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1Geochemical characteristics of pore water in shallow sediments from Shenhu area of South China Sea and their significance for gas hydrate occurrence显示文摘The Shenhu area is one of the promise target areas for marine gas hydrate exploration in the northern margin of the South China Sea.Pore water samples were collected from two piston cores (8.75 and 8.52 m) in site HS-A and site HS-B in the Shenhu area,and their major anion and cation contents and trace element contents have been analyzed in this study.Cl- concentrations in pore waters are similar to the seawater value and no systematic change along depth profiles has been found for the Cl- content in both sites.In site HS-A,the SO 2- 4 contents show a limited range in pore waters from 0 to 3 m depths,but a dramatic decrease is documented in depth below 3 m.Other elements such as Ca 2+,Mg 2+ and Sr 2+ show similar variation patterns as the SO 2- 4,i.e.,no variation in 0-3 m,but large decrease in depth below 3 m.In site HS-B,both the SO 4 and Ca 2+,Mg 2+ and Sr 2+ display a decrease pattern along the depth profile,but in 0-3 m the variation is less significant than those in depth below 3 m.In both sites HS-A and HS-B,I contents show a dramatic increase along depth profiles.Calculations show that the SMI depths are very shallow (10 and 11 m) in both sites,and the sulfate flux and I flux are very high.These geochemical characteristics and anomalies at Shenhu are quite similar to those found in other gas hydrate locations in the world,and a genetic link is suggested to be related to the gas hydrate occurrence at depths in the study area.In summary,we suggest that combined geochemical parameters in shallow sediment pore waters are useful indicators to indicate the gas hydrate occurrence at depths.YANG Tao JIANG ShaoYong GE Lu YANG JingHong WU NengYou ZHANG GuangXue LIU Jian 2010Chinese Science Bulletin2010,55,8:30
2Cadmium accumulation and tolerance of two castor cultivars in relation to antioxidant systems显示文摘To investigate the effects of Cd on tolerance and antioxidant activities of castor, two different castor(Ricinus communis L.) cultivars(Zibo No. 5 and Zibo No. 8) were used for a hydroponic experiment(0, 1 and 2 mg/L Cd) and a pot experiment using Cd-contaminated soil(34 mg/kg) with the addition of ethylenedinitrilotetraacetic acid(EDTA). The results indicated that there were significant differences between the two cultivars with respect to Cd uptake in shoots(113–248 mg/kg for Zibo No. 5 and 130–288 mg/kg Zibo No. 8), biomass tolerance indexes(64.9%–74.6% for Zibo No. 5 and 80.1%–90.9% for Zibo No. 8) in the hydroponic experiment and survival rates(0% for Zibo No. 5 and 100% for Zibo No. 8)determined by the addition of EDTA in the pot experiment, suggesting that Zibo No. 8 has higher tolerance than Zibo No. 5. Moreover, the castor cultivars have low bioconcentration factors(4.80% for Zibo No. 5 and 5.43% for Zibo No. 8) and low translocation factors(<1%).Consequently, Zibo No. 8 can participate in Cd phytostabilization in highly Cd-polluted areas. The results indicated that glutathione(GSH) as a non-enzymatic antioxidant, and antioxidant enzymes including superoxide dismutase(SOD), catalase(CAT) and guaiacol peroxidase(GPX), were cultivar- and dose-dependent. The higher tolerance of Zibo No. 8compared with Zibo No. 5 can be attributed to the higher GSH levels in the root and higher GPX activity in the leaf.Hanzhi Zhang Qingjun Guo Junxing Yang Tongbin Chen Guangxu Zhu Marc Peters Rongfei Wei Liyan Tian Chunyu Wang Deyun Tan Jie Ma Gangming Wang Yingxin Wan 2014Journal of Environmental Sciences2014,26,10:15
