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1Stable classi?cation with limited sample: transferring a 30-m resolution sample set collected in 2015 to mapping 10-m resolution global land cover in 2017显示文摘As the world strives to reduce the impact of population growth, urbanization, agricultural expansion, and climate change on food security, energy and water shortage, resource over-exploration, biodiversity loss, environmental pollution, and ultimately human health, timely and higher resolution land cover information is urgently needed to achieve the sustainable development goals of the United Nations.Peng Gong Han Liu Meinan Zhang Congcong Li Jie Wang Huabing Huang Nicholas Clinton Luyan Ji Wenyu Li Yuqi Bai Bin Chen Bing Xu Zhiliang Zhu Cui Yuan Hoi Ping Suen Jing Guo Nan Xu Weijia Li Yuanyuan Zhao Jun Yang Chaoqing Yu Xi Wang Haohuan Fu Le Yu Iryna Dronova Fengming Hui Xiao Cheng Xueli Shi Fengjin Xiao Qiufeng Liu Lianchun Song 2019Science Bulletin2019,64,6:166
2Effects of field application of phosphate fertilizers on the availability and uptake of lead, zinc and cadmium by cabbage (Brassica chinensis L.) in a mining tailing contaminated soil显示文摘A field trial was conducted to evaluate the reduction of bioavailability of heavy metals including lead (Pb), zinc (Zn) and cadmium (Cd) in a soil contaminated by mining tailings in Shaoxing, Zhejiang, China. Three commercial phosphate (P) fertilizers including phosphate rock (PR), calcium magnesium phosphate (CMP), and single superphosphate (SSP) were applied to the plot at three P application rates, 50, 300, and 500 g/m2 with 9 treatments and control (CK). Plants, water soluble and exchangeable (WE) extraction procedure and modified toxicity characteristic leaching procedure (TCLP) were employed. It was found that the addition of all three P fertilizers significantly decreased WE Pb (22.0%-81.4%), Cd (1.5%-30.7%) and Zn (11.7%-75.3%, exception of SSP treatments with no significant difference) and TCLP Pb concentration (27.1%-71.2%), compared with the control, leading to reduced uptake of Pb (16.0%-58.0%), Cd (16.5%-66.9%) and Zn (1.2%-73.2%) by cabbage (Brassica chinensis L.). It was suggested that P fertilizers induced immobilization of heavy metals such as Pb, Cd, and Zn. CMP provided the most effective method of reducing metal toxicity, mobility, and phytoavailability. At the P application rate of 300 g/m2, CMP would be cost-effective to decrease WE Pb, Zn, and Cd concentration from 666 to 137 mg/kg, from 31.2 to 8.71 mg/kg, and from 1.69 to 1.36 mg/kg, respectively. SSP was more effective in reducing Pb bioavailability than PR but had variable effects on Zn bioavailability. Cd uptake by cabbage was negatively correlated with soil pH rather than with WE or TCLP, indicating that Cd uptake by cabbage was a complex process. It should be careful to evaluate the impact of phosphate application on Cd availability in soil.Biling WANG Qiufeng SU 2008Journal of Environmental Sciences2008,20,9:39
3Altered trends in carbon uptake in China’s terrestrial ecosystems under the enhanced summer monsoon and warming hiatus显示文摘The carbon budgets in terrestrial ecosystems in China are strongly coupled with climate changes.Over the past decade,China has experienced dramatic climate changes characterized by enhanced summer monsoon and decelerated warming.However,the changes in the trends of terrestrial net ecosystem production(NEP)in China under climate changes are not well documented.Here,we used three ecosystem models to simulate the spatiotemporal variations in China's NEP during 1982–2010 and quantify the contribution of the strengthened summer monsoon and warming hiatus to the NEP variations in four distinct climatic regions of the country.Our results revealed a decadal-scale shift in NEP from a downtrend of–5.95 Tg C/yr^2(reduced sink)during 1982–2000 to an uptrend of 14.22 Tg C/yr^2(enhanced sink)during 2000–10.This shift was essentially induced by the strengthened summer monsoon,which stimulated carbon uptake,and the warming hiatus,which lessened the decrease in the NEP trend.Compared to the contribution of 56.3%by the climate effect,atmospheric CO2 concentration and nitrogen deposition had relatively small