AIM: To investigate the therapeutic effects of simultaneous horizontal and vertical operations on dissociated vertical deviation(DVD) associated with other deviations.METHODS: Forty-five cases of DVD with horizontal a...AIM: To investigate the therapeutic effects of simultaneous horizontal and vertical operations on dissociated vertical deviation(DVD) associated with other deviations.METHODS: Forty-five cases of DVD with horizontal and torsional strabismus underwent combined operation were collected retrospectively. All clinical records were analyzed. All patients were followed up for 6 to 24 mo. Wilcoxon signed-ranks test was performed to evaluate the changes of vertical and horizontal deviation. χ~2 test was used to evaluate the changes of binocular visual function. RESULTS: Forty-five cases included 36 patients with intermittent exotropia and binocular inferior oblique overaction(IOOA), 5 patients with concomitant esotropia and binocular IOOA, 4 patients with intermittent exotropia and monocular superior oblique palsy. The superior rectus recession(SRR) combined with horizontal rectus recession and the myectomy of inferior oblique or anterior transposition were operated simultaneously to correct all types of strabismus. There were 43 cases who achieved normal eye position in vertical direction, while 2 cases were with undercorrection of 5~Δ to 6~Δ. In patients with horizontal strabismus, 2 cases of exotropia were with overcorrection of 6~Δ to 8~Δ, 1 case of esotropia was with undercorrection of 6~Δ, and 1 case of monocular superior oblique palsy with compensatory head posture was not significantly improved. The binocular visual function of most patients recovered after operation. The difference of the binocular visual function and eye position were significant compared with that before operation(P<0.05).CONCLUSION: The simultaneous operation on DVD with horizontal and torsional strabismus is successful.展开更多
The high temperature gas occurs behind shock or near the wall surface of vehicle in the hypersonic flight. As the temperature exceeds 2 000 K, 4 000 K, respectively, O2 and N2 molecules are successively dissociated. B...The high temperature gas occurs behind shock or near the wall surface of vehicle in the hypersonic flight. As the temperature exceeds 2 000 K, 4 000 K, respectively, O2 and N2 molecules are successively dissociated. Because of variable components at dif- ferent temperatures and pressures, the dissociated air is no longer a perfect gas, In this paper, a new method is developed to calculate accurate thermal physical parameters with the dissociation degree providing the thermochemical equilibrium procedure. Based on the dissociation degree, it is concluded that few numbers of equations and the solutions are easily obtained. In addition, a set of formulas relating the parameter to the dissociation degree are set up four-species, O2 molecule The thermodynamic properties of dissociated air containing and N2 molecule, O atom and N atom, are studied with the new method, and the results are consistent with those with the traditional equilibrium constant method. It is shown that this method is reliable for solving thermal physical parameters easily and directly.展开更多
BACKGROUND Inferior oblique anterior transposition(IOAT)has emerged as an effective surgery in the management of dissociated vertical deviation(DVD)combined with superior oblique palsy(SOP).Traditional IOAT usually pr...BACKGROUND Inferior oblique anterior transposition(IOAT)has emerged as an effective surgery in the management of dissociated vertical deviation(DVD)combined with superior oblique palsy(SOP).Traditional IOAT usually provides satisfactory primary position alignment and simultaneously restricts the superior floating phenomenon.However,it also increases the risk of the anti-elevation syndrome and narrowing of the palpebral fissure in straight-ahead gaze,especially after the unilateral operation.CASE SUMMARY We report the outcomes of the modified unilateral IOAT in two patients with unilateral DVD combined with SOP.The anterior-nasal fibers of the inferior oblique muscle were attached at 9 mm posterior to the corneal limbus along the temporal board of the inferior rectus muscle,the other fibers were attached a further 5 mm temporal to the anterior-nasal fibers.Postoperatively,both hypertropia and floating were improved,and no obvious complications occurred.CONCLUSION In these cases,the modified unilateral IOAT was an effective and safe surgical method for treating DVD with SOP.展开更多
