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| 1 | Relative pollen productivities of typical steppe species in northern China and their potential in past vegetation reconstruction显示文摘The Relative Pollen Productivities(RPPs)of common steppe species are estimated using Extended R-value(ERV)model based on pollen analysis and vegetation survey of 30 surface soil samples from typical steppe area of northern China.Artemisia,Chenopodiaceae,Poaceae,Cyperaceae,and Asteraceae are the dominant pollen types in pollen assemblages,reflecting the typical steppe communities well.The five dominant pollen types and six common types(Thalictrum,Iridaceae,Potentilla,Ephedra,Brassicaceae,and Ulmus)have strong wind transport abilities;the estimated Relevant Source Area of Pollen(RSAP)is ca.1000 m when the sediment basin radius is set at 0.5 m.Ulmus,Artemisia,Brassicaceae,Chenopodiaceae,and Thalictrum have relative high RPPs;Poaceae,Cyperaceae,Potentilla,and Ephedra pollen have moderate RPPs;Asteraceae and Iridaceae have low RPPs.The reliability test of RPPs revealed that most of the RPPs are reliable in past vegetation reconstruction.However,the RPPs of Asteraceae and Iridaceae are obviously underestimated,and those of Poaceae,Chenopodiaceae,and Ephedra are either slightly underestimated or slightly overestimated,suggesting that those RPPs should be considered with caution.These RPPs were applied to estimating plant abundances for two fossil pollen spectra(from the Lake Bayanchagan and Lake Haoluku)covering the Holocene in typical steppe area,using the'Regional Estimates of Vegetation Abundance from Large Sites'(REVEALS)model.The RPPs-based vegetation reconstruction revealed that meadow-steppe dominated by Poaceae,Cyperaceae,and Artemisia plants flourished in this area before 6500–5600 cal yr BP,and then was replaced by present typical steppe. | XU QingHai CAO XianYong TIAN Fang ZHANG ShengRui LI YueCong LI ManYue LI Jie LIU YaoLiang LIANG Jian | 2014 | Science China Earth Sciences2014，57，6： | 13 |
| 2 | Surface pollen assemblages of human-disturbed vegetation and their relationship with vegetation and climate in Northeast China显示文摘Pollen assemblages of 53 surface pollen samples from farmlands and wastelands in Northeast China were analyzed. Tree pollen percentages were usually higher than 30%, with Pinus (26.9%), Quercus (0.9%), Betula (0.9%) and Populus (0.7%) as the major types, and herb pollen percentages were usually higher than 50%, with weedy Poaceae (8.7%), Chenopodiaceae (7.1%), Artemisia (1.9%) and Compositae (3.5%) as the major taxa. Thus, the pollen assemblages were consistent with the regional vegetation compositions. However, there were differences in pollen assemblages among regions, especially among different geomorphological units. For example, in the mountains, there were more types of tree pollen and higher total percentages (average 42%) than in other areas, while cereal pollen percentages were lowest (11.2%). In the hills and high plains, herbs made up more than 60% of the pollens, with cereals (average 53.6%) the dominant type. In the low plains, pollen types were similar to those in the hills and high plains, but total pollen concentrations and the proportion of Concentricystes were much higher, while cereal pollen percentages were slightly lower (average 41.6%). Pollen assemblages in different land use types also differed. For example, in farmland, cereal pollen percentages were more than 40% and Chenopodiaceae was usually less than 2.5%, while in wasteland, weedy Poaceae was usually less than 10% and Chenopodiaceae was usually higher than 25%. Total pollen concentrations in farmland (average 3909 grains/g) were much lower than in wasteland (average 15074 grains/g). Redundancy analysis revealed that pollen assemblages were significantly negatively correlated with mean annual temperature (-0.73) and July mean temperature (-0.81) and significantly positively correlated with mean annual precipitation (0.48), indicating that pollen assemblages in the artificial or human-disturbed vegetation reflect regional climate well. Comparison of pollen assemblages in different areas of northern China showed that pollen concentrations reflect the intensities of human impact to some degree. For example, pollen concentrations decrease as human impacts increase in intensity. The cereal pollen proportions in farmland differed by area. In Northeast China, cereal pollen proportions were distinctly higher than in most other areas of northern China, suggesting differences in planting habits and climate. | LI ManYue LI YueCong XU QingHai PANG RuiMing DING Wei ZHANG ShengRui HE ZhiGuo | 2012 | Chinese Science Bulletin2012，57，5： | 10 |
