Due to the need for massive device connectivity,low communication latency,and various customizations in 6G architecture,a distributed cloud deployment approach will be more relevant to the space-air-ground-sea integra...Due to the need for massive device connectivity,low communication latency,and various customizations in 6G architecture,a distributed cloud deployment approach will be more relevant to the space-air-ground-sea integrated network scenario.However,the openness and heterogeneity of the 6G network cause the problems of network security.To improve the trustworthiness of 6G networks,we propose a trusted computing-based approach for establishing trust relationships inmulti-cloud scenarios.The proposed method shows the relationship of trust based on dual-level verification.It separates the trustworthy states of multiple complex cloud units in 6G architecture into the state within and between cloud units.Firstly,SM3 algorithm establishes the chain of trust for the system’s trusted boot phase.Then,the remote attestation server(RAS)of distributed cloud units verifies the physical servers.Meanwhile,the physical servers use a ring approach to verify the cloud servers.Eventually,the centralized RAS takes one-time authentication to the critical evidence information of distributed cloud unit servers.Simultaneously,the centralized RAS also verifies the evidence of distributed RAS.We establish our proposed approach in a natural OpenStack-based cloud environment.The simulation results show that the proposed method achieves higher security with less than a 1%system performance loss.展开更多
The principle and technique were reported here to produce lignin-based sand stabilizing material （LSSM） using extracted lignin from black liquor of straw paper mills. Field tests using LSSM to stabilize and green sa...The principle and technique were reported here to produce lignin-based sand stabilizing material （LSSM） using extracted lignin from black liquor of straw paper mills. Field tests using LSSM to stabilize and green sand dunes were started in 2002. The field experiment was carded out in August 2005 when the newly formed plant community was 3 years old. The results from the comprehensive field experiment demonstrated that unlike polyvinyl acetate or foamed asphalt commonly used for dune stabilization, LSSM was plant- friendly material and could be used in combination with seeding and planting of desert species. With the help of LSSM, the desert species （i.e., Agriophyllum squarrosum （L.） Moq. and Artemisia desertorum Spreng. etc.） could be used to form community in 2-3 yeas and to stabilize sand dune effectively. The newly formed community was sustainable under an extremely dry climate condition. The organic matter and total nitrogen in the soil increased significantly as the community were formed, while the change in P and K contents in the soil was negligible.展开更多
The Global Stratotype Section and Point （GSSP） for the boundary between the Capitanian and Wuchiapingian stages, also the boundary between the Guadalupian and Lopingian Series is defined at the First Appearance Dat...The Global Stratotype Section and Point （GSSP） for the boundary between the Capitanian and Wuchiapingian stages, also the boundary between the Guadalupian and Lopingian Series is defined at the First Appearance Datum （FAD） of the conodont Clarkina postbitteri postbitteri at the base of Bed 6k in the Penglaitan Section along the Hongshui River in Guangxi Province, South China. This point is within a chronomorphocline from Clarkina postbitteri hongshuiensis to C. dukouensis and nearly coincides with the Middle-Upper Absaroka Megasequence boundary and as such is documented within a continuously deposited carbonate lowstand succession with deep-water facies of the Maokou Formation below and deep-water facies of the Heshan Formation above. Furthermore, this point also coincides with a major extinction of various Permian fossils including corals, fusulinaceans, ammonoids and brachiopods. The proximity to an apparently global major sequence boundary and extinction event will serve as a means of correlation of this GSSP into other regions in which the defining taxon is not present because of profound provincialism during the Middle and Upper Permian. Carbon isotopic trends and magnetostratigraphic signatures are also provided to help correlate this GSSP into other regions, including those with continental facies successions. The Tieqiao Section near the county town of Laibin is also described as a supplementary reference section.展开更多
Exercise training is beneficial to the cardiovascular system. MicroRNAs （miRNAs, miRs） are a class of conserved non-coding RNAs and play a wide-ranging role in the regulation of eukaryotic gene expression. Exercise ...Exercise training is beneficial to the cardiovascular system. MicroRNAs （miRNAs, miRs） are a class of conserved non-coding RNAs and play a wide-ranging role in the regulation of eukaryotic gene expression. Exercise training alters the expression levels of large amounts ofmiRNAs in the heart. In addition, circulating miRNAs appear to be regulated by exercise training. In this review, we will summarize recent advances in the regulation of miRNAs during physical exercise intervention in various cardiovascular diseases, including pathologic cardiac hypertrophy, myocardial fibrosis, ischemia-reperfusion injury, myocardial infarction, and heart failure. The regulatory role of circulating miRNAs after exercise training was also reviewed. In conclusion, miRNAs might be a valuable target for treatment of cardiovascular diseases and have great potential as biomarkers for assessment of physical performance.2018 Published by Elsevier B.V.on behalf of Shanghai University of Sport. This is an open access article under the CC BY-NC-ND license. （http：//creativecommons.org/licenses/by-nc-nd/4.0/）.展开更多
Purpose： The aims of this study were to assess differences of limb symmetry index （LSI） in strength- and coordination-related tasks between high-level, competitive, noninjured ski racers of different age-related pe...Purpose： The aims of this study were to assess differences of limb symmetry index （LSI） in strength- and coordination-related tasks between high-level, competitive, noninjured ski racers of different age-related performance levels and to prospectively assess limb differences as a possible risk factor for traumatic and overuse injury in youth ski racers. Methods： The study （Study 1） included 285 high-level competitive ski racers （125 females, 160 males） of 3 age-related performance levels and based on the school system： 95 youth （10-14 years, secondary modem school）, 107 adolescent （15-19 years, grammar school）, and 83 elite athletes （20-34 years）. To investigate the second aim （Study 2）, 67 of the 95 youth athletes were included and any traumatic or overuse injuries were prospectively recorded over 2 seasons. All athletes performed 4 unilateral tests （strength related： one-leg counter movement jump （OL-CMJ） and one-leg isometric/isokinetic press strength test （OL-ILS）; coordination related： one-leg stability test （OL-ST） and one-leg speedy jump test （OL-SJ））. The LSI was calculated by dividing the dominant leg by the nondominant leg and multiplying by 100. Kruskal-Wallis H tests and binary logistic regression analyses were conducted. Results： There were significant differences between the LSI of the 3 age-related performance-level groups only in the strength-related tests： the OL-CMJ （X^2（2, 285） = 9.09; p = 0.01） and the OL-ILS （X^2（2,285） = 14.79; p 〈 0.01）. The LSI for OL-ILS was found to be a significant risk factor for traumatic injury in youth ski racers （Wald = 7.08; p 〈 0.01）. No significant risk factors were found for overuse injuries. Conclusion： Younger athletes display slightly greater LSI values only in the strength-related tests. The cut-off value of limb differences of 〈 10% for return to sport decisions seems to be appropriate for elite athletes, but for youth and adolescent athletes it has to be critically discussed. It seems to be necessary to define thresholds based on specific performance tasks （strength vs. coordination related） rather than on generalizations, and age-related performance levels must be considered. Limb differences in unilateral leg extension strength represent a significant injury risk factor in youth ski racers.2018 Published by Elsevier B.V. on behalf of Shanghai University of Sport. This is an open access article under the CC BY-NC-ND license. （http：//creativecommons.org/licenses/by-nc-nd/4.0/）.展开更多
A proper edge coloring of a graph G is called adjacent vertex-distinguishing acyclic edge coloring if there is no 2-colored cycle in G and the coloring set of edges incident with u is not equal to the coloring set of ...A proper edge coloring of a graph G is called adjacent vertex-distinguishing acyclic edge coloring if there is no 2-colored cycle in G and the coloring set of edges incident with u is not equal to the coloring set of edges incident with v, where uv∈ E（G）. The adjacent vertex distinguishing acyclic edge chromatic number of G, denoted by X＇Aa（G）, is the minimal number of colors in an adjacent vertex distinguishing acyclic edge coloring of G. If a graph G has an adjacent vertex distinguishing acyclic edge coloring, then G is called adjacent vertex distinguishing acyclic. In this paper, we obtain adjacent vertex-distinguishing acyclic edge coloring of some graphs and put forward some conjectures.展开更多
By means of vector-valued product Calderón-Zygmund operators and some subtle estimates,the boundedness in product Hardy spaces on R^n × R^m of Calderón-Zygmund operators introduced by J.L. Journé i...By means of vector-valued product Calderón-Zygmund operators and some subtle estimates,the boundedness in product Hardy spaces on R^n × R^m of Calderón-Zygmund operators introduced by J.L. Journé is established.展开更多
A new mineral,jichengite ideally 3CuIr_2S_4·(Ni,Fe)_9S_8,was found as a constituent of placer concentrates at a branch of the Luanhe River,about 220 km NNE of Beijing.Its associated minerals are chromite,magnetit...A new mineral,jichengite ideally 3CuIr_2S_4·(Ni,Fe)_9S_8,was found as a constituent of placer concentrates at a branch of the Luanhe River,about 220 km NNE of Beijing.Its associated minerals are chromite,magnetite,ilmenite,zircon,native gold,iridium,ferrian platinum and osmium.The placer is distributed at places around ultrabasic rock,which hosts chromite orebodies,from which PGM originated.Jichengite occurs commonly as massive or granular aggregates.No perfect morphology of jichengite was observed.It is steel gray and opaque with metallic luster and black streak.It has a Mohs hardness of 5,VHN(d) urn 21.65,H_m 4.465,Hv = 268.1 N/um^2.It is brittle and weakly magnetic. Cleavage {010} is rarely observed.No fracture was observed.Density could not be measured because of its too small grain size.Density(calc.) is 7.003 g/cm^3.Reflect light is reddish-brown,without internal reflections.Anisotropism is distinct with grayish or yellowish white in crossed nicols and bluish violetcopper red in uncrossed nicols.Jichengite shows weak pleochroism and strong bireflectance.The reflectance values in air at the Standard Commission on Ore Mineralogy wavelengths are:38.9,34.3 at 470 nm,38.9,34.5 at 546 nm,39.1,35.3 at 590 nm,39.2,36.8 at 650 nm,parallel-axial extinction.The six strongest lines in the X-ray powder-diffraction pattern[d in A,(I),(hkl)]are:3.00(100)(116),2.80(50) (205),2.48.(50)(208),1.916(40)(2,1,10),1.765(60)(220),1.753(50)(2,0,16).Five chemical analyses carried out,yielding the following results:S 25.76(25.49-5.97),Fe 10.03(9.78-10.31),Co 0.78 (0.75-0.81),Ni 12.48(12.32-12.85),Cu 4.77(4.69-4.83),Ir 46.98(46.14-47.89),sum 100.80wt%,which produced a formula(Cu_(1.556)Fe_(0.976))_(2.532)(Ir_(5.063)S_(10.126))·(Fe_(2.7451)Ni_(4.404)Co_(0.273))_(7.422)S_(6.517).The ideal formula is X_(10)Ir_5S_(17.5),which was calculated by single crystal structure analyses,where X=Cu(Ⅱ)+Fe(Ⅱ)+Ni(Ⅱ) +Co(Ⅱ).The single crystal data were collected using a diffractometer with Mo Kαradiation and a graphite monochromate.The crystal system is trigonal with space group R3m and unit cell parameters a=7.0745(14) A,c=34.267(10) A(The superstructure not found),and the final R Indices[with 564 observed reflections,I>2sigma(Ⅰ)]are R_1=0.0495,wR_2=0.1349.The specimens are deposited in the Geological Museum of China.展开更多
Maize (Zea mays) is among the major cereals grown in the high rainfall areas of the subSaharan Africa’s (SSA) such as the Ethiopian part of the Blue Nile basin. However, its productivity is severely constrained by po...Maize (Zea mays) is among the major cereals grown in the high rainfall areas of the subSaharan Africa’s (SSA) such as the Ethiopian part of the Blue Nile basin. However, its productivity is severely constrained by poor soil, water and crop management practices. This study simulated the water productivity of the crop under varying soil fertility scenarios (poor, near optimal and none limiting) using hybrid seeds under rainfed conditions using the FAO AquaCrop model. The result indicated that grain yield of maize increased from 2.5 tons.ha–1 under poor to 6.4 and 9.2 tons.ha–1 with near optimal and non-limiting soil fertility conditions. Correspondingly, soil evaporation decreased from 446 mm to 285 and 204 mm, while transpiration increased from 146 to 268 and 355 mm. Consequently, grain water productivity was increased by 48% and 54%, respectively, with the near optimal and non-limiting soil fertility conditions. The water productivity gain mainly comes from reduced evaporation and increased transpiration without significantly affecting water left for downstream ecosystem services. This has a huge implication for a basin scale water management planning for various purposes.展开更多
