期刊文献+
共找到17篇文章
< 1 >
每页显示 20 50 100
Assimilating FY-4A AGRI Radiances with a Channel-Sensitive Cloud Detection Scheme for the Analysis and Forecasting of Multiple Typhoons
1
作者 Feifei SHEN Aiqing SHU +4 位作者 Zhiquan LIU Hong LI Lipeng JIANG Tao ZHANG dongmei xu 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2024年第5期937-958,共22页
This paper presents an attempt at assimilating clear-sky FY-4A Advanced Geosynchronous Radiation Imager(AGRI)radiances from two water vapor channels for the prediction of three landfalling typhoon events over the West... This paper presents an attempt at assimilating clear-sky FY-4A Advanced Geosynchronous Radiation Imager(AGRI)radiances from two water vapor channels for the prediction of three landfalling typhoon events over the West Pacific Ocean using the 3DVar data assimilation(DA)method along with the WRF model.A channel-sensitive cloud detection scheme based on the particle filter(PF)algorithm is developed and examined against a cloud detection scheme using the multivariate and minimum residual(MMR)algorithm and another traditional cloud mask–dependent cloud detection scheme.Results show that both channel-sensitive cloud detection schemes are effective,while the PF scheme is able to reserve more pixels than the MMR scheme for the same channel.In general,the added value of AGRI radiances is confirmed when comparing with the control experiment without AGRI radiances.Moreover,it is found that the analysis fields of the PF experiment are mostly improved in terms of better depicting the typhoon,including the temperature,moisture,and dynamical conditions.The typhoon track forecast skill is improved with AGRI radiance DA,which could be explained by better simulating the upper trough.The impact of assimilating AGRI radiances on typhoon intensity forecasts is small.On the other hand,improved rainfall forecasts from AGRI DA experiments are found along with reduced errors for both the thermodynamic and moisture fields,albeit the improvements are limited. 展开更多
关键词 FY-4A AGRI radiance particle filter multiple typhoons data assimilation numerical weather prediction
下载PDF
Assimilating All-sky Infrared Radiances from Himawari-8 Using the 3DVar Method for the Prediction of a Severe Storm over North China 被引量:5
2
作者 dongmei xu Zhiquan LIU +2 位作者 Shuiyong FAN Min CHEN Feifei SHEN 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2021年第4期661-676,共16页
Although radar observations capture storm structures with high spatiotemporal resolutions, they are limited within the storm region after the precipitation formed. Geostationary satellites data cover the gaps in the r... Although radar observations capture storm structures with high spatiotemporal resolutions, they are limited within the storm region after the precipitation formed. Geostationary satellites data cover the gaps in the radar network prior to the formation of the precipitation for the storms and their environment. The study explores the effects of assimilating the water vapor channel radiances from Himawari-8 data with Weather Research and Forecasting model data assimilation system(WRFDA) for a severe storm case over north China. A fast cloud detection scheme for Advanced Himawari imager(AHI)radiance is enhanced in the framework of the WRFDA system initially in this study. The bias corrections, the cloud detection for the clear-sky AHI radiance, and the observation error modeling for cloudy