contributions(8.6 and 11.3%,respectively)to the shift.In conclusion,within the context of the global-warming hiatus,the strengthening of the summer monsoon is a critical climate factor that enhances carbon uptake in China due to the asymmetric response of photosynthesis and respiration.Our study not only revealed the shift in ecosystem carbon sequestration in China in recent decades,but also provides some insight for understanding ecosystem carbon dynamics in other monsoonal areas.Honglin He Shaoqiang Wang Li Zhang Junbang Wang Xiaoli Ren Lei Zhou Shilong Piao Hao Yan Weimin Ju Fengxue Gu Shiyong Yu Yuanhe Yang Miaomiao Wang Zhongen Niu Rcmg Ge Huimin Yan Mei Huang Guoyi Zhou Yongfei Bai Zongqiang Xie Zhiyao Tang Bingfang Wu Leiming Zhang Nianpeng He Qiufeng Wang Guirui Yu 2019National Science Review2019,6,3:24
4Changing trends of disease burden of gastric cancer in China from 1990 to 2019 and its predictions:Findings from Global Burden of Disease Study显示文摘Objective:China is one of the countries with the heaviest burden of gastric cancer(GC)in the world.Understanding the epidemiological trends and patterns of GC in China can contribute to formulating effective prevention strategies.Methods:The data on incidence,mortality,and disability-adjusted life-years(DALYs)of GC in China from1990 to 2019 were obtained from the Global Burden of Disease Study(2019).The estimated annual percentage change(EAPC)was calculated to evaluate the temporal trends of disease burden of GC,and the package Nordpred in the R program was used to perform an age-period-cohort analysis to predict the numbers and rates of incidence and mortality in the next 25 years.Results:The number of incident cases of GC increased from 317.34 thousand in 1990 to 612.82 thousand in2019,while the age-standardized incidence rate(ASIR)of GC decreased from 37.56 per 100,000 in 1990 to 30.64 per 100,000 in 2019,with an EAPC of-0.41[95%confidence interval(95%CI):-0.77,-0.06].Pronounced temporal trends in mortality and DALYs of GC were observed.In the next 25 years,the numbers of new GC cases and deaths are expected to increase to 738.79 thousand and 454.80 thousand,respectively,while the rates of incidence and deaths should steadily decrease.The deaths and DALYs attributable to smoking were different for males and females.Conclusions:In China,despite the fact that the rates of GC have decreased during the past three decades,the numbers of new GC cases and deaths increased,and will continue to increase in the next 25 years.Additional strategies are needed to reduce the burden of GC,such as screening and early detection,novel treatments,and the prevention of risk factors.Tongchao Zhang Hui Chen Xiaolin Yin Qiufeng He Jinyu Man Xiaorong Yang Ming Lu 2021Chinese Journal of Cancer Research2021,33,1:19
5Vulnerability assessment of areas affected by Chinese cryospheric changes in future climate change scenarios显示文摘Using the definition of vulnerability provided by the Intergovernmental Panel on Climate Change,this paper assesses the vulnerability of areas affected by Chinese cryospheric changes from 2001 to 2020 and from 2001 to 2050 in A1 and B1scenarios.Seven indices are used in the vulnerability assessment:glacial area fraction,interannual variability of permafrost depth,interannual variability of surface snow area fraction,interannual variability of surface runoff,interannual variability of surface temperature,interannual variability of vegetation growth,and interannual variability of the human development index.Assessment results show that the overall vulnerability of the studied areas in China increases from east to west.The areas in the middle and eastern parts of China are less vulnerable compared with western parts and parts of the Tibetan Plateau.The highest vulnerability values are found from 1981 to 2000,and the least ones are found from 2001 to 2050.The vulnerable areas increase from the period of 1981 to 2000 to the period of 2001 to 2050,and the less vulnerable areas decrease.The highly vulnerable areas increase from the period of 1981 to 2000 to the period of 2001 to 2020 and then decrease from the period of 2001 to 2020 to the period of 2001 to 2050.This decrease in vulnerability is attributed to the decrease in exposure and sensitivity to Chinese cryospheric changes along with a concomitant increase in adaptation.HE Yong WU YongFeng LIU QiuFeng 2012Chinese Science Bulletin2012,57,36:18