Purpose： The aim of this study was to compare mechanical muscle function in the eccentric/concentric phases of vertical bilateral jumping in anterior cruciate ligament-reconstructed （ACLR）, elite （ELITE）, and ado...Purpose： The aim of this study was to compare mechanical muscle function in the eccentric/concentric phases of vertical bilateral jumping in anterior cruciate ligament-reconstructed （ACLR）, elite （ELITE）, and adolescent （ADOL） alpine ski racers and ski cross athletes. Methods： Alpine ski racers/ski crossers （ACLR： n = 12, age = 26.7 ± 3.8 years; ELITE： n = 12, age = 23.9 ± 3.0 years; ADOL： n = 12, age = 17.8 ± 0.7 years; females： n = 6 per group, males： n = 6 per group） performed 5 maximal countermovement jumps （CMJs） and 5 squat jumps. The ground reaction forces for each limb were analyzed using dual force plate recording to obtain body center of mass （BCM） velocity, displacement, and power. The eccentric deceleration （ECC） and concentric phases were determined from BCM velocity. CMJ net concentric and ECC impulses were calculated （body mass normalized） along with the peak and mean BCM power and maximal vertical jump height. CMJ lower limb stiffness （LLS） was determined by the slope of the ground reaction forces vs. the BCM displacement curve over the ECC phase. Concentric and ECC asymmetry indices were calculated for each leg, and the left vs. right LLS was compared. Outcome measures （reported as mean ± SD） calculated as a 5-jump mean were normalized to body mass and compared using an analysis of variance. Results： No between-group differences were found for peak and mean power or jump heights. There were no group differences for LLS or net concentric phase impulse, but the net ECC impulse was lower in the ADOL group compared with ELITE skiers （ADOL： 1.33 ± 0.32 Ns/kg; ELITE： 1.59 ± 0.16 Ns/kg; p 〈 0.05）. Although no group differences were found for ECC asymmetry indices, a group × limb interaction was found for LLS （p 〈 0.01）, which was systematically higher in the right vs. the left limb of ADOL skiers （right： 54.1 ± 17.9 N/m/kg; left： 48.7 ± 15.7 N/m/kg;p 〈 0.01）. Conclusion： ADOL skiers demonstrated decreased ECC impulse and systematic right limb dominance in LLS compared with ACLR and ELITE skiers. The implication of these findings for injury and performance are unknown, but further investigation into these potential relationships is warranted.2018 Published by Elsevier B.V. on behalf of Shanghai University of Sport. This is an open access article under the CC BY-NC-ND license. （http：//creativecommons.org/licenses/by-nc-nd/4.0/）.展开更多
We report near-zero crossover for vanadium cross-permeation through single-layer graphene immobilized at the interface of two Nafion?polymer electrolyte membranes.Vanadium ion diffusion and migration,including proton ...We report near-zero crossover for vanadium cross-permeation through single-layer graphene immobilized at the interface of two Nafion?polymer electrolyte membranes.Vanadium ion diffusion and migration,including proton mobility through membrane composites,were studied with and without graphene under diffusion and migration conditions.Single-layer graphene was found to effectively inhibit vanadium ion diffusion and migration under specific conditions.The single-layer graphene composites also enabled remarkable ion transmission selectivity improvements over pure Nafion membranes,with proton transport being four orders of magnitude faster than vanadium ion transport.Resistivity values of 0.02±0.005Ωcm^(2) for proton and 223±4Ωcm^(2) for vanadium ion through single atomic layer graphene are reported.This high selectivity may have significant impact on flow battery applications or for other electrochemical devices where proton conductivity is required,and transport of other species is detrimental.Our results emphasize that crossover may be essentially completely eliminated in some cases,enabling for greatly improved operational viability.展开更多
This work focuses on the relationship between flexibility of molecular chains and thermal properties of polyurethane elastomer（PUE）, which laid the foundation of further research about how to improve thermal propert...This work focuses on the relationship between flexibility of molecular chains and thermal properties of polyurethane elastomer（PUE）, which laid the foundation of further research about how to improve thermal properties of PUE. A series of PUE samples with different flexibility of molecular chains was prepared by using 1,4-butanediol（1,4-BDO）/bisphenol-a（BPA） blends with different mole ratios including9/1, 8/2, 7/3, 6/4 and 5/5. As comparison, PUE extended with pure 1,4-BDO and BPA was also synthesized.These samples were characterized by differential scanning calorimetry（DSC）, thermogravimetric analysis（TGA）, dynamic mechanical analysis（DMA）, etc. The results showed that with the decrease in flexibility of molecular chains the glass transition temperature（Tg） increased and low-temperature properties became worse. Besides, all samples had a certain degree of microphase separation, and soft segments in some samples were crystallized, i.e. the decreasing flexibility of molecular chains led to the impossibility of chains tightly packing and crystalline domains forming so that the degree of microphase separation decreased and the thermal properties became worse.展开更多
Background： Sedentary behavior （SB）, physical activity （PA）, and attributes of physical fitness have been shown to be related to depressive symptoms in adolescents. The purpose of the present study was to investi...Background： Sedentary behavior （SB）, physical activity （PA）, and attributes of physical fitness have been shown to be related to depressive symptoms in adolescents. The purpose of the present study was to investigate whether SB and fitness-producing activity predicted depression in active adolescents over and above gender and fitness attributes. Methods： Participants were 249 adolescents （age： 12.85 ± 0.89 years, mean ± SD） from 3 public middle schools who wore Actical accelerometers to assess their SB and PA. Participants also completed the FITNESSGRAM health-related fitness assessment and a brief depression questionnaire. A 3-step hierarchical regression analysis was conducted with gender and fitness attributes （i.e., body mass index （BMI）, maximal volume oxygen uptake （VO2max）, curlups, and pushups）, moderate- and vigorous-intensity activity, and SB entered in respective steps. Results： Regression analysis indicated activity variables （i.e., moderate- and vigorous-intensity activity） significantly predicted depression （△R^2= 0.12, p 〈 0.01） beyond gender and fitness attributes. Overall, gender, fitness attributes, activity variables, SB explained 31% of the variance in depression. Structure coefficients revealed VO2max （rs= -0.77）, moderate-intensity activity （rs= -0.67）, vigorous-intensity activity （rs = -0.81）, and SB （rs = 0.57） were substantially correlated with the criterion variable; thus, they were the strongest predictors of depression. Conclusion： The findings of the current study indicated SB and PA were both significant predictors of depression; however, sufficient fitness-producing activity and adequate cardiorespiratory fitness may nullify the negative influence of SB on depressive symptoms in active adolescents.2018 Published by Elsevier B.V. on behalf of Shanghai University of Sport. This is an open access article under the CC BY-NC-ND license. （http：//creativecommons.org/licenses/by-nc-nd/4.0/）.展开更多
