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A Restriction Theorem on the Reduced Product Heisenberg Group
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作者 何建勋 《Chinese Quarterly Journal of Mathematics》 CSCD 1999年第2期59-62, ,共4页
In this paper,we give the Plancherel formula on the reduced product Heisenberg group,and obtain a restriction theorem on this group.
关键词 reduced product Heisenberg group Plancherel formula restriction theorem
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Development and Utilization of the World's and China's Bulk Mineral Resources and their Supply and Demand Situation in the Next Twenty Years 被引量:9
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作者 ZHANG Zhaozhi JIANG Guangyu +1 位作者 WANG Xianwei ZHANG Jianfeng 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2016年第4期1370-1417,共48页
Bulk mineral resources of iron ores, copper ores, bauxite, lead ores, zinc ores and potassium salt play a pivotal role on the world's and China's economic development. This study analyzed and predicted their resourc... Bulk mineral resources of iron ores, copper ores, bauxite, lead ores, zinc ores and potassium salt play a pivotal role on the world's and China's economic development. This study analyzed and predicted their resources base and potential, development and utilization and their world's and China's supply and demand situation in the future 20 years. The supply and demand of these six bulk mineral products are generally balanced, with a slight surplus, which will guarantee the stability of the international mineral commodity market supply. The six mineral resources (especially iron ores and copper ores) are abundant and have a great potential, and their development and utilization scale will gradually increase. Till the end of 2014, the reserve- production ratio of iron, copper, bauxite, lead, zinc ores and potassium salt was 95 years, 42 years, 100 years, 17 years, 37 years and 170 years, respectively. Except lead ores, the other five types all have reserve-production ratio exceeding 20 years, indicative of a high resources guarantee degree. If the utilization of recycled metals is counted in, the supply of the world's six mineral products will exceed the demand in the future twenty years. In 2015-2035, the supply of iron ores, refined copper, primary aluminum, refined lead, zinc and potassium salt will exceed their demand by 0.4-0.7 billion tons (Gt), 5.0-6.0 million tons (Mt), 1.1-8.9 Mt, 1.0-2.0 Mt, 1.2-2.0 Mt and 4.8-5.6 Mt, respectively. It is predicted that there is no problem with the supply side of bulk mineral products such as iron ores, but local or structural shortage may occur because of geopolitics, monopoly control, resources nationalism and trade friction. Affected by China's compressed industrialized development model, the demand of iron ores (crude steel), potassium salt, refined lead, refined copper, bauxite (primary aluminum) and zinc will gradually reach their peak in advance. The demand peak of iron ores (crude steel) will reach around 2015, 2016 for potassium salt, 2020 for refined lead, 2021 for bauxite (primary aluminum), 2022 for refined copper and 2023 for zinc. China's demand for iron ores (crude steel), bauxite (primary aluminum) and zinc in the future 20 years will decline among the world's demand, while that for refined copper, refined lead and potassium salt will slightly increase. The demand for bulk mineral products still remains high. In 2015-2035, China's accumulative demand for iron ores (crude steel) will be 20.313 Gt (13.429 Gt), 0.304 Gt for refined copper, 2.466 Gt (0.616 Gt) of bauxite (primary aluminum), 0.102 Gt of refined lead, 0.138 Gt of zinc and 0.157 Gt of potassium salt, and they account for the world's YOY (YOY) accumulative demand of 35.17%, 51.09%, 48.47%, 46.62%, 43.95% and 21.84%, respectively. This proportion is 49.40%, 102.52%, 87.44%, 105.65%, 93.62% and 106.49% of that in 2014, respectively. From the supply side of China's bulk mineral resources, it is forecasted that the accumulative supply of primary (mine) mineral products in 2015-2035 is 4.046 Gt of iron ores, 0.591 Gt of copper, 1.129 Gt of bauxite, 63.661 Mt of (mine) lead, 0.109 Gt of (mine) zinc and 0.128 Gt of potassium salt, which accounts for 8.82%, 13.92%, 26.67%, 47.09%, 33.04% and 15.56% of the world's predicted YOY production, respectively. With the rapid increase in the smelting capacity of iron and steel and alumina, the rate of capacity utilization for crude steel, refined copper, alumina, primary aluminum and refined lead in 2014 was 72.13%, 83.63%, 74.45%, 70.76% and 72.22%, respectively. During 2000-2014, the rate of capacity utilization for China's crude steel and refined copper showed a generally fluctuating decrease, which leads to an insufficient supply of primary mineral products. It is forecasted that the supply insufficiency of iron ores in 2015-2035 is 17.44 Gt, 0.245 Gt of copper in copper concentrates, 1.337 Gt of bauxite, 38.44 Mt of lead in lead concentrates and 29.19 Mt of zinc in zinc concentrates. China has gradually raised the utilization of recycled metals, which has mitigated the insufficient supply of primary metal products to some extent. It is forecasted that in 2015-2035 the accumulative utilization amount of steel