radiance are conducted before the data assimilation. All AHI radiance observations are fully applied without any quality control for all-sky AHI radiance data assimilation. Results show that the simulated all-sky AHI radiance fits the observations better by using the cloud dependent observation error model, further improving the cloud heights. The all-sky AHI radiance assimilation adjusts all types of hydrometeor variables, especially cloud water and precipitation snow. It is proven that assimilating all-sky AHI data improves hydrometeor specifications when verified against the radar reflectivity. Consequently, the assimilation of AHI observations under the all-sky condition has an overall improved impact on both the precipitation locations and intensity compared to the experiment with only conventional and AHI clear-sky radiance data. 展开更多
关键词 Himawari-8 data assimilation ALL-SKY storm case
下载PDF
玛湖凹陷砂砾岩储层岩石力学特征与压裂对策研究 被引量:2
3
作者 郝红永 杨兴渝 +5 位作者 牛丽 郭晟豪 孙占玲 徐冬梅 徐景润 周红梅 《石油天然气学报》 CAS 2018年第4期47-53,共7页
玛湖凹陷百口泉组砂砾岩油藏储量大,但储层孔渗差、单井产量低、综合开釆成本髙,“水平井+压裂”是开发该类储层的有效措施,由于对其地应力和岩石力学特征认识不清严重制约了压裂改造的有效性。通过室内声学、力学试验发现玛湖凹陷... 玛湖凹陷百口泉组砂砾岩油藏储量大,但储层孔渗差、单井产量低、综合开釆成本髙,“水平井+压裂”是开发该类储层的有效措施,由于对其地应力和岩石力学特征认识不清严重制约了压裂改造的有效性。通过室内声学、力学试验发现玛湖凹陷百口泉组砂砾岩储层存在两向地应力差髙、最小水平主地应力髙、岩心弹性模量小、硬度低等特点,压裂改造无法形成复杂缝网,推荐采用密切割分段体积压裂工艺增大改造体积、采用前置液挤酸预处理结合小粒径段塞方式减少压裂加砂施工难度、适当加大支撑剂铺设厚度以及近井地带使用滑溜水造长复杂缝等措施提髙改造效果。结合以上压裂施工建议,2015年底顺利完成了对试验井MaHW1325井22段体积压裂,入井压裂液23,700 m3、支撑剂1702 m3,截止到2017年8月下旬MaHW1325井累计生产528 d,累计产油12,786.8 t,平均日产油24.2 t,生产效果好,说明压裂改造方案成功,在该区块具有极髙推广价值. 展开更多
关键词 准噶尔盆地 玛湖凹陷 砂砾岩 岩石力学 压裂对策 试验研究
下载PDF
阴道超声OmniView对宫腔粘连及其分型的评估价值 被引量:1
4
作者 徐冬梅 岳敏 《西藏医药》 2022年第3期44-46,共3页
目的探讨阴道三维超声自由解剖(OmniView)成像对宫腔粘连(IUA)及分型的价值。方法对我院2019年11月~2021年4月间就诊的疑诊为宫腔粘连的患者92例。均行经阴道超声,并以OmniView成像模式行宫腔成像。以宫腔镜检查结果为“金标准”,观察Om... 目的探讨阴道三维超声自由解剖(OmniView)成像对宫腔粘连(IUA)及分型的价值。方法对我院2019年11月~2021年4月间就诊的疑诊为宫腔粘连的患者92例。均行经阴道超声,并以OmniView成像模式行宫腔成像。以宫腔镜检查结果为“金标准”,观察OmniView成像模式对IUA诊断及其分型的评估价值。结果92例患者最终经宫腔镜确诊81例IUA,其中,中央型29例,周围型21例,混合型31例。OmniView成像模式共检出78例IUA,其中76例诊断正确,诊断准确率为93.83%(76/81)。其中,中央型IUA正确检出28例(96.55%),混合型IUA正确检出29例(93.55%),周围型IUA正确检出19例(90.48%),OmniView成像模式诊断IUA及其分型的敏感度、特异度、诊断符合率、kappa值均较高(P<0.05)。结论OmniView成像技术对IUA诊断及其分型的价值较高,对IUA及其分型的诊断具有一定的优势。 展开更多
关键词 阴道三维超声 宫腔粘连 分型
下载PDF
Assimilation of GPM Microwave Imager Radiance for Track Prediction of Typhoon Cases with the WRF Hybrid En3DVAR System 被引量:1
5
作者 dongmei xu Feifei SHEN +1 位作者 Jinzhong MIN Aiqing SHU 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2021年第6期983-993,共11页
The impact of assimilating radiance data from the advanced satellite sensor GMI(GPM microwave imager)for typhoon analyses and forecasts was investigated using both a three-dimensional variational(3DVAR)and a hybrid en... The impact of assimilating radiance data from the advanced satellite sensor GMI(GPM microwave imager)for typhoon analyses and forecasts was investigated using both a three-dimensional variational(3DVAR)and a hybrid ensemble-3DVAR method.The interface of assimilating the radiance for the sensor GMI was established in the Weather Research and Forecasting(WRF)model.The GMI radiance data are assimilated for Typhoon Matmo(2014),Typhoon Chan-hom(2015),Typhoon Meranti(2016),and Typhoon Mangkhut(2018)in the Pacific before their landing.The results show that after assimilating the GMI radiance data under clear sky condition with the 3DVAR method,the wind,temperature,and humidity fields are effectively adjusted,leading to improved forecast skills of the typhoon track with GMI radiance assimilation.The hybrid DA method is able to further adjust the location of the typhoon systematically.The improvement of the track forecast is even more obvious for later forecast periods.In addition,water vapor and hydrometeors are enhanced to some extent,especially with the hybrid method. 展开更多
