期刊文献+
共找到11篇文章
< 1 >
每页显示 20 50 100
Combined Promoting Effects of Specific Organic Functional Groups and Alumina Surface Characteristics for the Design of a Highly Efficient NiMo/Al_(2)O_(3) Hydrodesulfurization Catalyst 被引量:2
1
作者 Li Huifeng Li Mingfeng +2 位作者 Zhang Le Wang Wei Nie Hong 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS CSCD 2024年第1期1-11,共11页
To prepare a highly efficient NiMo/Al_(2)O_(3) hydrodesulfurization catalyst,the combined effects of specific organic functional groups and alumina surface characteristics were investigated.First,the correlation betwe... To prepare a highly efficient NiMo/Al_(2)O_(3) hydrodesulfurization catalyst,the combined effects of specific organic functional groups and alumina surface characteristics were investigated.First,the correlation between the surface characteristics of four different alumina and the existing Mo species states was established.It was found that the Mo equilibrium adsorption capacity can be used as a specific descriptor to quantitatively evaluate the changes in surface characteristics of different alumina.A lower Mo equilibrium adsorption capacity for alumina means weaker metal-support interaction and the loaded Mo species are easier to transform into MoS2.However,the Mo-O-Al bonds still exist at the metal-support interface.The introduction of cationic surfactant hecadecyl trimethyl ammonium bromide(CTAB)can further improve Mo species dispersion through electrostatic attraction with Mo anions and interaction of its alkyl chain with the alumina surface;meanwhile,the introduction of ethylenediamine tetraacetic acid(EDTA)can complex with Ni ions to enhance the Ni-promoting effect on Mo.Therefore,the NiMo catalyst designed using alumina with lower Mo equilibrium adsorption capacity and the simultaneous addition of EDTA and CTAB exhibits the highest hydrodesulfurization activity for 4,6-dimethyl dibenzothiophene because of its proper metal-support interaction and more well-dispersed Ni-Mo-S active phases. 展开更多
关键词 ALUMINA Mo equilibrium adsorption capacity organic functional groups metal-support interaction HYDRODESULFURIZATION
下载PDF
The Trace Elements are Bounded by Organic Functional Groups in Coal:A Studying Result Based on FTIR Analysis 被引量:5
2
作者 YANG Jianye WANG Guangheng ZHANG Weiguo 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2016年第1期154-165,共12页
The relationship between trace elements in coal and organic functional groups of coal, also some of aromatic structure, was investigated by using curve fitting of infrared spectra. Cluster analysis was also performed ... The relationship between trace elements in coal and organic functional groups of coal, also some of aromatic structure, was investigated by using curve fitting of infrared spectra. Cluster analysis was also performed according to the degree of affinity of organic groups to the trace elements. The results show that there is a possibility that trace elements, especially LREE, were bound to peripheral organic functional groups of middle rank coal macromolecule. The most possible functional group that binds trace element is the hydroxyl, and to the less degree, the asymmetric -CH3 and 〉CH2 stretching, -CH3 stretching, etc. The degree of affinity of trace elements to different functional groups varies. The tendency obeys the natural structural changing law of trace elements-- the periodic law. The deviation of some trace elements from this regular trend is attributed to the deviation of intrinsic "confusion degree" (conventional molar entropy) of the matter system of coal basin, which is affected by the inner and outer factors during the evolution. 展开更多
关键词 curve fitting organic functional groups in coal trace element periodic law of elements
下载PDF
我国非国家组织药品集中采购模式比较 被引量:10
3
作者 熊康 陈昊 《中国卫生资源》 北大核心 2021年第1期20-23,共4页
