In Tian Qin spaceborne gravitational-wave detectors, the stringent requirements on the magnetic cleanliness of the test masses demand the high resolution ground-based characterization measurement of their magnetic pro...In Tian Qin spaceborne gravitational-wave detectors, the stringent requirements on the magnetic cleanliness of the test masses demand the high resolution ground-based characterization measurement of their magnetic properties. Here we present a single frequency modulation method based on a torsion pendulum to measure the remanent magnetic moment mr of 1.1 kg dummy copper test mass, and the measurement result is(6.45 ± 0.04(stat) ± 0.07(syst)) × 10^(-8)A · m^(2). The measurement precision of the mr is about 0.9 n A · m^(2), well below the present measurement requirement of Tian Qin. The method is particularly useful for measuring extremely low magnetic properties of the materials for use in the construction of space-borne gravitational wave detection and other precision scientific apparatus.展开更多
For a hereditary torsion theory T,this paper mainly discuss properties of A-τ- injective modules,where A is a fixed left R-module.It is proved that if M is an A-τ-injective, B is a submodule of A,then 1)M is A/B-τ-...For a hereditary torsion theory T,this paper mainly discuss properties of A-τ- injective modules,where A is a fixed left R-module.It is proved that if M is an A-τ-injective, B is a submodule of A,then 1)M is A/B-τ-injective;2)M is B-τ-injective when B isτ- dense in A.Furthermore,we show that if A_1,A_2,…,A_n are relatively injective modules, then A_1⊕A_2⊕…⊕A_n is self-τ-injective if and only if A_i is self-τ-injective for each i.展开更多
In the paper, we define(inco) project modules of relatively hereditary torsion theory τ by intersection complement of module and study their properties; secondly, we define the(inco) τ-semisimple ring by(inco) τ-pr...In the paper, we define(inco) project modules of relatively hereditary torsion theory τ by intersection complement of module and study their properties; secondly, we define the(inco) τ-semisimple ring by(inco) τ-projective module and study their properties. When τ is a trivial torsion theory on R-mod, we prove that R is a semisimple ring if and only if R is a(inco) semisimple ring and satisfies(inco) condition.展开更多
A transverse relaxation determination of spin-exchange relaxation free (SERF) magnetometer based on polarization modulation technique is proposed. Compared with the radio-frequency (RF) excitation and light intens...A transverse relaxation determination of spin-exchange relaxation free (SERF) magnetometer based on polarization modulation technique is proposed. Compared with the radio-frequency (RF) excitation and light intensity excitation meth- ods used in SERF magnetometer, the light polarization modulation method has a high stability in low-frequency range, which indicates a more accurate transverse relaxation measurement.展开更多
Let τ be a torsion theory on R-rood and M be a left R-mod. In this paper the τ-cotorsionfree radical Cτ(M) of M is studied. When τ is stable, the construction and the supplementing radical of Cτ (M) are obtai...Let τ be a torsion theory on R-rood and M be a left R-mod. In this paper the τ-cotorsionfree radical Cτ(M) of M is studied. When τ is stable, the construction and the supplementing radical of Cτ (M) are obtained.展开更多
Let G be a finitely generated torsion-free nilpotent group and a an automorphism of prime order p of G. If the map ψ : G → G defined by g^φ = [g, α] is surjective, then the nilpotent class of G is at most h(p),...Let G be a finitely generated torsion-free nilpotent group and a an automorphism of prime order p of G. If the map ψ : G → G defined by g^φ = [g, α] is surjective, then the nilpotent class of G is at most h(p), where h(p) is a function depending only on p. In particular, if α^3 = 1, then the nilpotent class of G is at most 2.展开更多
