Explicitly correlated configuration interaction investigation on low-lying states of SiO^+ and SiO

SiO^+ and SiO, which play vital roles in astrophysics and astrochemistry, have long attracted considerable attention.However, accurate information about excited states of SiO^+ is still limited. In this work, the structures of 14 Λ–S states and 30? states of SiO^+ are computed with explicitly correlated configuration interaction method. On the basis of the calculated potential energy curves of those Λ–S states and ? states, the spectroscopic constants of bound states are evaluated, which are in good agreement with the latest experimental results. The predissociation mechanism of B^2Σ^+ state is illuminated with the aid of spin–orbit coupling matrix elements. On the basis of the calculated potential energy curves and transition dipole moments, the radiative lifetime for each of low-lying vibrational states B^2Σ^+and A^2Π is estimated. The laser cooling scheme of SiO^+ is proposed by employing B^2Σ^+–X^2Σ^+ transition. Finally, the vertical ionization energy values from SiO(X^1Σ^+) to ionic states: SiO^+ , X^2Σ^+, B^2Σ^+, and A^2Π are calculated, which agree well with experimental measurements.

Predicting thermoelectric properties from chemical formula with explicitly identifying dopant effects

Dopants play an important role in synthesizing materials to improve target materials properties or stabilize the materials.In particular,the dopants are essential to improve thermoelectic performances of the materials.However,existing machine learning methods cannot accurately predict the materials properties of doped materials due to severely nonlinear relations with their materials properties.Here,we propose a unified architecture of neural networks,called DopNet,to accurately predict the materials properties of the doped materials.DopNet identifies the effects of the dopants by explicitly and independently embedding the host materials and the dopants.In our evaluations,DopNet outperformed existing machine learning methods in predicting experimentally measured thermoelectric properties,and the error of DopNet in predicting a figure of merit(ZT)was 0.06 in mean absolute error.In particular,DopNet was significantly effective in an extrapolation problem that predicts ZTs of unknown materials,which is a key task to discover novel thermoelectric materials.

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Submission of a manuscript implies:that the work described has not been published before(except in the form of an abstract or as part of a published lecture,review,or thesis);that it is not under consideration for publication elsewhere;that its publication has been approved by all co-authors,if any,as well as--tacitly or explicitly--by the responsible authorities at the institution where the work was carried out.The author warrants that his/her contribution is original

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Submission of a manuscript implies:that the work described has not been published before(except in the form of an abstract or as part of a published lecture,review,or thesis);that it is not under consideration for publication elsewhere;that its publication has been approved by all co-authors,if any,as well as-tacitly or explicitly-by the responsible authorities at the institution where the work was carried

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Submission of a manuscript implies:that the work described has not been published before(except in the form of an abstract or as part of a published lecture,review,or thesis);that it is not under consideration for publication elsewhere;that its publication has been approved by all co-authors,if any,as well as--tacitly or explicitly--by the responsible authorities at the institution where the work was carried out.The author warrants that his/her contribution is original

Acta Oceanologica Sinica

1 Copyright Information For Authors Submission of a manuscript implies:that the work described has not been published before(except in the form of an abstract or as part of a published lecture,review,or thesis);that it is not under consideration for publication elsewhere;that its publication has been approved by all co-authors,if any,as well as-tacitly or explicitly-by the responsible authorities at the institution where the work was

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Submission of a manuscript implies:that the work described has not been published before(except in the form of an abstract or as part of a published lecture.review.or thesis);that it is not under consideration for publication elsewhere;that its publication has been approved by all co-authors,if any,as well as-tacitly or explicitly-by the responsible authorities

Accurate all-electron calculation on the vibrational and rotational spectra of ground states for O2 and its ions

The potential energy curves, spectroscopic constants, and low-lying vibration–rotation levels of ground-state O2 and its cation O2+ and anion O2- were calculated with the explicitly correlated multireference configuration interaction method.The zeroth-order reference wavefunction was treated with the complete active space multiconfigurational self-consistent field method, in which the active space was carefully selected, and an additional molecular orbital πu was added into the full valence active space.The electron correlation of the 1s core in the oxygen atom was considered in the computations.The Davidson correction on molecular energy was considered to account for higher electron excitation.The relativistic effects, including the scalar relativistic effect and spin–orbit coupling, were considered in the computation of potential energy curves.These physical effects on the spectroscopic constants were examined.The low-lying levels of vibration–rotation spectra of O2 and its ions were determined based on the computed potential energy curves.Comparisons with available experiments were made and excellent agreement was obtained for the vibrational and rotational parameters.The spectroscopic constants and vibration–rotation spectrum of O2-, which is sparse in experiments, were provided.Our study will shed some light on further theoretical and experimental studies on these simple but important molecular systems.

