检索结果-南通市图书馆

Atom-referenced and stabilized soliton microcomb

Science China(Physics,Mechanics & Astronomy) 2024年第2期67卷 2-8页

作者： Rui Niu Shuai Wan Tian-Peng Hua Wei-Qiang Wang Zheng-Yu Wang Jin Li Zhu-Bo Wang Ming Li Zhen Shen Yu Robert Sun Shui-Ming Hu Brent ELittle Sai Tak Chu Wei Zhao Guang-Can Guo Chang-Ling Zou Yun-Feng Xiao wen-fu zhang Chun-Hua Dong State Key Laboratory of Transient Optics and Photonics Xi’an Institute of Optics and Precision MechanicsChinese Academy of SciencesXi’an 710119China CAS Key Laboratory of Quantum Information University of Science and Technology of ChinaHefei 230026China CAS Center for Excellence in Quantum Information and Quantum Physics University of Science and Technology of ChinaHefei 230026China University of Chinese Academy of Sciences Beijing 100049China Department of Chemical Physics University of Science and Technology of ChinaHefei 230026China Department of Physics and Materials Science City University of Hong KongHong Kong 999077China State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics School of PhysicsPeking UniversityBeijing 100871China

For the applications of the frequency comb in microresonators,it is essential to obtain a fully frequency-stabilized microcomb laser *** this study,we present a system for generating a fully atom-referenced stabilized soliton *** pump light around 1560.48 nm is locked to an ultra-low-expansion(ULE)*** pump light is then frequency-doubled and referenced to the atomic transition *** repetition rate of the soliton microcomb is injection-locked to an atomic-clockstabilized radio frequency(RF)source,leading to mHz stabilization at 1 *** a result,all comb lines have been frequencystabilized based on the atomic reference and the ULE cavity,achieving a very high precision of approximately 18 Hz at 1 s,corresponding to the frequency stability of 9.5×10^(-14).Our approach provides a fully stabilized microcomb experiment scheme with no requirement of f-2f technique,which could be easily implemented and generalized to various photonic platforms,thus paving the way towards the ultraprecise optical sources for high precision spectroscopy.

关键词： microcavity frequency comb dissipative Kerr solitons fully stabilized microcomb

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Can the bump in the composite spectrum of GRB 910503 be an emission line feature of gamma-ray bursts?

引用

Chinese Journal of Astronomy and Astrophysics 2005年第6期5卷 627-635页

作者： Yi-Ping Qin fu-wen zhang National Astronomical Observatories Yunnan Observatory Chinese Academ）： of SciencesKunming 650011 Physics Department Guangxi University Nanning 530004 Graduate University of Chinese Academy of Sciences Beijing 100049

Appearing in the composite spectral data of BATSE, EGRET and COMPTEL for GRB 910503, there is a bump at around 1600keV. We perform a statistical analysis on the spectral data, trying to find out if the bump could be accounted for by a blue-shifted and significantly broadened rest frame line due to the Doppler effect of an expanding fireball surface. We made an F-test and adopted previously proposed criteria. The study reveals that the criteria are well satisfied and the feature can be interpreted as the blue shifted 6.4 keV line. From the fit with this line taken into account, we find the Lorentz factor of this source to be F = 116-9^＋9 （at the 68% confident level, △X^2 = 1） and the rest frame spectral peak energy to be E0,p=2.96-0.18^＋0.24 ke *** the existence of the emission line feature requires other independent tests to confirm, the analysis suggests that it is feasible to detect emission line features in the high energy range of GRB spectra when taking into account the Doppler effect of fireball expansion.

