耦合mKdV系统的非奇异正子解、负子解及复子解

研究从二层流体模型中导出的变系数耦合mKdV模型,利用达布变换法,并依据系统中Lax对的谱参数的性质,给出了耦合mKdV系统的正子解、负子解、复子解及这些解的具体结构图形.其中所得到的耦合mKdV系统的正子解、负子解和复子解都是解析的,而复子解可看作一种形式的周期波解.

Investigation on Non-covalent Complexes of Cyclodextrins with Li＋ in Gas Phase by Mass Spectrometry

To investigate the non-covalent interaction between cyclodextrins （CD） and lithium ion, a stoichiometry of α-CD, β-CD, heptakis（2,6-di-O-methyl）-β-CD （DM-β-CD）, or heptakis（2,3,6-tri-O-methyl）-β-CD （TM-β-CD） was mixed with lithium salt, respectively, and then incubated at room temperature for 10 min to reach the equilibrium. In posi- tive mode, the electrospray ionization mass spectrometry （ESI-MS） results demonstrated that lithium ion can conjugate to α-, β-, DM-β- or TM-β-CD and form 1：1 stoichiometric non-covalent complexes. The binding of the complexes was further confirmed by collision- induced dissociation. The dissociation constants Kdl of four complexes （Li＋α-CD, Li＋β- CD, Li＋DM-β-CD, and Li＋TM-β-CD） were determined by mass spectrometric titration. The results showed Kdl were 18.7, 26.7, 33.6, 30.5 μmol/L for the complexes of Li＋ with α-CD, β-CD, DM-β-CD, and TM-β-CD, respectively. Kdl for the Li＋ complexes of/3-CD is smaller than that of DM-β-CD due to its steric effect of the partial substituted -CH3. The Kdl for the Li＋ complexes of DM-β-CD is nearly in agreement with that of TM-β-CD, indicating Li＋ is more likely to locate in the small rim of DM-β-CD＇s hydrophobic cavity. The DFT results showed through electrostatic interaction, one Li＋ can strongly conjugate to four neighboring oxygen atoms. For the （α-CD＋Li）＋ complex, one Li＋ may also situate the small rim of α-CD＇s hydrophobic cavity to form a non-specific host-guest complex.

Oxygen ionic conductivity of a composite electrolyte SDC-LSGM prepared via glycine-nitrate process

Ce0.8Sm0.2O1.9-δ-La0.9Sr0.1Ga0.8Mg0.2O3-δ（SDC-LSGM）is prepared by the glycine-nitrate process（GNP）.SDC-LSGM composite electrolyte samples with different weight ratios are prepared by the co-combustion method so as to obtain homogeneous nano-sized precursor powders. The X-ray diffraction （XRD） and the scan electron microscope （SEM） are used to investigate the phases and microstructures. The measurements and analyses of oxygen ionic conductivity of SDC-LSGM are carried out through the four-terminal direct current （DC） method and the electrochemical impendence spectroscopy, respectively. The optimum weight ratio of SDC-LSGM is 8∶2, of which the ionic conductivity is 0.113 S/cm at 800℃ and the conductivity activation energy is 0.620 eV. The impendence spectra shows that the grain boundary resistance becomes the main barrier for the ionic conductivity of electrolyte at lower temperatures. The appropriate introduction of LSGM to the electrolyte SDC can not only decrease the electronic conductivity but also improve the conditions of the grain and grain boundary, which is advantageous to cause an increase in oxygen ionic conductivity.