Non-Born-Oppenheimer study of the muonic molecule ion 4Heμ^+

Accurate non-Born-Oppenheimer variational calculations of all bound states of the positive muon molecular ion 4Heμ^+ have been performed using explicitly correlated Gaussian functions in conjunction with the global vectors.All the energies obtained are accurate in the order of 10-6 Hartree(1 Hartree=27.2114 eV).Compared with the binding energies obtained from calculations based on the Born-Oppenheimer potential with the mass-weighted adiabatic corrections(Chem.Phys.Lett.110487(1984)),the largest relative deviation is up to 15%.By analyzing the average interparticle distances and possibility distributions of interparticle distances of this system,it is confirmed that the Born-Oppenheimer approximation is reasonable for this system and that 4Heμ^+ can be regarded as a system of positive muon bound to a slightly distorted helium atom.

Generalized Energy-Based Fragmentation Approach for Accurate Binding Energies and Raman Spectra of Methane Hydrate Clusters

Methane hydrates(MHs)play important roles in the fields of chemistry,energy,environmental sciences,etc.In this work,we employ the generalized energy-based fragmentation(GEBF)approach to compute the binding energies and Raman spectra of various MH clusters.For the GEBF binding energies of various MH clusters,we first evaluated the various functionals of density functional theory(DFT),and compared them with the results of explicitly correlated combined coupled-cluster singles and doubles with noniterative triples corrections[CCSD(T)(F12^(*))]method.Our results show that the two best functionals are B3PW91-D3 and B97D,with mean absolute errors of only 0.27 and 0.47 kcal/mol,respectively.Then we employed GEBF-B3PW91-D3 to obtain the structures and Raman spectra of MH clusters with mono-and double-cages.Our results show that the B3PW91-D3 functional can well reproduce the experimental C-H stretching Raman spectra of methane in MH crystals,with errors less than 3 cm^(-1).As the size of the water cages increased,the C-H stretching Raman spectra exhibited a redshift,which is also in agreement with the experimental“loose cage-tight cage”model.In addition,the Raman spectra are only slightly affected by the neighboring environment(cages)of methane.The blueshifts of C-H stretching frequencies are no larger than 3 cm^(-1) for CH_(4) from monocages to doublecages.The Raman spectra of the MH clusters could be combined with the experimental Raman spectra to investigate the structures of methane hydrates in the ocean bottom or in the interior of interstellar icy bodies.Based on the B3PW91-D3 or B97D functional and machine learning models,molecular dynamics simulations could be applied to the nucleation and growth mechanisms,and the phase transitions of methane hydrates.

Radial Shocks in Advection-Dominated Accretion Flows Around Black Holes

We have solved the set of equations for advection-dominated accretion flows(ADAFs)around black holes,and found a new class of global solutions with standing radial shocks.Suchα-X-type shocks may exist in flows when 0≤α<0.05.An example solution is given explicitly,for whichα=0.01 andγ=1.5.The shock position is R_(sh)=8.68R_(g),which is between the inner sonic point R_(s1)=3.88R_(g) and the outer sonic point R_(s2)=85.92R_(g).

China's National Economic Development and Priority Fields Attracting Foreign Investments In 1990s—Excerpts from a report by Vice-Minister Gan Ziyu of the State Planning Commission at a Conference on foreign economic and technological cooperation of Chin

Development Highlights of China’s National Economy in 1990s Since the beginning of the 1990s, our national economy has sustained favourable growth. In 1991, Gross National product (GNP) maintained an increase of 7.3% although our country encountered disastrous floods. After Deng Xiaoping’s important speech made during his Southern China inspection in early 1992, and the proposal

Non-Governmental Organizations in Public Diplomacy: Bright Prospects

In recent years, as one of the important diplomatic spheres China has vigorously explored, public diplomacy has attracted great attention. In July 2009, President Hu Jintao for the first time explicitly put forward that "We should strengthen public diplomacy and cultural diplomacy, carry out various forms of cultural exchanges with other countries and make steady headway in spreading China’s excellent culture", thus has elevated public diplomacy to

Improved method for studying the propagation dynamics of ultrafast electron pulses based on mean-field models

We have studied the propagation dynamics of ultrafast electron pulses by using an improved mean-field model, in which the propagation of the electron pulses across the boundary of the acceleration region is explicitly considered. A large decrease in the speed spread of the electron pulses（we called “boundary kick”） is observed and properly treated leading to a significant improvement in the simulation accuracy, particularly when the density of electrons is very large. We show that our method is consistent with the simulation by the N-particle method, while others can introduce factorial error.