3Geochemistry of pore waters from HQ-1PC of the Qiongdongnan Basin, northern South China Sea, and its implications for gas hydrate exploration显示文摘The Qiongdongnan Basin is one of the target areas for marine gas hydrate exploration in the northern margin of the South China Sea. In this study, major anion (e.g., SO42 , Cl, Br, I), cation (e.g., Ca, Mg, K, Na), and trace element (e.g., Sr, Ba) con- centrations of pore water samples collected from site HQ-1PC in the Qiongdongnan Basin were analyzed. These geochemical data suggest that the process of AOM (Anaerobic Oxidation of Methane) is dominant in sulfate-reduction zone in this site due to high upwelling iodine flux and strong microbial activities. The iodine-rich fluids, which may carry methane for the gas hydrate formation, pass through the gas hydrate stability zone, mix with brine released during gas hydrate formation, and cause the geochemical anomalies observed at site HQ-1PC. The pore water geochemical characteristics and anomalies in the Qiongdongnan Basin are quite similar to those found in other gas hydrate locations in the Shenhu area in the northern South China Sea, and a genetic link is suggested with the possibility of gas hydrate occurrence in the study area.YANG Tao JIANG ShaoYong GE Lu YANG JingHong WU NengYou ZHANG GuangXue LIU Jian CHEN DaoHua 2013Science China Earth Sciences2013,56,4:14
4Traditional Chinese medicine in COVID-19显示文摘COVID-19 pandemic caused by severe acute respiratory syndrome coronavirus 2(SARSCo V-2)has spread across the globe,posing an enormous threat to public health and safety.Traditional Chinese medicine(TCM),in combination with Western medicine(WM),has made important and lasting contributions in the battle against COVID-19.In this review,updated clinical effects and potential mechanisms of TCM,presented in newly recognized three distinct phases of the disease,are summarized and discussed.By integrating the available clinical and preclinical evidence,the efficacies and underlying mechanisms of TCM on COVID-19,including the highly recommended three Chinese patent medicines and three Chinese medicine formulas,are described in a panorama.We hope that this comprehensive review not only provides a reference for health care professionals and the public to recognize the significant contributions of TCM for COVID-19,but also serves as an evidence-based in-depth summary and analysis to facilitate understanding the true scientific value of TCM.Ming Lyu Guanwei Fan Guangxu Xiao Taiyi Wang Dong Xu Jie Gao Shaoqin Ge Qingling Li Yuling Ma Han Zhang Jigang Wang Yuanlu Cui Junhua Zhang Yan Zhu Boli Zhang 2021Acta Pharmaceutica Sinica B2021,11,11:14
5Efficient InGaN-based yellow-light-emitting diodes显示文摘Realization of efficient yellow-light-emitting diodes(LEDs) has always been a challenge in solid-state lighting.Great effort has been made, but only slight advancements have occurred in the past few decades. After comprehensive work on InGaN-based yellow LEDs on Si substrate, we successfully made a breakthrough and pushed the wall-plug efficiency of 565-nm-yellow LEDs to 24.3% at 20 A∕cm^2 and 33.7% at 3 A∕cm^2. The success of yellow LEDs can be credited to the improved material quality and reduced compressive strain of InGaN quantum wells by a prestrained layer and substrate, as well as enhanced hole injection by a 3 D pn junction with V-pits.FENGYI JIANG JIANLI ZHANG LONGQUAN XU JIE DING GUANGXU WANG XIAOMING WU XIAOLAN WANG CHUNLAN MO ZHIJUE QUAN XING GUO CHANGDA ZHENG SHUAN PAN JUNLIN LIU 2019Photonics Research2019,7,2:13
