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1.
Recent commissioning of the Cooler Storage Ring at the Heavy Ion Research Facility in Lanzhou enabled us to conduct high-precision mass measurements at the Institute of Modern Physics in Lanzhou (IMP). In the past few years, mass measurements were performed using the CSRe-based isochronous mass spectrometry employing the fragmentation of the energetic beams of 58Ni, 78Kr, 86Kr, and 112Sn projectiles. Masses of short-lived nuclides on both sides of the stability valley were addressed. Relative mass precision of down to 10−6 ~ 10−7 is routinely achieved. The mass values were used as an input for dedicated nuclear structure and astrophysics studies, providing for instance new insights into the rp-process of nucleosynthesis in X-ray bursts. In this contribution, we briefly review the so far conducted experiments and the main achieved results, as well as outline the plans for future experiments. 相似文献
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Brane world black holes in teleparallel theory equivalent to general relativity and their Killing vectors, energy, momentum and angular momentum
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Gamal G.L. Nashed 《中国物理 B》2010,19(2):20401-020401
The energy--momentum tensor, which is coordinate-independent, is
used to calculate energy, momentum and angular momentum of two
different tetrad fields. Although, the two tetrad fields reproduce
the same space--time their energies are different. Therefore, a
regularized expression of the gravitational energy--momentum tensor
of the teleparallel equivalent of general relativity (TEGR), is
used to make the energies of the two tetrad fields equal. The
definition of the gravitational energy--momentum is used to
investigate the energy within the external event horizon. The
components of angular momentum associated with these space--times
are calculated. In spite of using a static space--time, we get
a non-zero component of angular momentum! Therefore, we derive
the Killing vectors associated with these space--times using the
definition of the Lie derivative of a second rank tensor in the
framework of the TEGR to make the picture more clear. 相似文献
3.
Random-injection-based two-channel chaos with enhanced bandwidth and suppressed time-delay signature by mutually coupled lasers: Proposal and numerical analysis
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Simultaneous bandwidth(BW) enhancement and time-delay signature(TDS) suppression of chaotic lasing over a wide range of parameters by mutually coupled semiconductor lasers(MCSLs) with random optical injection are proposed and numerically investigated. The influences of system parameters on TDS suppression(characterized by autocorrelation function(ACF) and permutation entropy(PE) around characteristic time) and chaos BW are investigated. The results show that, with the increasing bias current, the ranges of parameters(detuning and injection strength) for the larger BW(> 20 GHz) are broadened considerably, while the parameter range for optimized TDS(< 0.1) is not shrunk obviously.Under optimized parameters, the system can simultaneously achieve two chaos outputs with enhanced BW(> 20 GHz)and perfect TDS suppression. In addition, the system can generate two-channel high-speed truly physical random number sequences at 200 Gbits/s for each channel. 相似文献
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We discuss quantum fluctuation in excited states(named thermo number states) of mesoscopic LC circuits at a finite temperature.By introducing the coherent thermo state into the thermo field dynamics pioneered by Umezawa and using the natural representation of thermo squeezing operator we can concisely derive the fluctuation.The result shows that the noise becomes larger when either temperature or the excitation number increases. 相似文献
5.
Pressure effect study on the Ⅰ-Ⅴ property of the GaAs-based resonant tunnelling structure by photoluminescence measurement
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This paper discusses the Ⅰ-Ⅴ property of the GaAs-based resonant tunnelling structure(RTS) under external uniaxial pressure by photoluminescence studies.Compressive pressure parallel to the [110] direction,whose value is determined by Hooke's law,is imposed on the sample by a helix micrometer.With the increase of the applied external uniaxial compressive pressure,the blue shift and splitting of the luminescence peaks were observed,which have some influence on the I-V curve of RTS from the point of view of the energy gap,and the splitting became more apparent with applied pressure.Full width at half maximum broadening could also be observed. 相似文献
6.