| 3 | A novel procedure for pollen-based quantitative paleoclimate reconstructions and its application in China显示文摘Traditionally, the evaluation of pollen-based quantitative paleoclimate reconstructions focuses on the ability of calibration sets to infer present climatic conditions and/or the similarity between fossil and modern assemblages. Objective criteria for choosing the most appropriate climate parameter(s) to be reconstructed at a specific site are thus lacking. Using a novel approach for testing the statistical significance of a quantitative reconstruction using random environmental data, in combination with the advantageous large environmental gradients, abundant vegetation types and comprehensive modern pollen databases in China, we describe a new procedure for pollen-based quantitative paleoclimatic reconstructions. First, the most significant environmental variable controlling the fossil pollen assemblage changes is identified. Second, a calibration set to infer changes in this targeted variable is built up, by limiting the modern ranges of other environmental variables. Finally, the pollen-based quantitative reconstruction is obtained and its statistical significance assessed. This novel procedure was used to reconstruct the mean annual precipitation(Pann) from Gonghai Lake in the Lvliang Mountains, and Tianchi Lake in the Liupan Mountains, on the eastern and western fringe of the Chinese Loess Plateau, respectively. Both Pann reconstructions are statistically significant(p<0.001), and a sound and stable correlation relationship exists in their common period, showing a rapid precipitation decrease since 3300 cal yr BP. Thus, we propose that this procedure has great potential for reducing the uncertainties associated with pollen-based quantitative paleoclimatic reconstructions in China. | CHEN JianHui LV FeiYa HUANG XiaoZhong H.John B.BIRKS Richard J.TELFORD ZHANG ShengRui XU QingHai ZHAO Yan WANG HaiPeng ZHOU AiFeng HUANG Wei LIU JianBao WEI GuoYing | 2017 | Science China Earth Sciences2017，60，11： | 6 |
| 4 | Spatial patterns of vegetation and climate in the North China Plain during the Last Glacial Maximum and Holocene climatic optimum显示文摘Reconstructing the spatial patterns of regional climate and vegetation during specific intervals in the past is important for assessing the possible responses of the ecological environment under future global warming scenarios. In this study, we reconstructed the history of regional vegetation and climate based on six radiocarbon-dated pollen records from the North China Plain. Combining the results with existing pollen records, we reconstruct the paleoenvironment of the North China Plain during the Last Glacial Maximum(LGM) and the Holocene Climatic Optimum(HCO). The results show that changes in the regional vegetation since the LGM were primarily determined by climatic conditions, the geomorphic landscape and by human activity.During the LGM, the climate was cold and dry;mixed broadleaf-coniferous forest and deciduous-evergreen broadleaf forest developed in the southern mountains, and cold-resistant coniferous forest and mixed broadleaf-coniferous forest were present in the northern mountains. The forest cover was relatively low, with mesophytic and hygrophilous meadow occupying the southern part of the plain, and temperate grassland and desert steppe were distributed in the north;Chenopodiaceae-dominated halophytes grew on the exposed continental shelf of the Bohai Sea and Yellow Sea. During the HCO, the climate was warm and wet;deciduous broadleaf forest and deciduous-evergreen broadleaf forest, with subtropical species, developed in the southern mountains, and deciduous broadleaf forest with thermophilic species was present