期刊文献+
共找到46篇文章
< 1 2 3 >
每页显示 20 50 100
“听”之内外——当代音乐之“泛结构”视野概述
1
作者 徐志博 《天津音乐学院学报》 2014年第2期67-75,共9页
当代音乐(声音)艺术作品中的意义逻辑线索与形式化声音构造间具有广泛的关联结构和互为因果的印证关系。不同于"共性音乐时期"的艺术审美,当下的听觉艺术具有同等重要的"外在"的音乐形态结构和"内在"的... 当代音乐(声音)艺术作品中的意义逻辑线索与形式化声音构造间具有广泛的关联结构和互为因果的印证关系。不同于"共性音乐时期"的艺术审美,当下的听觉艺术具有同等重要的"外在"的音乐形态结构和"内在"的音乐意义结构。借"源属"概念及创作、演绎、欣赏三重视角的提出,作品的"声音形态"与"意象形态"间包含了作为单一主体的多方位认知联想与多重主体认知联想间的"对位"。"泛结构"是承接两种音乐结构并将其"泛化"为一种"想象"的思维结构,具有"广泛"、"透出"、"延伸"、"一般性"的特点,并且是一种流动的、强调人的主体性的思维结构。"泛结构"的应用范围涵盖各类听觉艺术作品,并对作品的构成及其创作、认知过程起到关键作用。这些都体现了音乐(声音)艺术作品创造性思维中的某些共性特征。 展开更多
关键词 当代音乐 “泛结构” 形态结构 意义结构 “源属” 三重视角
下载PDF
Microstructures and properties of welded joint of aluminum alloy to galvanized steel by Nd:YAG laser + MIG arc hybrid brazing-fusion welding 被引量:5
2
作者 秦国梁 苏玉虎 王术军 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2014年第4期989-995,共7页
According to the differences in melting point between aluminum alloy and steel, 6013-T4 aluminum alloy was joined to galvanized steel by large spot Nd:YAG laser + MIG arc hybrid brazing-fusion welding with ER4043(A... According to the differences in melting point between aluminum alloy and steel, 6013-T4 aluminum alloy was joined to galvanized steel by large spot Nd:YAG laser + MIG arc hybrid brazing-fusion welding with ER4043(AlSi5) filler wire. The microstructures and mechanical properties of the brazed-fusion welded joint were investigated. The joint is divided into two parts of fusion weld and brazed seam. There is a zinc-rich zone at fusion weld toe, which consists of α(Al)-Zn solid solution and Al-Zn eutectic. The brazed seam is the Fe-Al intermetallic compounds (IMCs) layer of 2-4μm in thickness, and the IMCs include FeAl2, Fe2Al5 and Fe4Al13. FeAl2 and Fe2Al5 are located in the compact reaction layer near the steel side, and Fe4Al13 with tongue shape or sawtooth shape grows towards the fusion weld. The tensile strength of the joint firstly increases and then decreases as the welding current and laser power increase, the highest tensile strength can be up to 247.3 MPa, and the fracture usually occurs at fusion zone of the fusion weld. The hardness is the highest at the brazed seam because of hard Fe-Al IMCs, and gradually decreases along the fusion weld and galvanized steel, respectively. 展开更多
关键词 brazing-fusion weldingi welding of dissimilar metals hybrid welding mechanical properties intermetallic compounds
下载PDF
Meiotic Behavior of 1BL/1RS Translocation Chromosome and Alien Chromosome in Two Tri-genera Hybrids 被引量:3
3
作者 李义文 李振声 贾旭 《Acta Botanica Sinica》 CSCD 2002年第7期821-826,共6页
The behavior of wheat-rye translocation chromosome and alien chromosome including Thinopyrum and Haynaldia chromosome at meiosis was investigated in two hybrids by fluorescence in situ hybridization (FISH). Misdivisio... The behavior of wheat-rye translocation chromosome and alien chromosome including Thinopyrum and Haynaldia chromosome at meiosis was investigated in two hybrids by fluorescence in situ hybridization (FISH). Misdivision of translocation chromosome at anaphase I and rye chromatin micronucleus at tetrad stage were observed, A plant with one normal 1BL/1RS translocation chromosome and one 1BL/1RS translocation chromosome deleted about 1/3 of rye chromosome arm in length was identified. One plant with wheat-Thinopyrum non-Robertson translocation chromosome was also detected in the F-2 population of Yi4212 x Yi4095. That could be the results of unequal misdivision of wheat-rye 1BL/1RS translocation chromosome and Thinopyrum chromosome during meiosis. No interaction between translocation chromosome and alien chromosome at meiosis was supported by the data of the distribution frequencies of translocation chromosome and Thinopyrum or Haynaldia chromosome in the progeny of two hybrids. The results may be useful to cultivate new germplasms with different length of rye 1R short arm and wheat-alien non-Robertson translocation tines under wheat background. 展开更多
关键词 MEIOSIS chromatin univalent 1BL/1RS translocation chromosome fluorescence in situ hybridization
