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Corrosion Study of Base Material and Welds of a Ni-Cr-Mo-W Alloy

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Acta Metallurgica Sinica(English Letters) 2017年第4期30卷 326-332页

作者： Ajit Mishra haynes international Inc. 1020 West Park AvenueKokomo IN 46904 USA

Alloys containing chromium （Cr） and molybdenum （Mo）, as the major alloying elements, are widely used in various industries where the material experiences corrosive environments. Chromium （Cr）, when added in an optimum amount, forms a Cr203 passive film which protects the underlying metal in aggressive solutions. Molybdenum （Mo） forms its oxides in the low pH solutions, thus, enhances the uniform corrosion resistance of an alloy in reducing acids and assists in inhibition to localized corrosion. Minor alloying elements, like tungsten （W） and copper （Cu）, also improve the overall corrosion resistance of an alloy in specific solutions. In the present study, corrosion resistance behavior of commercial iron- based alloys （316L SS, 254 SMO and 20Cb3） and nickel-based alloys （Mone1400, Alloy 625 and C-276） was studied in the acidic solutions. While the corrosion behavior of wrought alloys has been widely studied, there is little to no information on the corrosion performance of their welds, typically being the weak regions for corrosion initiation and propagation. Therefore, an attempt was undertaken to investigate the uniform and localized corrosion performance of base metal, simulated heat-affected zone and all-weld-metal samples of a Ni-Cr-Mo-W alloy, C-276. The study was conducted in aggressive acidic solutions. Various corrosion and surface analytical techniques were utilized to analyze the results.

关键词： Iron-chromium-molybdenum Nickel-chromium-molybdenum-tungsten All-weld-metal Heat-affected-zone Acids Acidified ferric chloride Potentiodynamic Scanning electronmicroscopy (SEM)

Performance of Corrosion-Resistant Alloys in Concentrated Acids

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Acta Metallurgica Sinica(English Letters) 2017年第4期30卷 306-318页

作者： Ajit Mishra Research and Technology Haynes International 1020 ParkAve Kokomo IN 46902 USA

Nickel alloys containing optimum amounts of chromium （Cr）, molybdenum （Mo） and tungsten （W） are widely used in the chemical processing industries due to their tolerance to both oxidizing and reducing conditions. Unlike stainless steel （SS）, Ni-Cr-Mo （W） alloys exhibit remarkably high uniform corrosion resistance in major concentrated acids, like hydrochloric acid （HC1） and sulfuric acid （H2SO4）. A higher uniform corrosion resistance of Ni-Cr-Mo （W） alloys, compared to other alloys, in concentrated acids can be attributed to the formation of protective oxide film of Mo and W in reducing acids, and Cr oxide film in oxidizing solutions. The localized corrosion resistance of Ni-Cr-Mo （W） alloys, containing high amount Cr as well as Mo （or Mo ＋ W）, is also significantly higher than that of other commercially available alloys. The present study investigates the role of alloying elements, in nickel alloys, to uniform corrosion resistance in concentrated acids （HC1, HC1 ＋ oxidizing impurities and H2SO4） and localized corrosion performance in chloride-rich environments using ASTM G-48 test methodology. The corrosion tests were conducted on various alloys, and the results were analyzed using weight loss technique and electrochemical techniques, in conjunction with surface char- acterization tools.

关键词： Nickel-chromium-molybdenum-tungsten Corrosion-resistant alloys Reducing acid Oxidants Localized corrosion Surface characterization

A meaningful learning method for zero-shot semantic segmentation

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Science China(Information Sciences) 2023年第11期66卷 35-53页

作者： Xianglong LIU Shihao BAI Shan AN Shuo WANG Wei LIU Xiaowei ZHAO Yuqing MA State Key Lab of Software Development Environment Beihang University JD Health international inc.