关键词： gamma-rays bursts - gamma-rays theory - radiation mechanisms nonthermal - relativity

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

The isotropic energy function and formation rate of short gamma-ray bursts

引用

Research in Astronomy and Astrophysics 2021年第10期21卷 127-134页

作者： Zhi-Ying Liu fu-wen zhang Si-Yuan Zhu College of Science Guilin University of TechnologyGuilin 541004China Key Laboratory of Dark Matter and Space Astronomy Chinese Academy of SciencesNanjing 210008China

Gamma-ray bursts(GRBs)are brief,intense,gamma-ray flashes in the universe,lasting from a few milliseconds to a few thousand *** short gamma-ray bursts(sGRBs)with duration less than 2 seconds,the isotropic energy(E_(iso))function may be more scientifically meaningful and accurately measured than the luminosity(Lp)*** this work we construct,for the first time,the isotropic energy function of s GRBs and estimate their formation ***,we derive the L_(p)-E_(p) correlation using 22 s GRBs with known redshifts and well-measured spectra and estimate the pseduo redshifts of 334 Fermi s ***,we adopt the Lynden-Bell c-method to study isotropic energy functions and formation rate of s GRBs without any assumption.A strong evolution of isotropic energy E_(iso)∝(1+z)^(5.79) is found,which is comparable to that between L_(p) and *** removing effect of the cosmic evolution,the isotropic energy function can be reasonably fitted by a broken power law,which is φ(E_(iso,0))∝E_(iso,0)^(-0.045) for dim sGRBs andφ(E_(iso,0))∝E_(iso,0)^(-1.11) for bright sGRBs,with the break energy 4.92×10^(49)*** obtain the local formation rate of s GRBs is about 17.43 events Gpc^(-3)yr^(-1).If assuming a beaming angle is 6° to 26°,the local formation rate including off-axis s GRBs is estimated as ρ_(0,all)=155.79-3202.35 events Gpc^(-3)yr^(-1).

关键词： gamma-ray bursts:general methods:data analysis

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Modification of Sn–1.0Ag–0.5Cu solder using nickel and boron

引用

Rare Metals 2015年第11期34卷 783-788页

作者： Jun-Feng Qu Jun Xu Qiang Hu fu-wen zhang Shao-Ming zhang National Engineering Research Center for Nonferrous Metal Composites General Research Institute for Nonferrous Metals Technology Department Beijing COMPO Advanced Technology Co. Ltd.

Effects of Ni and B additions on the microstructure and growth behavior of the intermetallic compound(IMC) of Sn–1.0Ag–0.5Cu alloys(SAC105) were investigated in this study. Results show that microadditions of Ni and B result in volume fraction of primary Sn increasing and the grain size decreasing observably. It is found that a large number of fine reinforcement particles with network-like shape are found in the solder, and the thickness of interfacial IMC layer in the solder joint is grew less than that of SAC105 with longer aging time. Shear test results reveal that as-soldered solder joints of microalloyed SAC105 have better shear strength than that of SAC105 solder alloy.

关键词： Lead-free solder Sn–1.0Ag–0.5Cu Interfacial reacti

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

X-Ray Afterglows of GRBs 050318 and 060124 and their External Shock Origin

引用

Chinese Journal of Astronomy and Astrophysics 2007年第4期7卷 516-520页

作者： Jin zhang Yi-Ping Qin fu-wen zhang Bin-Bin zhang National Astronomical Observatories / Yunnan Observatory Chinese Academy of Sciences Kunming 650011 Center for Astrophysics of Guangzhou University Guangzhou 510006 Physics Department Guangxi University Nanning 530004 Graduate School of Chinese Academy of Sciences Beijing 100049

The observations with Swift X-ray telescope （XRT） challenge the conventional gamma-ray burst model in many aspects. The XRT light curves are generally composed of four consecutive segments, i.e., a steep decay segment, a shallow decay segment, a normal decay segment, a jet-like steep decay segment, and sometimes erratic flares as well. The physical origin of the X-ray emission is highly debatable. We focus here on the physical origin of the X-ray emissions of GRBs 050318 and 060124. We present the XRT light curves and spectra of the two bursts. The light curve decay slopes of the two bursts are normal, and their relations to the spectral indices are consistent with the prediction of the standard forward shock model. The multi-wavelength light curves at 0.5 keV, 1.0 keV, 2.0 keV and 4.0 keV can be reproduced by this model with an isotropic kinetic energy Ek = 2.2 × 10^52 erg, εe = 0.04, εB = 0.01 for GRB 050318 and Ek = 4.2 × 10^53 erg, εe = 0.05, εB = 0.01 for GRB 060124. These facts suggest that the normal decay phases of the X-rays for the two bursts are of the forward shock origin.