in northern mountains. Although the degree of forest cover was greater than during the LGM, the vegetation of the plain area was still dominated by herbs, while halophytes had migrated inland due to sea level rise. In addition, the expansion of human activities, especially the intensification of cultivation,had a significant influence on the natural vegetation. Our results provide data and a scientific basis for paleoclimate modelling and regional carbon cycle assessment in north China, with implications for predicting changes in the ecological environment under future global warming scenarios. | Manyue LI Shengrui ZHANG Qinghai XU Jule XIAO Ruilin WEN | 2019 | Science China Earth Sciences2019，62，8： | 4 |
| 5 | Study on growing thick AlGaN layer on c-plane sapphire substrate and free-standing GaN substrate显示文摘In this study,the thick AlGaN epilayers have been grown on the c-plane sapphire substrate and the free-standing GaN substrate using low-temperature AlN nucleation layers by low-pressure metal-organic chemical vapor deposition(LPMOCVD).High resolution X-ray diffraction(HRXRD),atom force microscopy(AFM),scanning electron microscopy(SEM),photoluminescence(PL) and Raman scattering measurements have been employed to study the crystal quality,threading dislocation density,surface morphology,optical properties and phonon properties of thick AlGaN epifilms.The results indicate that AlGaN epifilms crystal quality can be improved greatly when grown on the free-standing GaN substrate.We calculated the threading dislocation density and found that thick AlGaN epifilm grown on the free-standing GaN substrate is much lower in total threading dislocation density than that grown on the sapphire substrate,although the surface morphology is rougher than that of sapphire substrate. | WANG DangHui ZHOU Hao ZHANG JinCheng XU ShengRui ZHANG LinXia MENG FanNa AI Shan HAO Yue | 2012 | Science China(Physics,Mechanics & Astronomy)2012，55，12： | 3 |
| 6 | Proton irradiation effects on HVPE GaN显示文摘GaNs grown by hydride vapor phase epitaxy(HVPE) were irradiated by protons with different fluences.The changes of surface topography of as-grown and irradiated samples were characterized by atomic force microscopy(AFM).The crystal quality and optical properties of GaN films were examined by the variations of the micro-Raman and photoluminescence(PL) spectra with proton fluence.It was observed that the surface became a little more rough after irradiation.The Raman spectra indicated that the strain of materials and carrier concentration were not affected by the proton injection.The full-width at half-maximum(FWHM) of E 2 high phonon mode narrowed,which was consistent with the FWHM of PL near-band-edge emission(BE).The spectra of yellow luminescence and blue luminescence normalized to the intensity of BE demonstrated a little increase of Ga vacancy and a large decrease of O N,which may be the main reason for the change of optical properties. | LU Ling HAO Yue ZHENG XueFeng ZHANG JinCheng XU ShengRui LIN ZhiYu AI Shan MENG FanNa | 2012 | Science China(Technological Sciences)2012，55，9： | 2 |
| 7 | Mixing of Enriched Lithospheric Mantle-Derived and Crustal Magmas: Evidence from the Habo Cenozoic Porphyry in Western Yunnan显示文摘New zircon U–Pb ages, whole-rock geochemistry and zircon Hf isotopes from the Habo porphyry Western Yunnan, China, were determined to provide constraints on the timing of uplift of the Eastern Tibetan Plateau. The intrusive rocks consist of shoshonitic porphyry(syenite porphyry and monzonite porphyry). Zircon laser ablation inductively coupled plasma mass spectrometry(LA-ICPMS) U–Pb dating indicates coeval emplacement ages of ~35 Ma. The porphyries have alkaline affinities, enrichment in large ion lithophile elements(LILEs) and light rare earth elements(LREEs)(e.g., Rb, Th, U, Pb), with depletion of high field strength elements(HFSEs)(e.g., Nb, Ti, Ta) and weak Eu anomalies. They display uniform Lu–Hf isotopic compositions with negative zircon εHf(t) values ranging from-3.9 to-0.6. The chemical characteristics of the syenite porphyries indicated that they most likely originated from the lower crust, with mantle-derived material involved in their generation. Geochemically, the