Critical Factors Dictating Reversibility of the Zinc Metal Anode

With high energy density and improved safety,rechargeable battery chemistries with a zinc(Zn)metal anode offer promising and sustainable alternatives to those based on lithium metal or lithium-ion intercalation/alloying anode materials;however,the poor electrochemical reversibility of Zn plating/stripping,induced by parasitic reactions with both aqueous and non-aqueous electrolytes,presently limits the practical appeal of these systems.Although recent efforts in rechargeable Zn metal batteries(RZMBs)have achieved certain advancements in Zn metal reversibility,as quantified by the Coulombic efficiency(CE),a standard protocol for CE has not been established,and results across chemistries and systems are often conflicting.More importantly,there is still an insufficient understanding regarding the critical factors dictating Zn reversibility.In this work,a rigorous,established protocol for determining CE of lithium metal anodes is transplanted to the Zn chemistry and is used for systematically examining how a series of factors including current collector chemistry,current density,temperature,and the upper voltage limit during stripping affect the measured reversibility of different Zn electrolytes.With support from density functional theory calculations,this standardized Zn CE protocol is then leveraged to identify an important correlation between electrolyte solvation strength toward Zn2+and the measured Zn CE in the corresponding electrolyte,providing new guidance for future development and evaluation of Zn electrolytes.

Upstream Operations in the Oil Industry： Rigorous Modeling ofan Electrostatic Coalescer

This paper deals with a first-principle mathematical model that describes the electrostatic coalescer unitsdevoted to the separation of water from oil in water-in-oil emulsions, which are typical of the upstreamoperations in oil fields. The main phenomena governing the behavior of the electrostatic coalescer are denscribed, starting from fundamental laws. In addition, the gradual coalescence of the emulsion droplets isconsidered in the mathematical modeling in a dynamic fashion, as the phenomenon is identified as a keystep in the overall yield of the unit operation. The resulting differential system with boundary conditionsis then integrated via performing numerical libraries, and the simulation results confirm the available lit-erature and the industrial data. A sensitivity analysis is provided with respect to the main parameters. Themathematical model results in a flexible tool that is useful for the purposes of design, unit behavior predic-tion. performance rnoniroring, and ontimization.

A Rigorous Spectral Representation of Relativistic Random Phase Approximation

A rigorous spectral representation of relativistic random-phase approximation is presented.Explicit expression is derived for the effective particle-hole interaction which contains the direct term Kan,the exchange term KaQ and the kernel for the fermion line renormalization K_(fr).It is shown that according to our method,not only K_(an) but also K_(sc) and K_(fr) can be given rigorously in a form which depends only on one ω(energy)-variable and they all take account of the retardation effect properly.

Systematic exploration of the applicability of the idiomatic vapor balance rule to distillation column consolidation

For N-component distillation(N≥3),consolidation between different column sections is an inevitable manipulation when synthesizing complex distillation configurations.In the consolidation,the idiomatic vapor balance(IVB)rule,in which the larger vapor flowrate in the two columns before consolidation will be chosen as the balanced vapor flowrate at the consolidation point,has been widely used.However,the applicability of the IVB rule has not been verified,which is of essential importance to the accuracy of the distillation configuration synthesis.In the present study,the applicability of the IVB rule to distillation column consolidation was systematically explored by rigorous method for the first time.First,the separation of ideal and non-ideal three-component mixtures with variable compositions was studied,and the optimized configurations before and after consolidation were determined by a rigorous method.The results indicated that for the separation of an ideal mixture,the IVB rule was applicable for the whole composition range,while for the separation of a non-ideal mixture,the IVB rule was only applicable for very limited composition range.Finally,two cases of synthesizing distillation configurations for the separation of non-ideal mixtures were studied to verify the remarkable deviations the IVB rule may cause.The results indicated that the applicability of the shortcut method using the IVB rule to the distillation configuration synthesis depended on the composition of the non-ideal mixture,and a remarkable error might result and the truly optimal configuration might be missed if the IVB rule is applied to a non-ideal mixture.