关键词 WRF model GMI microwave imager data TYPHOON data assimilation
下载PDF
Separation of isopropyl alcohol+isopropyl acetate azeotropic mixture:Selection of ionic liquids as entrainers and vapor-liquid equilibrium validation
6
作者 Lianzheng Zhang Jie Wang +4 位作者 Lin Yang dongmei xu Yixin Ma Jun Gao Yinglong Wang 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2022年第10期326-334,共9页
Based on the COSMO-SAC model,1-ethyl-3-methylimidazolium acetate and 1-ethyl-3-methylimidazolium p-toluenesulfonate were selected from 30 ILs as entrainers to investigate the separation of the isopropyl alcohol+isopro... Based on the COSMO-SAC model,1-ethyl-3-methylimidazolium acetate and 1-ethyl-3-methylimidazolium p-toluenesulfonate were selected from 30 ILs as entrainers to investigate the separation of the isopropyl alcohol+isopropyl acetate azeotrope.Two screening indicators,σ-profile and infinite dilution selectivity(S^(∞)),were adopted as the basis.The iso baric vapor-liquid equilibrium experiments for isopropyl alcohol+isopropyl acetate binary system and isopropyl alcohol+isopropyl acetate+confirmed ILs ternary systems were performed at the pressure of atmospheric pressure.The experimental measurement demonstrated that the adopt ILs enhanced the relative volatility of the above alcohol-ester azeotrope,leading to the elimination of the azeotropic point with a certain amount ILs.Meanwhile,the thermodynamic correlation for two systems containing ILs was explored with the NRTL model,which also reflects the extensive applicability of that by comparing the deviation between experimental and calculated data.And its binary interaction parameters were regressed,which can provide a basis for its simulation process. 展开更多
关键词 Vapor-liquid equilibrium Ionic liquids NRTL Alcohol-ester azeotrope COSMO-SAC model
下载PDF
通过诱变选育低去甲基烟碱深色晾烟品系
7
作者 Yanxin SHEN dongmei xu +2 位作者 David Norman Mark Nielsen 任民(译) 《中国烟草科学》 CSCD 北大核心 2009年第1期49-49,共1页
目前已经分离到两个在烟草去甲基烟碱形成过程中起作用的基因。阻断这两个基因可使烟草植株中的去甲基烟碱含量较低,从而使得一种在烟叶调制过程中经亚硝化形成的TSNA—N′-亚硝基去甲基烟碱(NNN)的含量降低。我们通过乙基甲烷磺酸盐... 目前已经分离到两个在烟草去甲基烟碱形成过程中起作用的基因。阻断这两个基因可使烟草植株中的去甲基烟碱含量较低,从而使得一种在烟叶调制过程中经亚硝化形成的TSNA—N′-亚硝基去甲基烟碱(NNN)的含量降低。我们通过乙基甲烷磺酸盐(EMS)处理创造了一个深色晾烟的孟德尔遗传近等基因系突变群体。本研究中,我们报道了一个新的深色烟多突变体的发现,这一突变体能够消除主效和微效脱甲基酶的活性。第一代突变群体在大田环境下种植,第二代突变群体在大田和温室两种环境下种植。 展开更多
关键词 烟碱含量 深色 诱变选育 近等基因系 品系 烟草植株 孟德尔遗传 甲烷磺酸盐
下载PDF
Fuzzy comprehensive evaluation of five forage shrubs in Mu Us sandland, China
8
作者 dongmei xu Xinzhong xu +1 位作者 Hongbin Ma Yan Shen 《Agricultural Sciences》 2012年第1期75-82,共8页
Chemical compositions during different growing periods, preference and in vitro digestibility at the post-fruiting period of five psammophyte shrubs, which include Caragana intermedia, Caragana korshinskii, Hedysarum ... Chemical compositions during different growing periods, preference and in vitro digestibility at the post-fruiting period of five psammophyte shrubs, which include Caragana intermedia, Caragana korshinskii, Hedysarum scoparium, Hedysarum laeve, Salix psammophylla were determined. The nutritive values were