6Frequency comparative study of coal-fired fly ash acoustic agglomeration显示文摘Particulate pollution is main kind of atmospheric pollution.The fine particles are seriously harmful to human health and environment.Acoustic agglomeration is considered as a promising pretreatment technology for fine particle agglomeration.The mechanisms of acoustic agglomeration are very complex and the agglomeration efficiency is affected by many factors.The most important and controversial factor is frequency.Comparative studies between high-frequency and low-frequency sound source to agglomerate coal- fired fly ash were carried out to investigate the influence of frequency on agglomeration efficiency.Acoustic agglomeration theoretical analysis,experimental particle size distributions (PSDs) and orthogonal design were examined.The results showed that the 20 kHz high-frequency sound source was not suitable to agglomerate coal-fired fly ash.Only within the size ranging from 0.2 to 0.25 μm the particles agglomerated to adhere together,and the agglomerated particles were smaller than 2.5 μm.The application of low-frequency (1000-1800 Hz) sound source was proved as an advisable pretreatment with the highest agglomeration efficiency of 75.3%,and all the number concentrations within the measuring range decreased.Orthogonal design L16 (4) 3 was introduced to determine the optimum frequency and optimize acoustic agglomeration condition.According to the results of orthogonal analysis,frequency was the dominant factor of coal-fired fly ash acoustic agglomeration and the optimum frequency was 1400 Hz.Jianzhong Liu Jie Wang Guangxue Zhang Junhu Zhou Kefa Cen 2011Journal of Environmental Sciences2011,23,11:13
7Effect of ammonium on nitrous oxide emission during denitrification with different electron donors显示文摘Nitrous oxide(N2O) emission during denitrification is receiving intensive attention due to its high potential to cause greenhouse effects.In this study,denitrifiers were acclimated in sequencing batch reactors with methanol or acetate as the electron donor and nitrate as the electron acceptor.The effects of ammonium on N2O emission were examined in batch experiments with various electron donors.With the addition of ammonium,N2O emission increased under all the examined conditions compared to experiments without ammonium addition.With different electron donors,the highest ratio of N2O emission to the removed oxidized nitrogen was 0.70% for methanol,5.34% for acetate,and 34.79% for polyhydroxybutyrate.Guangxue Wu Xiaofeng Zhai Chengai Jiang Yuntao Guan 2013Journal of Environmental Sciences2013,25,6:12
8Glycerol ether biomarkers and their carbon isotopic compositions in a cold seep carbonate chimney from the Shenhu area, northern South China Sea显示文摘At modern cold seeps,the anaerobic oxidation of methane(AOM)is the dominant pathway for methane consumption in marine sediments.AOM,which is mediated by a consortium of methane oxidizing archaea and sulfate reducing bacteria,is proposed to be responsible for authigenic carbonate formation.A methane-derived carbonate chimney was collected from the Shenhu area, northern South China Sea.The membrane lipids and their very low carbon isotopic compositions(?115‰to?104‰)in the Shenhu chimney suggest the presence of an AOM process.Three specific archaeal and bacterial biomarkers were detected,including Ar,DAGE 1f,and monocyclic MDGD.Their strongly depleted??13C values(?115‰to?104‰),which are lower than those of the normal marine lipids in sediments,reveal biogenic methane as their origin.The carbonate deposits exhibiting a chimney structure indicate that a vigorous methane-rich fluid expulsion may have occurred at the seafloor.We propose that the decomposition of gas hydrates at depth is the likely cause of seepage and cold seep carbonate formation in the Shenhu area.GE Lu JIANG ShaoYong YANG Tao YANG JingHong WU NengYou ZHANG GuangXue LIU Jian 2011Chinese Science Bulletin2011,56,16:12