Synthesis and Characterization of Proton-conducting Polymer Electrolytes Based on Acrylonitrile-Styrene Sulfonic Acid Copolymer/Layered Double Hydroxides Nanocomposltes

Acrylonitrile-sodium styrene sulfonate copolymer/layered double hydroxides nanocomposites were prepared by in situ aqueous precipitation copolymerization of acrylonitrile （AN） and sodium styrene sulfonate （SSS） in the presence of 4-vinylbenzene sulfonate intercalated layered double hydroxides （MgA1-VBS LDHs） and transferred to acrylonitrile-styrene sulfonic acid （AN-SSA） copolymer/LDHs nanocomposites as a proton-conducting polymer electrolyte. MgA1-VBS LDHs were prepared by a coprecipitation method, and the structure and composition of MgAl-VBS LDHs were determined by X-ray diffraction （XRD）, infrared spectroscopy, and elemental analysis. X-ray diffraction result of AN-SSS copolymer/LDHs nanocomposites indicated that the LDHs layers were well dispersed in the AN-SSS copolymer matrix. All the AN-SSS copolymer/LDHs nanocomposites showed significant enhancement of the decomposition temperatures compared with the pristine AN-SSS copolymer, as identified by the thermogravimetric analysis. The methanol crossover was decreased and the proton conductivity was highly enhanced for the AN-SSA copolymer/LDHs nanocomposite electrolyte systems. In the case of the nanocomposite electrolyte containing 2% （by mass） LDHs, the proton conductivity of 2.60×10^- 3 S·m^-1 was achieved for the polymer electrolyte.

Fast-ionic conductor Li_(2.64)(Sc_(0.9)Ti_(0.1))_(2)(PO_(4))_(3) doped PVDF-HFP hybrid gel-electrolyte for lithium ion batteries

With increasing demand on energy density of lithium-ion battery,wide electrochemical window and safety performance are the crucial request for next generation electrolyte.Gel-electrolyte as a pioneer for electrolyte solidization development aims to solve the safety and electrochemical window problems.However,low ionic conductivity and poor physical performance prohibit its further application.Herein,a fast-ionic conductor(Li_(2.64)(Sc_(0.9)Ti_(0.1))_(2)(PO_(4))_(3))(LSTP)was added into poly(vinylidene fluoride-co-hexafluoropropylene)(PVDF-HFP)base gel-electrolyte to enhance mechanical properties and ionic conductivity.Evidences reveal that LSTP was able to weaken interforce between polymer chains,which increased the ionic conductibility and decreased interface resistance during the cycling significantly.The obtained LiFePO_(4)/hybrid gel-electrolyte/Li-metal coin cell exhibited excellent rate capacity(145 mA·h/g at 1C,95 mA·h/g at 3C,28℃)which presented a potential that can be comparable with commercialized liquid electrolyte system.

Modified Mohr-Coulomb strength criterion considering rock mass intrinsic material strength factorization

With the increase of mining depth of mineral resources,the rock mass stress state is being more and more complex.The rock mass show different features,namely,with the increase of hydrostatic pressure,rock mass failure mode turns from brittle tension failure to structure ductile failure and its limit strength also increases.The restriction of minimal principal stress on the initiation and development of microcrack and the change of micro-unit stress state by the intermediate principal stress play a decisive role in the increase of rock mass limit strength.Based on the rock mass failure behavior law under complex stress state and the σ2-dependence on the rock mass strength,we proposed a Modified Mohr-Coulomb(M-MC) strength criterion which is smooth and convex.Finally,the M-MC criterion is validated by multiaxial test data of eight kinds of rock mass.We also compared the fitting results with Mohr-Coulomb criterion(MC).It shows that the new criterion fits the test data better than the Mohr-Coulomb criterion.So the M-MC strength criterion well reveals the rock mass bearing behavior and can be widely used in the rock mass strength analysis.The results can provide theoretical foundations for stability analysis and reinforcement design of complex underground engineering.

NEW FAST ALGORITHM FOR 2-D ANGLE-OF-ARRIVAL ESTIMATION

Based on propagator method, a fast 2-D Angle-Of-Arrival (AOA) algorithm is proPosed in this paper. The proposed algorithm does not need the Eigen-Value Decomposition (EVD) or Singular Value Decomposition (SVD) of the Sample Covariance Matrix (SCM), thus the fast algorithm has lower computational complexity with insignificant performance degradation when comparing with conventional subspace approaches. Furthermore, the proposed algorithm has no performance degradation. Finally, computer simulations verify the effectiveness of the proposed algorithm.

