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On the Performance of Active Analog Self-Interference Cancellation Techniques for Beyond 5G Systems

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China Communications 2021年第10期18卷 158-168页

作者： Haifeng Luo mark Holm Tharmalingam Ratnarajah Institute for Digital Communications School of EngineeringThe University of EdinburghEdinburghUK Huawei Technologies(Sweden)AB GothenburgSweden

The in-band full-duplex(IBFD)mechanism is of interest in beyond 5 G systems due to its potential to enhance spectral efficiency and reduce *** achieve the maximum gain of IBFD systems,the significant self-interference(SI)must be efficiently *** challenges of wideband selfinterference cancellation(SIC)lie in the radio frequency(RF)domain,where the performance will be limited by the *** paper reviews current RF cancellation mechanisms and investigates an efficient mechanism for future wideband systems with minimum *** working principle and implementation details of multi-tap cancellers are first introduced,then an optical domain-based RF canceller is reviewed,and a novel low-cost design is *** minimize the cost and complexity of the canceller,the minimum required number of taps are *** results show that with the commonly used 12-bits analog-to-digital converter(ADC)at the receiver,the novel optical domain-based canceller can enable efficient SIC in the 3 GPP LTE specifications compatible system within 400 MHz bandwidth.

关键词： full-duplex beyond 5G system self-interference cancellation optical domain-based canceller

Risk Acceptability and Cost-Effectiveness of Protective Measures Against Terrorist Threats to Built Infrastructure Considering Multiple Threat Scenarios

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Transactions of Tianjin University 2008年第5期14卷 313-317页

作者： STEWART mark G Centre for Infrastructure Performance and Reliability The University of Newcastle

Decisions are often needed about the need and/or extent of protective measures against explosive blast loads on built infrastructure. A decision support analysis considers fatality risks and cost-effectiveness of protective measures expressed in terms of expected cost spent on risk reduction per life saved for terrorist threats to infrastructure. The analysis is applicable to any item of infrastructure, but in this paper is applied to casualties arising from building facade glazing damage. Risks may be compared with risk acceptance criteria in the form of quantitative safety goals. The risk acceptability and cost-effectiveness of protective measures includes cost of the protective measures, attack probability,reduction in risk due to protective measures,probability of fatality conditional on successful terrorist attack and number of exposed individuals.

关键词： risk terrorism cost-benefit analysis infrastructure decision analysis

Sex-specific life-history strategies among immature jumping spiders:Differences in body parameters and behavior

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Current Zoology 2023年第5期69卷 535-551页

作者： LászlóMezőfi Viktor markó DóraÁgnes Taranyi Gábor markó Institute of Plant Protection Hungarian University of Agriculture and Life SciencesBudapest 1118Hungary Institute of Viticulture and Enology Hungarian University of Agriculture and Life SciencesBudapest 1118Hungary

Selection forces often generate sex-specific differences in various traits closely related to *** in adult spiders(Araneae),sexes often differ in coloration,body size,antipredator,or foraging behavior,such sex-related differences are less pronounced among ***,sex-specific life-history strategies may also be adaptive for ***,we hypothesized that among spiders,immature individuals show different life-history strategies that are expressed as sex-specific differences in body parameters and behavioral features,and also in their *** used immature individuals of a protandrous jumping spider,Carrhotus xanthogramma,and examined sex-related *** results showed that males have higher mass and larger prosoma than *** were more active and more risk tolerant than *** activity increased with time,and larger males tended to capture the prey faster than small ones,while females showed no such ***,females reacted to the threatening abiotic stimuli more with the increasing number of test *** both males and females,individuals with better body conditions tended to be more risk *** showed no sex-specific differences in interindividual behavioral consistency and in intraindividual behavioral variation in the measured behavioral ***,we also found evidence for behavioral syndromes(i.e.,correlation between different behaviors),where in males,only the activity correlated with the risk-taking behavior,but in females,all the measured behavioral traits were *** present study demonstrates that *** sexes follow different life-history strategies even before attaining maturity.