6LA-ICP-MS Zircon U-Pb Dating of Intermediate-Acidic Intrusive Rocks and Molybdenite Re-Os Dating from the Bangpu Mo (Cu) Deposit, Tibet and its Geological Implication显示文摘The multi-stage intrusions of intermediate-acid magma occur in the Bangpu mining district, the petrogenic ages of which have been identified. The times and sequences of their emplacement have been collated and stipulated in detail in this paper by using the laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) zircon U-Pb dating method. The ages of biotite monzogranite that were formed before mineralization in the southwest of this mining district are 70±1 Ma (mean square of weighted deviates (MSWD) =9.5, n=8) and 60.60±0.31 Ma (MSWD=3.8, n=16), which belong to the late Cretaceous-early Paleocene in age. That means, they are products of an early tectonicmagmatic event of the collision between the Indian and Asian continentals. The ages of ore-bearing monzogranite porphyry and ore-bearing diorite porphyrite are 16.23±0.19 Ma (MSWD=2.0, n=26) and 15.16±0.09 Ma (MSWD=3.9, n=5) separately, which belong to the middle Miocene in age; namely, they are products of the Gangdese post-collision extensional stage when crust-mantle materials melted and mixed as well as magmatic intrusion simultaneously occurred. Some zircons with ages of 203.6±2.2 Ma (MSWD=1.18, n=7) were captured in the ore-bearing diorite porphyrite, which shows that there had been tectono-magmatic events in the late Triassic-early Jurassic. Molybdenum (copper) ore-bodies produced in the monzogranite porphyry and copper (molybdenum) ore-bodies produced in the diorite porphyrite are the main ore types in this ore deposit. The model ages of Re-Os isotopic dating for the 11 molybdenite are 13.97-15.84 Ma, while isochron ages are 14.09±0.49 Ma (MSWD=26). The isochron ages of seven molybdenite from molybdenum (copper) ore with monzogranite porphyry type are 14.11±0.31 Ma (MSWD=5.2). There is great error in the isochron ages of four molybdenite from copper (molybdenum) ore with diorite porphyrite type, and their weighted average model ages of 14.6±1.2 Ma (MSWD=41), which generally represent the mineralization age. The results about the Re-Os isotopic dating of molybdenite in the ore of different types have limited exactly that, the minerlazation age of this ore deposits is about 14.09 Ma, which belongs to the middle Miocene mineralization. The Bangpu deposit has a uniform metallogenic dynamics background with the porphyry type and skarn-type deposits such as Jiama, Qulong and others.WANG Liqiang CHEN Yuchuan TANG Juxing LU Pengrui LUO Maocheng WANG Huan CHEN Wei LENG Qiufeng 2012Acta Geologica Sinica(English Edition)2012,86,5:13
7Effects of Temperature and Moisture on Soil Organic Matter Decomposition Along Elevation Gradients on the Changbai Mountains, Northeast China显示文摘Decomposition of soil organic matter(SOM) is of importance for CO_2 exchange between soil and atmosphere and soil temperature and moisture are considered as two important factors controlling SOM decomposition. In this study, soil samples were collected at 5 elevations ranging from 753 to 2 357 m on the Changbai Mountains in Northeast China, and incubated under different temperatures(5, 10, 15, 20, 25, and 30?C) and soil moisture levels(30%, 60%, and 90% of saturated soil moisture) to investigate the effects of both on SOM decomposition and its temperature sensitivity at different elevations. The results showed that incubation temperature(F = 1 425.10, P < 0.001), soil moisture(F = 1 327.65, P < 0.001), and elevation(F = 1 937.54, P < 0.001) all had significant influences on the decomposition rate of SOM. The significant effect of the interaction of incubation temperature and soil moisture on the SOM decomposition rate was observed at all the 5 sampling elevations(P < 0.001). A two-factor model that used temperature and moisture as variables fitted the SOM decomposition rate well(P < 0.001) and could explain 80%–93% of the variation of SOM decomposition rate at the 5 elevations. Temperature