There is increasing interest in the clinical use of flattening filter-free(FFF) beams.In this study,we aimed to investigate the dosimetric characteristics of volumetric modulated arc radiotherapy(VMAT) with FFF beams ...There is increasing interest in the clinical use of flattening filter-free(FFF) beams.In this study,we aimed to investigate the dosimetric characteristics of volumetric modulated arc radiotherapy(VMAT) with FFF beams for nasopharyngeal carcinoma(NPC).Ten NPC patients were randomly selected to undergo a RapidArc plan with either FFF beams(RA-FFF) or conventional beams(RA-C).The doses to the planning target volumes(PTVs),organs at risk(OARs),and normal tissues were compared.The technical delivery parameters for RapidArc plans were also assessed to compare the characteristics of FFF and conventional beams.Both techniques delivered adequate doses to PTVs.For PTVs,RA-C delivered lower maximum and mean doses and improved conformity and homogeneity compared with RA-FFF.Both techniques provided similar maximum doses to the optic nerves and lenses.For the brain stem,spinal cord,larynx,parotid glands,oral cavity,and skin,RA-FFF showed significant dose increases compared to RA-C.The dose to normal tissue was lower in RA-FFF.The monitor units(MUs) were(536 ± 46) MU for RA-FFF and(501± 25) MU for RA-C.The treatment duration did not significantly differbetween plans.Although both treatment plans could meet clinical needs,RA-C is dosimetrically superior to RA-FFF for NPC radiotherapy.展开更多
In this paper we introduced a definition for the primary radical of a submodule with some of its basic properties. We also define the P-radical submodule and review some results about it. We find a method to character...In this paper we introduced a definition for the primary radical of a submodule with some of its basic properties. We also define the P-radical submodule and review some results about it. We find a method to characterize the primary radical of a finitely generated submodule of a free module.展开更多
Objective The aim of the study was to compare flattening filter-free(FFF) beams and conventional flattening filter(FF) beams in volumetric modulated arc therapy(VMAT) for cervical cancer after surgery, through a retro...Objective The aim of the study was to compare flattening filter-free(FFF) beams and conventional flattening filter(FF) beams in volumetric modulated arc therapy(VMAT) for cervical cancer after surgery, through a retrospective planning study.Methods VMAT plans of FFF beams and normal FF beams were designed for a cohort of 15 patients. The prescribed dose was 45 Gy to 1.8 Gy per fraction, and at least 95% of the planning target volume received this dose. Doses were computed with a commercially available treatment planning system using a Monte Carlo(MC) algorithm. Plans were compared according to dose-volume histogram analysis in terms of planning target volume homogeneity and conformity indices(HI and CI), as well as organs at risk(OAR) dose and volume parameters. Results FFF-VMAT was similar to FF-VMAT in terms of CI, but inferior to FF-VMAT considering HI. No statistically differences were observed between FFF-VMAT and FF-VMAT in following organ at risks including pelvic bone marrow, small bowel, bladder, rectum, and normal tissue(NT)..Conclusion For patients with cervical cancer after hysterectomy, the FFF beam achieved target and OAR dose distribution similar to that of the FF beam. Reduction of beam-on time in cervical cancer is beneficial.展开更多
对于光伏阵列而言,阴影遮挡和阵列损坏会导致其输出功率降低。为了提升光伏阵列的输出功率,提出了一种优化的奇偶重构方法(Optimized Odd Even Configuration,OOEC),纠正了奇偶重构法(Odd Even Configuration,OEC)在局部阴影超过4列时,...对于光伏阵列而言,阴影遮挡和阵列损坏会导致其输出功率降低。为了提升光伏阵列的输出功率,提出了一种优化的奇偶重构方法(Optimized Odd Even Configuration,OOEC),纠正了奇偶重构法(Odd Even Configuration,OEC)在局部阴影超过4列时,重构效果差的缺点。所提出的方法将光伏阵列分为自由重构模块和固定重构模块,根据不同的阴影情况调整连接方式,确定最佳的连接关系,并与Arrow So Du ku,Zig-zag,OEC三种方法进行仿真实验对比,仿真结果表明,经过OOEC重构后的光伏阵列输出功率明显提高,光伏阵列的PU输出特性曲线更加趋向于单峰,并且从失配损耗,功率提升百分比,性能比,均衡指数上看来,OOEC有着更好的性能。展开更多