目的比较分析我国各省市的药品集中采购方案及相关政策,探讨各地非国家组织药品集中采购模式的特点。方法围绕采购内容、采购规则等比较分析各地的非国家组织药品集中采购模式的特点,以及采购内容、采购环境、采购规则之间的内在关系。... 目的比较分析我国各省市的药品集中采购方案及相关政策,探讨各地非国家组织药品集中采购模式的特点。方法围绕采购内容、采购规则等比较分析各地的非国家组织药品集中采购模式的特点,以及采购内容、采购环境、采购规则之间的内在关系。结果我国目前的非国家组织药品集中采购模式可划分为药品集中采购组织(group purchasing organization,GPO)、非过评仿制药带量采购、专项药品带量采购、带量议价以及分类采购框架下的带量采购5种。我国非国家组织药品集中采购的特点是分品种、分批次,以政府主导为主,执行机构主要为医疗保障局。结论目前,各地的非国家组织药品集中采购仅覆盖了部分品种的药品,对非过评仿制药进行集中采购是未来的重要趋势,建立公平、科学的质量分组规则是非国家组织药品集中采购亟待解决的重要技术问题。 展开更多
关键词 药品drug 带量集中采购centralized procurement with quantity 非国家组织集中采购non-national volumebased procurement 集中采购组织group procurement organization GPO 非过评仿制药带量采购procurement of drug which cannot pass quality and efficacy consistency evaluation 专项药品带量采购procurement of special drug 带量议价price bargaining 分类采购框架下的带量采购procurement under the classified procurement framework 仿制药一致性评价generics quality and efficacy consistency evaluation GQCE 质量分组规则quality grouping rule system
下载PDF
Geochemical characteristics and mode of occurrence of trace elements in coal at West Bokaro coalfield 被引量:5
4
作者 Sk. Md. Equeenuddin Subhasish Tripathy +1 位作者 Prafuila Kumar Sahoo Amit Ranjan 《International Journal of Coal Science & Technology》 EI 2016年第4期399-406,共8页
The mineralogy and trace element contents in coals from the West Bokaro coalfield, which is the one of the biggest Gondwana coalfields of India, were studied to delineate enrichment of trace elements and their modes o... The mineralogy and trace element contents in coals from the West Bokaro coalfield, which is the one of the biggest Gondwana coalfields of India, were studied to delineate enrichment of trace elements and their modes of occur- rence. Elemental concentrations with reference to their crustal abundances indicated that coals are relatively enriched in As (4.4-15.5 mg/kg), Cd (0.3-3.0 mg/kg), Cu (28.0-68.1 mg/kg) and V (46.6-178.0 mg/kg); depleted in Co (10.8-28.4 mg/ kg), Mn (7.6-483.4 mg/kg), Ni (13.0-31.6 mg/kg), Cr (14.2-85.5 mg/kg) and Zn (5.25-70.4 mg/kg). The concentration of As, Cd, Co, Cu and V were higher than the average values of world and Indian coals. Mineralogical study carried out by X-ray diffraction shows that quartz and kaolinite occur as dominant mineral phases in this coal. Fourier transform infrared spectroscopy pattern suggests organic structures primarily containing aromatic nuclei, aliphatic side chain and some oxygen containing groups. The modes of occurrence of trace elements present in these coals have been determined through statistical approach. Both Cu and Cr are more closely associated with mineral matter, whereas Co is dominantly present with its organic form. The concentrations of Cd, Mn, Ni, Zn, As and V have apparently occur in both organic and inorganic constituents. This study would be helpful to assess the potential environmental impacts during mining and combustion of this coal. 展开更多
关键词 MINERALOGY Organic group Trace elements COAL West Bokaro
下载PDF
Adsorption behaviour of Eu(Ⅲ) on natural bamboo fibres: effects of pH, humic acid, contact time, and temperature 被引量:2
5
作者 Tao Yu Jun Yang Ze-Yang Wang 《Nuclear Science and Techniques》 SCIE CAS CSCD 2020年第1期32-41,共10页
To study the adsorption properties of organic functional groups in plant fibres and identify a highly efficient and affordable adsorbent for radioactive wastewater treatment,natural bamboo fibre(NBF)samples were prepa... To study the adsorption properties of organic functional groups in plant fibres and identify a highly efficient and affordable adsorbent for radioactive wastewater treatment,natural bamboo fibre(NBF)samples were prepared,and the adsorption properties of Eu(Ⅲ)on NBFs were studied under given experimental conditions.The effects of the pH,solid-to-liquid ratio,background ions,humic acid,contact time,and temperature on the adsorption behaviour of Eu(Ⅲ)on NBFs were investigated.Adsorption was greatly influenced by pH,and the adsorption curves presented two inflection points at pH≈7 and pH≈11.Moreover,while the ionic strength presented a negative effect at pH<7,the high ionic strength favoured adsorption at pH>7.During adsorption on NBFs,the–OH,C–H,O–H,C–O,and C=O were the main adsorption groups.Hydrolysis occurring on the NBF surface caused the adsorption process to become increasingly difficult at pH>7.The maximum adsorption capacity of NBFs was 147.6 mg/g at 308 K,and the adsorption could be described using the pseudo-second-order kinetic model.The adsorption of Eu(Ⅲ)on NBFs was a spontaneous and endothermic process according to the thermodynamic parameters of the process,and the adsorption thermodynamics could be well described using the Freundlich adsorption model.Therefore,NBFs were determined to be an efficient,inexpensive,and easily disposable sewage treatment material. 展开更多
