4,212 research outputs found
A simplified method for calculating the ac Stark shift of hyperfine levels
The ac Stark shift of hyperfine levels of neutral atoms can be calculated
using the third order perturbation theory(TOPT), where the third order
corrections are quadratic in the atom-photon interaction and linear in the
hyperfine interaction. In this paper, we use Green's function to derive the
method which can give close values to those of TOPT for the
differential light shift between two hyperfine levels. It comes with a simple
form and easy incorporation of theoretical and experimental atomic structure
data. Furthermore, we analyze the order of approximation and give the condition
under which method is valid.Comment: 7 pages, 5 figure
Can pro-environmental behavior increase farmers’ income?—Evidence from arable land quality protection practices in China
In China, agricultural non-point source pollution is one of the key
factors limiting farmers’ income growth, and pro-environmental
behavior can address agricultural surface pollution. Based on field
survey data from 591 farmers in Xinjiang, China, this study empirically
estimates the impact of pro-environmental behavior on
farmers’ income growth. The results show that pro-environmental
behavior plays a significant positive role in increasing farmers’
income, and the positive effect continues in the long run.
Specifically, pro-environmental behavior can optimize the allocation
of agricultural production factors, thus resulting in farmers’
income growth. The mechanism analysis shows that pro-environmental
behavior affects farmers’ income growth by promoting
the increase in the size of arable land and farmers’ willingness to
transfer their land in the future. These findings indicate that a
sound reward–punishment system for pro-environmental behavior
should be established; training on pro-environmental behavior
should be strengthened, and a mechanism for linking the benefits
of pro-environmental behavior among stakeholders should be
constructed
Anti-Hyperon polarization in high energy pp collisions with polarized beams
We study the longitudinal polarization of the Sigma_bar and Xi_bar
anti-hyperons in polarized high energy pp collisions at large transverse
momenta, extending a recent study for the Lambda_bar anti-hyperon. We make
predictions by using different parametrizations of the polarized parton
densities and models for the polarized fragmentation functions. Similar to the
Lambda_bar polarization, the Xi_bar0 and Xi_bar+ polarizations are found to be
sensitive to the polarized anti-strange sea in the nucleon. The Sigma_bar- and
Sigma_bar+ polarizations show sensitivity to the light sea quark polarizations,
\Delta \bar u(x) and \Delta \bar d(x), and their asymmetry.Comment: 17 pages, 9 figures,version to appear in PR
RESEARCH ON VISUALIZATION TECHNOLOGY OF CYBERCITY 3D SCENE
3D visualization is a Key Technology in CyberCity. It has been applied in many fields. In this paper, we discussed and studied several key techniques of 3D visualization in CyberCity. These key techniques contain Oriented Object 3D Data Model, Advanced Modeling Techniques which contain Particle System and Billboard, 3D Scene Accelerate Rendering Techniques, Information Inquire techniques in 3D scene and so on. The 3D Scene Accelerate Rendering Techniques contain Object Culling, Back Face Culling and LOD (level of detail) technique. Based on these techniques, we designed and implemented an advanced 3D Rendering Engine. At the end of paper, we give some results created by the 3D Rendering Engine. The results show that the 3D engine can render highly reality 3D scene and user can obtain highly immersion by rambling in 3D scene and inquiring information based on database.
(E)-4-Amino-N′-(3-nitrobenzylidene)benzohydrazide
In the title compound, C14H12N4O3, the dihedral angle between the benzene rings is 7.6 (4)°. In the crystal, infinite sheets linked by N—H⋯O and bifurcated N—H⋯(O,N) hydrogen bonds propagate in the (10-1) plane, in which R
4
4(36) loops are apparent. Neighbouring layers may interact by way of very weak π–π stacking interactions [centroid–centroid distances = 3.9329 (13) and 4.0702 (13) Å]
Family and Individual Risk and Protective Factors of Depression among Chinese Migrant Children with Oppositional Defiant Disorder Symptoms
Migrant children reached 35.81 million in China and were vulnerable to serious emotional problems including depression. The present study aimed to identify the family and individual risk and protective factors for depression in an at-risk sample of Chinese migrant children. Participants were 368 children (9.47 ± 1.46 years old, 73.4% boys) who had at least one symptom of Oppositional Defiant Disorder symptoms (ODD) and their parents in Mainland China. Risk and protective factors within both family (i.e., family maltreatment and family functioning) and individual (i.e., automatic thoughts and resilience) perspectives. Family maltreatment and negative automatic thoughts served as risk factors in relation to children's depression. Further, automatic thoughts mediated the relationship between family maltreatment and children's depression. Family functioning (cohesion, but bot adaptability) and individual resilience could buffer the effects of risk factors in the Structure Emotion Model such that both cohesion and resilience moderated the relationship between family maltreatment and children's automatic thoughts only. Our findings highlighted the urgent need to decrease risk factors and increase protective factors of both family and child individual characteristics in prevention and intervention depression among migrant children with ODD symptoms in China
Risk of Multiple Myeloma In Rheumatoid Arthritis: A Meta-Analysis of Case-Control and Cohort Studies
Multiple myeloma is a malignant neoplasm of plasma cells mainly affecting elderly patients. Despite the wealth of information available on therapeutic strategies, the etiology and pathogenesis of myeloma remain unclear. In the current study, a meta-analysis was conducted to assess the possible association between rheumatoid arthritis and myeloma
- …