下载PDF
Synthesis of high-capacity LiNi_(0.8)Co_(0.1)Mn_(0.1)O_2 cathode by transition metal acetates 被引量:3
4
作者 肖政伟 张英杰 王一帆 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2015年第5期1568-1574,共7页
LiNi0.8Co0.1Mn0.1O2 cathode was synthesized using transition metal acetates under different synthesis conditions. Simultaneous thermogravimetric–differential scanning calorimetry–derivative thermogravimetric analysi... LiNi0.8Co0.1Mn0.1O2 cathode was synthesized using transition metal acetates under different synthesis conditions. Simultaneous thermogravimetric–differential scanning calorimetry–derivative thermogravimetric analysis was applied to investigating the mixture of transition metal acetates. X-ray powder diffraction and charge–discharge test were adopted to characterize the as-prepared LiNi0.8Co0.1Mn0.1O2. The mixture of transition metal acetates undergoes dehydration and decomposition during heating. All the examined LiNi0.8Co0.1Mn0.1O2 samples have a layered structure with R3 m space group. LiNi0.8Co0.1Mn0.1O2 samples prepared with different lithium sources under different synthesis conditions exhibit very different charge–discharge performances. The sample synthesized via the procedure of sintering at 800 °C after heating lithium carbonate and transition metal acetates at 550 °C achieves a highest capacity of 200.8 m A·h/g and an average capacity of 188.1 mA ·h/g in the first 20 cycles at 0.2C. 展开更多
关键词 Ni-rich cathode material transition metal acetate lithium source synthesis procedure
下载PDF
Relationship Between Heterosis and Endogenous Plant Hormones in Liriodendron 被引量:2
5
作者 李周岐 王章荣 《Acta Botanica Sinica》 CSCD 2002年第6期698-701,共4页
To investigate the possible involvement of endogenous plant hormones in heterosis of Liriodendron interspecific hybrid, growth traits and contents of endogenous GA 1/3 (gibberellin A 1, A 3), IAA (indole_3_a... To investigate the possible involvement of endogenous plant hormones in heterosis of Liriodendron interspecific hybrid, growth traits and contents of endogenous GA 1/3 (gibberellin A 1, A 3), IAA (indole_3_acetic acid) and iPA (isopentenyl adenine) of tulip tree ( L. chinense (Hemsl.) Sarg.), yellow poplar ( L. tulipifera L.) and their interspecific hybrid ( L. chinense × L. tulipifera ) were examined. Results showed that: (1) the heterosis in height growth trait of the interspecific hybrid was mainly caused by the reletively greater elongation of internodes. Although the uppermost three internodes had the potential of elongation, the first one, which had the greatest elongation amount, contributed to the heterosis of the height growth trait; (2) the contents of endogenous GA 1/3 , IAA and iPA were greatly different among tulip tree, yellow poplar and their interspecific hybrid. All of the three interspecific hybrid families studied significantly contained higher amount of endogenous GA 1/3 and iPA in the uppermost first internode than their parental species. And thus, a correlation between the contents of endogenous GA 1/3 and iPA, and hybrid vigor for height growth trait in Liriodendron was observed; (3) the rankings of endogenous GA 1/3 and iPA contents in the uppermost first internode of three hybrid families studied were not similar to the ranking for height of 3_year_old trees. Therefore, the contents of endogenous GA 1/3 and iPA in the uppermost first internode could not be used in predicting hybrid vigor among hybrid families. 展开更多
关键词 LIRIODENDRON heterosis (hybrid vigor) endogenous plant hormone
下载PDF
Strategic equilibrium price analysis and numerical simulation of preponderant high-tech metal mineral resources 被引量:3
6
作者 钟美瑞 谌杰宇 +1 位作者 朱学红 黄健柏 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2013年第10期3153-3160,共8页
