Unveiling the pressure-driven metal–semiconductor–metal transition in the doped TiS_(2)

Conventional theories expect that materials under pressure exhibit expanded valence and conduction bands,leading to increased electrical conductivity.Here,we report the electrical properties of the doped 1T-TiS_(2) under high pressure by electrical resistance investigations,synchrotron x-ray diffraction,Raman scattering and theoretical calculations.Up to 70 GPa,an unusual metal-semiconductor-metal transition occurs.Our first-principles calculations suggest that the observed anti-Wilson transition from metal to semiconductor at 17 GPa is due to the electron localization induced by the intercalated Ti atoms.This electron localization is attributed to the strengthened coupling between the doped Ti atoms and S atoms,and the Anderson localization arising from the disordered intercalation.At pressures exceeding 30.5 GPa,the doped TiS_(2) undergoes a re-metallization transition initiated by a crystal structure phase transition.We assign the most probable space group as P2_(1)2_(1)2_(1).Our findings suggest that materials probably will eventually undergo the Wilson transition when subjected to sufficient pressure.

Dehydrogenation of methylcyclohexane over Pt supported on Mg–Al mixed oxides catalyst:The effect of promoter Ir

To enhance the hydrogen release during hydrogen storage,several Pt-Ir supported on Mg-Al mixed oxide catalysts were prepared and then applied into the dehydrogenation of methylcyclohexane(MCH)in this study.The effects of iridium content,reduction temperature on the activity and stability of the catalysts were studied in detail.In the presence of Ir,metal particle size was decrea sed and electron transfer between Ir and Pt was observed.High reduction temperature increased the metallic Ir content but enlarged the particle size of active site s.During the dehydrogenation reaction on Pt-Ir bimetallic catalyst,MCH was efficiently converted into toluene and PtIr-5/Mg-Al-275 exhibited the highe st activity.After prolonging the residence time and raising the reaction temperature to 350℃the conversion and hydrogen evolution rate were increased to 99.9%and 578.7 mmol·(g Pt)^-1·min^-1,respectively.Moreover,no carbon deposition was observed in the spent catalyst,presenting a high anti-coking ability and good potential for industrial application.

Expert consensus on diagnosis and treatment of ulcerative colitis with integrated traditional Chinese and Western medicine:A nursing perspective

Ulcerative colitis(UC)is a chronic nonspecific intestinal inflammatory disease of unclear etiology,characterized by continuous and diffuse inflammatory changes of colorectal mucosa.In recent years,the incidence rate of UC in China has increased year by year,but there is no effective cure method in Western medicine.Traditional Chinese medicine treatment based on syndrome differentiation has the unique advantages of simplicity,convenience,effectiveness,and low cost.Therefore,integration of Chinese and Western medicine has become an important strategy for UC diagnosis and treatment,and has made significant progress in UC.On the basis of learning from a number of consensuses at home and abroad,combined with Chinese research results and the actual clinical situation of traditional Chinese and Western medicine,the UC group of the Chinese Association of Integrative Medicine has formulated the expert consensus on the diagnosis and treatment of UC with integrated traditional Chinese and Western medicine.In this consensus,the pathogenesis,etiology and pathogenesis,diagnosis,integrated traditional Chinese and Western medicine treatment,and chronic disease management with integrated traditional Chinese and Western medicine for UC were recommended by experts.This article interprets the consensus from the perspective of nursing in order to provide reference basis for clinical nursing workers.

Structural transitions in NaNH2 via recrystallization under high pressure

Multiple phase transitions are detected in sodium amide(NaNH2), an important hydrogen storage material, upon compression in diamond anvil cells(DAC) by using Raman spectroscopy and x-ray diffraction(XRD) measurements.Additional Bragg reflections appear on lower and higher angle sides of the original ones at ~1.07 GPa and 1.84 GPa,accompanied by obvious changes in Raman spectroscopy, respectively.It reveals that NaNH2 undergoes the high-pressure phase sequence(α-β-γ) up to 20 GPa at room temperature.Spectral analysis indicates an orthorhombic structure with PBAN space group for the γ phase.We also experimentally observe high pressure induced recrystallization in alkaline amide compounds for the first time.