Zero-shot semantic segmentation, which is developed to segment unseen categories, has attracted inc.easing attention due to its strong practicability. Previous approaches usually applied semantic-visual mapping based on seen categories to unseen categories, and thus failed to generate meaningful unseen visual representations and struggled to balance the seen and unseen concepts in the classifier. To overcome the above limitations, we propose a novel meaningful learning method that could be embedded into any generationbased zero-shot semantic segmentation model, borrowing the idea from the educational psychology field. The proposed meaningful learning method refers to the process that the new concepts could be learned by relating to existing comprehensible concepts and harmoniously inc.rporated into the concept schema. Specifically, we introduce a generator with conjugate conceptual correlation(G3C) which generates meaningful unseen visual information through anchoring into existing concepts. Moreover, simulating the rational thinking mechanism,we introduce a fast-slow concept modulator to alleviate the noisy over-correlation problem introduced by G3C and further construct a comprehensive concept schema. Extensive experiments conducted on three benchmarks demonstrate the superior performance of our method, especially according to the commonlyacknowledged h-m Io U(e.g., 4% improvement on the Pascal-VOC dataset).

关键词： meaningful learning zero-shot learning semantic segmentation conjugate conceptual correlation fast-slow conceptual modulator

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The synergetic effects of two CCAAT boxes in Aspergillus niger glaA gene promoter on activation of PglaA transcription

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Science China(Life Sciences) 2004年第2期47卷 139-147页

作者： WANG H. M. Genencor international Inc. 925 Page Mill Road Palo Alto California 94304 USA

EMSA and footprinting analyses have revealed that the -489—-414 bp and the -390—-345 bp (designated DC and PC respectively) upstream of the Aspergillus niger T21 glaA gene were bound by one protein factor in the A. niger T21 whole cell extract. Both DC and PC contained CCAAT pentanucleotides. The functions of DC and PC in regulation of expression of glucoamylase (GLA) were studied. CCAAT pentanucleotides were replaced with CGTAA and the mutated DNA fragments DCm and PCm lost the binding activities of protein factors in vitro. In vivo when either DC or PC was mutated or the relative orientations between them were changed on the PglaA, the transcriptional activity of PglaA decreased to a basal level. Introduction of multi-copies of DC into the original site at the PglaA in A. niger T21 decreased the expression of endogenous GLA expression and the exogenous reporter E. coli uidA gene introduced under the PglaA promoter, while having no effect on the uidA gene under the control of PgpdA. EMSA re-vealed that the levels of the specific DNA-binding protein factors in the transformants maintained the same meaning that introduction of multi-copies of DC caused the titration effect. AnghapC gene was cloned from A. niger T21 cDNA and introduced into the DC multi-copied strains. The expression of AnghapC improved the expression of the endogenous GLA and the exogenous gene controlled by PglaA. These results showed that both the CCAAT pentanucleotides were necessary for DC and PC binding to the protein factors, and the simultaneous binding of DC and PC to the protein was necessary for promoting the transcriptional activity of PglaA. AngHapC was the specific positive trans-acting protein factor binding to DC.

关键词： Aspergillus niger glucoamylase, synergetic effect, mutation analysis, multi-copy of CCAAT box, titration effect.

A facile approach to tricyclo[6.4.0.0^(4,9)]-dodecane framework

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Chinese Chemical Letters 2015年第2期26卷 238-242页

作者： Dong Wang William E.Crowe Longwood Biopharmaceuticals Inc. Tianjin international Joint.Academy of Biomedicine Department of Chemistry Louisiana State University

The unusual tricyclo[6.***.0.0^4,9]dodecane framework was constructed in eight linear steps in 13%overall *** innovative strategy accessing the framework from bicyclo[3.3.1]nonanes was *** key steps involve a Robinson a... 详细信息

关键词： Tricyclo[6.4.0.0^4 9]dodecane Vinigrol Robinson annulation Bicyclo[3.3.1]nonane

Challenges of mining the first right-handed longwall panel in a new reserve block in Pittsburgh Seam

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international Journal of Mining Science and Technology 2019年第1期29卷 145-149页

作者： Jun Lu Greg Hasenfus CONSOL Energy inc.

In this paper, the mining experience and challenges for the first right-handed longwall panel in the Pittsburgh Seam are introduced. The longwall headgate T-junction experienced very high face convergence(up to 61 cm), accompanied by roof sag, floor heave, and rib loading. The headgate convergence was so large that, in a few places, it threatened longwall retreat and ultimately required the bottom to be re-graded. Different underground instruments, such as a roof scope, de-gas drill, tell-tale, laser meter,and borehole pressure Cell(BPC), were employed to explore the roof geology and to monitor the entry convergence and the stress changes in the pillar. In addition, the impact of other geologic factors, such as large overburden depth, laminated sandstone roof geology, soft floor, and large headgate equipment,were also analyzed. Subsequently, geotechnical solutions were provided to avoid or mitigate the impact of these challenging geologic factors.

