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Enhanced thermal conductivity and microwave dielectric properties by mesostructural design of multiphase nanocomposite

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Nano Materials Science 2022年第2期4卷 133-138页

作者： liping zhou Peng Xu Faxiang Qin Institute for Composites Science Innovation(InCSI) School of Materials Science and EngineeringZhejiang University38 Zheda RoadHangzhou310027PR China

Next-generation packaging materials are expected to have higher thermal conductivity,because the heat accumulated in high-performance electronic equipment should be removed to increase the service life of the *** the same time,the dielectric loss of the material needs to be reduced to lessen signal delay and attenuation,especially for the applications under high *** this work,we introduce nano-silicon carbide(SiC)and carbon nanotubes(CNTs)into the polystyrene(PS)and poly(methyl methacrylate)(PMMA)blends *** design of two-way migration at the interface of CNTs and SiC nanoparticles is realized through the masterbatch method and processing technology *** a result,the thermal conductivity is successfully increased up to 75%.Meanwhile,compared to the CNTs single-phase migration system,it effectively reduces the dielectric loss of the nanocomposite and optimizes the electrical *** work has significant practical application value in the design of electronic device substrates and packaging materials,and provides an innovative methodology for the mesostructure design of multiphase nanocomposites.

关键词： Immiscible blends Nanocomposite Microwave dielectric properties Thermal conductivity

Year aridity index patterns in northwest China and the relationship to summer North Atlantic sea surface temperature

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Acta Oceanologica Sinica 2008年第3期27卷 161-171页

作者： YAN Yan ZHAO Xinyi zhou liping College of Urban and Environmental Sciences Laboratory for Earth Surface Processes of Ministry of Education Peking University Beijing 100871 China

Aim to linking the variability of drought in northwest China to the oceanic influence of North Atlantic SSTs at the background of global warming and at the regional climate change shifting stages, year aridity index variations in northwest China and summer North Atlantic sea surface temperature （SST） variations are examined for the 44 a period of 1961-2004 using singular value decomposition （SVD） analysis. Results show that the SST anomalies （SSTA）in the North Atlantic in summer reflected three basic models. The first SVD mode of SST pattern shows a dipole - like variation with the positive center located at southwest and negative center at northeast of extratropical North Atlantic. And it strongly relates to the positive trend in AI variation in northwest China. The second coupled modes display the coherent positive anomalies in extratropical North Atlantic SST and the marked opposite trend of AI variability between north and south of Xinjiang. In addition, the lag correlation analysis of the first mode of SSTA and geopotential heights at 500 hPa variations also shows that the indication of the former influencing the latter configuration, which result in higher air temperature and less precipitation when the SSTA in the North Atlantic Ocean in summer motivated Eurasian circulation of EA pattern, further to influence the wet - dry variations in northwest China by the ocean-to - atmosphere forcing.

关键词： aridity index SSTA teleconnection patterns SVD

Pollen indicators of human activity

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Chinese Science Bulletin 2008年第9期53卷 1281-1293页

作者： LIYiYin zhou liping GUI HaiTing Laboratory for Earth Surface Processes Department of Geography Peking University Beijing 100871 China

The study of past human activities and their environmental effect is high in the agenda of global change research. A record of pollen assemblages is one of the most common proxies employed for detecting the impact of human activities on the landscape. In this review, we provide a summary and discussion on the recent progress on the use of pollen as indicators of human activity. For most of the studies related to human impact, the following features have been focused on: (1) decline of certain tree pollen; (2) flourishing of pioneer plant pollen; (3) concomitant occurrence of cereal-type pollen and cropland weed pollen; (4) abrupt changes in pollen concentration and richness; and (5) occurrence of nitrophi- lous plants and pastoral weed. Pollen of anthropogenic plants (weeds and cereal-type plants) is ideal indicators of human activities. Different types of human activities will result in different pollen assem- blages. Patterns of human-impacted pollen spectra would vary between forested areas and grassland. In the study of human impact with pollen data, high resolution in both time and space must be consid- ered. High resolution in space will help to inform the complexity of the landscape. More importantly, it can help to reveal the interference of human activities on the landscape, hence avoiding the bias cre- ated by the limited data points. Fine resolution in time will make accurate recording of short-lived events possible, hence avoiding the exclusion of events related to human activities. The combination of palynology with other proxies will help to decipher more accurately landscape changes through time. Charcoal is a particularly useful proxy for recording the disturbance of humans on vegetation. Its peak values usually occur with pronounced drop of tree pollen and significant rise of anthropogenic pollen.

关键词：花粉植物发育除草方法人工授粉植物学

Luminescence chronology of “Old Red Sand” in Jinjiang and its implications for optical dating of sediments in South China

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Chinese Science Bulletin 2008年第4期53卷 591-601页

作者： ZHANG JiaFu YUAN BaoYin zhou liping Laboratory for Earth Surface Processes Department of Geography Peking University Beijing 100871 China Institute of Geology and Geophysics Chinese Academy of Sciences Beijing 100029 China

A weathered deposit in South China is widespread on the coastal areas of Fujian and Guangdong provinces,*** deposit consists of slightly cemented,medium-to fine-grained sands,and is characterized by its colors of red,brown red,light reddish brown or dark yellowish orange,and is usually called "Old Red Sand".The uncertainty in its formation age has been a major obstacle to the study of this type of *** this paper,optically stimulated luminescence(OSL) techniques were used to date the "Old Red Sand" sediments from Jinjiang,Fujian Province,*** effect of the geochemical behavior of uranium and thorium in sediment during chemical weathering on estimation of annual dose was *** results show that the change in annual dose due to weathering poses a major problem for the optical dating of such weathered *** optical dating of these weathered deposits will produce erroneous ages if average annual dose during burial cannot be correctly *** the profiles studied,the OSL dates obtained on samples from the upper part do not represent the burial age of the *** is highly likely that they are underestimated due mainly to the accumulated radioactive elements as a result of chemical *** is concluded that changes in annual dose due to chemical weathering must be considered when dating similar sediments in South *** a detailed analysis of the OSL dating results,the chronology of the marine terraces in this area was *** lowest terrace was formed at ～3.5 ka and the second terrace was dated to ～74 *** age of the highest terrace may not be established accurately,but is inferred to be older than the apparent OSL date of～77 ka and so is the Paleolithic artifacts from it.