monzonite porphyries are similar to the syenite porphyries; however, the lower MgO contents suggest that they were produced by different degrees of partial melting of the same lower crust source. Combined with the geochemical and isotopic data in this paper, imply that the alkali-rich porphyries of the Habo polymetallic deposit were derived from the partial melting of lower crust, enriched by mantle magma, formed in a conversion stage from stress extrusion(a strike-slip shear process) to local stress relaxation(a strike-slip pull-apart process) at the Ailaoshao tectonic zone. | XIA Bin LU Ye YUAN Yajuan CHEN Weiyan ZHANG Xiao XU Chi YU Shengrui WAN Zhifeng | 2018 | Acta Geologica Sinica(English Edition)2018，92，5： | 2 |
| 8 | Investigation of β-Ga2O3 films and β-Ga2O3/GaN heterostructures grown by metal organic chemical vapor deposition显示文摘In this work,(-201)β-Ga2O3 films are grown on GaN substrate by metal organic chemical vapor deposition(MOCVD).It is revealed that theβ-Ga2O3 film grown on GaN possesses superior crystal quality,material homogeneity and surface morphology than the results of common heteroepitaxialβ-Ga2O3 film based on sapphire substrate.Further,the relevance between the crystal quality of epitaxialβ-Ga2O3 film and theβ-Ga2O3/GaN interface behavior is investigated.Transmission electron microscopy result indicates that the interface atom refactoring phenomenon is beneficial to relieve the mismatch strain and improve the crystal quality of subsequentβ-Ga2O3 film.Moreover,the energy band structure ofβ-Ga2O3/GaN heterostructure grown by MOCVD is investigated by X-ray photoelectron spectroscopy and a large conduction band offset of 0.89 eV is obtained.The results in this work not only convincingly demonstrate the advantages ofβ-Ga2O3 films grown on GaN substrate,but also show the great application potential of MOCVDβ-Ga2O3/GaN heterostructures in microelectronic applications. | YaChao Zhang YiFan Li ZhiZhe Wang Rui Guo ShengRui Xu ChuanYang Liu ShengLei Zhao JinCheng Zhang Yue Hao | 2020 | Science China(Physics,Mechanics & Astronomy)2020，63，11： | 2 |
| 9 | Environmental magnetic studies of sediment cores from Gonghai Lake: implications for monsoon evolution in North China during the late glacial and Holocene显示文摘 | Fahu Chen Jianbao Liu Qinghai Xu Yuecong Li Jianhui Chen Haitao Wei Qingsong Liu Zongli Wang Xianyong Cao Shengrui Zhang | 2013 | Journal of Paleolimnology2013，，3： | 1 |
| 10 | Study on stratigraphic age, climate changes and environment background of Houjiayao site in Nihewan Basin显示文摘 | Li Zhengtao Xu Qinghai Zhang Shengrui | 2014 | Quaternary International2014，349，： | 1 |
| 11 | Pollen assemblages of cultivated vegetation in central and southern Hebei Province显示文摘从在 Hebei 省的中央、南部的部分的栽培植被的不同类型的 82 件表面土壤花粉样品上的学习显示从在平原的农田的花粉集合从附近的山有不仅他们的自己的工厂类型,而且花粉部件。树木的花粉百分比和集中(由 Pinus 统治了) 从在山区的农田比在平原的那些高,并且它与增加的距离逐渐地减少离开山。作为一个例子在 Taihang 山拿 Pinus 花粉,它的内容是 20%30% , 10%20% , 20%30% 并且低于 16% 分别地为来自离开东方 Taihang 山的 050, 50100, 100150 和超过 150 km 的区域的样品。在中央平原的 Pinus 花粉比例的增加可能与 fohn 效果有关。到在 Hebei 省的平原的从山的 AP 的空间变化可能类似于由在早历史的时期的人的活动的森林清理。灌木状的花粉比例在山并且在平原是小的,但是他们的主要部件是不同的。Elaeagnaceae, Corylus, Ostryopsis 和 Oleaceae 在山区是普通的,当在平原有 Rosaceae 和 Vitaceae 的相对高的内容时。在平原(大约 60%) 的植物内容在山,谷物和十字花科花粉百分比分别地更高在之中是 5% 和 2% 比那高是 15% 。在平原的 Artemisia 花粉百分比在山是比那低的。因为人的活动在平原与那相比在山是更弱的,一般趋势是 Chenopodiaceae 花粉逐渐地从山增加到平原,反映人的活动的涨的紧张。在山的 Selaginella sinensis 的蕨纲植物孢子在平原比那高,但是它仍然在平原到达到大约 7% 。Selaginella sinensis 的蕨纲植物孢子不是容易的被风散布,显示那些可以被从在平原的免职期间的山的河水在平原的表面土壤带。 | PANG Ruiming | 2011 | Journal of Geographical Sciences2011，21，3： | 1 |
| 12 | 1.7 kV normally-off p-GaN gate high-electron-mobility transistors on a semi-insulating SiC substrate显示文摘A study of 1.7 kV normally-off p-GaN gate high-electron-mobility transistors(HEMTs)on SiC substrates is presented.The fabricated p-GaN HEMT with a gate-drain spacing LGD=5μm exhibited a threshold voltage of 1.10 V,a maximum drain current of 235 mA/mm,an ON/OFF ratio of 10^(8),and a breakdown voltage of 440 V.Benefiting from the semi-insulating and high-critical-electric-field substrate,the p-GaN HEMT with LGD=23μm achieved the remarkably high breakdown voltage of 1740 V with substrate grounded.This breakdown voltage is very high compared with the reported values for p-GaN HEMTs on silicon substrates with substrate grounded.The vertical breakdown voltage for the p-GaN-on-SiC material exceeded 3 kV with substrate grounded.In addition,the maximum drain current at 500 K was 48%of that at 300 K with a negligible threshold voltage shift.These results indicate the substantial potential of p-GaN gate HEMTs on SiC substrates for high-voltage power applications. | Shenglei ZHAO Jincheng ZHANG Yachao ZHANG Lansheng FENG Shuang LIU Xiufeng SONG Yixin YAO Jun LUO Zhihong LIU Shengrui XU Yue HAO | 2023 | Science China(Information Sciences)2023，66，2： | 1 |