Polarization singularities in near-field of Gaussian vortex beam diffracted by a circular aperture

Polarization singularities in the near-field of Gaussian vortex beams diffracted by a circular aperture are studied by a rigorous electromagnetic theory. It is shown that there exist C-points and L-lines, which depend on off-axis displacement parameters along the x and y directions, waist width, wavelength, and topological charge of the diffracted Gaussian vortex beam, as well as on propagation distance. The results are illustrated by numerical calculations.

Master’s Degree, a New Requirement to Become an RDN by 2024: A Comparison of Nutrition Graduate Programs Offered in the USA

Background: The registered dietetic four-year degree educational structure has been intact since 1926. Master level nutrition programs exist in the U.S., but are not standardized or accredited unlike four-year degrees. Academic requirements for nutrition graduate programs vary regionally across the nation. Objective: To 1) quantify and describe the availability of Master level nutrition programs regionally;and 2) examine the current M.A. and M.S. program requirements for a nutrition graduate degree in the U.S. Methods: Nutrition graduate programs (n = 201) were analyzed and compared by geographical region. Data were collected between August 2017 and May 2018. Inclusion criteria were defined as: nutrition graduate programs listed in the American Society of Nutrition (ASN) database that had a nutrition graduate program website. Descriptive statistical analysis measured evaluated variables. Results: A total of 201 nutrition graduate programs in the U.S. were identified. The title of the programs was categorized into 29 main themes. The most common nutrition graduate program title was a M.S. in Nutrition, 55 institutions (27.4%). A total of 181 institutions offered a M.S. with a required thesis, whereas 95 offered a M.S. with a non-thesis option, and only eight offered a M.A. Region 3-South offered the highest number of nutrition graduate programs (66), followed by region 2-Midwest with 49 programs, region 1-Northeast offered a total of 46 programs, and 37 programs were offered in region 4-West. Conclusion: In 2024, as part of the RD eligibility criteria, it will be required that students possess a master’s degree. To date, only one master’s program in the U.S. is accredited, which assures the student a measure of confidence of program rigor and accountability. Dietitians’ three major professional concerns: respect, recognition and rewards are predicated on rigorous educational programs that meet ACEND standards. It is unlikely that all U.S. master level programs will be accredited by 2024.

应用于燃料电池的高速单级空气压缩机波箔轴承技术

The motivation to use air foil bearings in fuel cell compressors is driven by the demand for oil-free and high-power density system to reduce system volume and weight. The characteristics of air foil bearings that realize this demand are its independency on auxiliary system and no scheduled maintenance as well as their superb performance at high speeds. However, integration of the foil bearings to the compressor needs rigorous developmental tests for the bearing to withstand high g-load during vehicle maneuver and to remain stable in rotordynamics under external destabilizing forces. This paper presents multi-pads foil bearing technology applicable to single stage high speed fuel cell air compressors.Two different multi-pad air foil bearing designs(two-pad vs three-pad) were tested using a high-speed spin test rig to identify the differences in rotordynamics responses. The two-pad bearing is superior in rotordynamics without any sub-synchronous vibration while three-pad bearing provides more uniform load capacity in all directions with less rotordynamics stability. Frequency-domain modal analyses verify the experimental observations. Axial foil bearings with 38 mm outer diameter was designed and tested up to 140 krpm with load capacity of 90 N(1.4 bar specific load capacity).Finally, a platform design of single stage 15 k W fuel cell compressor with rated speed of 130 krpm is proposed using the multi-pad foil bearings and axial foil bearings developed through this paper.

Rigorous Coupled-Wave Approach for Sandwich Gratings

Rigorous Coupled-Wave Approach (RCWA) has been used successfully and accurately to study simple grating structures, such as one-layer gratings, one-whole gratings. In this paper, RCWA is expanded to solve Sandwich gratings (SG), which is composed of two identical planar dielectric gratings adjoined by thin metallic or dielectric film. The electromagnetic analytic expressions for each layer of SG structure are given and rigorous coupled-wave equations are deduced. The numerical investigations for the diffraction spectra of SG by our theoretical and computer programs are in good agreement with the results of classical RCWA in the condition when a Sandwish grating is simplified to a classical one-layer grating. The calculations by our programs of another condition when a Sandwish grating is degenerated to a classical single planar structure also conform to the results of classical electromagnetic theory. The research results above indicate that the extended theoretical formula has backwards compatibility and is self-consistent with the classical theory.