sensitivity of SOM decomposition, expressed as the change of SOM decomposition rate in response to a 10?C increase in temperature(Q_(10)), was significantly different among the different elevations(P < 0.01), but no apparent trend with elevation was discernible. In addition, soil moisture and incubation temperature both had great impacts on the Q_(10) value(P < 0.01), which increased significantly with increasing soil moisture or incubation temperature. Furthermore, the SOM decomposition rate was significantly related to soil total Gram-positive bacteria(R^2= 0.33, P < 0.01) and total Gram-negative bacteria(R^2= 0.58, P < 0.001). These findings highlight the importance of soil moisture to SOM decomposition and its Q_(10) value,which needs to be emphasized under warming climate scenarios.WANG Dan HE Nianpeng WANG Qing LV Yuliang WANG Qiufeng XU Zhiwei ZHU Jianxing 2016Pedosphere2016,26,3:12
8Research on 2D imaging technique for concrete cross section显示文摘二条信号处理途径被介绍在具体 structures.When 的超声的 NDT 改进成像分辨率低频率的B扫描数据被合成的孔集中处理技术( SAFT ),因为低频率的察觉信号盖住一种相对长 period.Wavepacket 分解技术( WDT ), wavepacket 将进一步被伸长这里被介绍解决描述原版的使用一些参数表明的这个 problem.ThisLI Qiufeng SHI Lihua LIANG Dakai 2010Chinese Journal of Acoustics2010,29,1:11
9Effectiveness of Jinying capsule on pelvic inflammatory disease in patients with symptom pattern of damp and heat accumulation: a double-blinded, multicenter, randomized, placebo-controlled clinical trial显示文摘OBJECTIVE: To evaluate the therapeutic effectiveness and safety of Jinying capsule on pelvic inflammatory disease(PID) in patients with symptoms identified as the pattern of damp and heat accumulation in terms of Traditional Chinese Medicine(TCM).METHODS: We conducted a double-blinded, multicenter, randomized, placebo-controlled clinical trial which included 155 patients diagnosed with PID and identified as symptom pattern of damp and heat accumulation. They were randomly divided into experimental group(n = 78) and control group(n = 77) according to a random number table. The treatment lasted for a period of 28 d. The experimental group was given Jinying capsules and oral levofloxacin plus oral metronidazole for first 7 d.They continued with Jinying capsules and levofloxacin placebo and metronidazole placebo for another 7 d. For the remaining 14 d, they continued with Jinying capsules only. Whereas, the control group was treated with oral levofloxacin and metronidazole and Jinying capsule placebo for the first 14 d in the same way as the experimental group and then continued with Jinying capsule placebo only for the remaining 14 d. The clinical efficacy was assessed using McCormack scale, TCM symptom pattern scores, physicochemical indexes including white blood cell and erythrocyte sedimentation rate, C-reaction protein, smear of vaginal discharge,and pelvic ultrasound.RESULTS: Comparing McCormack scale between both groups after treatment, the difference in curative effect between both groups was significant (P = 0.0269). The cure rate of the experimental group and control group is 76.32% and 59.46% respectively at week 4. Comparing TCM symptom pattern scores between both groups before and after treatment, the differences in total effective rate were both significant(P < 0.05). The curative effect rate of experimental group is 2.63% and 13.70% of the control group at week 1(P = 0.0131), and73.33% of the experimental group and 56.94% of the control group at week 4(P = 0.0369). No significant differences were found between the two groups on the Physicochemical indexes(all P >0.05). No adverse events or reactions occurred in the experimental groups.CONCLUSION: Jinying capsule can reduce the dosage of antibiotics needed for PID treatment, and improve the symptoms in PID patients.Yang Yan Lu Yao Zhou Deping Pei Fenglan Li Qin Chen Shuqiong Wang Qiufeng Wang Yanting Jin Zhe Liu Yanxia 2020Journal of Traditional Chinese Medicine2020,40,3:10