A fourth-order variational inequality of the second kind arising in a plate frictional bending problem is considered. By using regularization method, the original problem can be formulated as a differentiable variatio...A fourth-order variational inequality of the second kind arising in a plate frictional bending problem is considered. By using regularization method, the original problem can be formulated as a differentiable variational equation, and the corresponding discrete FEM variational equation is presented afterwards. Abstract error estimates and error estimates of the approximation are derived in terms of energy norm and L^2-norm.展开更多
In this paper, we obtain the strong comparison principle and Hopf Lemma for locally Lipschitz viscosity solutions to a class of nonlinear degenerate elliptic operators of the form △2ψ ＋ L（x,△ ψ）, including the ...In this paper, we obtain the strong comparison principle and Hopf Lemma for locally Lipschitz viscosity solutions to a class of nonlinear degenerate elliptic operators of the form △2ψ ＋ L（x,△ ψ）, including the conformal hessian operator.展开更多
The purpose of this paper is to analyze sleep stages accurately using fast and simple classifiers based on the frequency domain of electroencephalography(EEG) signal. To compare and evaluate system performance, the ru...The purpose of this paper is to analyze sleep stages accurately using fast and simple classifiers based on the frequency domain of electroencephalography(EEG) signal. To compare and evaluate system performance, the rules of Rechtschaffen and Kales(R&K rule) were used. Parameters were extracted from preprocessing process of EEG signal as feature vectors of each sleep stage analysis system through representatives of back propagation algorithm and support vector machine (SVM). As a result, SVM showed better performance as pattern recognition system for classification of sleep stages. It was found that easier analysis of sleep stage was possible using such simple system. Since accurate estimation of sleep state is possible through combination of algorithms, we could see the potential for the classifier to be used for sleep analysis system.展开更多
The zeta potential and cationic demands of various kraft pulps - unbleached, bleached and beaten to different freeness levels were determined in the laboratory. The zeta potential of pulp where the final stage was a l...The zeta potential and cationic demands of various kraft pulps - unbleached, bleached and beaten to different freeness levels were determined in the laboratory. The zeta potential of pulp where the final stage was a lignin degrading and dissolving treatment such as alkaline extraction or hypochlorite was lower than the unbleached pulp. The cationic demand of unbleached pulp was higher compared to that of bleached pulp. Beaten pulps showed larger cationic demands than the unbeaten pulps, which can be attributed to the larger specific surface area of pulp components. Fibres become increasingly electronegative when beaten and therefore cationic demand of pulps increases with beating. When the zeta potential method is used with furnishes of different freeness, the linear relationship is observed. However, the slope is decreasing with the decrease in freeness of the pulp.展开更多
Tolerance in isolations of Trichoderma was developed by exposing two strains of T. harzianum and three of T. asperelloides to increasing concentrations of chemical fungicides. These isolation of Trichoderma were expos...Tolerance in isolations of Trichoderma was developed by exposing two strains of T. harzianum and three of T. asperelloides to increasing concentrations of chemical fungicides. These isolation of Trichoderma were exposed to three fungicides: Captan, Thiabendazol and the mixture Captan-Carboxin. Some selected lines of these strains reached tolerance to Captan and partial tolerance to the mixture Captan-Carboxin. The biological and genetic changes in these tolerant lines were monitored by determining the relative growth rate of the fungus, inhibition of Fusarium and by analyzing the genomic changes through UP-PCR. The results show that the tolerance to fungicides can be developed without affecting the parameters of biological activity in these lines of Trichoderma (growth and parasitism against Fusarium). Chemical tolerance to the fungicide was verified by means of changes at the DNA level (UP-PCR), mainly in the lines tolerant to Captan. This suggests that Trichoderma survives in environments with remnants of fungicide molecules.展开更多
Most measurements for beef improvement in South Africa are per individual (weaning weight, calving interval, growth rate, etc.). A measurement that expresses performance per constant unit, e.g. kilogram calf weaned pe...Most measurements for beef improvement in South Africa are per individual (weaning weight, calving interval, growth rate, etc.). A measurement that expresses performance per constant unit, e.g. kilogram calf weaned per Large Stock Unit (LSU) can eventually be translated to kilogram calf produced per kg CO2 equivalent. A LSU is defined as a bovine requiring 75 MJ Metabolisable Energy (ME) per day. If more kilogram weaner calf can be produced per LSU (KgC/LSU), the carbon footprint of beef can be reduced. This study used breed average values to investigate the KgC/LSU for the 30 beef and dual purpose breeds in South Africa. The breeds were categorized in the following breed types: Sanga (indigenous to South Africa) Sanga derived, Zebu, Zebu derived, British and European. No relationship was found between cow weights and KgC/LSU, indicating that it is independent of cow weight between breeds. However, when the data is summarized into breed types, the Sanga and European breed types produce the least KgC/ LSU and Sanga derived breed types the most. This high value of the Sanga derived breeds is probably due to retained heterosis. Composite breeds are mostly intermediate to parental breeds for individual traits but superior for composite traits and KgC/LSU is a composite trait. These calculations were only done on breed averages. A genetic analysis on a breed level to estimate genetic parameters for this trait, and its genetic correlations with other traits now needs to be done before a decision can be taken whether selection for KgC/LSU will be feasible. The ultimate aim with a trait like this is to reduce the carbon footprint of weaner calf production since more kilogram calf will be produced per LSU (constant feed unit).展开更多
基金This work was supported by the Ministry of Education and China Mobile Research Fund Project(MCM20200102)the 173 Project(No.2019-JCJQ-ZD-342-00)+2 种基金the National Natural Science Foundation of China(No.U19A2081)the Fundamental Research Funds for the Central Universities(No.2023SCU12129)the Science and Engineering Connotation Development Project of Sichuan University(No.2020SCUNG129).