Based on exploitation compensation value system of preponderant high-tech metal mineral resources and distortion of pricing mechanism, social utility function was constructed to modify decision utility function of dev... Based on exploitation compensation value system of preponderant high-tech metal mineral resources and distortion of pricing mechanism, social utility function was constructed to modify decision utility function of developers, and was extended to Stackelberg production decision model of preponderant high-tech metal mineral resources development. Analyzing the influences on market monopoly, output and price decision-making exerted by altruistic preferences, inequity aversion and sequential reciprocity fairness belief equilibrium, game fairness equilibrium which is significant in experimental economics can be obtained and verified by numerical simulation. In process of strategic pricing, method that uses the variation of producer surplus to measure strategic value from psychological preferences was proposed for the first time and technical support to improve exploitation compensation value system of preponderant metal mineral resources was available. 展开更多
关键词 METAL high-tech mineral mineral resources equilibrium price numerical simulation
下载PDF
Effects of Exogenous Amylases and Metal Ions on the Amylase Specific Activities and Starch Degradation of the Upper Leaves of ‘KRK_(26)' during Flue-curing 被引量:1
7
作者 赵昶灵 崔国民 孟凡来 《Agricultural Science & Technology》 CAS 2014年第10期1676-1683,共8页
Objective] The aim of this study was to investigate the effects of exoge-nous amylases and Ca2+, Mn2+ and K+ on the amylase specific activities and starch degradation of the upper leaves of 'KRK26' planted in Yun... Objective] The aim of this study was to investigate the effects of exoge-nous amylases and Ca2+, Mn2+ and K+ on the amylase specific activities and starch degradation of the upper leaves of 'KRK26' planted in Yunnan Province during flue-curing. [Method] The amylase specific activities and starch degradation of the leaves were determined by using spectrophotometry. [Result] The 8 U/g exogenous α-amy-lase could improve the specific activity of the leaf α-amylase at yel owing and color-fixing stages, but could not at stem-drying stage, and similarly, the 80 U/g exoge-nous β-amylase could improved the specific activity of the leaf β-amylase at the yel owing stage and the early period of color-fixing stage. The leaf starch could be enhanced to degrade by the exogenous α- or β-amylases and the enhancing effect of the former was stronger than that of the later. 1.50 mg/ml Ca2+ improved the specific activity of the leaf (α+β)-amylase mainly due to its enhancing effect on the leaf α-amylase, and increased the starch degradation. 4 mmol/L Mn2+ inhibited the leaf α-amylase from yel owing to the early period of color-fixing and the β- and (α+β)-amylases from the yel owing to the later period of color-fixing, but enhanced the leafα-amylase from the later period of color-fixing to the later period of stem-drying and the β- and (α+β)-amylases at the later period of stem-drying. Meanwhile, Mn2+ ham-pered the starch degradation during yel owing, but promoted it from the early period of color-fixing to stem-drying. 1 mg/ml K+ enhanced the leaf α-, β- and (α+β)-amy-lases during the yel owing stage, but lowered them from the early period of color-fix-ing to the later period of stem-drying, and always inhibited the leaf starch degrada-tion. [Conclusion] The exogenous α-, β- amylases and Ca2+ of suitable concentra-tions could be used to treat the tobacco leaves before flue-curing to improve the leaf starch degradation during the curing. 展开更多
关键词 Exogenous amylases and metal ions Amylase specific activity Starchdegradation Upper leaves of flue-cured tobacco variety 'KRK26' Flue-curing
下载PDF
Ore-forming material of Dachang tin deposit in Guangxi, China:Lead isotope evidence 被引量:3
8
作者 成永生 彭程 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2014年第11期3652-3659,共8页