10Effects of climate and forest age on the ecosystem carbon exchange of afforestation显示文摘Afforestation is believed to be an effective practice to reduce global warming by sequestering large amounts of carbon in plant biomass and soil.However,the factors that determine the rate of carbon sequestration with afforestation are still poorly understood.We analyzed ecosystem carbon exchange after afforestation based on eddy covariance measurements with the aim to identify factors responsible for the rate of carbon exchange following afforestation.The results indicated that afforestation in the tropical/subtropical and temperate climate zones had greater capacities for carbon sequestration than those in boreal zones.Net ecosystem production(NEP),gross primary production(GPP)and ecosystem respiration(RE)varied greatly with age groups over time.Specifically,NEP was initially less than zero in the\10 year group and then increased to its peak in the 10-20 year group.Afforestation of varied previous land use types and planting of diverse tree species did not result in different carbon fluxes.The general linear model showed that climate zone and age of afforestation were the dominant factors influencing carbon sequestration.These factors jointly controlled 51%,61%and 63%of the variation in NEP,GPP and RE,respectively.Compared to the strong regulation of climate on GPP and RE,NEP showed greater sensitivity to the age of afforestation.These results increase our understanding of the variation in ecosystem carbon exchange of afforestation and suggest that afforestation in subtropical and temperate areas after 20 years would yield greater carbon sink benefits than would afforestation of boreal regions.Zhi Chen Guirui Yu Qiufeng Wang 2020Journal of Forestry Research2020,31,2:7
11Simulating the exchanges of carbon dioxide, water vapor and heat over Changbai Mountains temperate broad- leaved Korean pine mixed forest ecosystem显示文摘A process-based ecosystem productivity model BEPS (Boreal Ecosystem Productivity Simulator) was updated to simulate half-hourly exchanges of carbon, water and energy between the atmosphere and terrestrial ecosystem at a temperate broad-leaved Korean pine forest in the Changbai Mountains, China. The BEPSh model is able to capture the diurnal and seasonal variability in carbon dioxide, water vapor and heat fluxes at this site in the growing season of 2003. The model validation showed that the simulated net ecosystem productivity (NEP), latent heat flux (LE), sensible heat flux (Hs) are in good agreement with eddy covariance measurements with an R2 value of 0.68, 0.86 and 0.72 for NEP, LE and Hs, respectively. The simulated annual NEP of this forest in 2003 was 300.5 gC/m2, and was very close to the observed value. Driving this model with different climate scenarios, we found that the NEP in the Changbai Mountains temperate broad-leaved Korean pine mixed forest ecosystem was sensitive to climate variability, and the current carbon sink will be weakened under the condition of global warming. Furthermore, as a process-based model, BEPSh was also sensitive to physiological parameters of plant, such as maximum Rubisco activity (Vcmax) and the maximum stomatal conductance (gmax), and needs to be carefully calibrated for other applications.WANG Qiufeng, NIU Dong, YU Guirui, REN Chuanyou, WEN Xuefa, CHEN Jingming & JU Weimin Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China Bureau of Science and Technology for Resources and Environment, Chinese Academy of Sciences, Beijing 100864, China Department of Geography, University of Toronto, Toronto M5S 3G3, Canada Graduate School of the Chinese Academy of Sciences, Beijing 100039, China Shenyang Agricultural University, Shenyang 100161, China 2005Science China Earth Sciences2005,48,z1:6
12Automatic grape leaf diseases identification via UnitedModel based on multiple convolutional neural networks显示文摘Grape diseases are main factors causing serious grapes reduction.So it is urgent to develop an automatic identification method for grape leaf diseases.Deep learning techniques have recently achieved impressive successes in various computer vision problems,which inspires us to apply them to grape diseases identification task.In this paper,a united convolutional neural networks(CNNs)architecture based on an integrated method is proposed.The proposed CNNs architecture,i.e.,UnitedModel is designed to distinguish leaves with common grape diseases i.e.,black rot,esca and isariopsis leaf spot from healthy leaves.The combination of