关键词： Coal mining Horizontal stress Ground control Roof convergence

Effect of binary conductive additive mixtures on electrochemical performance of polyoxomolybdate as cathode material of lithium ion battery

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Journal of Central South University 2016年第10期23卷 2506-2512页

作者：李文良倪尔福李新海郭华军 School of Metallurgy and Environment Central South University Changsha 410083 China Highpower international inc. Xinxia Road Pinghu Town Longgang District Shenzhen 518111 China

Binary carbon mixtures, carbon black ECP 600JD(ECP) combined with vapor grown carbon fiber(VGCF) or carbon nanotube(CNT), or graphene(Gr) in different mass ratios, are investigated as the conductive additives for the cathode material polyoxomolybadate Na_3[AlMo_6O_(24)H_6](NAM). Field emission scanning electron microscopy and energy dispersive X-ray spectroscopy show that the surfaces of NAM particles are covered homogeneously with the binary conductive additive mixtures except the combination of ECP and CNT. The optimum combination is the mixture of ECP and VGCF, which shows higher discharge capacity than the combinations of ECP and CNT or Gr. Initial discharge capacities of 364, 339, and 291 m A·h/g are obtained by the combination of ECP and VGCF in the mass ratios of 2:1, 1:1, and 1:2, respectively. The results of electrochemical impedance spectra and 4-pin probe measurements demonstrate that the combination of ECP and VGCF exhibits the highest electrical conductivity for the electrode.

关键词： lithium ion battery cathode Na3[AlMo6O24H6](NAM) conductive additive

Development of a multiple level underground limestone mine from geology through mine planning

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international Journal of Mining Science and Technology 2020年第1期30卷 63-67页

作者： Christopher Newman David Newman Robert Dupuy Appalachian Mining&Engineering Inc.LexingtonKYUSA Rogers Group Inc.NashvilleTNUSA

The development of a multiple level underground mine is a complex task in which geology,engineering,ground control,and unit operations are integrated into a single mine *** components are interdependent and must function cohesively to ensure a profitable underground mining *** optimize reserve recovery,mine planning should begin from the lowest level and progress *** limits any misjudgments or oversights of a given level affecting the underlying levels and ensures the ability to maximize recovery from each *** planning should start with the exploration and characterization of the geologic *** the reserve geology and quality is well understood,then mine planning can begin with respect to the following:(1)orientation of mine works with respect to horizontal stress;(2)access to the reserve;(3)determination of opening widths;(4)selection of back,floor horizons and pillar centers;(5)selection of development and secondary mining heights;(6)appropriate inter-burden thicknesses;and(7)examining the stability of the multiple level mine through numerical *** multiple level mine design process and decisions are presented through a case history *** theme is that there is one opportunity to"get it right"and many chances to overlook a small aspect within the design that will plague the mine throughout all levels and through the entirety of its operating life.

关键词： Limestone Mine planning Geology Multiple level Rock mechanics

Sorghum Insect Problems and Management

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Journal of Integrative Plant Biology 2011年第3期53卷 178-192页

作者： Chunshan Guo Wei Cui Xue Feng Jianzhou Zhao Guihua Lu Beijing Kaituo DNA Biotech Research Center Beijing 100085 China pioneer Hi-Bred international inc. a DuPont Company Johnston IA 50131 USA

Sorghum （Sorghum bicolor） has high levels of starch, sugar, and fiber and is one of the most important energy crops in the world. Insect damage is one of the challenges that impacts sorghum biomass production. There are at least 150 insect species that can infest sorghum varieties worldwide. These insects can complete several generations within a growing season, they target various parts of sorghum plants at devel- opmental stages, and they cause significant biomass losses. Genetic research has revealed the existence of resistant genetics in sorghum and insect tolerant sorghum varieties have been identified. Various control methods have been developed, yet more effective management is needed for inc.easing sorghum biomass production. Although there are no transgenic sorghum products on the market yet, biotechnology has been recognized as an important tool for controlling insect pests and inc.easing sorghum production.

关键词： Sorghum Imports Production Productivity Products Pest insects Varieties Biomass Insecta