文摘Due to the need for massive device connectivity,low communication latency,and various customizations in 6G architecture,a distributed cloud deployment approach will be more relevant to the space-air-ground-sea integrated network scenario.However,the openness and heterogeneity of the 6G network cause the problems of network security.To improve the trustworthiness of 6G networks,we propose a trusted computing-based approach for establishing trust relationships inmulti-cloud scenarios.The proposed method shows the relationship of trust based on dual-level verification.It separates the trustworthy states of multiple complex cloud units in 6G architecture into the state within and between cloud units.Firstly,SM3 algorithm establishes the chain of trust for the system’s trusted boot phase.Then,the remote attestation server(RAS)of distributed cloud units verifies the physical servers.Meanwhile,the physical servers use a ring approach to verify the cloud servers.Eventually,the centralized RAS takes one-time authentication to the critical evidence information of distributed cloud unit servers.Simultaneously,the centralized RAS also verifies the evidence of distributed RAS.We establish our proposed approach in a natural OpenStack-based cloud environment.The simulation results show that the proposed method achieves higher security with less than a 1%system performance loss.
基金supported by the National Natural Science Foundation of China (No. 40675040, 30771687, and90302015)the National Basic Research Program of China (No. 2006CB400505)
文摘The principle and technique were reported here to produce lignin-based sand stabilizing material （LSSM） using extracted lignin from black liquor of straw paper mills. Field tests using LSSM to stabilize and green sand dunes were started in 2002. The field experiment was carded out in August 2005 when the newly formed plant community was 3 years old. The results from the comprehensive field experiment demonstrated that unlike polyvinyl acetate or foamed asphalt commonly used for dune stabilization, LSSM was plant- friendly material and could be used in combination with seeding and planting of desert species. With the help of LSSM, the desert species （i.e., Agriophyllum squarrosum （L.） Moq. and Artemisia desertorum Spreng. etc.） could be used to form community in 2-3 yeas and to stabilize sand dune effectively. The newly formed community was sustainable under an extremely dry climate condition. The organic matter and total nitrogen in the soil increased significantly as the community were formed, while the change in P and K contents in the soil was negligible.
文摘The Global Stratotype Section and Point （GSSP） for the boundary between the Capitanian and Wuchiapingian stages, also the boundary between the Guadalupian and Lopingian Series is defined at the First Appearance Datum （FAD） of the conodont Clarkina postbitteri postbitteri at the base of Bed 6k in the Penglaitan Section along the Hongshui River in Guangxi Province, South China. This point is within a chronomorphocline from Clarkina postbitteri hongshuiensis to C. dukouensis and nearly coincides with the Middle-Upper Absaroka Megasequence boundary and as such is documented within a continuously deposited carbonate lowstand succession with deep-water facies of the Maokou Formation below and deep-water facies of the Heshan Formation above. Furthermore, this point also coincides with a major extinction of various Permian fossils including corals, fusulinaceans, ammonoids and brachiopods. The proximity to an apparently global major sequence boundary and extinction event will serve as a means of correlation of this GSSP into other regions in which the defining taxon is not present because of profound provincialism during the Middle and Upper Permian. Carbon isotopic trends and magnetostratigraphic signatures are also provided to help correlate this GSSP into other regions, including those with continental facies successions. The Tieqiao Section near the county town of Laibin is also described as a supplementary reference section.
基金supported by grants from the National Natural Science Foundation of China(81722008,91639101,and81570362 to JX and 81800358 to LW)the Innovation Program of Shanghai Municipal Education Commission(2017-01-07-00-09-E00042 to JX)+1 种基金the Science and TechnologyCommission of Shanghai Municipality(17010500100 to JX)the development fund for Shanghai talents(to JX)
文摘Exercise training is beneficial to the cardiovascular system. MicroRNAs （miRNAs, miRs） are a class of conserved non-coding RNAs and play a wide-ranging role in the regulation of eukaryotic gene expression. Exercise training alters the expression levels of large amounts ofmiRNAs in the heart. In addition, circulating miRNAs appear to be regulated by exercise training. In this review, we will summarize recent advances in the regulation of miRNAs during physical exercise intervention in various cardiovascular diseases, including pathologic cardiac hypertrophy, myocardial fibrosis, ischemia-reperfusion injury, myocardial infarction, and heart failure. The regulatory role of circulating miRNAs after exercise training was also reviewed. In conclusion, miRNAs might be a valuable target for treatment of cardiovascular diseases and have great potential as biomarkers for assessment of physical performance.2018 Published by Elsevier B.V.on behalf of Shanghai University of Sport. This is an open access article under the CC BY-NC-ND license. （http：//creativecommons.org/licenses/by-nc-nd/4.0/）.