匀速圆周运动是曲线运动章节的教学重点.现行高中及中专教材均以两节的篇幅来讨论这种运动.一节是建立匀速圆周运动的概念,引入描述匀速圆周运动快慢的4个量,即周期(T)、频率(v)、角速度(ω)、线速度(v),并讨论这4个量的关系.另一节则从受力的角度讨论圆周运动的向心力及向心加速度.共涉及6个量.由于这6个量之间彼此存在一定的关系,这就使圆周运动具有较多的公式.如果学生能熟练掌握这些公式以及它们之间相互关系的规律,解题就能 相似文献
7.
Clear windows onto emergent hadron mass(EHM)and modulations thereof by Higgs boson interactions are provided by observable measures of pion and kaon structure,many of which are accessible via generalised parton distributions(GPDs).Beginning with algebraic GPD Ans?tze,constrained entirely by hadron-scaleπand K valence-parton distribution functions(DFs),in whose forms both EHM and Higgs boson influences are manifest,numerous illustrations are provided.They include the properties of electromagnetic form factors,impact parameter space GPDs,gravitational form factors and associated pressure profiles,and the character and consequences of allorders evolution.The analyses predict that mass-squared gravitational form factors are stiffer than electromagnetic form factors;reveal that K pressure profiles are tighter than profiles,with both mesons sustaining near-core pressures at magnitudes similar to that expected at the core of neutron stars;deliver parameter-free predictions for and K valence,glue,and sea GPDs at the resolving scale l=2GeV;and predict that at this scale the fraction of meson mass-squared carried by glue and sea combined matches that lodged with the valence degrees-of-freedom,with a similar statement holding for mass-squared radii. 相似文献
8.
The subsolidus phase relations of a ZnO-V 2 O 5-K 2 O system are investigated by X-ray powder diffraction.There is 1 ternary compound,11 binary compounds and 14 three-phase regions in this system.The phase diagrams of V 2 O 5 K 2 O with the K 2 O content ranging from 0 to 71 mol% and pseudo-binary system of ZnO-K 2 ZnV 2 O 7 are also studied by X-ray powder diffraction and differential thermal analysis methods. 相似文献
9.
Potential energy curves(PECs) for the ground state(X 2 Σ +) and the four excited electronic states(A 2 Π,B 2 Π,C 2 Σ +,4 Π) of a BeH molecule are calculated using the multi-configuration reference single and double excited configuration interaction(MRCI) approach in combination with the aug-cc-pVTZ basis sets.The calculation covers the internuclear distance ranging from 0.07 nm to 0.70 nm,and the equilibrium bond length R e and the vertical excited energy T e are determined directly.It is evident that the X2Σ+,A2Π,B2Π,C2Σ+ states are bound and 4Π is a repulsive excited state.With the potentials,all of the vibrational levels and inertial rotation constants are predicted when the rotational quantum number J is set to be equal to zero(J = 0) by numerically solving the radial Schr¨odinger equation of nuclear motion.Then the spectroscopic data are obtained including the rotation coupling constant ω e,the anharmonic constant ωexe,the equilibrium rotation constant Be,and the vibration-rotation coupling constant αe.These values are compared with the theoretical and experimental results currently available,showing that they are in agreement with each other. 相似文献
10.
