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| 1 | Holocene aeolian stratigraphic sequences in the eastern portion of the desert belt(sand seas and sandy lands) in northern China and their palaeoenvironmental implications显示文摘This paper presents the environmental history and its responses to palaeoclimatic changes since the start of the Holocene in the eastern portion of the desert belt(sand seas and sandy lands) in northern China by comparing the aeolian sandpalaeosol sequences and their palaeoclimatic proxies. The optically stimulated luminescence(OSL) ages of the aeolian sandpalaeosol sedimentary sequences and a series of palaeoenvironmental proxies show that:(1) The large-scale dune landscape currently in the Kubuqi Sand Sea was formed during the Holocene in general;and the palaeosol was generally developed during the period of 4–2 ka, indicating conditions favorable for vegetation growth, soil development, and organic carbon accumulation due to increased precipitation or effective moisture and weakened aeolian activities;the large-scale expansion of dunes in the recent 2 ka is closely linked to human activities. The variable discharge of the Yellow River with diversions for irrigation may have resulted in a more consistent supply of aeolian particles for dune field expansion.(2) The dune landscape of the Hunshandake Sandy Land was likely formed around 12 ka, and before this, the western part of the Hunshandake Sandy Land would have been covered by a single large lake;it was obviously wetter than today in the sandy land during the period of 9.6–3 ka and the palaeosols were developed at the same time. But the aeolian activities have not been completely dormant in this long-lasting wetter epoch;because the Holocene wetter period was likely time-transgressive across the region.(3) The palaeosol of the Hulunbuir Sandy Land began to develop as early as 14.5 ka, probably continuing until the last 2 ka. The palaeosol development of various dune fields in the eastern portion of the desert belt(sand seas and sandy lands) in northern China is spatially heterogeneous, and even the palaeosol development time in different locations within each sandy land is inconsistent. During the middle Holocene(especially the 7.5–3.5 ka), all the sandy lands were stabilized in general and the intensity of aeolian activities was significantly weakened. The number of palaeoenvironmental records in the eastern portion of the desert belt(sand seas and sandy lands) in northern China has increased rapidly in the past decade, but the amount of published data still does not match the vast extent of the dune fields. It does require much more in-depth palaeoenvironmental studies for a full understanding of the relationship between aeolian activities and climate change in northern China. | Xiaoping YANG Peng LIANG Deguo ZHANG Hongwei LI Patrick RIOUAL Xulong WANG Bing XU Zhibang MA Qianqian LIU Xiaozong REN Fangen HU Yuxin HE Gang RAO Ninghua CHEN | 2019 | Science China Earth Sciences2019，62，8： | 10 |
| 2 | Frictional behaviors of rough soft contact on wet and dry pipeline surfaces:With application to deepwater pipelaying显示文摘Elastic rubbers are widely used in nature and engineering.In order to better understand soft rough contact under dry and wet conditions during deepwater pipelaying process,various polyurethane(PU)discs both in PU-pipe and PU-steel sliding combinations have been investigated by using self-developed tribometer.The tribological test results show that the friction coefficient can be clearly seen:PU90 | TAN GuiBin WANG DeGuo LIU ShuHai WANG Hao ZHANG SiWei | 2013 | Science China(Technological Sciences)2013，56，12： | 4 |
| 3 | Preparation and nanotribological behavior of PAH/graphite oxide molecular deposition film显示文摘Polyallylamine hydrochloride/graphite oxides ultra thin film (coded as PAH/GO ultra thin film) was prepared by molecular deposition (MD) in laboratory. The resulting PAH/GO ultra thin film was heated to convert the electrostatic force towards covalent bond so as to increase the bonding strength of the film. The structure and nanotribological properties of the film were analyzed by means of atomic force microscopy and ultraviolet-visible spectroscopy. It was found that the PAH/GO ultra thin film had a much smaller friction force than the glass substrate and the friction force was dependent on the hardness and appearance of the glass substrate. | FENG Dapeng WANG Deguo ZHANG Siwei | 2004 | Science China(Technological Sciences)2004，47，4： | 4 |
| 4 | Shear of molecular deposition films on glass substrates determined by tribometer显示文摘The ultrathin polyelectrolyte molecular deposition films and polyelectrolyte composite nanoparticles molecular deposition films were prepared using layer-by-layer molecular deposition method and in situ growth method.A micro-tribometer has been developed to measure the shear response of those ultrathin molecular deposition films.By using a smooth steel sphere in a ball-on-flat configuration,the shear force was determined for molecular deposition films on glass substrate for different layers.The results indicate that the shear behaviors of molecular deposition film were mainly determined with the contact area and film layers.Moreover,the composite molecular deposition film with nanoparticles has better shear behaviors than the polyelectrolyte molecular deposition film.The shear force of polyelectrolyte molecular deposition film is more dependent on the speed than that of composite nanoparticle molecular deposition film. | GUO YanBao WANG DeGuo LIU ShuHai ZHANG SiWei | 2011 | Science China(Technological Sciences)2011，54，4： | 2 |
