859 research outputs found
Measuring and assessing HIV/AIDS stigma and discrimination among migrant workers in Zhejiang, China
Abstract Background The aim of this study was to develop a Chinese HIV/AIDS Stigma Scale (C-HSS) and test its reliability and validity among migrant workers in eastern China. Methods Nine hundred sixty four migrant workers completed the C-HSS questionnaire in Zhejiang province. The Split-half reliability coefficient (R) and Cronbach’s alpha coefficient (a) for internal consistency of the scale were used. Factor analysis was applied for construct validity. Scores of total and subscales were compared among migrants. Correlation between scores and knowledge of HIV/AIDS was analyzed. Results The 24-items scale and the four subscales of C-HSS had good internal consistency (R overall was 0.877, subscales ranged from 0.693 to 0.862; Cronbach’s alpha overall was 0.845, subscales ranged from 0.709 to 0.810). Correlation coefficients between each domain and total score were significant (p < 0.01). The cumulative contribution rate was 54.17 % by five public factors based on exploratory factor analysis. Except for the thirteenth item and twentieth item, four public factors were in accordance with the basic conceived concept. The confirmatory factor analysis indicated a good fit to the data for the four-domain structure. Negative correlation existed between the level of HIV/AIDS knowledge and stigma. Conclusion The results suggest that the C-HSS is a reliable and valid measure for HIV/AIDS stigma in migrant workers
Dichlorido{[2-(diphenylphosphino)phenyliminomethyl]ferrocene-κ2 N,P}platinum(II) dichloromethane hemisolvate
In the title compound, [FePt(C5H5)(C24H19NP)Cl2]·0.5CH2Cl2, the PtII atom adopts a distorted square-planar geometry defined by one P atom and one N atom from the bidentate [2-(diphenylphosphino)phenyliminomethyl]ferrocene ligand and two Cl atoms. Two disordered dichloromethane solvent molecules are each 0.25-occupied on a twofold rotation axis
Biphenyl-3,3′,4,4′-tetracarboxylic acid dihydrate
The asymmetric unit of the title compound, C16H10O8·2H2O, contains one-half of the centrosymmetric organic molecule and one water molecule. The dihedral angles between the carboxylate groups and the adjacent phenyl ring are 71.31 (3) and 16.67 (3)°, while the carboxylate groups are oriented at a dihedral angle of 72.01 (3)°. In the crystal structure, intermolecular O—H⋯O and bifurcated O—H⋯(O,O) hydrogen bonds link the molecules to form a three-dimensional supramolecular network
Iterative Learning Control of a Nonlinear Aeroelastic System despite Gust Load
The development of a control strategy appropriate for the suppression of aeroelastic vibration of a two-dimensional nonlinear wing section based on iterative learning control (ILC) theory is described. Structural stiffness in pitch degree of freedom is represented by nonlinear polynomials. The uncontrolled aeroelastic model exhibits limit cycle oscillations beyond a critical value of the free-stream velocity. Using a single trailing-edge control surface as the control input, a ILC law under alignment condition is developed to ensure convergence of state tracking error. A novel Barrier Lyapunov Function (BLF) is incorporated in the proposed Barrier Composite Energy Function (BCEF) approach. Numerical simulation results clearly demonstrate the effectiveness of the control strategy toward suppressing aeroelastic vibration in the presence of parameter uncertainties and triangular, sinusoidal, and graded gust loads
Topological optimization of hybrid quantum key distribution networks
With the growing complexity of quantum key distribution (QKD) network
structures, aforehand topology design is of great significance to support a
large-number of nodes over a large-spatial area. However, the exclusivity of
quantum channels, the limitation of key generation capabilities, the variety of
QKD protocols and the necessity of untrusted-relay selection, make the optimal
topology design a very complicated task. In this research, a hybrid QKD network
is studied for the first time from the perspective of topology, by analyzing
the topological differences of various QKD protocols. In addition, to make full
use of hybrid networking, an analytical model for optimal topology calculation
is proposed, to reach the goal of best secure communication service by
optimizing the deployment of various QKD devices and the selection of
untrusted-relays under a given cost limit. Plentiful simulation results show
that hybrid networking and untrusted-relay selection can bring great
performance advantages, and then the universality and effectiveness of the
proposed analytical model are verified.Comment: 12 pages, 4 figure
Variational-based data assimilation to simulate sediment concentration in the Lower Yellow River, China
The heavy sediment load of the Yellow River makes it difficult to simulate sediment concentration using classic numerical models. In this paper, on the basis of the classic one-dimensional numerical model of open channel flow, a variational-based data assimilation method is introduced to improve the simulation accuracy of sediment concentration and to estimate parameters in sediment carrying capacity. In this method, a cost function is introduced first to determine the difference between the sediment concentration distributions and available field observations. A one-dimensional suspended sediment transport equation, assumed as a constraint, is integrated into the cost function. An adjoint equation of the data assimilation system is used to solve the minimum problem of the cost function. Field data observed from the Yellow River in 2013 are used to test the proposed method. When running the numerical model with the data assimilation method, errors between the calculations and the observations are analyzed. Results show that (1) the data assimilation system can improve the prediction accuracy of suspended sediment concentration; (2) the variational inverse data assimilation is an effective way to estimate the model parameters, which are poorly known in previous research; and (3) although the available observations are limited to two cross sections located in the central portion of the study reach, the variational-based data assimilation system has a positive effect on the simulated results in the portion of the model domain in which no observations are available
Diaquabis(9-oxo-4,5-diazafluoren-3-olato-κ2 N 4,O 3)cadmium(II)
The title compound, [Cd(C11H5N2O2)2(H2O)2], is a mononuclear complex consisting of a CdII atom, two 3-hydroxy-4,5-diazafluoren-9-one ligands and two coordinated water molecules. The CdII atom, lying on a twofold axis, displays a distorted octahedral coordintion. Adjacent molecules are linked by O—H⋯O hydrogen bonds and π–π interactions [centroid–centroid distance = 3.84 (1) Å], leading to a one-dimensional chain. Weak C—H⋯O hydrogen bonds connect the chains into a two-dimensional supramolecular structure
- …