关键词 ADSORPTION EU(III) Natural bamboo fibre Organic functional group
下载PDF
Impact of intestinal ischemia/reperfusion and lymph drainage on distant organs in rats 被引量:8
6
作者 Gui-Zhen He Kai-Guo Zhou +2 位作者 Rui Zhang Yu-Kang Wang Xue-Feng Chen 《World Journal of Gastroenterology》 SCIE CAS CSCD 2012年第48期7271-7278,共8页
AIM:To investigate the impact of intestinal ischemia/reperfusion(I/R) injury and lymph drainage on distant organs in rats.METHODS:Thirty-two Sprague-Dawley male rats,weighing 280-320 g,were randomly divided into blank... AIM:To investigate the impact of intestinal ischemia/reperfusion(I/R) injury and lymph drainage on distant organs in rats.METHODS:Thirty-two Sprague-Dawley male rats,weighing 280-320 g,were randomly divided into blank,sham,I/R,and ischemia/reperfusion and drainage(I/R + D) groups(n = 8).All rats were subjected to 60 min ischemia by clamping the superior mesenteric artery,followed by 120 min reperfusion.The rats in the I/R + D group received intestinal lymph drainage for 180 min.In the sham group,the abdominal cavity was opened for 180 min,but the rats received no treatment.The blank group served as a normal and untreated control.A chromogenic limulus assay kit was used for quantita-tive detection of serum endotoxin.The serum concentrations of tumor necrosis factor-α(TNF-α),interleukin(IL)-6,IL-1β,soluble cell adhesion molecules(sICAM-1),and high mobility group protein box 1(HMGB1) were determined with an enzyme-linked immunosorbent assay kit.Histological evaluations of the intestine,liver,kidney,and lung were performed by hematoxylin and eosin staining and immunohistochemistry.HMGB1 protein expression was assayed by western blot analysis.RESULTS:The serum levels of endotoxin and HMGB1 in the I/R and I/R + D groups were significantly higher than those in the sham group(endotoxin,I/R and I/R + D vs sham:0.033 ± 0.004 EU/mL,0.024 ± 0.003 EU/mL vs 0.017 ± 0.009 EU/mL,respectively,P < 0.05;HMGB1,I/R and I/R + D vs sham:5.473 ± 0.963 EU/mL,4.906 ± 0.552 EU/mL vs 0.476 ± 0.406 EU/mL,respectively,P < 0.05).In addition,endotoxin and HMGB1 were significantly lower in the I/R + D group compared to the I/R group(P < 0.05).The serum inflammatory factors IL-6,IL-1β,and sICAM-1 in the I/R and I/R + D groups were significantly higher than those in the sham group(IL-6,I/R and I/R + D vs sham:41.773 ± 9.753 pg/mL,19.204 ± 4.136 pg/mL vs 11.566 ± 2.973 pg/mL,respectively,P < 0.05;IL-1β,I/R and I/R + D vs sham:144.646 ± 29.378 pg/mL,65.829 ± 10.888 pg/mL vs 38.178 ± 7.157 pg/mL,respectively,P < 0.05;sICAM-1,I/R and I/R + D vs sham:97.360 ± 12.714 ng/mL,48.401 ± 6.547 ng/mL vs 33.073 ± 5.957 ng/mL,respectively;P < 0.05).The serum TNF-α in the I/R group were significantly higher than in the sham group(45.863 ± 11.553 pg/mL vs 18.863 ± 6.679 pg/mL,respectively,P < 0.05).These factors were significantly lower in the I/R + D group compared to the I/R group(P < 0.05).The HMGB1 immunohistochemical staining results showed no staining or apparent injury in the blank group,and slight staining at the top of the microvillus was detected in the sham group.In the I/R group,both the top of villi and the basement membrane were stained for HMGB1 in most areas,and injury in the I/R + D group was less than that in the I/R group.HMGB1 expression in the liver,kidney,and lung of rats in the I/R + D group was significantly lower than the rats in the I/R group(P < 0.05).CONCLUSION:Lymph drainage could block the "gutlymph" pathway,improve intestinal barrier function,and attenuate distant organ injury incurred by intestinal I/R. 展开更多