The extended core structure of the dissociated edge dislocation in Al, Au, Ag, Cu and Ni is determined within lattice theory of dislocation. The 2D dislocation equation governing the displacements is coupled by the re...The extended core structure of the dissociated edge dislocation in Al, Au, Ag, Cu and Ni is determined within lattice theory of dislocation. The 2D dislocation equation governing the displacements is coupled by the restoring forces that are determined by the parameterization of the generalized stacking fault energies. The Ritz variational method is presented to solve the dislocation equation and the trial solution is constituted by two arctan-type functions with two undetermined parameters. The core widths of partial dislocations are wider than that obtained in generalized Peierls-Nabarro model due to the consideration of discreteness of crystal.展开更多
Classically, ion channels are classified into 2 groups: chemical-sensitive (ligand-gated) and voltage-sensitive channels. Single ATP-sensitive K+ (K-ATP) channel currents were recorded in acutely dissociated rat neo-c...Classically, ion channels are classified into 2 groups: chemical-sensitive (ligand-gated) and voltage-sensitive channels. Single ATP-sensitive K+ (K-ATP) channel currents were recorded in acutely dissociated rat neo-cortical neurons using patch clamp technique. A type of K-ATP channel has been found to be gated not only by intra-cellular ATP, but also by membrane potential ( Vm) , and proved to be a novel mechanism underlying the gating of ion channels, namely bi-gating mechanism. The results also show that the K-ATP channels possess heterogeneity and di-versity. These types of K-ATP channels have been identified in 40.12% of all patches, which are different in activa-tion-threshold and voltage-sensitivity. The present experiment studied the type-3 K-ATP channel with a unitary con-ductance of about 80 pS in detail ( n = 15). Taking account of all the available data, a variety of K-ATP channels are suggested to exist in body, and one type of them is bi-gated by both chemical substances and membrane potentials. This property of the K-ATP channels may be related to their pathophysiblogical function.展开更多
The purpose of this study was to compare cell growth characteristics,ciliated cell differentiation,and function of human nasal epithelial cells established as explant outgrowth cultures or dissociated tissue cultures....The purpose of this study was to compare cell growth characteristics,ciliated cell differentiation,and function of human nasal epithelial cells established as explant outgrowth cultures or dissociated tissue cultures.Human nasal mucosa of the uncinate process was obtained by endoscopy and epithelial cell cultures were established by explant outgrowth or dissociated tissue culture methods.Epithelial cell growth characteristics were observed by inverted phase contrast microscopy.Ciliated cell differentiation was detected byβ-tubulin IV and ZO-1 immunocytochemistry.Basal and ATP-stimulated ciliary beat frequency(CBF)was measured using a high-speed digital microscopic imaging system.Both the explant and dissociated tissue cultures established as monolayers with tight junctions and differentiated cell composition,with both types of cultures comprising ciliated and non-ciliated epithelial cells.Fibroblasts were also frequently found in explant cultures but rarely seen in dissociated tissue cultures.In both culture systems,the highest ciliated cell density appeared at 7th–10th culture day and declined with time,with the lifespan of ciliated cells ranging from 14 to 21 days.Overall,10%of the cells in explant cultures and 20%of the cells in the dissociated tissue cultures were ciliated.These two cultures demonstrated similar ciliary beat frequency values at baseline(7.78±1.99 Hz and 7.91±2.52 Hz,respectively)and reacted equivalently following stimulation with 100μM ATP.The results of this study indicate that both the explant outgrowth and dissociated tissue culture techniques are suitable for growing well-differentiated nasal ciliated and non-ciliated cells,which have growth characteristics and ciliary activity similar to those of nasal epithelial cells in vivo.展开更多