Composition Operators from B^0 to E(p,q) and E_0(p,q) Spaces

When φ is an analytic map of the unit disk D into itself, and X is a Banach space of analytic functions on D, define the composition operator Cφ by Cφ（f） ： f oφ, for f E X. This paper deals with a collection of subclasses of Bloch space by means of composition operators from a subspace B^0 of Qa to E（p,q） and Eo（p,q） and gets a new characterization of spaces E（p, q） and Eo（p, q）.

A Riemann-Hilbert Approach to the Harry-Dym Equation on the Line

In this paper, the authors consider the Harry-Dym equation on the line with decaying initial value. They construct the solution of the Harry-Dym equation via the solution of a 2 × 2 matrix Riemann-Hilbert problem in the complex plane. Further, onecusp soliton solution is expressed in terms of the Riemann-Hilbert problem.

A novel coral-like garnet for high-performance PEO-based all solid-state batteries

As one of the most promising next-generation energy storage devices,the lithium-metal battery has been extensively investigated.However,safety issues and undesired lithium dendrite growth hinder its development.The application of solid-state electrolytes has attracted increasing attention as they can solve safety issues and show great potential to inhibit the growth of lithium dendrites.Polyethylene oxide(PEO)-based electrolytes are very promising due to their enhanced safety and excellent flexibility.However,they suffer from low ionic conductivity at room temperature and cannot effectively inhibit lithium dendrites at high temperatures due to the intrinsic semicrystalline properties and poor mechanical strength.In this work,a novel coral-like Li_(6.25)Al_(0.25)La_(3)Zr_(2)O_(12)(C-LALZO)is synthesized to serve as an active ceramic filler in PEO.The PEO with LALZO coral(PLC)exhibits increased ionic conductivity and mechanical strength,which leads to uniform deposition/stripping of lithium metal.The Li symmetric cells with PLC do not cause a short circuit after cycling for 1500 h at 60℃.The assembled LiFePO_(4)/PLC/Li batteries display excellent cycling stability at both 60 and 50℃.This work reveals that the electrochemical properties of the composite electrolyte can be effectively improved by tuning the microstructure of the filler,such as the C-LALZO architecture.

Coagulation behaviors and in-situ flocs characteristics of composite coagulants in cyanide-containing wastewater:Role of cationic polyelectrolyte

In this paper, composite coagulants （PFS, PFSC05, PFSC1 and PFSC5）, prepared by mixing polyferric sulfate （PFS） and cationic polyelectrolyte （CP） coagulants with different weight percent （Wv） of CP （Wp = 0%, 0.5%, 1% and 5%, respectively）, were adopted to treat cyanide-containing wastewater. PFSC5 exhibited superior coagulation performances at optimal conditions： the removal of total cyanide （TCN） and chemical oxygen demand （COD） was 95%-97% and 50%-55%, respectively. The effects of CP on the properties and structure of flocs were investigated by laser diffraction instrument and small-angle laser light scattering （SALLS）, respectively. The results show that the flocs of PFSC5 have higher growth rate, higher strength factor and lower recovery factor than other flocs. They are also much denser and more uniform owing to the higher fractal dimension （DO and less microflocs （10-100μm）. Furthermore, the dense structure of the PFSC5 flocs can be restored after shear and is more resistant to hydraulic conditions. Particularly, detailed morphology evolution of the flocs was in-situ detected by on-line particle imaging. Due to strong ionic strength in wastewater, the CP in PFSC5 plays a significant role of adsorption, while the main mechanism of CP is electrostatic patch aggregation during the PFSC05 systems.

Shear of molecular deposition films on glass substrates determined by tribometer

The ultrathin polyelectrolyte molecular deposition films and polyelectrolyte composite nanoparticles molecular deposition films were prepared using layer-by-layer molecular deposition method and in situ growth method.A micro-tribometer has been developed to measure the shear response of those ultrathin molecular deposition films.By using a smooth steel sphere in a ball-on-flat configuration,the shear force was determined for molecular deposition films on glass substrate for different layers.The results indicate that the shear behaviors of molecular deposition film were mainly determined with the contact area and film layers.Moreover,the composite molecular deposition film with nanoparticles has better shear behaviors than the polyelectrolyte molecular deposition film.The shear force of polyelectrolyte molecular deposition film is more dependent on the speed than that of composite nanoparticle molecular deposition film.