9Controlling factors for gas hydrate occurrence in Shenhu area on the northern slope of the South China Sea显示文摘Temperature and pressure on seafloor of the northern slope in the South China Sea are suitable for gas hydrate formation, but bottom simulation reflector (BSR), an indication of gas hydrate occurrence, only occurred in limited areas of the slope. Drillings in the BSR-distributed area (the District S) on the northern slope of the South China Sea suggested that gas hydrate only occurred at Sites SH2, SH3, and SH7 with high saturation (up to 20%-40%), and there is no hydrate at Sites SH1 and SH5 although the distance between SH1 to SH3 is only 500m. In this paper, we investigated seafloor gradient, fault development, temperature, and pressure in the District S on the northern slope of the South China Sea to understand the possible factors con- trolling BSR distribution and gas hydrate occurrence. The District S is a structurally fractured continental slope zone and its seafloor gradient varied greatly. The BSR-occurred areas have an average gradient of 19.89×10 2 whereas the BSR-free zone has the average gradient of 10.57×10 2 . The calculated relative structural intensities from fault densities and displacements show that the BSR-distributed areas tend to occur in the areas with a moderately high structural intensity, where faults frequently developed close to the seafloor that are possibly favored for lateral migration of gases. On the basis of temperatures and pressures at drilling sites, hydrate-occurred Sites SH2, SH3, and SH7 are located within the thermodynamically stable area for methane hydrate, and hydrate-absent Sites SH1 and SH5 are out of the thermodynamically stable area for methane hydrate formation, suggesting that both BSR and the thermodynamic stability are necessary for hydrate occurrence in the subsurface.WANG HongBin YANG ShengXiong WU NengYou ZHANG GuangXue LIANG JinQiang CHEN DuoFu 2013Science China Earth Sciences2013,56,4:10
10Activating ZnO nanorod photoanodes in visible light by Cu ion implantation显示文摘Meng Wang Feng Ren Guangxu Cai Yichao Liu Shaohua Shen Liejin Guo 2014Nano Research2014,7,3:9
11Biological mechanism of controlling cotton aphid (Homoptera: aphididae) by the marginal alfalfa zone surrounding cotton field显示文摘At the beginning stage of cotton aphids (Aphis gossypii Glover) invading the cotton field, large numbers of insects have accumulated in the marginal alfalfa (Medicago sativa L.) zone surrounding it. They are 6.94 times (excluded natural enemies) as many as the aphids in cotton field. Most of these insects are Therioaphid maculata (Buckton), and occur in fields 10-15 d earlier than cotton aphids. Consequently, abundant natural enemies have bred in alfalfa zone when cotton aphids increase rapidly in cotton fields in the middle of June in Xinhe County, Xinjiang Autonomous Region. The total number of the major natural enemies, including Coccinellids, Chrysopids and Syphid flies in alfalfa zone, is 13.65 times that in cotton field within the same acreage of fields. At this period, it is very effective to force the natural enemies from the alfalfa zone into the nearby cotton field to control the rapid increase of cotton aphid population by cutting the alfalfa stands.ZHANG Runzhi LIANG Hongbin TIAN Changyan ZHANG Guangxue 2000Chinese Science Bulletin2000,45,4:9
12Nitrifiers activity and community characteristics under stress conditions in partial nitrification systems treating ammonium-rich wastewater显示文摘Long-term exposure of nitrifiers to high concentrations of free ammonia(FA) and free nitrous acid(FNA) may affect nitrifiers activity and nitrous oxide(N_2O) emission.Two sequencing batch reactors(SBRs) were operated at influent ammonium nitrogen(NH_4-N) concentrations of 800 mg/L(SBRH) and 335 mg/L(SBRL),respectively.The NH_4-N removal rates in SBRHand SBRLwere around 2.4 and 1.0 g/L/day with the nitritation efficiencies of 99.3% and 95.7%,respectively.In the simulated SBR cycle,the N_2O emission factors were 1.61% in SBRH and 2.30% in SBRL.N_2O emission was affected slightly by FA with the emission factor of0.22%–0.65%,while N_2O emission increased with increasing FNA