For revealing the ore sources of the Dachang tin?polymetallic ore deposit, the lead isotopes were analyzed systematically by using the single minerals of sulphides, including pyrite, pyrrhotite, sphalerite, and galena... For revealing the ore sources of the Dachang tin?polymetallic ore deposit, the lead isotopes were analyzed systematically by using the single minerals of sulphides, including pyrite, pyrrhotite, sphalerite, and galena. Then, the mineral sources and their characteristics were discussed based on the classical lead isotope discriminating model. The results show that the lead isotope ratios of206Pb/204Pb,207Pb/204Pb, and208Pb/204Pb range from 17.478 to 18.638, 15.440 to 15.858, and 37.556 to 39.501, respectively. According to Zartman lead model, the ore lead contains the upper crust composition; however, the granite does not provide all ore leads, and other material sources exist. Obviously, the ore deposit belongs to the result of the combined effect of crust?mantle. The source rocks are characterized by a certain degree of similarity with the island arc material. Moreover, its distant origin in the upper and lower crusts may be related to the subduction island arc material or oceanic crust. The mantle-derived material may have a certain status in the source region. Meanwhile, based on the lead isotope three-dimensional topology projection vectors, the ore leads are concentrated in zoneA, which indicates the characteristics of Yangtze lead isotope province and a possible genetic relationship with Yangtze block. 展开更多
关键词 lead isotope ore source ore genesis Dachang tin-polymetallic deposit GUANGXI
下载PDF
Modeling Rice rgMT as a Plant Metallothionein-Like Protein by the Distance Geometry and Homology Methods
9
作者 吕暾 刘进元 +1 位作者 张日清 赵南明 《Acta Botanica Sinica》 CSCD 2003年第11期1297-1306,共10页
Rice metallothionein-like protein (rgMT) shows characteristics of a three-section pattern composed of two highly conserved cysteine rich (CR) domains in the terminals and a spacer without cysteine (cys) residues in th... Rice metallothionein-like protein (rgMT) shows characteristics of a three-section pattern composed of two highly conserved cysteine rich (CR) domains in the terminals and a spacer without cysteine (cys) residues in the center of the molecule. In this paper, the two CR domains and the spacer region were modeled by the distance geometry and homology methods separately. For the CR domains, twenty random models were generated for each cys combination based on the constraint conditions of CXC (C represents cys, X represents any amino acid other than cys), and CXXC motifs and a metal-sulfur chelating cluster. Four models for the N-terminal and two for C-terminal CR domain containing metal chelating structures formed by different combinations of cys were selected from 900 possible conformations. The GOR method was used to predict the secondary structure of the spacer region and its model was built by the homology method. After three parts of the protein were modeled, they were connected to form a three-dimensional structure model of rgMT. The whole conformation showed that rgMT could form two independent metal-sulfur chelating structures connected by a spacer peptide, without a structural or energy barrier for them to form two independent metal-chelating clusters just as mammalian metallothionein (MT) proteins. As all plant metallothionein-like (MT-L) proteins have the same primary structural characteristic, two CR domains connected by a spacer region, and many have the same cys arrangement pattern as rgMT, the three-dimensional structure model of rgMT will provide an important reference for the structural study of other plant MT-L proteins. 展开更多
关键词 distance geometry homology method rice metallothionein-like protein structural modeling
下载PDF
Effects of Different Nitrogen Sources and Metal Ions on Biogas Generation by Corn Stalk Fermentation
10
作者 齐辉阳 黄世臣 +1 位作者 王慧 李文浩 《Agricultural Science & Technology》 CAS 2016年第11期2525-2528,共4页