We classify modules which are free of rank 1 when restricted to the negative part for the Euclidean Lie algebra.Sufficient and necessary conditions for the simplicity of these modules are given.From these modules we c...We classify modules which are free of rank 1 when restricted to the negative part for the Euclidean Lie algebra.Sufficient and necessary conditions for the simplicity of these modules are given.From these modules we construct modules which are infinitely generated when restricted to the maximal toral subalgebra.展开更多
基金supported by the National Key R&D Program of China (Grant No. 2020YFC2200500)the National Natural Science Foundation of China (Grant Nos. 12075325, 12005308, and 11605065)。
文摘In Tian Qin spaceborne gravitational-wave detectors, the stringent requirements on the magnetic cleanliness of the test masses demand the high resolution ground-based characterization measurement of their magnetic properties. Here we present a single frequency modulation method based on a torsion pendulum to measure the remanent magnetic moment mr of 1.1 kg dummy copper test mass, and the measurement result is(6.45 ± 0.04(stat) ± 0.07(syst)) × 10^(-8)A · m^(2). The measurement precision of the mr is about 0.9 n A · m^(2), well below the present measurement requirement of Tian Qin. The method is particularly useful for measuring extremely low magnetic properties of the materials for use in the construction of space-borne gravitational wave detection and other precision scientific apparatus.
基金Supported by the National Natural Science Foundation of China(10571026)Supported by the Research Foundation of the Education Committee of Anhui Province(2006kj050c)Supported by the Doctoral Foundation of Anhui Normal University
文摘For a hereditary torsion theory T,this paper mainly discuss properties of A-τ- injective modules,where A is a fixed left R-module.It is proved that if M is an A-τ-injective, B is a submodule of A,then 1)M is A/B-τ-injective;2)M is B-τ-injective when B isτ- dense in A.Furthermore,we show that if A_1,A_2,…,A_n are relatively injective modules, then A_1⊕A_2⊕…⊕A_n is self-τ-injective if and only if A_i is self-τ-injective for each i.
基金Supported by the Science and Technology Develop Foundation of Jilin Science and Technology Department(20040506-3)
文摘In the paper, we define(inco) project modules of relatively hereditary torsion theory τ by intersection complement of module and study their properties; secondly, we define the(inco) τ-semisimple ring by(inco) τ-projective module and study their properties. When τ is a trivial torsion theory on R-mod, we prove that R is a semisimple ring if and only if R is a(inco) semisimple ring and satisfies(inco) condition.
基金Project supported by the National Natural Science Foundation of China(Grant No.61227902)the National Key R&D Program of China(Grant No.2017YFB0503100)the Natural Science Foundation of Beijing Municipality,China(Grant No.4162038)
文摘A transverse relaxation determination of spin-exchange relaxation free (SERF) magnetometer based on polarization modulation technique is proposed. Compared with the radio-frequency (RF) excitation and light intensity excitation meth- ods used in SERF magnetometer, the light polarization modulation method has a high stability in low-frequency range, which indicates a more accurate transverse relaxation measurement.
文摘Let τ be a torsion theory on R-rood and M be a left R-mod. In this paper the τ-cotorsionfree radical Cτ(M) of M is studied. When τ is stable, the construction and the supplementing radical of Cτ (M) are obtained.
基金The NSF(11371124)of Chinathe NSF(F2015402033)of Hebei Provincethe Doctoral Special Foundation(20120066)of Hebei University of Engineering
文摘Let G be a finitely generated torsion-free nilpotent group and a an automorphism of prime order p of G. If the map ψ : G → G defined by g^φ = [g, α] is surjective, then the nilpotent class of G is at most h(p), where h(p) is a function depending only on p. In particular, if α^3 = 1, then the nilpotent class of G is at most 2.