scrap (iron ores) is 3.27 Gt (5.08 Gt), 70.312 Mt of recycled copper, 0.2 Gt of recycled aluminum, 48 Mt of recycled lead and 7.7 Mt of recycled zinc. The analysis on the supply and demand situation of China's bulk mineral resources in 2015-2035 suggests that the supply-demand contradiction for these six types of mineral products will decrease, indicative of a generally declining external dependency. If the use of recycled metal amount is counted in, the external dependency of China's iron, copper, bauxite, lead, zinc and potassium salt will be 79%, 65%, 26%, 8%, 16% and 18% in 2014, respectively. It is predicted that this external dependency will decrease to 62%, 64%, 20%, -0.93%, 16% and 14% in 2020, respectively, showing an overall decreasing trend. We propose the following suggestions correspondingly. (1) The demand peak of China's crude steel and potassium salt will reach during 2015-2023 in succession. Mining transformation should be planned and deployed in advance to deal with the arrival of this demand peak. (2) The supply-demand contradiction of China's bulk mineral resources will mitigate in the future 20 years, and the external dependency will decrease accordingly. It is suggested to adjust the mineral resources management policies according to different minerals and regions, and regulate the exploration and development activities. (3) China should further establish and improve the forced mechanism of resolving the smelting overcapacity of steel, refined copper, primary aluminum, lead and zinc to really achieve the goal of "reducing excess production capacity". (4) In accordance with the national strategic deployment of "One Belt One Road", China should encourage the excess capacity of steel, copper, alumina and primary aluminum enterprises to transfer to those countries or areas with abundant resources, high energy matching degree and relatively excellent infrastructure. Based on the national conditions, mining condition and geopolitics of the resources countries, we will gradually build steel, copper, aluminum and lead-zinc smelting bases, and potash processing and production bases, which will promote the excess capacity to transfer to the overseas orderly. (5) It is proposed to strengthen the planning and management of renewable resources recycling and to construct industrial base of renewable metal recycling. (6) China should promote the comprehensive development and utilization of paragenetic and associated mineral species to further improve the comprehensive utilization of bulk mineral resources. 展开更多
关键词 China bulk scarce mineral resource development and utilization demand prediction supply and demand analysis reducing excess production capacity
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Reduced Crossed Products of Pro-Banach Algebras
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作者 Lizhong HUANG Yu GUO 《Chinese Annals of Mathematics,Series B》 SCIE CSCD 2022年第2期295-306,共12页
This paper gives the concept of the reduced pro-Banach algebra crossed product associated with inversely pro-Banach algebra dynamical system,and shows that the reduced crossed product is an inverse limit of an inverse... This paper gives the concept of the reduced pro-Banach algebra crossed product associated with inversely pro-Banach algebra dynamical system,and shows that the reduced crossed product is an inverse limit of an inverse system of Banach algebra crossed products.Also,the authors show that if the locally compact group is amenable,then the crossed product and the reduced crossed product are isometrically isomorphic. 展开更多
关键词 Pro-Banach algebras dynamical systems reduced crossed products Crossed products REPRESENTATIONS
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Bio-immobilization and recovery of chromium using a denitrifying biofilm system: Identification of reaction zone, binding forms and end products
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作者 Yingxin Zhao Junzhi Gao +4 位作者 Xu Zhou Zhouran Li Cailian Zhao Xulong Jia Min Ji 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2023年第4期70-80,共11页
Chromium is an important resource in strategic metals.Different from most studies focusing on the bio-reduction of hexavalent chromium[Cr(VI)],this study aims to achieve the immobilization and recovery of chromium usi... Chromium is an important resource in strategic metals.Different from most studies focusing on the bio-reduction of hexavalent chromium[Cr(VI)],this study aims to achieve the immobilization and recovery of chromium using a sequencing batch biofilm reactor.Results showed that Cr(VI) removal efficiency remained more than 99%,and 97%of reduced Cr(III) was immobilized in the biofilm.Immobilization zone,chromium forms and extracellular polymeric substances composition changes were combined to reveal the mechanism of Cr(VI) reduction and immobilization.The chromium distribution in biofilm demonstrated that intercellular layer was the main active zone with an immobilization amount of 891.70±126.32 mg/g-VSS.The reduced products analysis confirmed that trivalent chromium[Cr(III)]chelated with carboxyl,amino and other functional groups and immobilized in the form of organic Cr(III).The digestion method realized a chromium recovery efficiency of 74.59%.This study provides an alternative method for the bioremediation and resources recovery in chromium polluted wastewater. 展开更多