synthetically evaluated in terms of chemical composition, preference and in vitro digestibility through fuzzy multifactorial model. The crude protein (CP) concentrations of the five shrubs had the tendency to decrease with growing stage, the peak values of C. intermedia, C. korshinskii and S. psammophylla appeared at blooming period and those of H. scoparium and H. laeve appeared at vegetative period. The neutral-detergent fiber (NDF), acid-detergent fiber (ADF) and lignin concentrations of C. intermedia, C. korshinskii and S. psammophylla were all decreased before post-fruiting period and then increased significantly;while the variation tendency of those of H. scoparium and H. leave were alike, and the lowest NDF, ADF and lignin concentrations were at vegetative period or post-fruiting period. The five shrubs can be used as feedstuffs, the synthetical nutritive value at the post-fruiting period were high in order of C. intermedia, H. scoparium, H. laeve, C. korshinskii and S. psammophylla. Considering the characteristics of growth and nutritive value, the optimum time to use these shrubs as feedstuffs is the post-fruiting period in autumn. Among the five shrubs, C. intermedia is the best as feed-stuff for raising the production of livestock. 展开更多
关键词 Chemical Composition Fuzzy MULTIFACTORIAL Model VITRO DIGESTIBILITY PREFERENCE PSAMMOPHYTE SHRUBS
下载PDF
可编织、可穿戴的宽带聚合物超声换能器
9
作者 邹君逸 郭星奕 +5 位作者 吴家琦 徐冬梅 许凯亮 陈培宁 他得安 彭慧胜 《Science China Materials》 SCIE EI CAS CSCD 2024年第8期2653-2660,共8页
新兴的物联网技术推动了可穿戴健康监测设备的快速发展.目前,医学超声技术在严重慢性疾病的长时间监测方面具有广阔的应用前景.然而,商用超声探头一般都是刚性的,需要手持,难以满足医疗可穿戴设备对柔性化、小型化和舒适性的要求.本文... 新兴的物联网技术推动了可穿戴健康监测设备的快速发展.目前,医学超声技术在严重慢性疾病的长时间监测方面具有广阔的应用前景.然而,商用超声探头一般都是刚性的,需要手持,难以满足医疗可穿戴设备对柔性化、小型化和舒适性的要求.本文提出了一种可编织、可穿戴的聚合物超声换能器,该换能器由匹配层、背衬层和压电层组成.聚合物压电材料的带宽(93%)是压电陶瓷的7倍,并且可以承受超过10,000次的弯曲和扭曲变形.该传感器能监测颈动脉血液流速,心脏血液流速和心脏血管的血管厚度,并具有与商用探头相当的信噪比.它的宽带特性(3.68–10.08 MHz)使其能通过调整频率来监测不同的组织.可编织超声换能器可以制成纤维形式,并编织成透气织物,在不牺牲穿戴舒适性的情况下进行实时血管监测. 展开更多
关键词 血液流速 超声换能器 可穿戴设备 超声探头 扭曲变形 匹配层 慢性疾病 压电材料
原文传递
扩展中国保护区以增强气候变化的响应韧性
10
作者 徐冬梅 彭建 +4 位作者 董建权 姜虹 刘梦琳 罗宇航 徐子涵 《Science Bulletin》 SCIE EI CAS CSCD 2024年第14期2273-2280,共8页
Expanding the network of connected and resilient protected areas(PAs)for climate change adaptation can help species track suitable climate conditions and safeguard biodiversity.This is often overlooked when expanding ... Expanding the network of connected and resilient protected areas(PAs)for climate change adaptation can help species track suitable climate conditions and safeguard biodiversity.This is often overlooked when expanding PAs and quantifying their benefits,resulting in an underestimate of the benefits of expanding PAs.We expanded PAs through terrestrial mammalian species distribution hotspots,Key Biodiversity Areas(KBAs),and wilderness areas.Then,we constructed climate connectivity networks using a resistance-based approach and further quantified the network resilience to propose resilient climate response strategies in China.The results showed that existing PAs suffered from location biases with important biodiversity areas.The existing PAs represented about half of the KBAs and wilderness areas,yet only 12.08%of terrestrial mammalian species distribution hotspots were located within existing PAs.Compared with the existing PA network,the network efficiency and resilience of the expanded PAs'climate connectivity increased to 1.80 times and 1.78 times,respectively.With 