Radiotherapy is widely used in the management of advanced colorectal cancer(CRC).However,the clinical efficacy is limited by the safe irradiated dose.Sensitizing tumor cells to radiotherapy via interrupting DNA repair...Radiotherapy is widely used in the management of advanced colorectal cancer(CRC).However,the clinical efficacy is limited by the safe irradiated dose.Sensitizing tumor cells to radiotherapy via interrupting DNA repair is a promising approach to conquering the limitation.The BRCA1-BARD1 complex has been demonstrated to play a critical role in homologous recombination(HR)DSB repair,and its functions may be affected by HERC2 or BAP1.Accumulated evidence illustrates that the ubiquitination-deubiquitination balance is involved in these processes;however,the precise mechanism for the cross-talk among these proteins in HR repair following radiation hasn’t been defined.Through activity-based profiling,we identified PT33 as an active entity for HR repair suppression.Subsequently,we revealed that BAP1 serves as a novel molecular target of PT33 via a CRISPR-based deubiquitinase screen.Mechanistically,pharmacological covalent inhibition of BAP1 with PT33 recruits HERC2 to compete with BARD1 for BRCA1 interaction,interrupting HR repair.Consequently,PT33 treatment can substantially enhance the sensitivity of CRC cells to radiotherapy in vitro and in vivo.Overall,these findings provide a mechanistic basis for PT33-induced HR suppression and may guide an effective strategy to improve therapeutic gain.展开更多
Composite solid electrolytes(CSEs)are considered among the most promising candidates for solid-state batteries.However,their practical application is hindered by low ionic conductivity and a limited lithium-ion transf...Composite solid electrolytes(CSEs)are considered among the most promising candidates for solid-state batteries.However,their practical application is hindered by low ionic conductivity and a limited lithium-ion transference number,primarily owing to the insufficient mobility of Li+.In this work,we design a heterojunc-tion nanoparticle composed of bimetallic zeolitic imidazolate frameworks(ZIFs)coupled with amorphous tita-nium oxide(TiO_(2)@Zn/Co–ZIF)as a filler to fabricate a composite solid-state electrolyte(PVZT).The amor-phous TiO_(2) coating facilitates salt dissociation through Lewis acid–base interactions with the anions of the lithium salt.Meanwhile,the Zn/Co–ZIF framework not only provides additional selective pathways for Li+transport but also effectively restricts anion migration through its confined pore size.The synergistic effect results in a high room-temperature ionic conductivity(8.8×10^(-4) S·cm^(-1))and a lithium-ion transference number of 0.47 for PVZT.A symmetrical cell using PVZT demonstrates stable Li+deposition/stripping for over 1100 h at a current density of 0.1 mA·cm^(-2).Additionally,a LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)/Li full cell using PVZT retains 75.0%of its capacity after 1200 cycles at a 2 C rate.This work offers valuable insights into the design of func-tional fillers for CSEs with highly efficient ion transport.展开更多
Carbon nanotube formation exemplifies atomically precise self-assembly,where atomic interactions dynamically engineer nanoscale architectures with emergent properties that transcend classical material boundaries.Howev...Carbon nanotube formation exemplifies atomically precise self-assembly,where atomic interactions dynamically engineer nanoscale architectures with emergent properties that transcend classical material boundaries.However,elucidating the transient molecular intermediates remains a critical mechanistic frontier.This study investigates the atomic-scale nucleation process of single-walled carbon nanotubes(SWCNTs)from acetylene on iron(Fe)clusters,utilizing GFN(-x)TB-based nanoreactor molecular dynamics simulations.The simulations reveal a consistent nucleation pathway,regardless