关键词： activity behavioral syndrome boldness intraindividual variability repeatability sexual dimorphism

Realistic magnetic thermodynamics by local quantization of a semiclassical Heisenberg model

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npj Computational Materials 2022年第1期8卷 1771-1776页

作者： Flynn Walsh mark Asta Lin-Wang Wang Materials Sciences Division Lawrence Berkeley National LaboratoryBerkeleyCA94720USA Graduate Group in Applied Science and Technology University of CaliforniaBerkeleyCA94720USA Department of Materials Science and Engineering University of CaliforniaBerkeleyCA94720USA Institute of Semiconductors Chinese Academy of Sciences100083BeijingChina

Classical Monte Carlo simulation of the Heisenberg model poorly describes many thermodynamic phenomena due to its neglect of the quantum nature of ***,we discuss how to semiclassically approach the quantum problem and demonstrate a simple method for introducing a locally approximate form of spin *** the procedure underestimates magnetic short-range order,our results suggest a simple correction for recovering realistic spin–spin correlations above the critical ***,ensemble fluctuations are found to provide reasonably accurate thermodynamics,largely reproducing quantum mechanically calculated heat capacities and experimental magnetometry for ferromagnetic Fe and antiferromagnetic *** of the method are proposed to address remaining inaccuracies.

关键词： temperature thermodynamics Heisenberg

Modification Design Method for an Enveloping Hourglass Worm Gear with Consideration of Machining and Misalignment Errors

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Chinese Journal of Mechanical Engineering 2013年第5期26卷 948-956页

作者： DENG Xingqiao WANG Jinge HORSTEMEYER mark F School of Mechanical Engineering and Automation Xihua University Center for Advanced Vehicular Systems Mississippi State University

The influences of machining and misalignment errors play a very critical role in the performance of the anti-backlash double-roller enveloping hourglass worm gear(ADEHWG).However,a corresponding efficient method for eliminating or reducing these errors on the tooth profile of the ADEHWG is seldom *** gear engagement equation and tooth profile equation for considering six different errors that could arise from the machining and gear misalignment are derived from the theories of differential geometry and gear ***,the tooth contact analysis(TCA) is used to systematically investigate the influence of the machining and misalignment errors on the contact curves and the tooth profile by means of numerical analysis and three-dimensional solid *** research results show that vertical angular misalignment of the worm wheel(Δβ) has the strongest influences while the tooth angle error(Δα) has the weakest influences on the contact curves and the tooth profile.A novel efficient approach is proposed and used to minimize the effect of the errors in manufacturing by changing the radius of the grinding wheel and the approaching point of *** results from the TCA and the experiment demonstrate that this tooth profile design modification method can indeed reduce the machining and misalignment *** modification design method is helpful in understanding the manufacturing technology of the ADEHWG.

关键词： worm gears tooth contact analysis machining and misalignment errors tooth profile errors modification method

Development of a fault-rupture environment in 3D: A numerical tool for examining the mechanical impact of a fault on underground excavations

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International Journal of Mining Science and Technology 2019年第1期29卷 105-111页

作者： Bo-Hyun Kim mark K.Larson Spokane Mining Research Division CDC/NIOSH

While faults are commonly simulated as a single planar or non-planar interface for a safety or stability analysis in underground mining excavation, the real 3D structure of a fault is often very complex, with different branches that reactivate at different times. Furthermore, these branches are zones of nonzero thickness where material continuously undergoes damage even during interseismic periods. In this study, the initiation and the initial evolution of a strike-slip fault was modeled using the FLAC3D software program. The initial and boundary conditions are simplified, and mimic the Riedel shear experiment and the constitutive model in the literature. The FLAC3D model successfully replicates and creates the 3D fault zone as a strike-slip type structure in the entire thickness of the model. The strike-slip fault structure and normal displacement result in the formation of valleys in the model. Three panels of a longwall excavation are virtually placed and excavated beneath a main valley. The characteristics of stored and dissipated energy associated with the panel excavations are examined and observed at different stages of shear strain in the fault to evaluate bump potential. Depending on the shear strain in the fault, the energy characteristics adjacent to the longwall panels present different degrees of bump potential, which is not possible to capture by conventional fault simulation using an interface.