关键词 Denitrifying biofilm Cr(Ⅵ)reduction Immobilization zone reduced product Mechanism
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Product Systems of C^(*)-correspondences and Baaj-Skandalis Duality
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作者 Fei Fei MIAO Li Guang WANG Wei YUAN 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2023年第2期240-256,共17页
Let X={X_(p)}p∈Pbe a product system over a lattice ordered group(G,P)with coefficients in a C*-algebra A.In this paper,we study the reduced crossed product of the gauge coactionδof G on the Cuntz-Pimsner algebra NO_... Let X={X_(p)}p∈Pbe a product system over a lattice ordered group(G,P)with coefficients in a C*-algebra A.In this paper,we study the reduced crossed product of the gauge coactionδof G on the Cuntz-Pimsner algebra NO_(X)^(r).When X is a product system of Morita equivalence bimodules,we show that the reduced crossed product of the gauge coaction is Morita equivalent to the C*-algebra A. 展开更多
关键词 Cuntz-Pimsner algebras product systems reduced crossed products Morita equivalence
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Development and industrial application of ultra-fast cooling technology 被引量:10
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作者 TIAN Yong TANG Shuai +2 位作者 WANG BingXing WANG ZhaoDong WANG GuoDong 《Science China(Technological Sciences)》 SCIE EI CAS 2012年第6期1566-1571,共6页
A new-generation TMCP(NG-TMCP) with ultra fast cooling(UFC) as core technique was suggested instead of the conventional TMCP in which some problems are to be solved.And the ultra fast cooling technology has been succe... A new-generation TMCP(NG-TMCP) with ultra fast cooling(UFC) as core technique was suggested instead of the conventional TMCP in which some problems are to be solved.And the ultra fast cooling technology has been successfully applied to the plate rolling production in Shouqin Metal Materials Co.Ltd.Industrial trials are reported for the production of X70 pipeline steels(about 70000 t) under UFC conditions.Pipeline steels with reasonably good properties have been produced on an industrial scale.UFC can improve the temperature uniformity,the mechanical properties and the plate profile of X70 pipeline steel.The performance features of the trial plates can meet the standard of X70 pipeline steel.Spot test results have shown that the qualification rate of shape control,the performance and charpy impact properties for the trial plates are 95%,97% and 98%,respectively.The impact values of X70 pipeline steel at UFC mode exceed the standard requirements of X80 pipeline steel.The productivity is enhanced because cutting quantity of head and tail of the plate is reduced.The enhancement of control accuracy of the red back temperatures is favorable for industrial production of X70 pipeline steel.The reduced production of the steel-making has been industrially achieved,since a new composition was designed by reducing the vanadium content to less than 0.045 wt.%. 展开更多
关键词 pipeline steel ultra fast cooling the reduced production PLATE
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Lipschitzness of *-homomorphisms between C*-metric algebras 被引量:4
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作者 WU Wei 《Science China Mathematics》 SCIE 2011年第11期2473-2485,共13页
A C*-metric algebra consists of a unital C*-algebra and a Leibniz Lip-norm on the C*-algebra. We show that if the Lip-norms concerned are lower semicontinuous, then any unital *-homomorphism from a C*-metric algebra t... A C*-metric algebra consists of a unital C*-algebra and a Leibniz Lip-norm on the C*-algebra. We show that if the Lip-norms concerned are lower semicontinuous, then any unital *-homomorphism from a C*-metric algebra to another one is necessarily Lipschitz. We come to the result that the free product of two unital completely Lipschitz contractive *-homomorphisms from upper related C*-metric algebras coming from *-filtrations to those which are lower related is a unital Lipschitz *-homomorphism. 展开更多
关键词 C^*-metric algebra unital ^*-homomorphism lower semicontinuous seminorm Leibniz seminorm reduced free product Lipschitz map
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Banach Algebra Dynamical Systems 被引量:2
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作者 Dong LI Shengzhi XU 《Chinese Annals of Mathematics,Series B》 SCIE CSCD 2014年第2期285-300,共16页
Abstract This paper generalizes the C*-dynamical system to the Banach algebra dynam- ical system (A, G, α) and define the crossed product A αG of a given Banach algebra dynamical system (A, G,α). Then the re... Abstract This paper generalizes the C*-dynamical system to the Banach algebra dynam- ical system (A, G, α) and define the crossed product A αG of a given Banach algebra dynamical system (A, G,α). Then the representation of A α G is described when A ad- mits a bounded left approximate identity. In a natural way, the authors define the reduced crossed product A αG and discuss the question when A α G coincides with A αG. 展开更多
关键词 Banach algebra dynamical systems REPRESENTATION Crossed product Left multiplier reduced crossed product
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