次世代微影术及其非破坏式光学量测系统之研究

本论文包含三项研究：一、极紫外光（extreme ultraviolet）微影系统：1.设计以40层钼/硅为基材之光子晶体（photoniccrystal）反射面镜,从数值计算得知,此面镜大幅提升对极紫外光之反射率,并能承受更高之照射温度与能量。2.改善传输线理论（transmission line theory）,使之用于加速多层钼/硅面镜之设计。

THE CALCULATION OF CRITICAL PROPERTIES OF MIXTURES FROM EQUATIONS OF STATE

The rigorous critical state criteria based on Helmholtz free energy is used with equations of state fordirect calculation of critical properties(T_c,P_c and V_c)of 44 binary and 5 ternary systems.Special at-tention is paid to systems containing polar component(s)and the improvement in critical volume prediction.For extending this method to polar systems,the recently developed Cubic Chain-of-Rotators equation ofstate has been applied.As compared with SRK and PR equations of state,the improvement in V_c pre-diction is most impressive.

ABOUT THE JOURNAL

International Journal of Mining Science and Technology is peer-reviewed journalpubllished birnonthly in English edition. It was founded in 1990 and previously entitled Journal of China University of Mining and Technology. This journal publishes original andinnovative research papers and high-quality reviews covering the latest advances theories,methodologies, and applications in the fields of mining sciences and technologies. It alsoprovides an international exchange forum for the readers and authors engaging in miningsciences and technologies all over the world.Papers to be published will be rigorously editedby specialists and authorities. The entire process from submission, review, to publication ishandled online.

Regarding the Distribution of Glue in the Pion

Understanding why the scale of emergent hadron mass is obvious in the proton but hidden in the pion may rest on mapping the distribution functions(DFs)of all partons within the pion and comparing them with those in the proton;and since glue provides binding in quantum chromodynamics,the glue DF could play a special role.Producing reliable predictions for the proton’s DFs is difficult because the proton is a three-valence-body bound-state problem.As sketched herein,the situation for the pion,a two-valence-body problem,is much better,with continuum and lattice predictions for the valence-quark and glue DFs in agreement.This beginning of theory alignment is timely because experimental facilities now either in operation or planning promise to realize the longstanding goal of providing pion targets,thereby enabling precision experimental tests of rigorous theory predictions concerning Nature’s most fundamental Nambu-Goldstone bosons.

Can Hydrogen be Incorporated inside Silicon Nanocrystals?

Hydrogen is omnipresent during the synthesis and processing of silicon nanocrystals (Si NCs).It is generally assumed that the incorporation of hydrogen leads to the passivation of Si dangling bonds at the NC surface.However,it is also speculated that hydrogen may be incorporated inside Si NCs.In this work the formation energy and probability of hydrogen in its three configurations,i.e.,hydrogen molecules,bond-centered atomic hydrogen,and antibonding atomic hydrogen,are calculated to rigorously evaluate the incorporation of hydrogen inside Si NCs.We find that hydrogen cannot be incorporated inside Si NCs with a diameter of a few nanometers at temperatures up to 1500K.

Large Dimuon Asymmetry and a Non-Universal Z′ Boson in the Bs−Bs System

Motivated by recently observed anomalously large dimuon charge asymmetry in neutral B decays reported by the D0 collaboration,we study the effects of a family of non-universal Z′bosons for possible solutions.The fitting results for the Z′parameters are presented under the constraints from the D0 result for asls and UTfit results for CBs andφBs in two limiting scenarios for left−and right-handed b-s-Z′couplings.We find the couplings BsbL and BsbR are rigorously bounded but not excluded,which means that the anomalies in the Bs−Bs system could be moderated simultaneously within a non-universal Z′model.Numerically,a new weak phaseφLs∼−60°(−80°)in scenario I or∼30°(10°)in scenario II is crucial to moderate the large dimuon charge asymmetry.