concentrations with the emission factor of 0.22%–0.96%.The dominant ammonia oxidizing bacteria(AOB) were Nitrosomonas spp.in both reactors,and their relative proportions were 38.89% in SBRHand13.36% in SBRL.Within the AOB genus,a species(i.e.,operational taxonomic unit [OTU] 76) that was phylogenetically identical to Nitrosomonas europaea accounted for 99.07% and 82.04% in SBRHand SBRL,respectively.Additionally,OTU 215,which was related to Nitrosomonas stercoris,accounted for 16.77% of the AOB in SBRL.Jia Miao Qidong Yin Tomoyuki Hori Tomo Aoyagi Hiroshi Habe Guangxue Wu 2018Journal of Environmental Sciences2018,30,11:8
13Sea surface temperature record from the north of the East China Sea since late Holocene显示文摘Using the alkenone paleotemperature index U k 37′, a high-resolution sea surface temperature (SST) record since 3600 a BP was reconstructed from the mud area in the north of the East China Sea. Combining with the grain size distribution curve of sensitive grain size group, which may reflect the East Asia Winter Monsoon activity, the palaeoenvironmental evolution cycle throughout the late Holocene in the area was obtained. The marine environment evolution during the last 3600 years displays a five-stage trend. (1) Temperature descending period from 0.85 cal. ka BP to present. The maximum temperature decrease amplitude is 2℃. The winter monsoon intensified and ‘Little Ice Age’ were recorded in this period. (2) Warming period from 1.90 to 0.85 cal. ka BP. The mean temperature increase amplitude is 0.8℃. The Sui-Tang warming period was recorded at about 0.85―1.35 cal. ka BP and a prominent cooling event was recorded at 1.4 cal. ka BP in this period. (3) Temperature descending period from 2.55 to 1.90 cal. ka BP. Temperature cooling amplitude is 0.9℃. This period is coincident with an integrated temperature circle recorded in the Antarctic ice core, with the temperature changes from a slow cooling stage to a rapid warming stage. (4) Temperature comparatively stable with a little ascending period from 3.2 to 2.55 cal. ka BP. Temperature warming amplitude is 0.3℃. This period is coincident with the temperature fluctuant ascending period recorded in Antarctic ice core. (5) Temperature comparatively stable with little descending period from 3.6 to 3.2 cal. ka BP. This period corresponds with the temperature fluctuant cooling period recorded in Antarctic ice core. Basically, those five periods were coincident with the Antarctic ice core record. During the global cooling stage, the SST change in the continental shelf sea can be adjusted simultaneously.LI GuangXue SUN XiaoYan LIU Yong BICKERT Torsten MA YanYan 2009Chinese Science Bulletin2009,54,23:7
14Experimental analysis on air-to-water sound transmission loss in shallow water显示文摘The research of propagation characteristics of air-to-water sound transmission is of great importance to the detection of aerial targets from underwater.In order to study the propagation characteristics of air-to-water sound transmission in shallow water,State Key Laboratory of Acoustics,Institute of Acoustics,conducted an experiment in the South China Sea in March,2013.During the experiment,multi-frequency signals transmitted by a hooter hung on a research ship were received by an underwater hydrophone,and the distance between the hooter and the hydrophone was from 2.4 km to 9.8 km approximately.Through analyzing experimental data in this work,the experimental air-to-water transmission loss at frequencies128 Hz and 256 Hz is estimated up to 9.8 km in range,and its oscillation structure is evident.The wave-number integration approach is used to simulate theoretical air-to-water transmission losses,which are in good agreement with experimental values and to explain the experimental air-to-water sound transmission characteristics.ZHANG Lingshan PENG Zhaohui WANG Guangxu LUO Wenyu 2017Chinese Journal of Acoustics2017,36,2:7