[Objective] The present study was conducted to explore the effects of dif- ferent nitrogen sources and metal ions on the biogas production process and biogas yield by fermentation of corn stalk powder using self-desig... [Objective] The present study was conducted to explore the effects of dif- ferent nitrogen sources and metal ions on the biogas production process and biogas yield by fermentation of corn stalk powder using self-designed anaerobic fermenta- tion system. [Method] The biogas produced during fermentation was collected by water displacement, and measured by ignition. [Result] Ammonium bicarbonate, urea and yeast extract powder all increased biogas yield. Among them, ammonium bi- carbonate was the best nitrogen source. Ammonium dihydrogen phosphate showed an inhibitory effect on biogas production. Biogas yield was significantly increased by adding NaCl, KCl, MgCl2 or CaCl2, among which, NaCl had the best effect. [Conclu- sion] It is not conducive to the growth and development of methanogenic flora in the production of biogas using corn stalks as the only material in fermentation. The biogas yield can be increased by adding exogenous nitrogen, which reduces the carbon to nitrogen (C:N) ratio of fermentation materials. The biogas yield can be significantly increased by adding appropriate types and amount of electrolytes, with appropriate C:N ratio. The methanogenic flora is more tolerant to NaCl and KCl than to MgCl2 and CaCl2. Moreover, NaCl can not only significantly increase the biogas production, but also shorten startup period of methanogenic flora, thereby shortening the gas producing cycle. 展开更多
关键词 FERMENTATION Corn stalk BIOGAS Nitrogen source Metal ion
下载PDF
Transition metal (Mo, Fe, Co, and Ni)-based catalysts for electrochemical CO_2 reduction 被引量:11
11
作者 Jinhui Hao Weidong Shi 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2018年第7期1157-1166,共10页
The electrochemical conversion of CO2 into value-added chemicals and fuels has attracted wide-spread concern since it realizes the recycling of greenhouse gases. Production of new materials lies at the very core of th... The electrochemical conversion of CO2 into value-added chemicals and fuels has attracted wide-spread concern since it realizes the recycling of greenhouse gases. Production of new materials lies at the very core of this technology as it enables the improvement of developmental efficiency and selectivity by chemical optimization of morphology and electronic structure. Transition metal-based catalysts are particularly appealing as their d bands have valence electrons which are close to the Fermi level and hence overcome the intrinsic activation barriers and reaction kinetics. The study of Mo, Fe, Co, and Ni-based materials in particular is a very recent research subject that offers various possibilities in electrochemical CO2 reduction applications. Herein, we summarize the recent re-search progress of Mo, Fe, Co, and Ni-based catalysts and their catalytic behavior in electrochemical CO〈sub〉2 reduction. We particularly focus on the relationship between structures and properties, with examples of the key features accounting for the high efficiency and selectivity of the CO2 reduction process. The most significant experimental and theoretical improvements are highlighted. Finally, we concisely discuss the scientific challenges and opportunities for transition metal-based catalysts. 展开更多
关键词 Transition metal Energyconversion ELECTROCATALYTIC CO2
下载PDF
Pb distribution and translocation in Jiaozhou Bay 被引量:1
12
作者 杨东方 苏畅 +2 位作者 高振会 孙培艳 曹丽歆 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2008年第3期296-299,共4页
The trends of distribution,translocation and seasonal change of heavy metal Pb were studied based on the surface and bottom water sampling in Jiaozhou Bay in 1979,and compared with those in 1990's.The results show... The trends of distribution,translocation and seasonal change of heavy metal Pb were studied based on the surface and bottom water sampling in Jiaozhou Bay in 1979,and compared with those in 1990's.The results showed that the source of Pb in the bay was from wastewater and sewage in the east of Jiaozhou Bay from ocean vessels.Pb concentration was higher in spring and lower in summer and autumn,and remained stable through sedimentation in the bottom layer.The overall water quality was good in 1970's.Compared with the environmental monitoring data of 1995-1999,Pb pollution had become serious.Therefore,more efforts should be made to protect the bay from Pb pollution. 展开更多