| 5 | Nanotribological behaviors of in situ nanoparticles doped molecular deposition films显示文摘The molecular deposition films of poly (diallyl dimethylammonium chloride) (PDDA) and poly (acrylicacid) (PAA) with Cu2+ on quartz and glass substrates were prepared in laboratory first, then different bilayers films were dipped into fresh Na2S aqueous solution. As a result, CuS nanoparticles were fabricated in multilayer molecular deposition films in situ. The structure and nanotribological properties of the composite films were analyzed by ultraviolet-visible (UV-visible) spectroscopy, XPS and atomic force microscope (AFM). It was found that the CuS nanoparticles were homogeneously distributed throughout the whole film. And these films had a much smaller friction force than their substrates and higher antiwear life than pristine PDDA/PAA molecular deposition films. The fluctuation and variation trend of the topography, hardness, and friction with the AFM indentation length were also investigated. | GUO YanBao WANG DeGuo ZHANG SiWei | 2009 | Chinese Science Bulletin2009，54，24： | 1 |
| 6 | Advances in studies of the tribological behavior of molecular deposition films显示文摘An overview of the advances in studies on tribology of molecular deposition(MD)films is presented here to summarize the studies of nanofrictional properties,adhesion,wear and mechanical behavior,as well as the molecular dynamics simulation of nanotribological properties of the film in the last decade.Some key research topics which need to be investigate further are addressed. | Xiao Yuqi Zhang Siwei Wang Deguo Gao Manglai | 2008 | Petroleum Science2008，5，4： | 1 |
| 7 | 显示文摘 | Zhang S W He Renyang Wang Deguo | 2001 | Journal of Materials Science2001，，36： | 1 |
| 8 | Nano-scratch study of molecular deposition films on silicon wafers using nano-indentation显示文摘 | Wang Deguo Zhang Siwei Gao Manglai | 2003 | Tribotest2003，9，3： | 1 |
| 9 | Tribological behaviors of composite molecular deposition films显示文摘 | Si-wei Zhang Dapeng Feng Deguo Wang | 2005 | Tribology International2005，38，1112： | 1 |
| 10 | Integration of root architecture,root nitrogen metabolism,and photosynthesis of‘Hanfu’apple trees under the cross-talk between glucose and IAA显示文摘Sugars and auxin have important effects on almost all phases of plant life cycle,which are so fundamental to plants and regulate similar processes.However,little is known about the effect of cross-talk between glucose and indole-3-acetic acid(IAA)on growth and development of apple trees.To examine the potential roles of glucose and IAA in root architecture,root nitrogen(N)metabolism and photosynthetic capacity in‘Hanfu’(Malus domestica),a total of five treatments was established:single application of glucose,IAA,and auxin polar transport inhibitor(2,3,5-triiodobenzoic acid,TIBA),combined application of glucose with TIBA and that of glucose with IAA.The combined application of glucose with IAA improved root topology system and endogenous IAA content by altering the mRNA levels of several genes involved in root growth,auxin transport and biosynthesis.Moreover,the increased N metabolism enzyme activities and levels of genes expression related to N in roots may suggest higher rates of transformation of nitrate(NO3--N)into amino acids application of glucose and IAA.Contrarily,single application of TIBA decreased the expression levels of auxin transport gene,hindered root growth and decreased endogenous IAA content.Glucose combined with TIBA application effectively attenuated TIBA-induced reductions in root topology structure,photosynthesis and N metabolism activity,and mRNA expression levels involved in auxin biosynthesis and transport.Taken together,glucose application probably changes the expression level of auxin synthesis and transport genes,and induce the allocation of endogenous IAA in root,and thus improves root architecture and N metabolism of root in soil with deficit carbon. | Bianbin Qi Xin Zhang Zhiquan Mao Sijun Qin Deguo Lv | 2023 | Horticultural Plant Journal2023，9，4： | 1 |
| 11 | Nano-scratch study of molecular deposition (MD) films on silicon wafer using nanoindentation^1显示文摘Experiment of the molecular deposition (MD) films with and without alkyl terminal de-posited on the silicon wafer were conducted by using nanoindentation. It was found that MD filmsand alkyl terminated MD films exhibit higher critical load (scratch resistance or adhesive strength)and lower coefficient of friction compared with the silicon substrate. Critical load (scratch resis-tance) increases with the number of layers, and coefficients of friction of those MD film with alkylterminal are still best for the same layer of MD film. | WANG Deguo ZHANG Siwei GAO Manglai University of Petroleum, Beijing 102200, China | 2001 | Science China Mathematics2001，44，S1： | 1 |
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