Composition Operators from α-Bloch Spaces into Q_K Type Spaces

Suppose φ is an analytic map of the unit disk D into itself, X is a Banach space of analytic functions on D. Define the composition operator Cφ: Cφf = f °φ, for all f ∈ X. In this paper, the boundedness and compactness of the composition operators from α-Bloch spaces into QK(p,q) and QK,0(p,q) spaces are discussed, where 0 < α < ∞.

Composite electrolytes based on poly(ethylene oxide) and binary ionic liquids for dye-sensitized solar cells

The sunlight is the largest single available source of clean and renewable energy to ensure human society＇s sustainable devel- opment. Owing to their low production cost and high energy conversion efficiency, dye-sensitized solar cells （DSSCs） have been regarded as good alternatives to conventional photovoltaic devices. Herein, a series of composite electrolytes based on poly（ethylene oxide） （PEO） and the binary ionic liquids 1-propyl-3-methy-imidazolium iodide （[PMIm]I） and l-ethyl-3- methylimidazolium thiocyanate （[EMIm][SCN]） were prepared and then applied to fabricate six DSSCs. The composite elec- trolytes were characterized by fourier transform infrared spectroscopy （FTIS）, X-ray diffraction （XRD）, and electrochemical impedance spectra （EIS）. It was shown that the addition of binary ionic liquids would reduce the degree of crystallinity of PEO thus improving the ionic conductivities of the electrolytes by about 2 orders of magnitude. Investigation on the photovoltaic performances of these DSSCs showed that the fill factor （FF） could reach up to 0.67 and energy conversion efficiency （η） could reach up to 4.04% under AM 1.5 full sunlight （100 mW/cm^2）.

Unlocking solid-state conversion batteries reinforced by hierarchical microsphere stacked polymer electrolyte

Pursuing all-solid-state lithium metal batteries with dual upgrading of safety and energy density is of great significance. However, searching compatible solid electrolyte and reversible conversion cathode is still a big challenge. The phase transformation at cathode and Li deformation at anode would usually deactivate the electrode-electrolyte interfaces. Herein, we propose an all-solid-state Li-FeF_(3) conversion battery reinforced by hierarchical microsphere stacked polymer electrolyte for the first time. This gC_(3)N_(4) stuffed polyethylene oxide(PEO)-based electrolyte is lightweight due to the absence of metal element doping, and it enables the spatial confinement and dissolution suppression of conversion products at soft cathode-polymer interface, as well as Li dendrite inhibition at filler-reinforced anode-polymer interface. Two-dimensional(2 D)-nanosheet-built porous g-C_(3)N_(4) as three-dimensional(3 D) textured filler can strongly cross-link with PEO matrix and Li TFSI(TFSI: bistrifluoromethanesulfonimide) anion, leading to a more conductive and salt-dissociated interface and therefore improved conductivity(2.5×10^(-4) S/cm at 60℃) and Li+transference number(0.69). The compact stacking of highly regular robust microspheres in polymer electrolyte enables a successful stabilization and smoothening of Li metal with ultra-long plating/striping cycling for at least 10,000 h. The corresponding Li/LiFePO_(4) solid cells can endure an extremely high rate of 12 C. All-solid-state Li/FeF_(3) cells show highly stabilized capacity as high as 300 m Ah/g even after 200 cycles and of 200 m Ah/g at extremely high rate of 5 C, as well as ultra-long cycling for at least 1200 cycles at 1 C. High pseudocapacitance contribution(>55%) and diffusion coefficient(as high as10^(-12) cm^(2)/s) are responsible for this high-rate fluoride conversion. This result provides a promising solution to conversion-type Li metal batteries of high energy and safety beyond Li-S batteries, which are difficult to realize true "all-solid-state" due to the indispensable step of polysulfide solid-liquid conversion.