| 13 | Quantitative indicative significance of pollen assemblages on vegetation coverage in deciduous Quercus forest in the central Loess Plateau, China显示文摘We compared the pollen assemblages of surface moss samples and corresponding vegetation inventory data from 34 sites in the Huangling region of the central Loess Plateau. Our aims were to determine the characteristics of the pollen assemblages from the deciduous broadleaved forest climax community and its significance in terms of vegetation type and species composition. The pollen assemblages are dominated by woody plants such as Quercus(42% of total terrestrial pollen),Betula(16%) and Pinus(12%), with minor differences between different plant communities. The pollen assemblages of individual sampling sites differed from the vegetation composition within the 0–100 m scope and were more similar to the vegetation coverage within the 0–1000 m scope. This indicates that the surface pollen assemblages mainly reflect the comprehensive information from the vegetation composition of a large area, rather than the vegetation composition close to the sampling site. The contents of Quercus, Betula and Pinus pollen are high, and close to their vegetation coverage; whereas the contents of deciduous broadleaved arbor taxa(such as Malus and Acer) are lower, but their corresponding regional vegetation cover is higher. This suggests that the vegetation information conveyed by poorly-represented pollen taxa should be considered when interpreting stratigraphic pollen assemblages. Using the observed quantitative relationships between pollen and vegetation of the main taxa, we reconstructed the regional vegetation composition in the Gonghai Lake area of the northeastern Loess Plateau during the middle Holocene(7300–5000 yr BP). The results indicated that Quercus-dominated deciduous broadleaved forest climax community developed in the mountains surrounding the lake. | Yuanhao SUN Shengrui ZHANG Qinghai XU Yiwen LI Wei SHEN Tao WANG Zhongze ZHOU Ruchun ZHANG | 2019 | Science China Earth Sciences2019，62，6： | 1 |
| 14 | Reaction mechanism and kinetics of Criegee intermediate and hydroperoxymethyl formate显示文摘The reaction mechanism and kinetics of the simplest Criegee intermediate CH_(2)OO reaction with hydroperoxymethyl formate(HPMF)was investigated at high-level quantum chemistry calculations.HPMF has two reactive functional groups,-C(O)OH and-OOH.The calculated results of thermodynamic data and rate constants indicated that the insertion reactions of CH_(2) OO with-OOH group of HPMF were more favorable than the reactions of CH_(2)OO with-C(O)OH group.The calculated overall rate constant was 2.33×10^(−13) cm^(3)/(moleculesec)at 298 K and the rate constants decreased as the temperature increased from 200 to 480 K.In addition,we also proved the polymerization reaction mechanism between CH_(2)OO and-OOH of HPMF.This theoretical study interpreted the previous experimental results,and supplied the structures of the intermediate products that couldn’t be detected during the experiment. | Meifang Chen Shengrui Tong Zhen Wang Weiran Li Yanyong Xu Sufan Wang Maofa Ge | 2021 | Journal of Environmental Sciences2021，33，7： | 0 |