关键词： gamma-rays- bursts-individual: GRB 050318 GRB 060124

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Are Type Ia Supernovae Reliable Distance Indicators?

引用

Chinese Journal of Astronomy and Astrophysics 2007年第5期7卷 649-656页

作者： Lian-Zhong Lü Yi-Ping Qin fu-wen zhang National Astronomical Observatories / Yunnan Observatory Chinese Academy of Sciences Kunming 650011 Physics Department Guangxi University Nanning 530004 Center for Astrophysics of Guangzhou University Guangzhou 510006 Graduate School of Chinese Academy of Sciences Beijing 100049

Recent applications of type Ia supernovae （SNe Ia） in cosmology have successfully revealed the accelerating expansion of the universe. However, as distance indicators used in measuring the expansion history of the universe and probing the nature of dark energy, these objects must pass more strict tests. We propose a K-S test to investigate if there exists any systematic bias when deriving the luminosity distances under the standard candle assumption. Two samples, one comprising 71 high-redshift SNe Ia and the other, 44 nearby ones, are used in our investigation. We find that it is likely there exists a bias in the adopted samples, which is probably caused by a systematic error, e.g. in the color parameter used in the luminosity calibration and a bias may be caused by the SN evolution or by varying properties of the dust surrounding the SNe Ia.

关键词： cosmology observations -- distance scale -- galaxies distances and redshifts -- methods statistical -- supernovae general

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

A Close Correlation between the Spectral Lags and Redshifts of Gamma-Ray Bursts

引用

Chinese Journal of Astronomy and Astrophysics 2008年第1期8卷 81-86页

作者： Ting-Feng Yi Guang-Zhong Xie fu-wen zhang Physics Department Yunnan University Kunming 650091 National Astronomical Observatories/-Yunnan Observatory Chinese Academy of Sciences Kunming 650011 Yunnan Astronomical Center Yunnan University Kunming 650091 Graduate School of Chinese Academy of Sciences Beijing 100049

Based on nine BATSE GRBs with known redshifts, we found that the maximum spectral lag of all the pulses in a gamma-ray burst （GRB） appears to be anti-correlated with the redshift of the burst. In order to confirm this finding, we analyzed 10 GRBs detected by HETE-2 with known redshifts and found a similar relation. Using the relation, we estimated the redshifts of 878 long GRBs in the BATSE catalog, then we investigated the distributions of the redshifts and 869 Eiso of these GRBs. The distribution of the estimated redshifts is concentrated at z = 1.4 and the distribution of Eiso peaks at 10^52.5 erg. The underlying physics of the correlation is unclear at present.

关键词： gamma-rays bursts - gamma-rays observations - methods statistical

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Solder paste metamorphism

引用

Rare Metals 2021年第5期40卷 1329-1336页

作者： fu-wen zhang Hui-Jun He Zhi-Gang Wang Gang Lin Jie Zhu Jiang-Song zhang Shao-Ming zhang General Research Institute for Nonferrous Metals Beijing 100088China Beijing COMPO Advanced Technology Co.Ltd Beijing 101407China

Solder paste quality can be improved from microstructure and surface status of the solder *** this work,the micro-morphology of solder paste was observed and the particle surface condition was ***,the conditions of corrosion and the corrosion products in different organic acid groups(activators)were *** result shows that the SnO passive film on the solder powder surface reacts with the COO-in the active agent of the solder *** reaction led the passivation layer to be peeled *** also caused the change in solder powders’physical and chemical properties and made the metal boundary to be *** is the root cause of solder paste exsiccation and *** study on the details shows that to obtain high-quality solder paste,one of the key methods is using the solder powder with ideal passivation shell structure and defect-free surface.