The Intellectual Property Court Edges Its Way Forward

INTELLECTUAL property is highly valued the world over,including in China.The Decision on Some Major Issues Concerning Comprehensively Deepening Reform,released in November 2013 at the Third Plenary Session of the 18th Communist Party of China（CPC）Central Committee,said explicitly：＂We will strengthen the application and protection of intellectual property rights（IPR）,improve the technological innovation incentive mechanism,and explore ways to set up IPR courts.＂ On August 31, 2014, the National People＇s Congress, China＇s top legislature, voted to establish IPR courts in Beijing, Shanghai, and Guangzhou. They soon came into being, constituting a milestone in China＇s IPR protection.

Machine learning for optical quantum metrology

Machine learning(ML)is one of the most acclaimed areas of science and technology,leading to countless real-world benefits,from industry to healthcare.ML involves creating algorithms to perform specific tasks by recognizing patterns in the data and without requiring extensive instructions,namely without being explicitly programmed.This possibility has recently attracted the attention of a broad community of scientists interested in learning,controlling,and making optimal use of quantum systems of increasing complexity,1,2 potentially leading to revolutionary progresses in many fields.

Atomistic Line Graph Neural Network for improved materials property predictions

Graph neural networks(GNN)have been shown to provide substantial performance improvements for atomistic material representation and modeling compared with descriptor-based machine learning models.While most existing GNN models for atomistic predictions are based on atomic distance information,they do not explicitly incorporate bond angles,which are critical for distinguishing many atomic structures.Furthermore,many material properties are known to be sensitive to slight changes in bond angles.We present an Atomistic Line Graph Neural Network(ALIGNN),a GNN architecture that performs message passing on both the interatomic bond graph and its line graph corresponding to bond angles.We demonstrate that angle information can be explicitly and efficiently included,leading to improved performance on multiple atomistic prediction tasks.We ALIGNN models for predicting 52 solid-state and molecular properties available in the JARVIS-DFT,Materials project,and QM9 databases.ALIGNN can outperform some previously reported GNN models on atomistic prediction tasks by up to 85%in accuracy with better or comparable model training speed.

A BOUNDARY VALUE PROBLEM FOR A NONLINEAR ORDINARY DIFFERENTIAL EQUATION INVOLVING A SMALL PARAMETER——The Riemann problem for a Generalized Diffusion Equation

This paper studies the boundary value problem involving a small parameter(（k（V（t））+ε）[V’（s）[n-1V’（s）’+(sg（V（s））+f（V（s））V’（s）=0 for s∈R,V（-∞）=A,V（+∞）=B;A【B,which originates from the Riemann problem for a generalized diffusion equntiong（U）DtU=p’（t）pN（t）Dx(（k（U）+ε）|DxU|N-1DxU+p’（t）f（U）DxU for x∈R,t】0,U（x,0）=A for x【0,U（x,0）=B for x】0,under the hypotheses H1—H4.The author’s aim is not only to determine explicitly thediscontinuous solution U0（x,t）=V0（s）,s=x/p（t）,to the reduced problem,and the formand the number of its curves of discontinuity,but also to present,in an extremely naturalway,the jump conditions which it must satisfy on each of its curves of discontinuity.Itis proved that the problem has a unique solution Uε（x,t）=Vε（s）,s=x/p（t）,ε≥0,Vε（s）pointwise converges to V0（s）as ε 0,V0（s）has at least one jump point if and only if k（y）possesses at least one interval of degeneracy in[A,B],and there exists a one-to-onecorrespondence between the collection of all intervals of degeneracytof k（y）in[A,B]andthe set of all jump points of V0（s）.

Possible hadronic molecular states composed of S-wave heavy-light mesons

We perform a systematical study of possible molecular states composed of the S wave heavy light mesons,where the S–D mixing and η-η＇ mixing are explicitly included.Our calculation indicates that the observed X（3872） could be a loosely shallow molecular state composed of D＊＋ h.c,while neither Z_c（3900）/Z_c（4020） nor Z_b（10610）/Z_b（10650） is supported to be a molecule.Some observed possible molecular states are predicted,which could be searched for by further experimental measurements.

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Submission of a manuscript implies:that the work described has not been published before(except in the form of an abstract or as part of a published lecture,review,or thesis);that it is not under consideration for publication elsewhere;that its publication has been approved by all co-authors,if any,as well as--tacitly or explicitly--by the responsible authorities at the institution where the work was