关键词 Intestinal ischemia/reperfusion Lymph drainage Distant organ injury High mobility group protein box 1 Endotoxin Cytokines
下载PDF
A NEW POLYMER-BOUND 1,2-DIOL AS A PROTECTING AGENT FOR SYMMETRICAL DIALDEHYDE
7
作者 任启生 黄文强 +1 位作者 赵芬芝 何炳林 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 1989年第4期346-353,共8页
A novel polymer-bound 1,2-diol, 3-polystyrylsulfonyl-1,2-propanediol (6) had been prepared by the reaction of sodium polystyrylsulfinate with allyl bromide, followed by oxidation and. hydrolysis or directly with 3-chl... A novel polymer-bound 1,2-diol, 3-polystyrylsulfonyl-1,2-propanediol (6) had been prepared by the reaction of sodium polystyrylsulfinate with allyl bromide, followed by oxidation and. hydrolysis or directly with 3-chloro-1,2-propanediol in the presence of a phase transfer catalyst, n-tetrabutylammonium iodide. The capacity of resin 6 for terephthaidehyde reached 1.43 mmol/g. The aldehydic groups attached to polymer 6 reacted with hydroxylamine hydrochloride or reduced by sodium borohydride giving p-formylbenzaldoxime (yield: 89%)and p-formyl-benzalcohol (yield: 734%), respectively. The high yields of these polymer-supported reactions showed that the polymer 6 possessed the effective isolation of its reactive sites. 展开更多
关键词 3-polystyrylsulfonyl-1 2 - propanediol polymer-supported protecting group solid - phase organic synthesis cleavage of aldol linkages
下载PDF
The reaction of perfluoroalkanesulfonyl halides Ⅷ. A mild method for introducing BrCF_2 group to organic molecules 被引量:3
8
作者 HUANG, Wei-Yuan ZHANG, Han-Zhong Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032 《Chinese Journal of Chemistry》 SCIE CAS CSCD 1992年第3期274-277,共0页
BrCF_2SO_2Br, prepared from sulfinatodehalogenation of CF_2Br_2 followed by bromination of the intermediate BrCF_2SO_2Na, was shown to be a mild and efficient bromodifluoromethylating agent.
关键词 PPM CF A mild method for introducing BrCF2 group to organic molecules The reaction of perfluoroalkanesulfonyl halides
全文增补中
Discovering Functional Organized Keyword Recommendation Point of Interest Groups for Spatial
9
作者 Yan-Xia Xu Wei Chen +3 位作者 Jia-Jie Xu Zhi-Xu Li Guan-Feng Liu Lei Zhao 《Journal of Computer Science & Technology》 SCIE EI CSCD 2018年第4期697-710,共14页
A point of interest (POI) is a specific point location that someone may find useful. With the development of urban modernization, a large number of functional organized POI groups (FOPGs), such as shopping malls, ... A point of interest (POI) is a specific point location that someone may find useful. With the development of urban modernization, a large number of functional organized POI groups (FOPGs), such as shopping malls, electronic malls, and snacks streets, are springing up in the city. They have a great influence on people's lives. We aim to discover functional organized POI groups for spatial keyword recommendation because FOPGs-based recommendation is superior to POIs-based recommendation in efficiency and flexibility. To discover FOPGs, we design clustering algorithms to obtain organized POI groups (OPGs) and utilize OPGs-LDA (Latent Dirichlet Allocation) model to reveal functions of OPGs for further recommendation. To the best of our knowledge, we are the first to study functional organized POI groups which have important applications in urban planning and social marketing. 展开更多
关键词 functional organized point of interest (POI) group POI clustering OPG-LDA (organized point of interest group-latent Dirichlet allocation) model spatial keyword recommendation
原文传递
Adsorption Kinetics of 2,2′,4,4′-Tetrabromodiphenyl Ether(BDE-47) on Maize Straw-Derived Biochars 被引量:3
10
作者 LIU Guangxia SONG Yang +6 位作者 SHENG Hongjie YE Mao Robert DSTEDTFELD BIAN Yongrong GU Chenggang JIANG Xin WANG Fang 《Pedosphere》 SCIE CAS CSCD 2019年第6期721-729,共9页