关键词 heavy metal Pb DISTRIBUTION pollution source TRANSLOCATION Jiaozhou Bay
下载PDF
Biotech key to unlock mineral resources value 被引量:2
13
作者 Guan-zhou QIU Xue-duan LIU 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2022年第7期2309-2317,共9页
This work aims to describe the history of biometallurgy in China,introduce the development and application of biometallurgy technologies in exploitation of mineral resources,and identify the main challenges and future... This work aims to describe the history of biometallurgy in China,introduce the development and application of biometallurgy technologies in exploitation of mineral resources,and identify the main challenges and future directions.Although the earliest biometallurgy activities in China were documented in 6th−7th century BC,fundamental research and biometallurgy applications started relatively late in this country.Rapid development,from phenotypic to genotypic characterization of biometallurgy microorganisms,as well as from theoretical to practical applications,has been made in China since the 1950s.The integrated applications of biometallurgy technology in copper,gold,and uranium extraction ensured China’s economic reserves of strategic mineral resources.Developing more efficient microorganisms and strengthening the micro-interface reactions will be an effective way to improve the biometallurgy efficiency.Biometallurgy technologies can also be adapted to recovery of valuable metal from marine minerals and e-wastes and environmental protection including carbon sequestration and heavy metal polluted soil/sediment bioremediation. 展开更多
关键词 BIOTECHNOLOGY biometallurgy BIOLEACHING mineral resources nonferrous metals
下载PDF
Cloning and characterization of a FLORICAULA/LEAFY ortholog, PFL, in polygamous papaya 被引量:4
14
作者 Qingyi YU Paul H. MOORE +2 位作者 Henrik H. ALBERT Adrienne H.K. ROADER Ray MING 《Cell Research》 SCIE CAS CSCD 2005年第8期576-584,共9页
The homologous genes FLORICAULA (FLO) in Antirrhinum and LEAFY (LFY) in Arabidopsis are known to regu- late the initiation of flowering in these two distantly related plant species. These genes are necessary also for ... The homologous genes FLORICAULA (FLO) in Antirrhinum and LEAFY (LFY) in Arabidopsis are known to regu- late the initiation of flowering in these two distantly related plant species. These genes are necessary also for the expression of downstream genes that control floral organ identity. We used Arabidopsis LFY cDNA as a probe to clone and sequence a papaya ortholog of LFY, PFL. It encodes a protein that shares 61% identity with the Arabidopsis LFY gene and 71% identity with the LFY homologs of the two woody tree species: California sycamore (Platanus racemosa) and black cottonwood (Populus trichocarpa). Despite the high sequence similarity within two conserved regions, the N-terminal proline-rich motif in papaya PFL differs from other members in the family. This difference may not affect the gene function of papaya PFL, since an equally divergent but a functional LFY ortholog NEEDLY of Pinus radiata has been reported. Genomic and BAC Southern analyses indicated that there is only one copy of PFL in the papaya genome. In situ hybridization experiments demonstrated that PFL is expressed at a relatively low level in leaf primordia, but it is expressed at a high level in the floral meristem. Quantitative PCR analyses revealed that PFL was expressed in flower buds of all three sex types - male, female, and hermaphrodite with marginal difference between hermaphrodite and unisexual flowers. These data suggest that PFL may play a similar role as LFY in flower development and has limited effect on sex differentiation in papaya. 展开更多
关键词 DIVERGENCE floral meristem identity gene flower development gene expression molecular phylogeny.