15Denitrification and biofilm growth in a pilot-scale biofilter packed with suspended carriers for biological nitrogen removal from secondary effluent显示文摘Tertiary denitrification is an effective method for nitrogen removal from wastewater. A pilot-scale biofilter packed with suspended carriers was operated for tertiary denitrification with ethanol as the organic carbon source. Long-term performance, biokinetics of denitrification and biofilm growth were evaluated under filtration velocities of 6, 10 and 14 m/hr. The pilot-scale biofilter removed nitrate from the secondary effluent effectively, and the nitrate nitrogen(NO_3-N) removal percentage was 82%, 78% and 55% at the filtration velocities of 6, 10 and 14 m/hr, respectively. At the filtration velocities of 6 and 10 m/hr, the nitrate removal loading rate increased with increasing influent nitrate loading rates, while at the filtration velocity of 14 m/hr, the removal loading rate and the influent loading rate were uncorrelated.During denitrification, the ratio of consumed chemical oxygen demand to removed NO_3-N was 3.99–4.52 mg/mg. Under the filtration velocities of 6, 10 and 14 m/hr, the maximum denitrification rate was 3.12, 4.86 and 4.42 g N/(m^2·day), the half-saturation constant was 2.61, 1.05 and 1.17 mg/L, and the half-order coefficient was 0.22, 0.32 and 0.24(mg/L)1/2/min,respectively. The biofilm biomass increased with increasing filtration velocity and was 2845,5124 and 7324 mg VSS/m^2 at filtration velocities of 6, 10 and 14 m/hr, respectively. The highest biofilm density was 44 mg/cm^3 at the filtration velocity of 14 m/hr. Due to the low influent loading rate, biofilm biomass and thickness were lowest at the filtration velocity of 6 m/hr.Yunhong Shi Guangxue Wu Nan Wei Hongying Hu 2015Journal of Environmental Sciences2015,27,6:6
16Determination of quorum-sensing signal substances in water and solid phases of activated sludge systems using liquid chromatography–mass spectrometry显示文摘The detection of acyl homoserine lactones(AHLs) in activated sludge is essential for clarifying their function in wastewater treatment processes. An LC–MS/MS method was developed for the detection of AHLs in both the aqueous and solid phases of activated sludge. In addition, the effects of proteases and extracellular polymeric substances(EPS) on the detection of AHLs were evaluated by adding protease inhibitors and extracting EPS,respectively. Recoveries of each AHL were improved by adding 50 μL of protease inhibitor,and recoveries were also improved from 0 to 56.9% to 24.2%–105.8% by EPS extraction.Applying the developed method to determine the type and concentration of AHLs showed that C4-HSL, C_6-HSL, C_8-HSL and 3-oxo-C_8-HSL were widely detected in a suspended activated sludge system. The dominant AHL was C_8-HSL, with a highest concentration of304.3 ng/L. C_4-HSL was mainly distributed in the aqueous phase, whereas C_6-HSL, C_8-HSL and 3-oxo-C_8-HSL were preferentially distributed in the sludge phase.Yuepeng Sun Kai He Qidong Yin Shinya Echigo Guangxue Wu Yuntao Guan 2018Journal of Environmental Sciences2018,30,7:6
17Simultaneous determination of seven principal constituents in Asari Radix et Rhizoma by HPLC显示文摘建立了同时测定细辛中花椒酚、卡枯醇、甲基丁香酚、l–芝麻脂素、黄樟醚、细辛素和l–细辛脂素7种主要成分含量的HPLC方法,并测定了55份不同来源的细辛药材(35份北细辛、3份汉城细辛和17份华细辛)中这7种成分的含量,比较了不同品种细辛中7种成分含量差异。采用Agilent Zorbax SB–C18色谱柱(4.6 mm×25 cm,5μm),水(A)–乙腈(B)为流动相进行梯度洗脱55 min,DAD检测器检测,柱温20°C,检测波长287 nm。被测成分在测试范围内线性关系良好,r2>0.999;加样回收率96.0%–103.1%,RSD小于2.54%。该方法准确、灵敏、重复性好。测定结果表明不同来源的细辛样品中7种成分的含量差异显著,其中挥发性成分甲基丁香酚在辽细辛(汉城细辛与北细辛的根及根茎)中的含量为(6.17±5.13)mg/g,显著高于其在华细辛(华细辛的根及根茎)中的含量(0.58±0.39)mg/g,有毒成分黄樟醚在辽细辛中的含量为(2.66±2.16)mg/g,低于其在华细辛的含量(6.44±3.88)mg/g。本文首次报道了细辛中花椒酚和细辛素的含量。Chen Cao Jingzhe Wang Lu Wang Mingying Shang Guangxue Liu Feng Xu Xuan Wang Shaoqing Cai 2015Journal of Chinese Pharmaceutical Sciences2015,24,8:6