文摘There is increasing interest in the clinical use of flattening filter-free(FFF) beams.In this study,we aimed to investigate the dosimetric characteristics of volumetric modulated arc radiotherapy(VMAT) with FFF beams for nasopharyngeal carcinoma(NPC).Ten NPC patients were randomly selected to undergo a RapidArc plan with either FFF beams(RA-FFF) or conventional beams(RA-C).The doses to the planning target volumes(PTVs),organs at risk(OARs),and normal tissues were compared.The technical delivery parameters for RapidArc plans were also assessed to compare the characteristics of FFF and conventional beams.Both techniques delivered adequate doses to PTVs.For PTVs,RA-C delivered lower maximum and mean doses and improved conformity and homogeneity compared with RA-FFF.Both techniques provided similar maximum doses to the optic nerves and lenses.For the brain stem,spinal cord,larynx,parotid glands,oral cavity,and skin,RA-FFF showed significant dose increases compared to RA-C.The dose to normal tissue was lower in RA-FFF.The monitor units(MUs) were(536 ± 46) MU for RA-FFF and(501± 25) MU for RA-C.The treatment duration did not significantly differbetween plans.Although both treatment plans could meet clinical needs,RA-C is dosimetrically superior to RA-FFF for NPC radiotherapy.
文摘In this paper we introduced a definition for the primary radical of a submodule with some of its basic properties. We also define the P-radical submodule and review some results about it. We find a method to characterize the primary radical of a finitely generated submodule of a free module.
基金Supported by a grant of the Military Medical Metrology Project(No.2011-JL2-005)
文摘Objective The aim of the study was to compare flattening filter-free(FFF) beams and conventional flattening filter(FF) beams in volumetric modulated arc therapy(VMAT) for cervical cancer after surgery, through a retrospective planning study.Methods VMAT plans of FFF beams and normal FF beams were designed for a cohort of 15 patients. The prescribed dose was 45 Gy to 1.8 Gy per fraction, and at least 95% of the planning target volume received this dose. Doses were computed with a commercially available treatment planning system using a Monte Carlo(MC) algorithm. Plans were compared according to dose-volume histogram analysis in terms of planning target volume homogeneity and conformity indices(HI and CI), as well as organs at risk(OAR) dose and volume parameters. Results FFF-VMAT was similar to FF-VMAT in terms of CI, but inferior to FF-VMAT considering HI. No statistically differences were observed between FFF-VMAT and FF-VMAT in following organ at risks including pelvic bone marrow, small bowel, bladder, rectum, and normal tissue(NT)..Conclusion For patients with cervical cancer after hysterectomy, the FFF beam achieved target and OAR dose distribution similar to that of the FF beam. Reduction of beam-on time in cervical cancer is beneficial.
文摘对于光伏阵列而言,阴影遮挡和阵列损坏会导致其输出功率降低。为了提升光伏阵列的输出功率,提出了一种优化的奇偶重构方法(Optimized Odd Even Configuration,OOEC),纠正了奇偶重构法(Odd Even Configuration,OEC)在局部阴影超过4列时,重构效果差的缺点。所提出的方法将光伏阵列分为自由重构模块和固定重构模块,根据不同的阴影情况调整连接方式,确定最佳的连接关系,并与Arrow So Du ku,Zig-zag,OEC三种方法进行仿真实验对比,仿真结果表明,经过OOEC重构后的光伏阵列输出功率明显提高,光伏阵列的PU输出特性曲线更加趋向于单峰,并且从失配损耗,功率提升百分比,性能比,均衡指数上看来,OOEC有着更好的性能。
基金supported by NSF of China(11801117,11971315)the Natural Science Foundation of Guangdong Province,China(2018A030313268)partially supported by NSFof China(11801390).
文摘We classify modules which are free of rank 1 when restricted to the negative part for the Euclidean Lie algebra.Sufficient and necessary conditions for the simplicity of these modules are given.From these modules we construct modules which are infinitely generated when restricted to the maximal toral subalgebra.