56%of the nodes remaining,the network efficiency of the expanded PAs was equivalent to that of the existing PAs with all nodes.The network resilience of preferentially protecting and restoring low human footprint patches was approximately 1.5–2 times that of the random scenario.These findings highlighted that confronted with the unoptimistic situation of global warming,nature conservation based on existing PAs was no longer optimal.It was critical to construct a connected and resilient conservation network relying on both important biodiversity areas and low human footprint patches. 展开更多
关键词 Expansion of protected areas Mammalian species Connectivity corridors Network resilience Climate change adaptation
原文传递
Enhanced separation of tetrafluoropropanol from water via carbon nanotubes membranes:insights from molecular dynamics simulations
11
作者 Qing Li Xiaomeng Wang +7 位作者 Ying Liu Zhun Ma Qun Wang dongmei xu Jun Gao Ruirui Wu Hui Sun xueli Gao 《Frontiers of Environmental Science & Engineering》 SCIE EI CSCD 2023年第11期251-262,共12页
Fluorinated alcohols exhibit promising prospects in chemical industry because of their special structure and many exciting properties,in which tetrafluoropropanol(TFP)is extensive applied in synthesis of pesticides,dy... Fluorinated alcohols exhibit promising prospects in chemical industry because of their special structure and many exciting properties,in which tetrafluoropropanol(TFP)is extensive applied in synthesis of pesticides,dyestuffs,variety of solvents and detergents.However,the presence of TFP in water garners increasing attention globally because of their intrinsic potential to threat ecosystems and human health.Carbon nanotubes(CNTs)membranes are burgeoning candidates for TFP-water separation owing to well-endowed extraordinary structural and transport properties.However,a grand challenge lies in the rational design of CNTs for improving separation performance.Herein,molecular dynamics(MD)simulations were performed to investigate the effects of various parameters on the separation of TFP-water mixtures including feed temperature,CNTs pore diameters,and fluorine functionalization position.It was found that TFP was pre-selected in CNTs ranging from 9.48 to 18.98Ådue to preferential adsorption and diffusion mechanism.Excellent separation factor of 16 was achieved by(7,7)CNTs and the mass fraction of TFP was purified from 75%to 97.51%.Fluorine modified CNTs separated TFP and water by preferentially permeating water due to hydrogen bonding interaction.Simulation results showed that CNTs modified at both the entrance and interior had better separation performance than CNT modified only at one of these positions.The 100wt%water content in permeate was achieved by(11,11)CNTs modified with fluorine at the entrance and interior.These findings provide valuable insights for designing potential candidates for fluorinated alcohol-water azeotropic mixtures membrane separation,and promise extensive application aspects for the reclamation of fluorinated alcohol. 展开更多
关键词 Fluorinated alcohol Carbon nanotube Molecular simulation Fluorine modified
原文传递
Milk selenium content and speciation in response to supranutritional selenium yeast supplementation in cows 被引量:9
12
作者 Lingling Sun Gentao Liu +5 位作者 dongmei xu Zhaohai Wu Lu Ma Sanz-Fernandez M.Victoria Lance H.Baumgard Dengpan Bu 《Animal Nutrition》 SCIE CSCD 2021年第4期1087-1094,共8页