Structural stability and vibrational characteristics of CaB6 under high pressure

In situ Raman spectroscopy and x-ray diffraction measurements are used to explore the structural stability of CaB6 at high pressures and room temperature. The results show no evidence of structural phase transitions up to at least 40 GPa.The obtained equation of state with smooth pressure dependencies yields a zero-pressure isothermal bulk modulus B0=170(5) GPa, which agrees well with the previous measurements. The frequency shifts for A1g, Eg, and T2g vibrational modes of polycrystalline CaB6 are obtained with pressure uploading. As the pressure increases, all the vibration modes have smooth monotonic pressure dependence. The Gr¨uneisen parameter of Eg modes is the largest, indicating its largest dependence on the volume of a crystal lattice.

Rational design of Ni-MoO_(3–x) catalyst towards efficient hydrodeoxygenation of lignin-derived bio-oil into naphthenes

Design of a robust catalyst with high activity but the low cost for the hydrodeoxygenation(HDO) of biooils is of great importance to bring the biorefinery concept into reality.In this study,density functional theory(DFT) calculation was adopted to analyze the optimal location of Ni on MoO_(3-x) containing oxygen vacancy,and the corresponding result demonstrated that metallic Ni cluster located at the neighborhood of oxygen vacancies would significantly evoke HDO activity.Enlightened by DFT results,NiMoO_(4) was first hydrothermally synthesized and then employed to fabricate Ni-MoO_(3-x) catalyst via a low-temperature reduction,where Ni escaped from NiMoO_(4) and was reduced to its metallic state.Such an evolution of Ni species also induced the formation of oxygen vacancies around metallic Ni cluster.In the HDO of p-cresol,Ni-MoO_(3-x) exhibited high activity with a complete conversion and a methylcyclohexane selectivity of 99.4% at 150℃.Moreover,the catalyst showed good versatility in catalyzing HDO of diverse lignin-derived oxygenates and lignin oil.2D HSQC NMR,gas chromatograph and elemental analysis of the lignin oil demonstrated the high deoxygenation efficiency and saturation of the benzene ring over Ni-MoO_(3-x).In the upgrading of crude lignin oil,the deoxygenation degree was up to 99%,and the overall carbon yield of the naphthenes was as high as 69.4%.Importantly,the structures and carbon numbers of the naphthene products are similar to jet fuel-range cycloalka nes,which are expected to have a high density that can be blended into jet fuel to raise the range(or payload) of airplanes.This work demonstrates the feasibility for improving the targeted catalytic reactivity by rational tailoring the catalyst structure under the guidance of theoretical analysis,and provides an energy-efficient route for the upgrading of lignin crude oil into valuable naphthenes.

基于IP网络的信息系统融合设计

客滚船上的信息系统包含有视频监控系统,电视系统,电话系统,局域网系统等,传统上是各自独立配,此种情况下,各系统的线路和终端布设复杂,日常管理不便。将上述系统进行基于IP网络的融合设计,可简化系统的设计,有效降低系统整体复杂度和建造成本。本文对客滚船基于IP网络的信息系统的架构、接入系统进行介绍,并阐述了这样设计的利弊及注意事项,对开展船舶信息系统融合设计有一定的指导意义。

Structural and Electrical Properties of Be(x)Zn_(1-x)O Alloys under High Pressure

We conduct extensive research into the structures of Be_(x)Zn_(1-x)OO ternary alloys in a pressure range of 0-60GPa,using the ab initio total energy evolutionary algorithm and total energy calculations,finding several metastable structures.Our pressure-composition phase diagram is constructed using the enthalpy results.In addition,we calculate the electronic structures of the Be_(x)Zn_(1-x)OO structures and investigate the bandgap values at varying pressures and Be content.The calculated results show that the bandgap of the Be_(x)Zn_(1-x)OO ternary alloys increases with an increase in Be content at the same pressure.Moreover,the bandgap of the Be_(x)Zn_(1-x)OO ternary alloys increases with the increasing pressure with fixed Be content.At the same Be content,the formation enthalpy of the Be_(x)Zn_(1-x)OO ternary alloys first decreases,then increases with the increasing pressure.

Ab initio studies on ammonium iodine under high pressure

Ammonium iodine(NH4I)as an important member of hydrogen-rich compounds has attracted a great deal of attention owing to its interesting structural changes triggered by the relative orientations of adjacent ammonium ions.Previous studies of ammonium iodide have remained in the low pressure range experimentally,which we first extended to so high pressure(250 GPa).We have investigated the structures of ammonium iodine under high pressure through ab initio evolutionary algorithm and total energy calculations based on density functional theory.The static enthalpy calculations show that phase V is stable until 85 GPa where a new phase Ibam is identified.Calculations of phonon spectra show that the Ibam phase is stable between 85 GPa and 101 GPa and the Cm phase is stable up to 130 GPa.In addition,ammonium iodine dissociates into NH3,H2,and I2 at 74 GPa.Subsequently,we analyzed phonon spectra and electronic band structures,finding that phonon softening is not the reason of dissociation and NH4I is always a semiconductor within the pressure range.