下载PDF
Catalytic reduction of NO_x by biomass-derived activated carbon supported metals 被引量:6
15
作者 Yun Shu Fan Zhang +1 位作者 Fan Wang Hongmei Wang 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2018年第10期2077-2083,共7页
In this study,to prepare a series of activated carbon-supported metals for the catalytic reduction of NO_x to N_2 in excess O_2,activated carbons derived from lignocellulosic and herbaceous biomasses were selected as ... In this study,to prepare a series of activated carbon-supported metals for the catalytic reduction of NO_x to N_2 in excess O_2,activated carbons derived from lignocellulosic and herbaceous biomasses were selected as the reducing agents,and alkali and transition metals were used as the catalytic active phases.The effects of the type of biomass,carbonization temperature and catalyst composition on NO_x reduction efficiency were analyzed in a fixed-bed flow reactor.The results showed that two temperature regimes are present for the NO_x-carbon reaction:at temperatures below 250°C,the NO_x adsorption process on the carbon surface was predominant,whereas true NO_x reduction by carbon occurred at temperatures above 250°C,producing N_2,CO_2 and CO.The influence of the carbonization temperature on carbon reactivity depended on the effect of the carbonization temperature on the carbon surface area and the reduction of the metal species on carbon.All studied metals catalyzed both NO_xand O_2reduction by carbon,and potassium could strongly enhance the C-NO_x reaction without substantial carbon consumption by O_2.Moreover,the potassium supported by sawdust-derived activated carbon exhibited higher selectivity and capacity towards NO_x reduction than did its previously reported coal-derived counterparts.These properties were ascribed to the high dispersion of the active potassium species on the carbon surface,as observed through the comparison of X-ray photoelectron spectroscopy and powder X-ray diffraction results for the carbons made from biomass and coal-based precursors. 展开更多
关键词 BIOMASS NOx reduction Activated carbon SELECTIVITY
下载PDF
Analysis on Refinery System as a Complex Task-resource Network 被引量:4
16
作者 刘苏昱 荣冈 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2013年第3期253-262,共10页
Refinery system, a typical example of process systems, is presented as complex network in this paper. The topology of this system is described by task-resource network and modeled as directed and weighted graph, in wh... Refinery system, a typical example of process systems, is presented as complex network in this paper. The topology of this system is described by task-resource network and modeled as directed and weighted graph, in which nodes represent various tasks and edges denote the resources exchanged among tasks. Using the properties of node degree distribution, strength distribution and other weighted quantities, we demonstrate the heterogeneity of the network and point out the relation between structural characters of vertices and the functionality of correspond- ing tasks. The above phenomena indicate that the design requirements and principles of production process contrib- ute to the heterogeneous features of the network. Besides, betweenness centrality of nodes can be used as an impor- tance indicator to provide additional information for decision making. The correlations between structure and weighted properties are investigated to further address the influence brought by production schemes in system con- nectivity patterns. Cascading failures model is employed to analyze the robustness of the network when targeted at- tack happens. Two capacity assignment strategies are compared in order to improve the robustness of the network at certain cost. The refinery system displays more reliable behavior when the protecting strategy considers heteroge- neous properties. This phenomenon further implies the structure-activity relationship of the refinery system and provides insightful suggestions for process system design. The results also indicate that robustness analysis is a _promising applicat!on of methodologies from complex networks to process system engineering.. 展开更多
关键词 zomplex network refinery system structure-activity relationship HETEROGENEITY robusmess
下载PDF
Challenges and new insights for exploitation of deep underground metal mineral resources 被引量:19
17
作者 Peng LI Mei-feng CAI 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2021年第11期3478-3505,共28页
Long-term and continuous large-scale exploitation has increasingly exhausted shallow metal mineral resources,and deep mining has become inevitable.The current global status of deep mining of metal mineral resources wa... Long-term and continuous large-scale exploitation has increasingly exhausted shallow metal mineral resources,and deep mining has become inevitable.The current global status of deep mining of metal mineral resources was presented,a series of engineering challenges faced by deep mining were systematically analyzed,and some progress and future innovation focus in key engineering technologies,such as the prediction and prevention of rockburst,cooling techniques,rock support techniques,deep hoisting techniques,and several nontraditional deep mining techniques,were highlighted.Meanwhile,new insights into development strategies of deep mining technology were proposed.The integration of these forward-looking key innovative technologies will form the overall framework of an innovative technology system for the deep mining of metal minerals.This technology system will help to achieve safe,efficient,and green exploitation of deep underground metal mineral resources and ensure the sustainable development of the metal mining industry. 展开更多
