3,356 research outputs found
Dynamical Computation on Coefficients of Electroweak Chiral Lagrangian from One-doublet and Topcolor-assisted Technicolor Models
Based on previous studies deriving the chiral Lagrangian for pseudo scalar
mesons from the first principle of QCD, we derive the electroweak chiral
Lagrangian and build up a formulation for computing its coefficients from
one-doublet technicolor model and a schematic topcolor-assisted technicolor
model. We find that the coefficients of the electroweak chiral Lagrangian for
the topcolor-assisted technicolor model are divided into three parts: direct
TC2 interaction part, TC1 and TC2 induced effective Z' particle contribution
part, and ordinary quarks contribution part. The first two parts are computed
in this paper and we show that the direct TC2 interaction part is the same as
that in the one-doublet technicolor model, while effective Z' contributions are
at least proportional to the p^2 order parameter \beta_1 in the electroweak
chiral Lagrangian and typical features of topcolor-assisted technicolor model
are that it only allows positive T and U parameters and the T parameter varies
in the range 0\sim 1/(25\alpha), the upper bound of T parameter will decrease
as long as Z' mass become large. The S parameter can be either positive or
negative depending on whether the Z' mass is large or small. The Z' mass is
also bounded above and the upper bound depend on value of T parameter. We
obtain the values for all the coefficients of the electroweak chiral Lagrangian
up to order of p^4.Comment: 52 pages, 15 figure
Derivation of Electroweak Chiral Lagrangian from One Family Technicolor Model
Based on previous studies deriving the chiral Lagrangian for pseudo scalar
mesons from the first principle of QCD in the path integral formalism, we
derive the electroweak chiral Lagrangian and dynamically compute all its
coefficients from the one family technicolor model. The numerical results of
the order coefficients obtained in this paper are proportional to the
technicolor number and the technifermion number ,
which agrees with the arguments in previous works, and which confirms the
reliability of this dynamical computation.Comment: 6 page
1,1′-(Butane-1,4-diÂyl)bisÂ[2-(pyridin-2-yl)-1H-benzimidazole]
The complete molÂecule of the title compound, C28H24N6, is generated by inversion symmetry with the inversion centre located at the mid-point of the central C–C bond of the butanediyl unit. The benzimidazole and pyridine rings are almost coplanar, the dihedral angle between their mean planes being 6.86 (11)°
The responding relationship between plants and environment is the essential principle for agricultural sustainable development on the globe
The mutual-responding relationship between plants and environment is involved in all life processes, which are the essential bases for different types of sustainable development on the globe, particularly the critical basis for agricultural sustainable development. How to regulate the above relationship between plants and the corresponding environment (in particular soil environment) is the key problem to modern sustainable agriculture development under global climate change, which is one of the hot topics in the field of plant biology. Detailed dissection of this responding relationship is also important for conducting global eco-environmental restoration and construction. Although powerful methodology and dataset related to genomics, post-genomics, and metabolomics have provided some insights into this relationship, crop physiological measures are also critical for crop full performance in field. With the increase of tested plants (including model plants) and development of integrated molecular biology, a complete understanding of the relationship at different scales under biotic and abiotic stresses will be accelerated. In the current paper, we will cover some important aspects in combination with the recent work from our laboratory and related advances reflected by international academic journals, as follows: plant physiological function performance under natural condition, plant gene regulatory network system under abiotic stresses, gene regulatory network system and drought resistance improvement, summary of the related work from our laboratory, conclusions, and acknowledgement
CryoEM structure of the human SLC4A4 sodium-coupled acid-base transporter NBCe1.
Na+-coupled acid-base transporters play essential roles in human biology. Their dysfunction has been linked to cancer, heart, and brain disease. High-resolution structures of mammalian Na+-coupled acid-base transporters are not available. The sodium-bicarbonate cotransporter NBCe1 functions in multiple organs and its mutations cause blindness, abnormal growth and blood chemistry, migraines, and impaired cognitive function. Here, we have determined the structure of the membrane domain dimer of human NBCe1 at 3.9 Å resolution by cryo electron microscopy. Our atomic model and functional mutagenesis revealed the ion accessibility pathway and the ion coordination site, the latter containing residues involved in human disease-causing mutations. We identified a small number of residues within the ion coordination site whose modification transformed NBCe1 into an anion exchanger. Our data suggest that symporters and exchangers utilize comparable transport machinery and that subtle differences in their substrate-binding regions have very significant effects on their transport mode
Drop dynamic analysis of half-axle flexible aircraft landing gear
Landing gear shock strut binding problem occurred during an unmanned aircraft’s flying test. The half-axle main landing gear of the unmanned aircraft was chosen to analyze the influences of shock strut flexibility on drop dynamics. The friction force was modeled based on the half-axle configuration and taking shock strut flexibility into account. Drop dynamic performances were analyzed and compared with those came from rigid strut model and drop test. Good correlation has been established between drop test data and the simulation predicated results. The results also showed that though the total axis force added merely 1 % when taking shock strut flexibility into account, the friction force added almost 45 %. A comprehensive deformation compatibility factor was presented to describe the actual deformation of shock strut bearings. Influence of deformation compatibility factor, flexibility of inner and outer cylinder were studied further
- …