of superconducting dipoles and 39 sets of combined multipoles,spanning a length of approximately 180 m.The dipoles are constructed using warm iron superferric technology.Meanwhile,the combined multipoles feature a coil dominated DCT(Discrete Cosine-Theta)coil structure,offering a large aperture,high polar field,compact design,and robust operation.展开更多
文摘本文以5个学科的SCI期刊和论文为研究对象,取不同底数的对数对每一学科论文被引频次进行转换,计算各期刊对数矫正影响因子(IF_(log)),以各期刊IF_(log)除以所在学科所有期刊IF_(log)平均值,进行学科标准化处理,创建学科标准化影响因子(cnIF_(log)),探讨cnIF_(log)在学术期刊跨学科评价中的优越性。研究结果显示,5个学科期刊的IF_(log)均呈正态分布,且无论同一学科还是不同学科期刊的IF_(log1.5)、IF_(ln)、IF_(log5)、IF_(log10)之间均呈100%正相关(r=1.000,P=0.000)。与影响因子(IF2018)、平均影响因子百分位(average impact factor percentile,aJIFP)、期刊PR8指数(journal index of eight percentile rank classes,JIPR8)、IFlog和相对影响因子(relative IF2018,rIF2018)等指标相比,cnIF_(log1.5)(category normalization for IF_(log1.5))在5个学科期刊中变异程度最小、与aJIFP和JIPR8的相关度最高,具有理想的区分度和稳定性。无论同一学科还是跨学科期刊评价,cnIF_(log1.5)均是理想的评价指标。
文摘以2015年自然科学版JCR(SCI-JCR)收录的8 778种期刊为研究对象,计算各期刊总被引频次构成中的自引率(self-citation rate for total citations,R_(SC,TC))和影响因子构成中的自引率(self-citation rate for impact factor,R_(SC,IF)),全方位比较二者差异程度,揭示不同国家和地区人为操纵期刊影响因子的倾向。结果显示:8 778种期刊集合R_(SC,TC)为0.072,集合R_(SC,IF)为0.112,R_(SC,TC)平均值为0.093,R_(SC,IF)平均值为0.132。排除17种无R_(SC,IF)者,8 761种期刊中,R_(SC,IF)>R_(SC,TC)者6 954种(79.2%),R_(SC,TC)>R_(SC,IF)者1 599种(18.2%),R_(SC,IF)=R_(SC,TC)者208种。Wilcoxon秩检验结果是,Z=59.836,P<0.001,2组差异有统计学意义。SCI来源期刊中R_(SC,IF)显著高于R_(SC,TC),捷克、印度、日本、匈牙利和加拿大等国家期刊尤为突出。R_(SC,IF)过度高于R_(SC,TC),怀疑有人为操纵的可能。
基金Supported by National Key R&D Program of China(2019YFA0405400)。
文摘In recent years,heavy ion accelerator technology has been rapidly developing worldwide and widely applied in the fields of space radiation simulation and particle therapy.Usually,a very high uniformity in the irradiation area is required for the extracted ion beams,which is crucial because it directly affects the experimental precision and therapeutic effect.Specifically,ultra-large-area and high-uniformity scanning are crucial requirements for spacecraft radiation effects assessment and serve as core specification for beamline terminal design.In the 300 MeV proton and heavy ion accelerator complex at the Space Environment Simulation and Research Infrastructure(SESRI),proton and heavy ion beams will be accelerated and ultimately delivered to three irradiation terminals.In order to achieve the required large irradiation area of 320 mm×320 mm,horizontal and vertical scanning magnets are used in the extraction beam line.However,considering the various requirements for beam species and energies,the tracking accuracy of power supplies(PSs),the eddy current effect of scanning magnets,and the fluctuation of ion bunch structure will reduce the irradiation uniformity.To mitigate these effects,a beam uniformity optimization method based on the measured beam distribution was proposed and applied in the accelerator complex at SESRI.In the experiment,the uniformity is successfully optimized from 75%to over 90%after five iterations of adjustment to the PS waveforms.In this paper,the method and experimental results were introduced.
文摘The electron cooler was installed in one of the straight sections of CSRe which is used to provide high-qualitybeams for experiments. Longitudinally the dynamics of the cooling process have been studied for a series of electronbeam parameters and the friction force was measured with the aid of an RF-buncher for C6+ (122 MeV/u) and O8+(122 MeV/u) ions. The cooling time at different electron beam state have been measured, too.
文摘[目的]从SSCI论文角度分析我国哲学社会科学2008—2017年国际化进程状况,并将结果与G7国家和有代表性的新兴国家作对比。研究结果有利于相关人员从宏观上了解我国哲学社会科学近10年国际化进程状况,也为后续研究提供数据资料。[方法]基于2008—2017年Web of Science,获得我国和美国、英国、德国、法国、日本、意大利、加拿大、印度、韩国、俄罗斯共11国的SSCI论文量(论文均特指Article和Review,且不限于第一作者),并作对比。[结果]2008—2017年我国SSCI论文量逐年显著增长,至2017年已超越德国和加拿大,但与美国和英国相比仍有较大差距,我国SSCI论文量的环比增长速度位居11国中第1位,平均为22.77%。[结论]我国哲学社会科学相对较低的国际话语权应引起相关政策制定者的注意。
基金Strategic Priority Research Program of Chinese Academy of Sciences(XDB34010000)Guangdong Major Project of Basic and Applied Basic Research(2021B0301030006)+1 种基金National Key R&D Program of China(2018YFA0404402)Frontier Science Key Project of Chinese Academy of Sciences(ZDBS-LY-SLH017)。
文摘Over the past years,experimentalists have launched an expedition to explore the predicted,centered near the double-magic Z=114,N=184 nucleus.With their remarkable e orts,elements from hydrogen up to element 118 at present.The discovery of the superheavy elements o ers the possibilities to study properties of nuclei under extremely strong Coulomb elds and to explore the limits of existence of nuclei.The fusion evaporation reactions induced by low-energy heavy ions are employed for synthesis and study of superheavy isotopes,and the gas-lled recoil separator technique is always used to e ectively separate the produced evaporation residues from projectile-like and target-like products.
文摘The super ferric superconducting dipoles are in development for the High Intensity high Energy FRagment Separator(HFRS)of the Heavy-ion Accelerator Facility(HIAF).The dipole magnets of the separator will have a deflection radius of 15.7 m,a field up to 1.6 T with a 320 mm wide good field region and an effective length of 2.74 m.In the HIAF-HFRS,there will be a total of 11 super ferric dipoles.The dipole consists of two superconducting coils,a coil box,a cryostat,and a warm iron warm laminated iron,as shown in Fig.1.The superconducting coils are protected by the active quench protection.
文摘The High Energy Fragment Separator(HFRS)within the Heavy-ion Accelerator Facility(HIAF)features a beamline comprised of 11 sets of superconducting dipoles and 39 sets of combined multipoles,spanning a length of approximately 180 m.The dipoles are constructed using warm iron superferric technology.Meanwhile,the combined multipoles feature a coil dominated DCT(Discrete Cosine-Theta)coil structure,offering a large aperture,high polar field,compact design,and robust operation.