Velocity and Stability of Condensed Polymorphic SiH4: A High-Temperature High-Pressure Brillouin Investigation

Silane(SiH4)is a promising hydrogen-rich compound for pursing high temperature superconducting.Previous high pressure measurements of Raman,x-ray diffraction and theoretical studies on SiH4 mainly focused on its polymorphic structures above 50 GPa,while the structure and the stability under lower pressure range are still unclear.Here we report an investigation of condensed SiH4 by Brillouin scattering measurements at high temperature up to 407 K and high pressure up to 18 GPa.Brillouin scattering frequencies of fluid SiH4 under compression are obtained under isothermal conditions of 300 K,359 K and 407 K.The SiH4 becomes unstable with increasing temperature and subsequently decomposes into silicon and H2.We find that compression at room temperature induces two velocity anomalies corresponding to a fluid-solid state transition and a phaseⅣto phase V transition,respectively.Brillouin scattering spectra has been a powerful tool to investigate the fruitful phases and structure transitions in the hydrogen-rich compound under extreme conditions.

Diversity–Multiplexing Tradeoff and Outage Performance for 2×2 Dual-Polarized Uncorrelated Rice MIMO Channels

In this paper, diversity-multiplexing tradeoff (DMT) curve for 2×2 Dual-Polarized uncorrelated Rice MIMO channels is studied. Exact expressions for statistic information of mutual information exponent are derived. Impacts of channel parameters such as signal to noise ratio (SNR), k-factor and cross polarization discrimination (XPD) on mutual information exponent are analyzed. Compared to conventional single-polarized (SP) Rice MIMO systems, a qualitatively different behavior is observed for DP Rice systems. The work in this paper, allows identifying quantitatively for which channels (k-factor) and SNR levels the use of dual polarization becomes beneficial. Gamma or lognormal distribution are used to describe mutual information component, and a theoretical formulation for finite-SNR DMT curve in 2×2 DP uncorrelated Rice channels is presented for the first time, which is valid in low and medium SNRs when multiplexing gain is larger than 0.75.

简牍所见秦汉时期人的肤色刍议

秦汉简牍中不乏黑色、墨色、黄色、黄白色、黄黑色、青色、青黑色、青白色、赤色、白皙色、黄皙色等人的肤色描写,主要出现在追捕文书、名籍简、家属符、出入符、私传等性质的文书中,涉及对象的身份包括逃犯、施刑士、狱囚、葆子、从者、私从者、奴婢、盗贼、田戍卒,吏家属等。追捕通缉类文书、出入凭证明确要求人的形貌记录,便于追查、核验和监管,普通的屯戍人员仅登记特殊的肤色,大众肤色不登记。

CEPC Technical Design Report

The Circular Electron Positron Collider(CEPC)is a large scientific project initiated and hosted by China,fostered through extensive collaboration with international partners.The complex comprises four accelerators:a 30 GeV Linac,a 1.1 GeV Damping Ring,a Booster capable of achieving energies up to 180 GeV,and a Collider operating at varying energy modes(Z,W,H,and tt).The Linac and Damping Ring are situated on the surface,while the subterranean Booster and Collider are housed in a 100 km circumference underground tunnel,strategically accommodating future expansion with provisions for a potential Super Proton Proton Collider(SPPC).The CEPC primarily serves as a Higgs factory.In its baseline design with synchrotron radiation(SR)power of 30 MW per beam,it can achieve a luminosity of 5×10^(34)cm^(-2)s^(-1)per interaction point(IP),resulting in an integrated luminosity of 13 ab^(-1)for two IPs over a decade,producing 2.6 million Higgs bosons.Increasing the SR power to 50 MW per beam expands the CEPC's capability to generate 4.3 million Higgs bosons,facilitating precise measurements of Higgs coupling at sub-percent levels,exceeding the precision expected from the HL-LHC by an order of magnitude.This Technical Design Report(TDR)follows the Preliminary Conceptual Design Report(Pre-CDR,2015)and the Conceptual Design Report(CDR,2018),comprehensively detailing the machine's layout,performance metrics,physical design and analysis,technical systems design,R&D and prototyping efforts,and associated civil engineering aspects.Additionally,it includes a cost estimate and a preliminary construction timeline,establishing a framework for forthcoming engineering design phase and site selection procedures.Construction is anticipated to begin around 2027-2028,pending government approval,with an estimated duration of 8 years.The commencement of experiments and data collection could potentially be initiated in the mid-2030s.