关键词： Solder powder Micro-morphology Metamorphic solder paste Surface corrosion

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Properties of (Fe-B)-doped Sn-1.0Ag-0.5Cu solders prepared by mechanical alloying

引用

Rare Metals 2019年第7期38卷 665-674页

作者： Ruo-Da Wang Qiang Hu Shao-Ming zhang fu-wen zhang Cai-Tao Lu Zhi-Gang Wang General Research Institute for Nonferrous Metals Beijing 100088 China Beijing COMPO Advanced Technology Co. Ltd. Beijing 101407 China

To introduce boron (B) into the Sn-1.0Ag-0.5Cu (SAC 105) solder, based on the thermodynamic calculations, iron (Fe) is a competent carrier component for bonding B and Sn. The Sn-Fe-B master alloys were prepared by mechanical alloying initially;then, the SAC 105- 0.05(Fe-B) and SAC 105-0.1 (Fe-B) solder alloys were prepared using 72-h-milling Sn-Fe-B master alloys. The preparation process and the properties of solders were studied in this work. For the Sn-Fe-B master alloys, the results show that with the increase in the ball-milling time, the powder changes illustrate a cold welding-crushingcold welding cyclic process. Moreover, the supersaturated solid solubility of (Fe-B) increases gradually in the alloys, matrix and the lattice distortion increases to 0.167% after 72-h milling. Meanwhile, the alloying degree is increasingly apparent, and after 72-h milling, the content of B in the Sn matrix reaches 2.38 wt%. For the solder alloys, with the (Fe-B) content in creasing, the melting point decreases and a significant grain refinement occurs in the matrix. Compared to the benchmark SAC105, the hardness of SAC105-0.05(Fe-B) and SAC 105-0.1 (Fe-B) solder alloys prepared by this method is improved by 20.65% and 34.79%, respectively. The present research provides a novel approach for introducing the immiscible component into the lead-free solder alloys.

关键词： Sn-1.0Ag-0.5Cu Sn-Fe-B Mechanical alloying Supersaturated solid solution

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

The Effect of Blending Ratio on the Structure and Properties of the PPR/PS In situ Fiber Reinforced System Prepared by Multi-Flow Vibration Injection Molding

引用

Chinese Journal of Polymer Science 2024年第6期42卷 851-863页

作者： Yan-Jiang Li Meng-Long Hu Jun-wen zhang Qiang fu Jie zhang College of Polymer Science and Engineering State Key Laboratory of Polymer Materials EngineeringSichuan UniversityChengdu610065China

To enhance the mechanical properties of polypropylene random copolymer(PPR),polystyrene(PS)with four different contents were added to the PPR matrix through melt ***,using the Multi-Flow Vibration Injection Molding(MFVIM)technology,PPR/PS in situ microfiber composites(MFC)with different blending ratios were *** results indicated that blending ratio had a great impact on the phase morphology and crystal structure of MFVIM samples,which was different from those of conventional injection molding(CIM)*** ultrafine fibers could be formed under the shear field and could absorb the PPR molecular chains to form hybrid shish-kebab ***,the PPR matrix could also form shish-kebab structures under the effect of strong *** the PS content reached 20%,under the combined action of PS in situ microfibers and highly oriented crystal structure,the tensile strength and Young’s modulus of the sample were obviously improved and the impact strength remained at a relatively high *** a strong and tough balanced PPR based material was *** results provide valuable insights for expanding the industrial and daily-life applications of PPR and show promising development prospects.

关键词： PPR MFVIM In situ microfibers Shearfield Hybrid shish-kebab structures

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：