关键词 deep metal mineral resources engineering challenges disaster control nontraditional mining technique sustainable development
下载PDF
3D-ordered macroporous N-doped carbon encapsulating Fe-N alloy derived from a single-source metal-organic framework for superior oxygen reduction reaction 被引量:2
18
作者 Ya-Ru Lv Xue-Jing Zhai +3 位作者 Shan Wang Hong Xu Rui Wang Shuang-Quan Zang 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 2021年第3期490-500,共11页
Fe-N compounds with excellent electrocatalytic oxygen reduction activity are considered to be one of the most promising non-precious metal materials for fuel cells.Fe-N compounds with excellent electrocatalytic oxygen... Fe-N compounds with excellent electrocatalytic oxygen reduction activity are considered to be one of the most promising non-precious metal materials for fuel cells.Fe-N compounds with excellent electrocatalytic oxygen reduction activity are considered to be one of the most promising non-precious metal materials for fuel cells,which focuses on the Fe-N4 single-atom catalysts and the iron nitride materials(such as Fe2N and Fe3N).A hybridized catalyst having a hierarchical porous structure with regular macropores could enable the desired mass transfer efficiency in the catalytic process.In this study,we have constructed a new type of hybrid catalyst having iron and iron-nitrogen alloy nanoparticles(Fe-N austenite,termed as Fe-NA)embedded in the three-dimensional ordered macroporous N-doped carbon(3DOM Fe/Fe-NA@NC)by direct pyrolysis of single-source dicyandiamide-based iron metal-organic frameworks.The as-synthesized composites preserve the hierarchical porous carbon framework with ordered macropores and high specific surface area,incorporating the uniformly dispersed iron/iron-nitrogen austenite nanoparticles.Thereby,the striking architectural configuration embedded with highly active catalytic species delivers a superior oxygen reduction activity with a half-wave potential of 0.88 V and a subsequent superior Zn-air battery performance with high open-circuit voltage and continuous stability as compared to those using a commercial 20%Pt/C catalyst. 展开更多
关键词 Metal-organic framework Single-source precursor Oxygen reduction reaction Iron-nitrogen alloy
下载PDF
Multi-Level Fuzzy Comprehensive Assessment of Tourism Resources in Laiyuan County of Hebei Province
19
作者 王利军 《Journal of Landscape Research》 2009年第11期94-98,共5页
The membership of every target and the mathematic model of multi-level fuzzy comprehensive assessment are set up by using fuzzy theories and means in this study.Tourism resources of main scenic spots areas in Laiyuan ... The membership of every target and the mathematic model of multi-level fuzzy comprehensive assessment are set up by using fuzzy theories and means in this study.Tourism resources of main scenic spots areas in Laiyuan County of Hebei Province are evaluated and classified by applying the model.The results of evaluation indicate that 10 of these scenic spots such as Baoziwo and Qingyunfeng are grade A,and 6 of them such as Yunpan Valley and Xianrenqiao are grade B.The peak forest scenic area in the Baishishan Geological Park and Shipuxia Scenic Area are grade A,and Jumayuan Scenic Area is grade B.Furthermore,suggestions are put forward based on the scientific and feasible development of tourism resources. 展开更多
关键词 Quality of tourism resources Membership function Multi-level fuzzy comprehensive assessment
下载PDF
Ash-and-Slag Wastes of Energy Sector as Raw Material for Production of Rare-Earth Metals and Alumina
20
作者 Irina Blayda Larisa Slysarenko +1 位作者 Tatiana Vasyleva Zinesh Abisheva 《Journal of Environmental Science and Engineering(A)》 2012年第5期704-713,共10页
The results to develop a complex technology of co-extraction of germanium and gallium from the ash-and-slag wastes of coal combustion in Ukraine were presented. Based on the study of phase changes occurring in initial... The results to develop a complex technology of co-extraction of germanium and gallium from the ash-and-slag wastes of coal combustion in Ukraine were presented. Based on the study of phase changes occurring in initial raw materials as a result of its processing, it was proposed to carry out a preliminary enrichment of the raw materials in order to produce secondary sublimates. Their further processing involves a combination of leaching soluble material with distillation of germanium in the form of tetrachloride. The resulting acidic solutions are trended to the gallium extraction. Optimum conditions of carrying out of processes are recommended.The chemical and phase composition of the resulting dump products and solutions have been defined. On the basis of it ways of their processing for the purpose of reception of alumina and building materials are recommended. 展开更多
关键词 GALLIUM germanium ALUMINA fly ash leaching restorative burning.
下载PDF
上一页 1 2 3 下一页 到第
使用帮助 返回顶部