Engineering “JiaoJiao”(maltose syrup) with chopsticks: From traditional Chinese sweet food to skin-like iontronics

The advancement of technology has had a profound impact on all areas of life, with an ever more intimate integration of the digital and biological spheres, but it may also be accompanied by an environmental crisis caused by the abuse of large quantities of electronics and petrochemicals.Next-generation "green" electronics or iontronics with high biocompatibility, biodegradation, low cost and mechanical compliance promise to mitigate these adverse effects, but are often limited by the finite choices of materials and strategies.Herein, maltose syrup, a traditional water-dissolvable saccharide food called "JiaoJiao" in Chinese, is engineered to replace unsustainable conductive components of current electronic devices. After churning and pulling with two chopsticks, known as aeration, the aerated maltose syrup has optimized viscoelasticity, mechanical adaptation, robustness,remodeling and self-healing capability, yet with transient behavior. Moreover, the structural and viscoelastic evolution during aeration is also analyzed to maximize the contribution from structures. As a proof-of-concept, a type of "green" skinlike iontronics is prepared, which exhibits reliable strain sensing ability and is subsequently applied for intelligent information encryption and transmission based on a novel concept of sending Morse code. This work greatly extends the current material choice and is expected to shed light on the development of a sustainable future.

Modulating composite polymer electrolyte by lithium closo-borohydride achieves highly stable solid-state battery at 25℃

Rational composite design is highly important for the development of high-performance composite polymer electrolytes(CPEs)for solid-state lithium(Li)metal batteries.In this work,Li closo-borohydride,Li_(2)B_(12)H_(12),is introduced to poly(vinylidene fluoride)-Li-bis-(trifluoromethanesulfonyl)imide(PVDF-LiTFSI)with a bound N-methyl pyrrolidone plasticizer to form a novel CPE.This CPE shows superb Li^(+)conduction properties,as evidenced by its conductivity of 1.43×10^(-4) S cm^(-1) and Li^(+)transference number of 0.34 at 25℃.Density functional theory calculations reveal that Li_(2)B_(12)H_(12),which features electron-deficient multicenter bonds,can facilitate the dissociation of LiTFSI and enhance the immobilization of TFSI to improve the Li^(+)conduction properties of the CPE.Moreover,the fabricated CPE exhibits excellent electrochemical,thermal,and mechanical stability.The addition of Li_(2)B_(12)H_(12) can help form a protective layer at the anode/electrolyte interface,thereby preventing unwanted reactions.The above benefits of the fabricated CPE contribute to the high compatibility of the electrode.Symmetric Li cells can be stably cycled at 0.2mA cm^(-2) for over 1200 h,and Li||LiFePO_(4) cells can deliver a reversible specific capacity of 140mAh g^(-1) after 200 cycles at 1C at 25℃ with a capacity retention of 98%.

Development of cation exchanger-based nano-CdS hybrid catalyst for visible-light photodegradation of rhodamine B from water

A new polymeric nanocomposite photocatalyst A15-CdS with large spherical beads (0.70-0.80 mm in diameter) was fabricated for efficient Rhodamine B (RhB) photodegradation with facile separation during cyclic runs,and photocorrosion,a congenital drawback of CdS,was successfully inhibited for A15-CdS.The nanocomposite catalyst was obtained by impregnating CdS nanoparticles within porous polymeric cation exchanger A15 through a facile inner-surface deposition.CdS nanoparticles (<20 nm) immobilized in A15 were deliberately distributed within an outside ring-like region of 40-50 m in depth,which is dominant for photoreaction because visible light is not expected to permeate through the inner region of nontransparent A15.As expected,efficient RhB photodegradation by A15-CdS was achieved under visible light irradiation,and large-size A15-CdS beads are expected to result in their facile separation from solution for repeated use.More significantly,negligible photocorrosion for the hybrid catalyst A15-CdS was demonstrated by the constant photodegradation efficiency and negligible CdS loss during five-cycle runs.The results indicated that nano-CdS immobilization within A15 would greatly improve the applicability of CdS nanoparticles in practical environmental remediation.