Re-emergence of superconductivity via pressure-induced Lifshitz transition in preserved 6R-TaS_(2)crystal structure

Investigating the implications of interlayer coupling on superconductivity is vital for comprehending the intrinsic mechanisms of two-dimensional materials.Van der Waals heterojunctions have attracted extensive research owing to their exotic interlayer coupling.In this study,we investigated the natural heterostructure superconductor featuring 6R-TaS_(2)via measurements of electrical resistance,the Hall effect,and in-situ synchrotron X-ray diffraction(XRD)under various pressures.The study findings show that the superconducting transition temperature(T_(c))of 6R-TaS_(2)in the range of 0-32.5 GPa exhibits an unusual double-dome behavior as a function of pressure,with the first and second domes in the pressure range of 0-5.3 and 6.8-32.5 GPa,respectively.At 56.6GPa,a new superconducting phase with a T_(c)of 2 K was observed.The XRD results show that the singular evolution of the T_(c)is independent of the structural phase transition.Combining the XRD results,first-principles calculations,and Hall effect measurements,we found that different interlayer coupling effects resulted in double dome superconductivity and the re-emergence of superconducting.Our findings shed light on the pivotal role of interlayer coupling in driving the anomalous alterations in superconducting properties triggered by charge transfer and Fermi surface reconstruction and provide an alternative route for comprehending the mechanisms of superconductivity in transition metal dichalcogenides(TMDs).

A zincophilic molecular brush for a dendrite-free,corrosionresistant,zinc metal anode with a long life cycle

Zinc-based aqueous rechargeable batteries have attracted extensive attention due to their low cost,safety,and environmental friendliness.However,dendrite growth and hydrogen evolution of Zn anodes limit their large-scale application.A new strategy to produce a polyacrylamide/reduced graphene oxide(PAM@rGO)molecular nanobrush coating and control Zn electrolyte interface engineering is proposed for use in highly reversible Zn plating/stripping.Hydrogen evolution is inhibited,and Zn deposition is consolidated using the rich zincophilic functional groups of the branched polyacrylamide chain and the high conductivity of rGO.Due to the synergistic effects of corrosion resistance and dendrite-free growth,PAM@rGO/Zn provides prolonged and reversible Zn plating/stripping.Density functional theory(DFT)calculations expand on homogenized nucleation.The PAM@rGO/Zn||activated carbon(AC)capacitor exhibits long cyclic stability,fast ion transfer,and minimal interfacial impedance.This study provides experimental and theoretical bases for the structural design of Zn anode.

新型异卟啉的设计、合成与性能研究

卟啉具有四吡咯大环结构,在医药、催化和太阳能电池等多个领域被广泛应用.改变其大环母体可设计多种异卟啉,从而实现更加独特的结构与突出的性能.近年来本课题组合成了系列新型异卟啉单体与二聚体,实现了异卟啉化合物的特色大环转化、功能化与性能调控,为进一步设计、合成结构新颖、性能优异的异卟啉化合物提供了新的思路.本文在介绍异卟啉研究的重要性与合成策略基础上,重点综述了本课题组在线型多吡咯烯、卟啰啉和含错位吡咯单元的新型扩展卟啉等领域的研究进展.

Rational design of nitrogen doped hierarchical porous carbon for optimized zinc-ion hybrid supercapacitors

Aqueous rechargeable zinc-ion hybrid supercapacitors are considered to be a promising candidate for large-scale energy storage devices owing to their high safety,long life,and low price.In this paper,a nitrogen doped hierarchical porous carbon is evaluated as the cathode for aqueous rechargeable zinc-ion hybrid supercapacitors.Benefiting from the synergistic merits of excellent structural features of N-HPC and tiny zinc dendrite of Zn anode in ZnSO4 electrolyte,the zinc-ion hybrid supercapacitor exhibits excellent energy storage performance including high capacity of 136.8 mAh·g^−1 at 0.1·Ag^−1,high energy density of 191 Wh·kg^−1,large power density of 3,633.4 W·kg^−1,and satisfactory cycling stability of up to 5,000 cycles with a capacity retention of 90.9%.This work presents a new prospect of developing high-performance aqueous rechargeable zinc ion energy storage devices.