of iron cluster size(Fe_(13),Fe_(38),Fe_(55)),where the chemisorption and dissociation of acetylene molecules on the Fe clusters lead to the formation of C_(2)H and C_(2)intermediates.These species then undergo oligomerization,initiating the growth of carbon chains.As the chains cross-link and cyclize,five-membered carbon rings are preferentially formed,which eventually evolve into six-membered rings and more complex sp2-hybridized carbon networks,resembling the cap structures of nascent SWCNTs.Although the nucleation mechanism remains similar across all cluster sizes,larger clusters show enhanced catalytic activity,leading to higher molecular weight hydrocarbons and more extensive carbocyclic networks due to their higher density of active sites per reacting molecule.Crucially,the study highlights the role of C_(2)H as the key active species in the carbon network formation process.These findings offer critical insights into the initial stages of SWCNT nucleation,contributing to a deeper understanding of the mechanisms driving SWCNT growth and guiding the development of optimized synthetic strategies.展开更多
For a simple graph G,let A(G)and D(G)be the adjacency matrix and the diagonal degree matrix of G,respectively.[Appl.Anal.Discrete Math.,2017,11(1):81-107]defined the matrix A_(α)(G)of G as A_(α)(G)=αD(G)(1-α)A(G)...For a simple graph G,let A(G)and D(G)be the adjacency matrix and the diagonal degree matrix of G,respectively.[Appl.Anal.Discrete Math.,2017,11(1):81-107]defined the matrix A_(α)(G)of G as A_(α)(G)=αD(G)(1-α)A(G),α∈[0,1].The Aa-spectral radius is the largest eigenvalue of A_(α)(G).Let G_(n,β) be the set graphs with order n and dissociation numberβ.In this paper,we identify the b with maximal A_(α)-spectral radius among all graphs in G_(n,β).展开更多
The dicarbon(C_(2))molecule is an important molecular species observed in many carbon-containing gaseous environments.The spectroscopic and dissociative studies of C_(2)have attracted great attention for a long time f...The dicarbon(C_(2))molecule is an important molecular species observed in many carbon-containing gaseous environments.The spectroscopic and dissociative studies of C_(2)have attracted great attention for a long time for understanding its electronic characters as well as the evolution and cycling of carbon in the universe.In this study,the lifetimes of C_(2)populated at the three high-lying electronic states of(2-4)^(3)Δ_(g) in the vacuum ultraviolet(VUV)region have been experimentally measured using a time-of-flight mass spectrometer and the VUV-pump-UV-probe photoionization scheme.The measurements showed that all the rovibronic levels in the 2(g)^(3)Δ_(g) state exhibit shorter lifetimes than the dynamical limit of the experimental method,consistent with the theoretically predicted radiative lifetimes.Dependence of the lifetime on the vibrational level was observed in the 3^(3)Δ_(g) state,and a marginal rotational dependence was noticed in the vʹ=1 vibrational level.For the 4^(3)Δ_(g) state,the rotationally resolved lifetimes in the vʹ=1 vibrational level were found to be slightly longer than those in the vʹ=0 and 2 vibrational levels.Such a complicated dependence of the lifetime on the rovibronic level makes further experimental and theoretical investigations highly desired for understanding the dynamics in the high-lying excited states of C_(2).展开更多
As antibiotic pollutants cannot be incompletely removed by conventional wastewater treatment plants,ultraviolet(UV)based advanced oxidation processes(AOPs)such as UV/persulfate(UV/PS)and UV/chlorine are increasingly c...As antibiotic pollutants cannot be incompletely removed by conventional wastewater treatment plants,ultraviolet(UV)based advanced oxidation processes(AOPs)such as UV/persulfate(UV/PS)and UV/chlorine are increasingly concerned for the effective removal of antibiotics from wastewaters.However,the specific mechanisms involving degradation kinetics and transformation mechanisms are not well elucidated.Here we report a detailed examination of SO_(4)•−/Cl•-mediated degradation kinetics,products,and toxicities of sulfathiazole(ST),sarafloxacin(SAR),and lomefloxacin(LOM)in the two processes.Both SO_(4)•−/Cl•-mediated transformation