The effects of selenium(Se)yeast supplementation on performance,blood biochemical and antioxidant parameters,and milk Se content and speciation were evaluated.Thirty-six mid-lactation Holstein dairy cows were randomly... The effects of selenium(Se)yeast supplementation on performance,blood biochemical and antioxidant parameters,and milk Se content and speciation were evaluated.Thirty-six mid-lactation Holstein dairy cows were randomly assigned to 1 of 3 treatments:1)control(basal diet containing Se at 0.11 mg/kg DM),2)basal diet+0.5 mg supplemental Se/kg DM(SY-0.5),and 3)basal diet+5 mg supplemental Se/kg DM(SY-5).Selenium was supplemented as Se yeast.The trial consisted of a 1-week pretrial period and an 8-week experimental period.Milk somatic cell score decreased with SY-5 supplementation(P<0.05),but other performance parameters were not affected(P>0.05).The serum Se concentration increased with the increasing levels of Se yeast supplementation(P<0.05),however,blood biochemical parameters showed few treatment effects.The antioxidant capacity of dairy cows was improved with Se yeast supplementation reflected in increased serum glutathione peroxidase activity(P<0.05)and total antioxidant capacity(P=0.08),and decreased malondialdehyde concentration(P<0.05).Milk total Se concentration increased with Se dose(P<0.05).Also,the selenomethionine concentration increased with Se dose from 13.0±0.7 pg/kg in control to 33.1±2.1 pg/kg in SY-0.5 and 530.4±17.5 pg/kg in SY-5 cows(P<0.05).Similarly,selenocystine concentration increased from 15.6±0.9μg/kg in control and 18.9±1.1 pg/kg in SY-0.5 to 22.2±1.5 pg/kg in SY-5 cows(P<0.05).In conclusion,Se yeast is a good organic Se source to produce Se-enriched cow milk with increased Se species including selenomethionine and selenocystine.The results can provide useful information on milk Se species when a high dose Se yeast was supplemented in the cow diet. 展开更多
关键词 Dairy cow Selenium yeast Selenium speciation Milk performance
原文传递
Metal sulfides based composites as promising efficient microwave absorption materials:A review 被引量:6
13
作者 Bin Li Fenglong Wang +7 位作者 Kejun Wang Jing Qiao dongmei xu Yunfei Yang xue Zhang Longfei Lyu Wei Liu Jiurong Liu 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2022年第9期244-268,共25页
The increasingly severe electromagnetic microwave pollution raises higher requirements for the development of efficient microwave absorption(MA)materials.Metal sulfides are regarded as potential robust MA materials be... The increasingly severe electromagnetic microwave pollution raises higher requirements for the development of efficient microwave absorption(MA)materials.Metal sulfides are regarded as potential robust MA materials because of their unique optical,thermal,electrical,and magnetic properties,as well as the controllable microstructures.However,due to the limited MA performances of unary metal sulfides,morphology regulations and foreign materials hybridizations are adopted as effective strategies to improve their MA performances.Recent years witnessed the fast research progresses on the metal sulfides based MA materials and thus,a systematic literature survey on the materials design,fabrication,characterizations,MA behaviors,and the mechanisms behind is,highly desirable to summarize the rapid progress of this hot research area so as to provide guidance for the future development trend.This review firstly reviewed the research