multiple CNNs enables the proposed UnitedModel to extract complementary discriminative features.Thus the representative ability of United-Model has been enhanced.The UnitedModel has been evaluated on the hold-out PlantVillage dataset and has been compared with several state-of-the-art CNN models.The experimental results have shown that UnitedModel achieves the best performance on various evaluation metrics.The UnitedModel achieves an average validation accuracy of 99.17%and a test accuracy of 98.57%,which can serve as a decision support tool to help farmers identify grape diseases.Miaomiao Ji Lei Zhang Qiufeng Wu 2020Information Processing in Agriculture2020,7,3:6
13Primary estimation of Chinese terrestrial carbon sequestration during 2001-2010显示文摘在重新审视生态系统生产力概念体系的基础上,将中国的陆地区域假设为一个大尺度的生物-社会群区生态系统,采用不同时空尺度多源数据的整合分析方法,定量评估了中国区域陆地生态系统生产力及其在各种生态过程中的分配和消耗量,进而分析评价了中国区域陆地生态系统潜在的碳源/汇强度.统计分析结果表明,中国区域的陆地生态系统具有较高的碳吸收能力,该研究结果可以为中国区域陆地碳收支现状和增汇潜力的评估分析提供参考信息,也可作为中国区域碳管理决策分析的重要依据.Qiufeng Wang Han Zheng Xianjin Zhu Guirui Yu 2015Science Bulletin2015,60,6:6
14Superior adsorption performance of graphitic carbon nitride nanosheets for both cationic and anionic heavy metals from wastewater显示文摘Water pollution caused by highly toxic Cd(II), Pb(II), and Cr(VI) is a serious problem. In the present work,a green and low-cost adsorbent of g-C_3N_4 nanosheets was developed with superior capacity for both cationic and anionic heavy metals. The adsorbent was easily fabricated through one-step calcination of guanidine hydrochloride with thickness less than 1.6 nm and specific surface area of 111.2 m^2·g^(-1). Kinetic and isotherm studies suggest that the adsorption is an endothermic chemisorption process, occurring on the energetically heterogeneous surface based on a hybrid mechanism of multilayer and monolayer adsorption. The tri-s-triazine units and surface N-containing groups of g-C_3N_4 nanosheets are proposed to be responsible for the adsorption process.Further study on pH demonstrates that electrostatic interaction plays an important role. The maximum adsorption capacity of Cd(II), Pb(II), and Cr(VI) on g-C_3N_4 nanosheets is 123.205 mg·g^(-1), 136.571 mg·g^(-1),and 684.451 mg·g^(-1), respectively. The better adsorption performance of the adsorbent than that of the recently reported nanomaterials and low-cost adsorbents proves its great application potential in the removal of heavy metal contaminants from wastewater. The present paper developed a promising adsorbent which will certainly find applications in wastewater treatment and also provides guiding significance in designing adsorption processes.Gang Xiao Yaoqiang Wang Shengnan Xu Peifeng Li Chen Yang Yu Jin Qiufeng Sun Haijia Su 2019Chinese Journal of Chemical Engineering2019,27,2:5
15Photosynthesis-transpiration coupling model at canopy scale in terrestrial ecosystem显示文摘At the hypothesis of big leaf, an ecosystem photosynthesis-transpiration coupling cycle model was established by the scaled SMPT-SB model from single leaf to canopy, and model parameterization methods were discussed. Through simulating the canopy light distribution, canopy internal conductance to CO2 can be scaled from single leaf to canopy by integrating to canopy using the relationship between single internal conductance and photosynthetic photon flux density. Using the data observed by eddy covariance method from the Changbai Mountains site of ChinaFLUX, the application of the model at the canopy scale was examined. Under no water stress, the simulated net ecosystem photosynthesis rate fitted with the observed data very well, the slope and R2 of the line regression equation of the observed and simulated values were 0.7977 and 0.8892, respectively (n = 752), and average absolute error was 3.78 μmol CO2 m-2s-1; the slope, R2 and average absolute error of transpiration rate were 0.7314, 0.4355 and 1.60mmol H2O m-2 s-1, respectively (n = 752). The relationship between canopy photosynthesis,transpiration and external environmental conditions was discussed by treating the canopy as a whole and neglecting the comprehensive feedback mechanism within canopy, and it was noted that the precipitation course affected the transpiration rate simulation badly. Compared to the models based on eco-physiological processes, the SMPT-SB model was simple and easy to be used. And it can be used as a basic carbon and water coupling model of soil-plant-atmosphere continuum.REN Chuanyou, YU Guirui, WANG Qiufeng & GUAN Dexin Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China Shenyang Agricultural University, Shenyang 110161, China Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China Graduate School of the Chinese Academy of Sciences, Beijing 100039, China 2005Science China Earth Sciences2005,48,z1:5