kinetics were found to be dependent on pH(P<0.05),which was attributed to the disparate reactivities of their individual dissociated forms.Based on competition kinetic experiments and matrix calculations,the cationic forms(H_(2)ST^(+),H_(2)SAR^(+),and H_(2)LOM^(+))were more highly reactive towards SO_(4)•−in most cases,while the neutral forms(e.g.,HSAR^(0)and HLOM^(0))reacted the fastest with Cl•for the most of the antibiotics tested.Based on the identification of 31 key intermediates using tandem mass spectrometry,these reactions generated different products,of which the majority still retained the core chemical structure of the parent compounds.The corresponding diverse transformation pathways were proposed,involving S−N breaking,hydroxylation,defluorination,and chlorination reactions.Furthermore,the toxicity changes of their reaction solutions as well as the toxicity of each intermediate were evaluated by the vibrio fischeri and ECOSAR model,respectively.Many primary by-products were proven to be more toxic than the parent chemicals,raising the wider issue of extended potency for these compounds with regards to their ecotoxicity.These results have implications for assessing the degradative fate and risk of these chemicals during the AOPs.展开更多
BACKGROUND Left colon cancer surgery relies on laparoscopic hemicolectomy,with digestive tract reconstruction critical.End-to-side anastomosis(ESA)and side-to-side anastomosis(SSA)anastomoses are common,but their comp...BACKGROUND Left colon cancer surgery relies on laparoscopic hemicolectomy,with digestive tract reconstruction critical.End-to-side anastomosis(ESA)and side-to-side anastomosis(SSA)anastomoses are common,but their comparative outcomes,especially in splenic flexure handling and efficacy,need clarification.This study compares ESA and SSA to guide surgical practice.AIM To compare the clinical outcomes of laparoscopically assisted left hemicolectomy with ESA and SSA.METHODS A total of 334 patients were included,with 105 patients from the First Affiliated Hospital of Xiamen University and 229 patients from the First Affiliated Hospital of Fujian Medical University,between January 1,2012,and May 31,2020.The patients were divided into two groups:146 cases in the ESA group and 188 cases in the SSA group.Clinical data from both groups were compared,and the survival prognosis was followed up.RESULTS The operation time for the ESA group was significantly shorter than that of the SSA group(197.1±57.7 minutes vs 218.6±67.5 minutes,χ2=4.298,P=0.039).There were no significant differences between the two groups in intraoperative blood loss,postoperative pain score at 48 hours,time to first bowel movement,number of lymph nodes dissected,or postoperative complications such as anastomotic leakage,bleeding,stenosis.and adhesive intestinal obstruction at 6 months,12 months,and 24 months(P>0.05).Specifically,the incidence of complications like anastomotic leakage was 2.1%in the ESA group vs 4.3%in the SSA group(P=0.264).The 5-year disease-free survival(DFS)rate was 66.4%for the ESA group and 63.9%for the SSA group(P=0.693).There were no significant differences in the overall survival rate between the two groups.The incidence of splenic laceration was significantly higher in the SSA group(3.7%vs 0.7%,P=0.018).Overall,the 5-year DFS was 66.4%for ESA and 63.9%for SSA,with no significant difference in survival between the groups(P=0.693).CONCLUSION Both laparoscopically assisted left hemicolectomy with ESA and SSA are feasible and offer comparable long-term outcomes.ESA may reduce the need for splenic flexure dissociation,particularly when the tumor is located at the descending colon or its junction with the sigmoid colon,and especially in obese patients,elderly individuals with multiple complications,or those with severe adhesions in the splenic flexure of the surgical field.展开更多