Antireflective Characteristics of Sub-Wavelength Periodic Structure with Square Hole

In order to enhance transmittance in the long-wavelength infrared range,the major parameters of periodic sub-wavelength structures(SWS)with square holes on zinc sulfide(ZnS)substrates are designed and analyzed for applications in normal incidence by using rigorous coupled-wave analysis(RCWA)and thin Hilm theory(TFT).Finally the optimal antireflective parameters are achieved.The structures on ZnS substrates are fabricated on the basis of the simulation results by photolithography technology and reactive ion etching technology.A substantial antireflection effect is observed over the wavelength band 8-12μm by a factor greater than 4.5.

CONTINUOUS TIME RANDOM WALKS ON FRACTALS:RIGOROUS RESULTS

Continuous time random walk on fractals is studied.Asymptotic forms of<r^(2)(t)>,S(t)and P(t)are obtained rigorously by the generalized Blackwell theorem,where<r^(2)(t)>is the mean-square displacement,S(t)the number of distinct sites visited in time t,and P(t)the probability of return at time t.The spatial disorder turns out to be predominant for long time.

The rigorous adjustment of the global mean sea level budget during 2005-2015

Global mean sea level budget is rigorously adjusted during the period 2005-2015.The emphasis is to provide the best estimates for the linear rates of changes(trends)of the global mean sea level budget components during this period subject to the constraint:Earth’s hydrosphere conserves water.The newly simultaneously adjusted trends of the budget components suggest a larger correction for the global mean sea level trend implicated by the other budget components’trends under the budget constraint.The simultaneous estimation of the linear trends of the budget components subject to the constraint for closure improves their uncertainties and enables a holistic assessment of the global mean sea budget,which has implications for future sea level science studies,including the future Intergovernmental Panel on Climate Change(IPCC)Assessment Reports,and the US Climate Assessment Reports.

Surface relief resonant Brewster filters with multiple channels

In this paper, a new type of resonant Brewster filters （RBF） with surface relief structure for the multiple channels is first presented by using the rigorous coupled-wave analysis and the S-matrix method. By tuning the depth of homogeneous layer which is under the surface relief structure, the multiple channels phenomenon is obtained. Long range, extremely low sidebands and multiple channels are found when the RBF with surface relief structure is illuminated with Transverse Magnetic incident polarization light near the Brewster angle calculated with the effective media theory of sub wavelength grating. Moreover, the wavelengths of RBF with surface relief structure can be easily shifted by changing the depth of homogeneous layer while its optical properties such as low sideband reflection and narrow band are not spoiled when the depth is changed. Furthermore, the variation of the grating thickness does not effectively change the resonant wavelength of RBF, but have a remarkable effect on its line width, which is very useful for designing such filters with different line widths at desired wavelength.

Excellent polarization-independent reflector based on guided mode resonance effect

A broad band polarization-independent reflector working in the telecommunication C＋L band is proposed using the guided mode resonance effect of a periodic surface relief element deposited by a layer of silicon medium. It is shown that this structure can provide high reflection （R 〉 99.5%） and wide angular bandwidth （θ≈ 20°, R 〉 98%） for both TE and TM polarizations over a wide spectrum band 1.5 μm-l.6 μm. Furthermore, it is found by rigorous coupled wave analysis that the polarization-independent reflector proposed here is tolerant of a deviation of grating thickness, which makes it very easy to fabricate in experiments.

Single-particle distribution function of a quantum dot system at finite temperature

In the present paper, we shall rigorously re-establish the result of the single-particle function of a quantum dot system at finite temperature. Unlike the proof given in our previous work （Phys. Rev. B 74 195414 （2006））, we take a different approach, which does not exploit the explicit expression of the Gibbs distribution function. Instead, we only assume that the statistical distribution function of the quantum dot system is thermodynamically stable. As a result, we are able to show clearly that the electronic structure in the quantum dot system is completely determined by its thermodynamic stability. Furthermore, the weaker requirements on the statistical distribution function also make it possible to apply the same method to the quantum dot systems in non-equilibrium states.