In vitro and in vivo correlation for lipid-based formulations: Current status and future perspectives

Lipid-based formulations(LBFs)have demonstrated a great potential in enhancing the oral absorption of poorly water-soluble drugs.However,construction of in vitro and in vivo correlations(IVIVCs)for LBFs is quite challenging,owing to a complex in vivo processing of these formulations.In this paper,we start with a brief introduction on the gastrointestinal digestion of lipid/LBFs and its relation to enhanced oral drug absorption;based on the concept of IVIVCs,the current status of in vitro models to establish IVIVCs for LBFs is reviewed,while future perspectives in this field are discussed.In vitro tests,which facilitate the understanding and prediction of the in vivo performance of solid dosage forms,frequently fail to mimic the in vivo processing of LBFs,leading to inconsistent results.In vitro digestion models,which more closely simulate gastrointestinal physiology,are a more promising option.Despite some successes in IVIVC modeling,the accuracy and consistency of these models are yet to be validated,particularly for human data.A reliable IVIVC model can not only reduce the risk,time,and cost of formulation development but can also contribute to the formulation design and optimization,thus promoting the clinical translation of LBFs.

Iron polyphthalocyanine-derived ternary-balanced Fe_(3)O_(4)/Fe_(3)N/Fe-N-C@PC-2.5 as a high-performance electrocatalyst for the oxygen reduction reaction

The oxygen reduction reaction (ORR) is the cornerstone reaction of the cathode in metal±air batteries;however,slow kinetics requires high-performance catalysts to promote the reaction.Polyphthalocyanine (PPc) has a typical chemical cross-linking structure and uniformly dispersed metal active sites,but its poor activity and conductivity limit its applications as an ORR catalyst.Herein,a manageable and convenient strategy is proposed to synthesize ternary ORR catalysts through the low-temperature pyrolysis of Fe PPc.The optimal catalyst,Fe_(3)O_(4)/Fe_(3)N/Fe-N-C@PC-2.5,exhibits excellent ORR activity in alkaline solution with a half-wave potential of 0.90 V,which is significantly higher than that of commercial 20%Pt/C (0.84 V).Electrochemical tests and extended X-ray absorption fine structure spectroscopy reveal that the superior ORR activity of Fe_(3)O_(4)/Fe_(3)N/Fe-N-C@PC-2.5 could be ascribed to the balance of its ternary components(i.e.,Fe_(3)O_(4),Fe_(3)N,and Fe-N;species).A Zn±air battery incorporating Fe_(3)O_(4)/Fe_(3)N/Fe-N-C@PC-2.5 as an air cathodic catalyst delivers a high open-circuit voltage and peak power density.During galvanostatic discharge,the battery demonstrates a specific capacity of 815.7 mA h g^(-1).The facile strategy of using PPc to develop high-performance composite electrocatalysts may be expanded to develop new types of catalysts in the energy field.

Maternal butyrate supplementation affects the lipid metabolism and fatty acid composition in the skeletal muscle of offspring piglets

Maternal sodium butyrate(SB)intake has important effects on offspring growth and development.This study aimed to investigate the impacts of maternal SB supplementation during gestation and lactation on fatty acid composition and lipid metabolism in the offspring skeletal muscle of pigs.Twenty sows(Yorkshire,parity 2 to 3)were assigned to the control group(diets without SB,n=10)and SB group(diets with 0.1%SB,n=10).The results showed maternal SB supplementation throughout gestation and lactation increased(P<0.05)body weight of offspring piglets at weaning.The concentrations of triglyceride in plasma and milk were enhanced(P<0.05).Maternal SB induced(P<0.05)lipid accumulation with increased expression of peroxisome proliferator activated receptorγ(PPARγ)by enrichment of the acetylation of H3 acetylation K27(H3 K27)in offspring skeletal muscle.Meanwhile,the concentrations of C18:2 n-6,C18:3 n-3,total polyunsaturated fatty acid(PUFA),n-6 PUFA and n-3 PUFA decreased(P<0.05)in skeletal muscle of weaning piglets derived from SB sows.Together,these results showed that maternal SB supplementation could influence offspring growth performance,lipid metabolism and fatty acid composition of the skeletal muscle.