16An Overlay Multicast Routing Algorithm Based on Genetic Algorithms显示文摘CHENG Peng DAI Qionghai WU Qiufeng 2007Chinese Journal of Electronics2007,16,1:4
17Dynamic Model and Motion Mechanism of Magnetotactic Bacteria with Two Lateral Flagellar Bundles显示文摘Cenyu Yang Chuanfang Chen Qiufeng Ma Longfei Wu Tao Song 2012Journal of Bionic Engineering2012,9,2:4
18TiO_2-modified nano-egg-shell Pd catalyst for selective hydrogenation of acetylene显示文摘Pd-based egg-shell nano-catalysts were prepared using porous hollow silica nanoparticles (PHSNs) as support, and the as-prepared catalysts were modified with TiO 2 to promote their selectivity for hydro-genation of acetylene. Pd nanoparticles were loaded evenly on PHSNs and TiO 2 was loaded on the active Pd particles. The effects of reduction time and temperature and the amount of TiO 2 added on catalytic performances were investigated by using a fixed-bed micro-reactor. It was found that the catalysts showed better performance when reduced at 300°C than at 500 °C, and if reduced for 1 h than 3 h. When the amount of Ti added was 6 times that of Pd, the catalyst showed the highest ethylene selectivity.Jin Gao Qiufeng Zhu Lixiong Wen 2010Particuology2010,8,3:3
19Enhancing effect of phase circular statistics vector for improvement imaging quality of ultrasonic total focusing method显示文摘To further improve the quality of the total focusing method(TFM)imaging,an ultrasonic TFM based on phase circular statistics vector(PCSV)has been presented.Firstly,the information of the signal phases of the full matrix capture(FMC)aperture data was extracted in the TFM implement processes.The phases of the same focusing pixel were regarded as the samples of the circular statistics.Then the PCSVs determined by the signal amplitudes and phases were acquired using the operation of saturation weighted statistics.Finally,the magnitudes of the PCSV were equivalent to the amplitudes of the TFM image.The results showed the TFM-PCSV was capable of improving SNR by amplifying the contribution of phase information.Also,the method could improve the lateral resolution by enhancing aperture beam directivity.Compared to the phase coherence weighted algorithm SCF and CCF,the TFM-PCSV had a higher tolerance to the error of phases.MAO Qiuqin CHEN Yao ZHANG Baiyuan SHI Wenze LU Chao LI Qiufeng 2021Chinese Journal of Acoustics2021,40,2:2
20Biosorption of Methylene Blue by Chemically Modifi ed Cellulose Waste显示文摘Citric acid modifi ed cellulose waste(CMCW) was prepared via esterifi cation and used as a low-cost biosorbent for the removal of methylene blue(MB) from aqueous solutions. The effects of biosorbent concentration, initial pH of MB solution, biosorption temperature, contact time, and initial MB concentration on the biosorption of MB were investigated using batch biosorption technique under static conditions. The experimental results showed that CMCW exhibited excellent biosorption characteristics for MB. The maximum biosorption capacity of MB was up to 214.5 mg/g at an adsorption temperature of 293 K. The removal rate of MB onto CMCW reached the maximum at pH>4 and the biosorption reached an equilibrium at about 50 min. The kinetic data can be described well with the pseudo-second-order model and the isotherm data was found to fi t the Langmuir isotherm with a monolayer adsorption capacity of 211.42 mg/g. The biosorption appears to be controlled by chemisorption and may be involved in surface adsorption and pore diffusion during the whole biosorption process.靳艳巧 ZHANG Yizhuan Lü Qiufeng CHENG Xiansu 2014Journal of Wuhan University of Technology(Materials Science)2014,29,4:2
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