18Si-substrate vertical-structure InGaN/GaN micro-LED-based photodetector for beyond 10 Gbps visible light communication显示文摘Visible light communication(VLC)has emerged as a promising communication method in 6G.However,the development of receiving devices is much slower than that of transmitting devices,limited by materials,structures,and fabrication.In this paper,we propose and fabricate an InGaN/GaN multiple-quantum-well-based vertical-structure micro-LED-based photodetector(μPD)on a Si substrate.A comprehensive comparison of the photoelectrical performance and communication performance of three sizes ofμPDs,10,50,and 100μm,is presented.The peak responsivity of all threeμPDs is achieved at 400 nm,while the passband full-widths at half maxima are 87,72,and 78 nm for 10,50,and 100μmμPDs,respectively.The−20 dB cutoff bandwidth is up to 822 MHz for 50μmμPD.A data rate of 10.14 Gbps is experimentally demonstrated by bit and power loading discrete multitone modulation and the proposed digital pre-equalizer algorithm over 1 m free space utilizing the self-designed 4×450μmμPD array as a receiver and a 450 nm laser diode as a transmitter.This is the first time a more than 10 Gbps VLC system has been achieved utilizing a GaN-based micro-PD,to the best of our knowledge.The investigation fully demonstrates the superiority of Si substrates and vertical structures in InGaN/GaNμPDs and shows its great potential for high-speed VLC links beyond 10 Gbps.JIANYANG SHI ZENGYI XU WENQING NIU DONG LI XIAOMING WU ZIWEI LI JUNWEN ZHANG CHAO SHEN GUANGXU WANG XIAOLAN WANG JIANLI ZHANG FENGYI JIANG SHAOHUA YU NAN CHI 2022Photonics Research2022,10,10:5
19Evolution history and trend of the modern Huanghe River Delta显示文摘The evolvement history of modern Huanghe River Delta tidal flat,coastline and underwater terrain were studied based on the analysis of remote sensing images and water depth data.Based on the analysis of seafloor terrain evolution on different historical stages,a formula simulating the erosion and deposition evolvement model of subaqueous Huanghe River Delta slope was proposed,and the evolvement trend of the subaqueous delta terrain was predicted.The result shows that the equilibrium transition zone is near the water depth of 12 m with seabed erosion in shallower water and accumulation in deeper water during the first 150 a after the river channel was deserted.In the meantime,the underwater slope became gentler and the coastal erosion rate became slow gradually.Then,the subaqueous delta slope changed to up concave from upper convex,and the shape of subaqueous delta disappeared.The coast type changed to silt-mud coast about 100-150 a after the river course was deserted.The erosion depth in the foot of the seawall is calculated based on the formula.MA Yanyan LI Guangxue 2010Acta Oceanologica Sinica2010,29,2:5
20Shaped Pt-Ni nanocrystals with an ultrathin Pt-enriched shell derived from one-pot hydrothermal synthesis as active electrocatalysts for oxygen reduction显示文摘有 3d 转变金属的磅的合金 nanocrystals (NC ) ,特别 Ni,是为氧减小反应(ORR ) 的优秀催化剂。在这个工作,第一次,我们表明了水阶段 Pt-M (M = Ni,公司和 Fe ) 的胶体的合成有通过一个灵巧的热水的方法的悦耳的作文和形态学的合金 NC。Pt-Ni 合金 NC 综合了,这个方法更好介绍了 ORR 活动比商业 Pt/C 催化剂。X 光检查精力印射技术的散系列(版本) 表明充实磅的壳在同样综合的 Pt-Ni 合金 NC 上存在。厚分层的充实磅的壳在磅上形成了的大约二个原子 < 潜水艇 class= “ a-plus-plus ” > 50 Ni < 潜水艇 class= “ a-plus-plus ” > 当 Ni 内容增加了, 50 NC 和充实磅的壳的厚度增加了。而且, X 光检查光电子光谱学分析表明 Pt-Ni 合金 NC 上的表面磅原子的氧化水平与一金属的磅 NC 相比减少了,暗示在表面磅原子的 oxophilicity 的减少。有表面磅原子的更低的 oxophilicity 的 Pt-Ni 合金 NC 给更高的 ORR 活动。最活跃的合金样品显示出高 13 倍的特定的活动和高六倍的质量在 0.9 V 对一个可逆的氢电极的活动什么时候与商业 Pt/C 相比。Pt-Ni 合金 NC 也在长期的 ORR 测试比商业 Pt/C 显示出更好的耐久性。Jun Gu Guangxu Lan Yingying Jiang Yanshuang Xu Wei Zhu Chuanhong Jin Yawen Zhang 2015Nano Research2015,8,5:5
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