文摘Purpose： The aims of this study were to assess differences of limb symmetry index （LSI） in strength- and coordination-related tasks between high-level, competitive, noninjured ski racers of different age-related performance levels and to prospectively assess limb differences as a possible risk factor for traumatic and overuse injury in youth ski racers. Methods： The study （Study 1） included 285 high-level competitive ski racers （125 females, 160 males） of 3 age-related performance levels and based on the school system： 95 youth （10-14 years, secondary modem school）, 107 adolescent （15-19 years, grammar school）, and 83 elite athletes （20-34 years）. To investigate the second aim （Study 2）, 67 of the 95 youth athletes were included and any traumatic or overuse injuries were prospectively recorded over 2 seasons. All athletes performed 4 unilateral tests （strength related： one-leg counter movement jump （OL-CMJ） and one-leg isometric/isokinetic press strength test （OL-ILS）; coordination related： one-leg stability test （OL-ST） and one-leg speedy jump test （OL-SJ））. The LSI was calculated by dividing the dominant leg by the nondominant leg and multiplying by 100. Kruskal-Wallis H tests and binary logistic regression analyses were conducted. Results： There were significant differences between the LSI of the 3 age-related performance-level groups only in the strength-related tests： the OL-CMJ （X^2（2, 285） = 9.09; p = 0.01） and the OL-ILS （X^2（2,285） = 14.79; p 〈 0.01）. The LSI for OL-ILS was found to be a significant risk factor for traumatic injury in youth ski racers （Wald = 7.08; p 〈 0.01）. No significant risk factors were found for overuse injuries. Conclusion： Younger athletes display slightly greater LSI values only in the strength-related tests. The cut-off value of limb differences of 〈 10% for return to sport decisions seems to be appropriate for elite athletes, but for youth and adolescent athletes it has to be critically discussed. It seems to be necessary to define thresholds based on specific performance tasks （strength vs. coordination related） rather than on generalizations, and age-related performance levels must be considered. Limb differences in unilateral leg extension strength represent a significant injury risk factor in youth ski racers.2018 Published by Elsevier B.V. on behalf of Shanghai University of Sport. This is an open access article under the CC BY-NC-ND license. （http：//creativecommons.org/licenses/by-nc-nd/4.0/）.
基金supported by NSFC of China (No. 19871036 and No. 40301037)Faculty Research Grant,Hong Kong Baptist University
文摘A proper edge coloring of a graph G is called adjacent vertex-distinguishing acyclic edge coloring if there is no 2-colored cycle in G and the coloring set of edges incident with u is not equal to the coloring set of edges incident with v, where uv∈ E（G）. The adjacent vertex distinguishing acyclic edge chromatic number of G, denoted by X＇Aa（G）, is the minimal number of colors in an adjacent vertex distinguishing acyclic edge coloring of G. If a graph G has an adjacent vertex distinguishing acyclic edge coloring, then G is called adjacent vertex distinguishing acyclic. In this paper, we obtain adjacent vertex-distinguishing acyclic edge coloring of some graphs and put forward some conjectures.
基金supported by the National Natural Science Foundation of China(10871025)
文摘By means of vector-valued product Calderón-Zygmund operators and some subtle estimates,the boundedness in product Hardy spaces on R^n × R^m of Calderón-Zygmund operators introduced by J.L. Journé is established.
基金supported by the Program"China's Mineral Species and Systematic Mineralogy Research"with Grant No.201011005-1A,B and C,from The Ministry of Science and Technology of the People's Republic of China
文摘A new mineral,jichengite ideally 3CuIr_2S_4·(Ni,Fe)_9S_8,was found as a constituent of placer concentrates at a branch of the Luanhe River,about 220 km NNE of Beijing.Its associated minerals are chromite,magnetite,ilmenite,zircon,native gold,iridium,ferrian platinum and osmium.The placer is distributed at places around ultrabasic rock,which hosts chromite orebodies,from which PGM originated.Jichengite occurs commonly as massive or granular aggregates.No perfect morphology of jichengite was observed.It is steel gray and opaque with metallic luster and black streak.It has a Mohs hardness of 5,VHN(d) urn 21.65,H_m 4.465,Hv = 268.1 N/um^2.It is brittle and weakly magnetic. Cleavage {010} is rarely observed.No fracture was observed.Density could not be measured because of its too small grain size.Density(calc.) is 7.003 g/cm^3.Reflect light is reddish-brown,without internal reflections.Anisotropism is distinct with grayish or yellowish white in crossed nicols and bluish violetcopper red in uncrossed nicols.Jichengite shows weak pleochroism and strong bireflectance.The reflectance values in air at the Standard Commission on Ore Mineralogy wavelengths are:38.9,34.3 at 470 nm,38.9,34.5 at 546 nm,39.1,35.3 at 590 nm,39.2,36.8 at 650 nm,parallel-axial extinction.The six strongest lines in the X-ray powder-diffraction pattern[d in A,(I),(hkl)]are:3.00(100)(116),2.80(50) (205),2.48.(50)(208),1.916(40)(2,1,10),1.765(60)(220),1.753(50)(2,0,16).Five chemical analyses carried out,yielding the following results:S 25.76(25.49-5.97),Fe 10.03(9.78-10.31),Co 0.78 (0.75-0.81),Ni 12.48(12.32-12.85),Cu 4.77(4.69-4.83),Ir 46.98(46.14-47.89),sum 100.80wt%,which produced a formula(Cu_(1.556)Fe_(0.976))_(2.532)(Ir_(5.063)S_(10.126))·(Fe_(2.7451)Ni_(4.404)Co_(0.273))_(7.422)S_(6.517).The ideal formula is X_(10)Ir_5S_(17.5),which was calculated by single crystal structure analyses,where X=Cu(Ⅱ)+Fe(Ⅱ)+Ni(Ⅱ) +Co(Ⅱ).The single crystal data were collected using a diffractometer with Mo Kαradiation and a graphite monochromate.The crystal system is trigonal with space group R3m and unit cell parameters a=7.0745(14) A,c=34.267(10) A(The superstructure not found),and the final R Indices[with 564 observed reflections,I>2sigma(Ⅰ)]are R_1=0.0495,wR_2=0.1349.The specimens are deposited in the Geological Museum of China.