The chars in the natural environment can affect the migration of polybrominated diphenyl ethers(PBDEs). However, there is insufficient research relating to the adsorption behavior and mechanisms of PBDEs on biochars. ... The chars in the natural environment can affect the migration of polybrominated diphenyl ethers(PBDEs). However, there is insufficient research relating to the adsorption behavior and mechanisms of PBDEs on biochars. This study examined the adsorption kinetics of 2,2′,4,4′-tetrabromodiphenyl ether(BDE-47) on maize straw-derived biochars(MSBCs) pyrolyzed at four different temperatures via batch experiments. The biochar samples were characterized using Fourier transform infrared(FTIR) spectroscopy,Raman spectra, and elemental analysis. A two-compartment first-order model and pseudo-second-order model exhibited a better fit compared to a pseudo-first-order model in describing the BDE-47 adsorption on biochars, which was dominated by a slow adsorption compartment and chemisorption. The MSBC pyrolyzed at 600 °C had the highest BDE-47 adsorption capacity owing to its relatively large specific surface area and relatively high aromaticity compared with the other three MSBCs pyrolyzed at 300, 400, and 500 ℃.However, there was no significant difference in adsorption capacity among the other three biochars. The organic functional groups coupled with the graphene structures of biochars and the hydrophobic effect of the functional groups promoted the adsorption of BDE-47. Pore diffusion was not the sole rate-limiting step;film diffusion was also involved in the adsorption process of BDE-47 on biochars. The overall results demonstrate the transport and potential treatment of PBDEs using biochars. 展开更多
关键词 Adsorption capacity Film diffusion Graphene structure Organic functional group Organic pollutant Polybrominated diphenyl ethers Pore diffusion Pyrolysis temperature
原文传递
Recent Progress and Design Principles for Rechargeable Lithium Organic Batteries 被引量:4
11
作者 Xiudong Chen Xiaojie Yin +2 位作者 Junaid Aslam Weiwei Sun Yong Wang 《Electrochemical Energy Reviews》 SCIE EI 2022年第4期190-221,共32页
The most commonly used electrode materials in lithium organic batteries(LOBs)are redox-active organic materials,which have the advantages of low cost,environmental safety,and adjustable structures.Although the use of ... The most commonly used electrode materials in lithium organic batteries(LOBs)are redox-active organic materials,which have the advantages of low cost,environmental safety,and adjustable structures.Although the use of organic materials as electrodes in LOBs has been reported,these materials have not attained the same recognition as inorganic electrode materials,mainly due to their slight electronic conductivity and possible solubility in organic electrolytes,resulting in a low reversible capacity.However,over the past 10 years,organic materials have achieved outstanding results when used as battery electrodes,and an increasing number of researchers have realized their significance.This review summarizes the recent progress in organic electrodes for use in rechargeable LOBs.By classifying Li-storage mechanisms with various functional organic groups and designing molecules for next-generation advanced lithium organic systems,we attempt to analyze the working principle and the effect of various organic functionalities on electrochemical performance,to reveal the advantages and disadvantages of various organic molecules and to propose possible design principles and development trends for future LOBs.In addition,we highlight the recently reported two-dimensional covalent organic framework that is unique in its extensiveπconjugated structure and Li-storage mechanisms based on benzene and N-containing rings;this framework is considered to be the most promising alternative to metal-based electrode materials with comparable large reversible capacities and long cycle lives. 展开更多
关键词 Lithium organic batteries Li-storage mechanism Organic electrode Organic functional group Redox mechanism
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部