Theoretical investigation of band-gap and mode characteristics of anti-resonance guiding photonic crystal fibres
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With the full-vector plane-wave method (FVPWM) and the full-vector beam propagation method (FVBPM),the dependences of the band-gap and mode characteristics on material index and cladding structure parameter in antiresonance guiding photonic crystal fibres (ARGPCFs) are sufficiently analysed.An ARGPCF operating in the nearinfrared wavelength is shown.The influences of the high index cylinders,glass interstitial apexes and silica structure on the characteristics of band-gaps and modes are deeply investigated.The equivalent planar waveguide theory is used for analysing such an ARGPCF filled by the isotropic materials,and the resonance and the anti-resonance characteristics can be well predicted. 相似文献
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利用X射线微区分析,对共价法得到的固定化L—天门冬酰胺酶的活性进行了分析。L—天门冬酰胺作为底物,MgCl2作为捕捉剂,底物经L-天门冬酰胺酶催化分解产生氨,后者和捕捉剂反应产生沉淀,可以确定固定化L-天门冬酰胺酶的催化活性部位。结果表明:大孔树脂载体,酶活较高,活性L-天门冬酰胺酶分布较均匀。并得到了固定化L-天门冬酰胺酶的活性定位的最佳条件。并对不同结构载体固定化酶活性进行了研究。 相似文献
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线性渐变滤光片光谱分光特性及检测方法研究 总被引:1,自引:0,他引:1
线性渐变滤光片(LVF)被广泛应用于各种小型快速分光测试设备中。分光特性进行研究,给出了其分光特性的高斯函数表达式,分析了各个参数与线性渐变滤光片中心透过率、谱线宽度和线性渐变系数等特性的关系。将光谱成像仪标定的单色仪法引入线性渐变滤光片的分光特性检测中,讨论了检测系统的敏感性,并给出了相应的误差容限公式。分析表明单色仪出射狭缝相对光轴平移量,以及滤光片倾斜角度对检测精度影响最大,实际测量中可通过光路和系统机构的调整达到精度要求。构建检测系统完成了对成品线性渐变滤光片分光特性的检测,结果表明对中心透过率的测量均方根误差小于0.05%,验证了方法的精确性,普适性,检测结果可为线性渐变滤光片相关系统的设计和标定提供参数指导。 相似文献
17.
建立了一套可以实现铁蛋白脱铁的机制并对脱铁前后铁蛋白的光谱进行了分析。应用连二亚硫酸钠(Sodium Hyposulfite)为还原剂与铁蛋白发生还原反应,促使铁蛋白矿化铁的还原释放,此过程中使用2,2-联吡啶(2,2-Dipyridyl)实时监测脱铁状况。通过ICP-MS检测显示,脱铁铁蛋白制备成功。紫外分析结果表明铁蛋白在脱铁之前没有吸收峰,而在脱铁后在280 nm处具有明显的吸收峰。荧光分析结果表明,铁蛋白脱铁前没有荧光发射光谱,而在脱铁后则具有荧光发射光谱。 相似文献
18.
在感应型速调管调制器中使用了纳米晶磁性材料制作大尺寸磁环,使用伏安向量法对材料试样的磁性能进行测量,得到频率为20.03 kHz和50 kHz时的动态磁化曲线、磁导率、磁场损耗等参数。使用脉冲法对成型的大尺寸磁环动态磁性能进行测量,励磁方式和工作中完全一致,在测量脉冲脉宽3.5~4.0 μs,重复频率50 Hz,初次线圈均为1匝,外径220 mm,内径80 mm,高60 mm,截面积4 200 mm2时,得到磁环实际能够达到的伏秒数为0.007 V·s,此时所需的偏磁电流大小为8 A。 相似文献
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基于SGS探测系统中放射性核废物桶、准直器及HPGe探测器的空间几何分布建立数学模型。对低、中放射性核废物桶中点源137Cs的探测效率响应函数进行了数值公式推导,然后利用蒙特卡罗工具包MCNP模拟计算了相应的效率函数。将这两种方法模拟的结果进行了对比分析发现:数值计算方法的数据普遍高于MCNP模拟的数据,最大相对误差达143.26%,误差平均值为37.15%。对数值计算方法进行修正后,最大值相对误差为17.22%,平均值为4.54%。在误差范围内,可以认为该修正方法有效。 相似文献
20.
固定化木瓜蛋白酶活性的X-射线微区分析 总被引:1,自引:0,他引:1
利用X-射线微区分析,对共价法得到的固定化木瓜蛋白酶的活性进行了分析;Na-苯甲酰-L-精氨酰胺盐酸盐作为底物,FeCl_3作为捕捉剂,底物经木瓜蛋白酶催化分解产生L-精氨酸及氨,后者和捕捉剂反应产生沉淀,可以确定固定化木瓜蛋白酶的催化活性部位。结果表明:以大孔结构吸附树脂为固定化酶载体,酶活较高,木瓜蛋白酶分布较均匀。并得到了固定化木瓜蛋白酶的活性定位的最佳条件。并对不同结构载体固定化木瓜蛋白酶的活性进行了研究。 相似文献