background,research progress,and basic principles of MA materials.Subsequently,the present synthetic methods and performance improvement strategies of metal sulfides based MA materials are systematically introduced.Then,by comparing the MA properties of one-dimensional,two-dimensional,and three-dimensional metal sulfides based composites,the influence of dimensionality and morphology on the MA properties are analyzed.By summarizing the research process of metal sulfides/dielectrics composites,metal sulfides/magnets composites,and metal sulfides/dielectrics/magnets composites MA materials,the influence of foreign materials hybridizations on the loss mechanisms and impedance matching conditions of metal sulfides based composites are revealed.Finally,the challenges and development prospects of metal sulfides based MA materials are presented.This review would provide a comprehensive understanding and insightful guidance for the exploration and development of efficient MA materials with thin thickness,light weight,wide absorption bandwidth,and strong absorption intensity. 展开更多
关键词 Metal sulfides Microwave absorption Structure regulation Materials hybridization Impedance matching
原文传递
Fluoride removal from secondary effluent of the graphite industry using electrodialysis:Optimization with response surface methodology 被引量:3
14
作者 Xiaomeng Wang Ning Li +8 位作者 Jianye Li Junjun Feng Zhun Ma Yuting xu Yongchao Sun dongmei xu Jian Wang xueli Gao Jun Gao 《Frontiers of Environmental Science & Engineering》 SCIE EI CAS CSCD 2019年第4期45-55,共11页
Response surface methodology was utilized to model and optimize the operational variables for defluoridation using an electrodialysis process as the treatment of secondary effluent of the graphite industry. Experiment... Response surface methodology was utilized to model and optimize the operational variables for defluoridation using an electrodialysis process as the treatment of secondary effluent of the graphite industry. Experiments were conducted using a Box-Behnken surface statistical design in order to evaluate the effects and the interaction of the influential variables including the operational voltage, initial fluoride concentration and flow rate. The regression models for defluoridation and energy consumption responses were statistically validated using analysis of variance (ANOVA);high coefficient of determination values (R^2 = 0.9772 and R^2 = 0.9814;respectively) were obtained. The quadratic model exhibited high reproducibility and a good fit of the experimental data. The optimum values of the initial fluoride concentration, voltage and flow rate were found to be 13.9 mg/L, 13.4 V, 102.5 L/h, respectively. A fluoride removal efficiency of 99.69% was observed under optimum conditions for the treatment of the secondary effluent of the graphite industry. 展开更多
关键词 Response surface METHODOLOGY FLUORIDE REMOVAL ELECTRODIALYSIS Box-Behnken design
原文传递
Determination of a suitable index for a solvent via two-column extractive distillation using a heuristic method 被引量:4
15
作者 Zhaoyou Zhu Guoxuan Li +3 位作者 Yao Dai Peizhe Cui dongmei xu Yinglong Wang 《Frontiers of Chemical Science and Engineering》 SCIE EI CAS CSCD 2020年第5期824-833,F0004,共11页
