4,341 research outputs found
Discussion of the Rural Land Property System Reform According to the Rural Land Contract Management in China
In the past two decades, the rural land contract management has activated the rural region economy and improved the agricultural productivity tremendously, however, has also restricted itself from progressing towards industrialization and scale economy. In order to solve this fundamental problem, we must carry on the reform of land property system and grant the peasantry with full land property right. Key words: Agricultural Industrialization; System of Farmhouse; Contract Management; Rural Land Ownershi
Stable nontrivial Z2 topology in ultrathin Bi (111) films: a first-principles study
Recently, there have been intense efforts in searching for new topological
insulator (TI) materials. Based on first-principles calculations, we find that
all the ultrathin Bi (111) films are characterized by a nontrivial Z2 number
independent of the film thickness, without the odd-even oscillation of
topological triviality as commonly perceived. The stable nontrivial Z2 topology
is retained by the concurrent band gap inversions at multiple
time-reversal-invariant k-points and associated with the intermediate
inter-bilayer coupling of the multi-bilayer Bi film. Our calculations further
indicate that the presence of metallic surface states in thick Bi(111) films
can be effectively removed by surface adsorption.Comment: 5 pages, 3 figure
Transitions between the quantum Hall states and insulators induced by periodic potentials
Journal ArticleTransitions between two quantum Hall states or between a quantum Hall state and a Mott insulator induced by periodic potentials are studied in the 1 /TV expansion. The transitions are found to be continuous in the large-TV limit and are described by a critical point that depends on a real parameter 0, which is determined by the topological orders in the quantum Hall states involved in the transition. Some critical exponents and universal quantities are calculated in the large-TV limit and shown to be 0 dependent
Research on the Running Speed Prediction Model of Interchange Ramp
AbstractRamp is an important part of the interchange. The ramp design concept based on the running speed is a new design idea of the highway and interchange. By analysis of the influence factors of the interchange ramp running speed, this paper formulates the orthogonal experiment, and collects 14 ramps, in total of 147 groups of the running speed as the samples, and then analyzes the characteristics of the running speed of the vehicles on interchange ramp. According to the change trend of the running speed, the ramp is divided into three sections: deceleration section, uniform section, acceleration section. This paper mainly analyzes the relationship between the interchange ramp running speed of the three sections and the influence factors; and then this paper builds the interchange ramp running speed prediction model of the three sections. At last, correlation test will be validated, and verify the applicability of the model
5,6-DihydrÂoxy-1,10-phenanthrolin-1-ium chloride dihydrate
The title compound, C12H9N2O2
+·Cl−·2H2O, exhibits a layered structure which is stabilized by interÂmolecular O—H⋯O, O—H⋯Cl− and N+—H⋯Cl− hydrogen bonds, and π–π interÂactions (centroid–centroid distances = 3.654 and 3.583 Å). The distances between the molecules are 3.371 and 3.294 Å
Enzyme or whole cell immobilization for efficient biocatalysis: focusing on novel supporting platforms and immobilization techniques
Biocatalysts represented by enzymes and enzyme-containing whole cells are generally fragile
and easily inactivated in practical application conditions. The immobilization concept and
techniques have been recognized as classic and powerful strategy for tackling such challenges
(Hanefeld et al., 2009). Based on this background, a special Research Topic entitled Enzyme or
Whole Cell Immobilization for Efficient Biocatalysis: Focusing on Novel Supporting Platforms and
Immobilization Techniques had been organized and presented in the platform of Frontiers in
Bioengineering and Biotechnology, which aimed to collect different insights and latest findings
regarding but not limited to new theories, techniques and methodologies in this area. Over the past
year since Sept. 2019, this Research Topic has attracted 242 authors from more than 10 countries
to participate and contribute their manuscripts. Consequently, this special issue has selected and
presented 40 peer-reviewed articles to meet the readers, including 31 Original Researches, four Brief
Research Reports, four Reviews, and one General Commentary, which involved various aspects and
every corner of this area
Localized Sparse Incomplete Multi-view Clustering
Incomplete multi-view clustering, which aims to solve the clustering problem
on the incomplete multi-view data with partial view missing, has received more
and more attention in recent years. Although numerous methods have been
developed, most of the methods either cannot flexibly handle the incomplete
multi-view data with arbitrary missing views or do not consider the negative
factor of information imbalance among views. Moreover, some methods do not
fully explore the local structure of all incomplete views. To tackle these
problems, this paper proposes a simple but effective method, named localized
sparse incomplete multi-view clustering (LSIMVC). Different from the existing
methods, LSIMVC intends to learn a sparse and structured consensus latent
representation from the incomplete multi-view data by optimizing a sparse
regularized and novel graph embedded multi-view matrix factorization model.
Specifically, in such a novel model based on the matrix factorization, a l1
norm based sparse constraint is introduced to obtain the sparse low-dimensional
individual representations and the sparse consensus representation. Moreover, a
novel local graph embedding term is introduced to learn the structured
consensus representation. Different from the existing works, our local graph
embedding term aggregates the graph embedding task and consensus representation
learning task into a concise term. Furthermore, to reduce the imbalance factor
of incomplete multi-view learning, an adaptive weighted learning scheme is
introduced to LSIMVC. Finally, an efficient optimization strategy is given to
solve the optimization problem of our proposed model. Comprehensive
experimental results performed on six incomplete multi-view databases verify
that the performance of our LSIMVC is superior to the state-of-the-art IMC
approaches. The code is available in https://github.com/justsmart/LSIMVC.Comment: Published in IEEE Transactions on Multimedia (TMM). The code is
available at Github https://github.com/justsmart/LSIMV
Assess Calibration Consistency of MODIS and AVHRR Thermal Infrared Bands Using SNO Observations Corrected for Atmospheric Effects
Monitoring environmental changes from space requires extremely well-calibrated observations to achieve the necessary high accuracy and stability. The calibration differences between the Moderate Resolution Imaging Spectroradiometer (MODIS) and the Advanced Very High Resolution Radiometer (AVHRR) thermal bands provide a valuable quality assessment of the instrument performance. This letter compares the calibration differences between the Aqua MODIS and NOAA-18 AVHRR bands at 11.0 and 12.0 /Lm using simultaneous nadir overpass observations obtained in nearly parallel orbits. Impacts due to the relative spectral-response differences between the two sensors are estimated by MODTRAN simulations with real-time atmospheric profiles of temperature, water vapor, atmospheric pressure and ozone, and surface skin temperatures. Results show that the temperature difference after the removal of atmospheric impacts is within 0.30 K (or 0.40% in radiance) across the effective calibration range (or the 1l.0 l'm band/channel. For the 12.0 pm band, the differences are OAO K (or 0.50%) at the typical radiance and up to 0.70 K (or 0.90%) close to the maximum radiance, indicating an excellent calibration consistency between MODIS and AVHRR for both bands
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