关键词：红土发光年代学化学风化第四纪沉淀物

Loess deposition in Asia： its initiation and development before and during the Quaternary

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Episodes 2008年第2期31卷 222-225页

作者： Andrey E. Dodonov liping zhou Geological Institute Russian Academy of Sciences Pyzhevsky 7 119017 Moscow Russia Laboratory for Earth Surface Processes Department of Geography Peking University Beijing 100871 China

Dust is important in the Earth environment system. However; the role of dust in climate change remains largely unknown. A better understanding of the temporal and spatial variability of the dust accumulation in Asia forms an important step towards establishing the link between dust deposition and climate change. Here, a summary is given for the timing of the onset and expansion of loess deposition in Asia beginning in the early, Miocene. Recent progress on some aspects of loess chronology and palaeoenvironmental reconstruction is also reviewed.

关键词：亚洲黄土沉积第四纪地质时代地球环境

Skyrmion Hall effect with spatially modulated Dzyaloshinskii-Moriya interaction

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Frontiers of physics 2019年第5期14卷 71-79页

作者： liping zhou Ren Qin Ya-Qing Zheng Yong Wang School of Physics Nankai UniversityTianjin 300071China

The skyrmion Hall effect is theoretically studied in the chiral ferromagnetic film with spatially modulated Dzyaloshinskii-Moriya *** cases including linear,sinusoidal,and periodic rectangular modulations have been considered,where the increase,decrease,and the periodic modification of the size and velocity of the skyrmion have been observed in the microscopic *** phenomena are well explained by the Thiele equation,where an effective force on the skyrmion is induced by the inhomogeneous Dzyaloshinskii Moriya *** results here suggest that tlic skyrmion Hall effect can be manipulated by artificially timing the DzvaloshinskiiMoriya interaction in chiral ferromagnetic film with material engineering methods,which will be useful to design skyrmion-based spintronics devices.

关键词： magnetic skyrmion skyrmion Hall effect Thiele equation

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Credit creation

China Finance and Economic Review 2014年第3期3卷 3-22页

作者： Li Yang zhou liping Chinese Academy of Social Sciences P.R.China Research Fellow Institute of Finance and BankingChinese Academy of Social SciencesP.R.China

With the development of financial markets and the rise of modern shadow banking system,new agents and new means of credit creation are constantly emerging,and their effects on the financial system and macro-economic system are also *** historical clues,this paper conducts a review and analysis of the literature on credit creation from the perspective of money so as to render some help for the understanding of credit creation in modern financial system.

关键词： credit creation money supply financial innovation

A direct method for solving projected generalized continuous-time Sylvester equations

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控制理论与应用（英文版） 2012年第3期10卷 319-324页

作者： Yiqin LIN Liang BAO Yanhua CAO liping zhou Department of Mathematics and Computational Science Hunan University of Science and Engineering Yongzhou Hunan 425100 China Department of Mathematics East China University of Science and Technology Shanghai 200237 China Department of Mathematics North China Electric Power University Beijing 102206 China

This article is devoted to the numerical solution of a projected generalized Sylvester equation with relatively small size. Such an equation arises in stability analysis and control problems for descriptor systems including model reduction based on balanced truncation. The algebraic formula of the solution of the projected generalized continuous-time Sylvester equation is presented. A direct method based on the generalized Schur factorization is proposed. Moreover, its low-rank version for problems with low-rank right-hand sides is also proposed. The computational cost of the direct method is estimated. Numerical simulation show that this direct method has high accurncv

关键词： Projected generalized Sylvester equation Matrix pencil Generalized Schur factorization Spectral pro-jection

Tribological Behaviors of Ni_3Al Intermetallics with MoO_3 Multilayer Ribbon Crystal Prepared by Spark Plasma Sintering

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Acta Metallurgica Sinica(English Letters) 2017年第6期30卷 576-584页

作者： Wenzheng Zhai Xiaoliang Shi Kang Yang Yuchun Huang liping zhou Wenlong Lu The State Key Laboratory of Digital Manufacturing Equipment and Technology School of Mechanical Science and Engineering Huazhong University of Science and Technology School of Mechanical and Electronic Engineering Wuhan University of Technology

This study reports that small amounts of MoO3 multilayer ribbon crystal （MOO3 MLRC） in Ni3Al intermetallics showed the decreased friction coefficients and improved wear resistance at different contact loads. Specifically, the friction coefficients （0.32-0.34） and wear rates [（2-4）× 10^-5 mm^3 N^-1 m^-1] are significantly reduced for NiaAl at 2-8 N. A possible explanation for the friction and wear reduction is that MoO3 MLRC as a multilayer material shears easily in the tribo-layer during the sliding contact, and provides low friction. In addition, this MoO3 MLRC with excellent bending strength is found to dissipate shear stress and suppress severe plastic deformation under a cyclic stress, thus drastically improving wear resistance of Ni3Al.

关键词： Intermetallics Tribologicai properties Powder metallurgy Microstructure Wear resistant