文摘Maize (Zea mays) is among the major cereals grown in the high rainfall areas of the subSaharan Africa’s (SSA) such as the Ethiopian part of the Blue Nile basin. However, its productivity is severely constrained by poor soil, water and crop management practices. This study simulated the water productivity of the crop under varying soil fertility scenarios (poor, near optimal and none limiting) using hybrid seeds under rainfed conditions using the FAO AquaCrop model. The result indicated that grain yield of maize increased from 2.5 tons.ha–1 under poor to 6.4 and 9.2 tons.ha–1 with near optimal and non-limiting soil fertility conditions. Correspondingly, soil evaporation decreased from 446 mm to 285 and 204 mm, while transpiration increased from 146 to 268 and 355 mm. Consequently, grain water productivity was increased by 48% and 54%, respectively, with the near optimal and non-limiting soil fertility conditions. The water productivity gain mainly comes from reduced evaporation and increased transpiration without significantly affecting water left for downstream ecosystem services. This has a huge implication for a basin scale water management planning for various purposes.
基金the Killam Foundation provided funding for this research
文摘Purpose： The aim of this study was to compare mechanical muscle function in the eccentric/concentric phases of vertical bilateral jumping in anterior cruciate ligament-reconstructed （ACLR）, elite （ELITE）, and adolescent （ADOL） alpine ski racers and ski cross athletes. Methods： Alpine ski racers/ski crossers （ACLR： n = 12, age = 26.7 ± 3.8 years; ELITE： n = 12, age = 23.9 ± 3.0 years; ADOL： n = 12, age = 17.8 ± 0.7 years; females： n = 6 per group, males： n = 6 per group） performed 5 maximal countermovement jumps （CMJs） and 5 squat jumps. The ground reaction forces for each limb were analyzed using dual force plate recording to obtain body center of mass （BCM） velocity, displacement, and power. The eccentric deceleration （ECC） and concentric phases were determined from BCM velocity. CMJ net concentric and ECC impulses were calculated （body mass normalized） along with the peak and mean BCM power and maximal vertical jump height. CMJ lower limb stiffness （LLS） was determined by the slope of the ground reaction forces vs. the BCM displacement curve over the ECC phase. Concentric and ECC asymmetry indices were calculated for each leg, and the left vs. right LLS was compared. Outcome measures （reported as mean ± SD） calculated as a 5-jump mean were normalized to body mass and compared using an analysis of variance. Results： No between-group differences were found for peak and mean power or jump heights. There were no group differences for LLS or net concentric phase impulse, but the net ECC impulse was lower in the ADOL group compared with ELITE skiers （ADOL： 1.33 ± 0.32 Ns/kg; ELITE： 1.59 ± 0.16 Ns/kg; p 〈 0.05）. Although no group differences were found for ECC asymmetry indices, a group × limb interaction was found for LLS （p 〈 0.01）, which was systematically higher in the right vs. the left limb of ADOL skiers （right： 54.1 ± 17.9 N/m/kg; left： 48.7 ± 15.7 N/m/kg;p 〈 0.01）. Conclusion： ADOL skiers demonstrated decreased ECC impulse and systematic right limb dominance in LLS compared with ACLR and ELITE skiers. The implication of these findings for injury and performance are unknown, but further investigation into these potential relationships is warranted.2018 Published by Elsevier B.V. on behalf of Shanghai University of Sport. This is an open access article under the CC BY-NC-ND license. （http：//creativecommons.org/licenses/by-nc-nd/4.0/）.
文摘We report near-zero crossover for vanadium cross-permeation through single-layer graphene immobilized at the interface of two Nafion?polymer electrolyte membranes.Vanadium ion diffusion and migration,including proton mobility through membrane composites,were studied with and without graphene under diffusion and migration conditions.Single-layer graphene was found to effectively inhibit vanadium ion diffusion and migration under specific conditions.The single-layer graphene composites also enabled remarkable ion transmission selectivity improvements over pure Nafion membranes,with proton transport being four orders of magnitude faster than vanadium ion transport.Resistivity values of 0.02±0.005Ωcm^(2) for proton and 223±4Ωcm^(2) for vanadium ion through single atomic layer graphene are reported.This high selectivity may have significant impact on flow battery applications or for other electrochemical devices where proton conductivity is required,and transport of other species is detrimental.Our results emphasize that crossover may be essentially completely eliminated in some cases,enabling for greatly improved operational viability.
基金supported financially by the National Natural Science Foundation of China (Grant No. 51372200)Program for New Century Excellent Talents in University of Ministry of Education of China (Grant No. NCET-12-1045)+2 种基金Special Program for local serving from Education Department of Shaanxi Provincial Government (Grant No. 2013JC19)Program for Innovation Team in Xi’an University of Technology (Grant No. 108-25605T401)Ph.D. Innovation Fund Projects of Xi’an University of Technology (Fund No. 310-252071501)
文摘This work focuses on the relationship between flexibility of molecular chains and thermal properties of polyurethane elastomer（PUE）, which laid the foundation of further research about how to improve thermal properties of PUE. A series of PUE samples with different flexibility of molecular chains was prepared by using 1,4-butanediol（1,4-BDO）/bisphenol-a（BPA） blends with different mole ratios including9/1, 8/2, 7/3, 6/4 and 5/5. As comparison, PUE extended with pure 1,4-BDO and BPA was also synthesized.These samples were characterized by differential scanning calorimetry（DSC）, thermogravimetric analysis（TGA）, dynamic mechanical analysis（DMA）, etc. The results showed that with the decrease in flexibility of molecular chains the glass transition temperature（Tg） increased and low-temperature properties became worse. Besides, all samples had a certain degree of microphase separation, and soft segments in some samples were crystallized, i.e. the decreasing flexibility of molecular chains led to the impossibility of chains tightly packing and crystalline domains forming so that the degree of microphase separation decreased and the thermal properties became worse.