关键词： 3D fault zone Strike-slip fault FLAC3D Bump potential Energy characteristics

Enabling silicon photoanodes for efficient solar water splitting by electroless-deposited nickel

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Nano Research 2018年第6期11卷 3499-3508页

作者： Jiheng Zhao Thomas mark Gill Xiaolin Zheng Department of Mechanical Engineering Stanford University Stanford 9430S USA

Enabling Si photoanodes for efficient solar water oxidation would facilitate the development of solar fuel conversion, but it is challenging owing to Si surface passivation via photo-induced corrosion in aqueous electrolytes. To overcome this challenge, most approaches have focused on improving the stability of Si by coating dense and thin protective layers using high vacuum-based techniques such as atomic layer deposition. However, these procedures are costly, making scalability for practical applications difficult. Herein, we report a modified electroless deposition （ELD） method to uniformly deposit protective and catalytic Ni films on Si wafers, resulting in efficient and stable Si photoanodes for solar water oxidation. The optimized Ni/n-Si photoanode achieves an onset potential of -1.09 V vs. a reversible hydrogen electrode and a saturation current density of -27.5 mA/cm^2 under AM 1.5 G illumination at pH 14. The ELD method is additionally capable of Ni deposition on a 4-inch n-Si wafer, demonstrating the first 4-inch Si photoanode. The solar water oxidation of the ELD-Ni/n-Si photoanode can be further improved by surface texturing, built-in n-p junctions, or coupling with more efficient catalysts.

关键词： Ni deposition electroless plating Si photoanode oxygen evolution reaction (OER) photoelectrochemical water splitting

Reaction kinetic model for a recent co-produced water treatment technology

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Journal of Environmental Sciences 2011年第3期23卷 360-365页

作者： Abdulwahab M Ali Tuwati mark A.Bentley Chemical & Petroleum Engineering University of Wyoming

With the increasing demand for fossil based energy and implementation of progressively strict environmental pollution control standards, treatment of a large amount of co-produced waters （CPWs） from fossil based energy production has become increasingly important. Removal of bicarbonate with H2SO4 has been recently studied as a simple and cost-effective method to decrease the alkalinity of CPWs. The present work investigates the kinetics of the reaction between H2SO4 and NaHCO3, which could provide the base for scaling-up the CPW treatment technology. Based on the measured quantity change of the CO2 gas generated from the reaction between H2SO4 and NaHCO3 with time under specified initial reaction conditions, the reaction orders with respect to H2SO4 and NaHCO3 were determined. Experiments were also conducted within the temperature of 15-30℃ to find various global rate coefficients of the reaction to calculate the activation energy and the pre-exponential factor of the empirical Arrhenius form of the bicarbonate removal reaction, which are 197.7 kJ/mol and 3.13 × 1034 （mol-3.7 ×L3.7 ×sec^-1 ）, respectively.

关键词： fossil fuels water wastewater alkalinity bicarbonate

Immunosuppressive therapies for inflammatory bowel disease

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World Journal of Gastroenterology 2014年第12期20卷 3146-3152页

作者： Talia Zenlea mark A Peppercorn Center for Women’s Gastrointestinal Medicine The Women’s Medicine CollaborativeAlpert Medical SchoolBrown University Division of Gastroenterology Beth Israel Deaconess Medical CenterHarvard Medical SchoolBoston

Inflammatory bowel disease (IBD) is comprised of Crohn’s disease and ulcerative colitis, both chronic inflammatory intestinal disorders of unknown etiology characterized by a waxing and waning clinical course. For many years, the drug therapy was limited to sulfasalazine and related aminosalicylates, corticosteroids and antibiotics. Studies suggesting that the pathophysiology of these disorders relates to a disregulated, over-active immune response to indigenous bacteria have led to the increasing importance of immunosuppressive drugs for the therapy of IBD. This review details the mechanisms of action, clinical efficacy, and adverse effects of these agents.

关键词： Crohn’ s disease, Ulcerative colitis, Inflammatory bowel disease, Immunosuppressives, Tumor necrosis factor inhibitors