| 15 | Application of nano-patterned InGaN fabricated by selfassembled Ni nano-masks in green InGaN/GaN multiple quantum wells显示文摘The nano-patterned InGaN film was used in green InGaN/GaN multiple quantum wells(MQWs)structure,to relieve the unpleasantly existing mismatch between high indium content InGaN and GaN,as well as to enhance the light output.The different self-assembled nano-masks were formed on InGaN by annealing thin Ni layers of different thicknesses.Whereafter,the InGaN films were etched into nano-patterned films.Compared with the green MQWs structure grown on untreated InGaN film,which on nano-patterned InGaN had better luminous performance.Among them the MQWs performed best when 3 nm thick Ni film was used as mask,because that optimally balanced the effects of nano-patterned InGaN on the crystal quality and the light output. | Ruoshi Peng Shengrui Xu Xiaomeng Fan Hongchang Tao Huake Su Yuan Gao Jincheng Zhang Yue Hao | 2023 | Journal of Semiconductors2023，44，4： | 0 |
| 16 | Enhancement of optical characteristic of InGaN/GaN multiple quantum-well structures by self-growing air voids显示文摘InGaN/GaN multiple quantum-well(MQW) structures with a wavelength range of green were successfully grown on a c-plane GaN template with SiO_2 stripe patterns along the [11-20] and [1-100] directions as a mask. The surface morphologies of both samples were investigated using scanning electron microscopy and demonstrated anisotropic growth characteristics of GaN. The optical characteristics were investigated using Raman spectra and photoluminescence(PL). The InGaN/GaN MQW structure grown on the GaN template with SiO_2 stripes along the [1-100] orientation exhibited less stress and higher PL intensity.Transmission electron microscopy results indicated that portions of MQWs were grown on an inclined semipolar plane, and air voids occurred only when the direction of the mask stripe was along the [1-100] orientation. The enhancement of the optical characteristic was due to the air-void structure and inclined semipolar quantum-well sidewalls. | DU JinJuan XU ShengRui PENG RuoShi FAN XiaoMeng ZHAO Ying TAO HongChang SU HuaKe NIU MuTong ZHANG JinCheng HAO Yue | 2021 | Science China(Technological Sciences)2021，64，7： | 0 |
| 17 | Investigation of etching method for fabricating deep through holes on ultra-high resistivity silicon显示文摘In this paper,the etching characteristics of the ultra-high resistivity silicon(UHRS) by using the Bosch process were investigated.The experimental results indicated that the sulfur hexafluoride flux,the temperature of the substrate,the platen power and the etching intermittence had important influence on the etching rate and the etching morphology of the UHRS.The profiles and morphologies of sidewall were characterized with scanning electron microscopy(SEM).By using an improved three-stage Bosch process,380-μm deep through holes were fabricated on the UHRS with the average etching rate of about 3.14 μm/min.Meanwhile,the fabrication mechanism of deep through holes on the UHRS by using the three-stage Bosch process was illustrated on the basis of the experimental results. | Lin Du Shengrui Xu Ying Wang Ling Lü Jincheng Zhang Yue Hao | 2017 | Journal of Semiconductors2017，38，5： | 0 |
| 18 | AGRICULTURAL GREEN DEVELOPMENT IN THE ERHAI LAKE BASIN-THE WAY FORWARD显示文摘Pollution of high-altitude lake basins by agriculture and rural activities,and the control of this pollution,have received increasing attention from academic research and government policy in China.Series of restrictions and regulations have been implemented to protect the surface,water quality.These restrictions and regulations have greatly impacted and transformed the agricultural systems and rural livelihoods surrounding these lake basins.Using Erhai Lake basin in Yunnan Province as a case study,three main challenges were identified for concurrently decreasing pollution in the lake and increasing farmer income.It is contended that scientifically-sound environmental protection policies and agricultural green development practices are key to reversing the current situation.This will help to protect the lake from pollution while smallholder farmers will be able to produce healthy food in an environmentally sustainable manner,and with a fair remuneration for all the services farmers providetothe society. | Yong HOU Wen XU Wen-Feng CONG Kemo JIN Jiuliang XU Hao YING Shengrui WANG Hu SHENG Linzhang YANG Wenqi MA Oene OENEMA Zhengxiong ZHAO Fusuo ZHANG | 2023 | Frontiers of Agricultural Science and Engineering2023，10，4： | 0 |
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