文摘Background： Sedentary behavior （SB）, physical activity （PA）, and attributes of physical fitness have been shown to be related to depressive symptoms in adolescents. The purpose of the present study was to investigate whether SB and fitness-producing activity predicted depression in active adolescents over and above gender and fitness attributes. Methods： Participants were 249 adolescents （age： 12.85 ± 0.89 years, mean ± SD） from 3 public middle schools who wore Actical accelerometers to assess their SB and PA. Participants also completed the FITNESSGRAM health-related fitness assessment and a brief depression questionnaire. A 3-step hierarchical regression analysis was conducted with gender and fitness attributes （i.e., body mass index （BMI）, maximal volume oxygen uptake （VO2max）, curlups, and pushups）, moderate- and vigorous-intensity activity, and SB entered in respective steps. Results： Regression analysis indicated activity variables （i.e., moderate- and vigorous-intensity activity） significantly predicted depression （△R^2= 0.12, p 〈 0.01） beyond gender and fitness attributes. Overall, gender, fitness attributes, activity variables, SB explained 31% of the variance in depression. Structure coefficients revealed VO2max （rs= -0.77）, moderate-intensity activity （rs= -0.67）, vigorous-intensity activity （rs = -0.81）, and SB （rs = 0.57） were substantially correlated with the criterion variable; thus, they were the strongest predictors of depression. Conclusion： The findings of the current study indicated SB and PA were both significant predictors of depression; however, sufficient fitness-producing activity and adequate cardiorespiratory fitness may nullify the negative influence of SB on depressive symptoms in active adolescents.2018 Published by Elsevier B.V. on behalf of Shanghai University of Sport. This is an open access article under the CC BY-NC-ND license. （http：//creativecommons.org/licenses/by-nc-nd/4.0/）.
基金Supported by the National Natural Science Foundation of China(10201026,10672111)
文摘A fourth-order variational inequality of the second kind arising in a plate frictional bending problem is considered. By using regularization method, the original problem can be formulated as a differentiable variational equation, and the corresponding discrete FEM variational equation is presented afterwards. Abstract error estimates and error estimates of the approximation are derived in terms of energy norm and L^2-norm.
基金partially supported by NSF grant DMS-1501004partially supported by NSFC(11701027)
文摘In this paper, we obtain the strong comparison principle and Hopf Lemma for locally Lipschitz viscosity solutions to a class of nonlinear degenerate elliptic operators of the form △2ψ ＋ L（x,△ ψ）, including the conformal hessian operator.
文摘The purpose of this paper is to analyze sleep stages accurately using fast and simple classifiers based on the frequency domain of electroencephalography(EEG) signal. To compare and evaluate system performance, the rules of Rechtschaffen and Kales(R&K rule) were used. Parameters were extracted from preprocessing process of EEG signal as feature vectors of each sleep stage analysis system through representatives of back propagation algorithm and support vector machine (SVM). As a result, SVM showed better performance as pattern recognition system for classification of sleep stages. It was found that easier analysis of sleep stage was possible using such simple system. Since accurate estimation of sleep state is possible through combination of algorithms, we could see the potential for the classifier to be used for sleep analysis system.
文摘The zeta potential and cationic demands of various kraft pulps - unbleached, bleached and beaten to different freeness levels were determined in the laboratory. The zeta potential of pulp where the final stage was a lignin degrading and dissolving treatment such as alkaline extraction or hypochlorite was lower than the unbleached pulp. The cationic demand of unbleached pulp was higher compared to that of bleached pulp. Beaten pulps showed larger cationic demands than the unbeaten pulps, which can be attributed to the larger specific surface area of pulp components. Fibres become increasingly electronegative when beaten and therefore cationic demand of pulps increases with beating. When the zeta potential method is used with furnishes of different freeness, the linear relationship is observed. However, the slope is decreasing with the decrease in freeness of the pulp.
文摘Tolerance in isolations of Trichoderma was developed by exposing two strains of T. harzianum and three of T. asperelloides to increasing concentrations of chemical fungicides. These isolation of Trichoderma were exposed to three fungicides: Captan, Thiabendazol and the mixture Captan-Carboxin. Some selected lines of these strains reached tolerance to Captan and partial tolerance to the mixture Captan-Carboxin. The biological and genetic changes in these tolerant lines were monitored by determining the relative growth rate of the fungus, inhibition of Fusarium and by analyzing the genomic changes through UP-PCR. The results show that the tolerance to fungicides can be developed without affecting the parameters of biological activity in these lines of Trichoderma (growth and parasitism against Fusarium). Chemical tolerance to the fungicide was verified by means of changes at the DNA level (UP-PCR), mainly in the lines tolerant to Captan. This suggests that Trichoderma survives in environments with remnants of fungicide molecules.
文摘Most measurements for beef improvement in South Africa are per individual (weaning weight, calving interval, growth rate, etc.). A measurement that expresses performance per constant unit, e.g. kilogram calf weaned per Large Stock Unit (LSU) can eventually be translated to kilogram calf produced per kg CO2 equivalent. A LSU is defined as a bovine requiring 75 MJ Metabolisable Energy (ME) per day. If more kilogram weaner calf can be produced per LSU (KgC/LSU), the carbon footprint of beef can be reduced. This study used breed average values to investigate the KgC/LSU for the 30 beef and dual purpose breeds in South Africa. The breeds were categorized in the following breed types: Sanga (indigenous to South Africa) Sanga derived, Zebu, Zebu derived, British and European. No relationship was found between cow weights and KgC/LSU, indicating that it is independent of cow weight between breeds. However, when the data is summarized into breed types, the Sanga and European breed types produce the least KgC/ LSU and Sanga derived breed types the most. This high value of the Sanga derived breeds is probably due to retained heterosis. Composite breeds are mostly intermediate to parental breeds for individual traits but superior for composite traits and KgC/LSU is a composite trait. These calculations were only done on breed averages. A genetic analysis on a breed level to estimate genetic parameters for this trait, and its genetic correlations with other traits now needs to be done before a decision can be taken whether selection for KgC/LSU will be feasible. The ultimate aim with a trait like this is to reduce the carbon footprint of weaner calf production since more kilogram calf will be produced per LSU (constant feed unit).