The traditional approach to solvent selction in the extractive distillation process strictly focuses on the change in the relative voltility of light-heavy components induced by the solvent.However,the total annual co... The traditional approach to solvent selction in the extractive distillation process strictly focuses on the change in the relative voltility of light-heavy components induced by the solvent.However,the total annual cost of the process may not be minimal when the solvent induces the largest change in relative volatility.This work presents a heuristic method for selecting the optimal solvent to minimize the total annual cost.The functional relationship between the relative volatility and the total annual cost is established,where the main factors,such as the relative volatility of the light-heavy components and the relative volatility of the heavy-component solvent,are taken into account.Binary azeotropic mixtures of methanol-toluene and methanol-acetone are separated to verify the feasibility of the model.The results show that using the solvent with the minimal two-column extractive distillation index,the process achieves a minimal total annual cost.The method is conducive for sustainable advancements in chemistry and engineering because a suitable solvent can be selected without simulation verification. 展开更多
关键词 heuristic method solvent selection extractive distillation total annual cost
原文传递
神经梅毒诊疗现状及进展 被引量:1
16
作者 许东梅 马小扬 黄宇明 《中华实验和临床感染病杂志(电子版)》 CAS 2022年第5期300-306,共7页
梅毒是我国最常见的性传播疾病之一,神经梅毒为最严重、最常见的梅毒并发症。中国疾病预防控制中心性病控制中心报告2014年至2019年中国梅毒发病率由2014年的30.93/10万增长至2019年的38.37/10万,呈逐年上升趋势;神经梅毒的发病率也随... 梅毒是我国最常见的性传播疾病之一,神经梅毒为最严重、最常见的梅毒并发症。中国疾病预防控制中心性病控制中心报告2014年至2019年中国梅毒发病率由2014年的30.93/10万增长至2019年的38.37/10万,呈逐年上升趋势;神经梅毒的发病率也随之增长。神经梅毒是梅毒螺旋体侵入神经系统所引起的脑、脊髓及周围神经损害的慢性感染性疾病,可出现于各期梅毒病程,一般认为,未经治疗的梅毒患者约20%可发展为无症状神经梅毒,后者中10%可进展为有症状神经梅毒。目前神经梅毒诊断尚无金标准,需依据患者病史、症状、体征、实验室、电生理、神经心理及神经影像等进行综合分析。目前用于治疗神经梅毒的抗菌药物包括β-内酰胺类、四环素类及大环内酯类,以青霉素为首选。神经梅毒药物治疗能否成功主要取决于抗菌药物在脑脊液中的有效浓度及维持时间,杀灭梅毒螺旋体所需脑脊液中青霉素浓度应>0.018 mg/L。神经梅毒推荐方案:青霉素1800~2400万U/d,静脉滴注(300~400万U/次,1次/4 h),连续10~14 d,继以苄星青霉素,240万U/周、肌肉注射、连用3次;或普鲁卡因青霉素240万U/d、肌肉注射、1次/d,同时口服丙磺舒,0.5 g/次、4次/d、共10~14 d,继以苄星青霉素,240万U/周、肌肉注射、连用3次。多学科协作治疗可有效改善患者精神症状及全身症状,对神经梅毒患者康复具有重要意义。糖皮质激素是否适合神经梅毒治疗,有待商榷;丙种球蛋白治疗神经梅毒的适应证、用药频次及疗效尚待进一步探讨。 展开更多
关键词 神经梅毒 诊断 抗菌药物 多学科协作治疗
原文传递
Cooperative effect from cation and anion of pyridine-containing anion-based ionic liquids for catalysing CO_2 transformation at ambient conditions 被引量:2
17
作者 Guangfeng Yuan Yanfei Zhao +4 位作者 Yunyan Wu Ruipeng Li Yu Chen dongmei xu Zhimin Liu 《Science China Chemistry》 SCIE EI CAS CSCD 2017年第7期958-963,共6页
Pyridine-containing anion-based ionic liquids(PA-ILs) with two kinds of interaction sites to bind CO_2, e.g., [P4444][2-OP], were found to be highly efficient for catalysing the cycloaddition reactions of atmospheric ... Pyridine-containing anion-based ionic liquids(PA-ILs) with two kinds of interaction sites to bind CO_2, e.g., [P4444][2-OP], were found to be highly efficient for catalysing the cycloaddition reactions of atmospheric CO_2 with epoxides at room temperature under metal-and halogen-free conditions, producing a series of cyclic carbonates in high yields. It was demonstrated that the cooperative interaction from two interaction sites in the anions of PA-ILs activated CO_2, while the cation activated the epoxides substrates via coordination to the central P+ unit, thus resulting in the high activity of the IL catalysts. 展开更多
关键词 ionic liquids CO2 transformation cyclic carbonates atmospheric pressure room temperature
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部