Even if dissociation has various facets,it is clear that knowledge of dissociative psychosis and a dissociative schizophrenia-based viewpoint may provide new perspectives on mental disorders.Many researchers screening...Even if dissociation has various facets,it is clear that knowledge of dissociative psychosis and a dissociative schizophrenia-based viewpoint may provide new perspectives on mental disorders.Many researchers screening for comorbid symptoms of“childhood traumatic experiences”and“dissociation”,where specific characteristics are significant to the presence of psychosis and schizophrenia,may lead to an acceptable definition.In recent years,researchers have also reported crucial advances in the understanding of dissociative psychosis and dissociative schizophrenia.Although clinical studies in this area have been ongoing for a long time,research has not demonstrated that a clear and valid relationship exists between dissociation,childhood traumatic experiences,and schizophrenia or psychotic spectrum disorders.However,some results of statistical comparisons have supported the existence of the clinical manifestation known as dissociative psychosis and dissociative schizophrenia.Dissociation,childhood traumatic experiences,and positive psychotic symptoms may be a prominent part of dissociative psychosis and schizophrenia.The intense presence of negative symptoms may indicate classical schizophrenia.In research and clinical practice,researchers and clinicians may use psychometric tests to detect symptoms of dissociative psychosis.Psychotic persons with traumatic experiences likely benefit from treatment focused on trauma symptomatolgy.展开更多
Electrochemical reduction of nitrate(NO_(3^(-)))serves as an eco-friendly friendly alternative to the conventional Haber-Bosch ammonia(NH_(3))synthesis process.The Cu electrocatalyst is widely recognized for its stron...Electrochemical reduction of nitrate(NO_(3^(-)))serves as an eco-friendly friendly alternative to the conventional Haber-Bosch ammonia(NH_(3))synthesis process.The Cu electrocatalyst is widely recognized for its strong adsorption capacity towards nitrate,but its limited H adsorption and slow hydrogenation of oxynitride intermediates hinder the efficiency of converting NO_(3^(-))into NH_(3).Herein,a series of nanocomposite catalysts composed of CuO nanostructure with low NiO content that grow in-situ on carbon paper(Cu O/Ni O_(x)-CP)were synthesized via hydrothermal method and calcination for enhanced nitrate electroreduction utilizing the strong nitrate adsorption capacity of copper and excellent water dissociation ability of NiO to supply hydrogen free radicals(·H).In-situ Raman spectroscopy reveals dynamic reconstruction of Cu/NiO_(x)during the electrochemical nitrate reduction process from Cu O/NiO_(x).Due to the synergistic effect of Cu and NiO,a high Faradaic efficiency(FE,~97.9%)and yield rate(YR,391.5μmol h^(-1)cm^(-2))of ammonia are achieved on CuO/NiO_(2.3%)-CP.Electron paramagnetic resonance(EPR)proves that the presence of Ni O enhances the generation of·H,which can be rapidly consumed during nitrate reduction process.Density functional theory(DFT)calculations indicate that the activation energy of Ni O(0.57 eV)is much lower than Cu(0.84 e V)for water splitting to generate·H,thus facilitating*NO hydrogenations.This drives us to create more effective catalysts for nitrate reduction under neutral conditions by promoting H2O dissociation.展开更多
As a highly reactive reaction intermediate,surface gallium hydride(Ga–H)has garnered significant attention due to its critical role in various catalytic reactions.However,the detailed experimental characterization of...As a highly reactive reaction intermediate,surface gallium hydride(Ga–H)has garnered significant attention due to its critical role in various catalytic reactions.However,the detailed experimental characterization of this unique species remains challenging.Recently,we have demonstrated that solid-state NMR can be an effective tool for studying surface Ga–H.In this work,we report a comparative solid-state NMR study on H_(2) activation over different Ga_(2)O_(3) polymorphs,specificallyα-,β-andγ-Ga_(2)O_(3).^(1)H solid-state NMR enabled the identification of Ga–H species formed on all the three samples following high-temperature H_(2) treatment.The characteristic ^(1)H NMR signals of Ga–H species are resolved using J-coupling-based double-resonance NMR methods,revealing highly similar lineshapes of Ga–H for all the Ga_(2)O_(3) samples.This suggests potentially similar surface Ga–H configurations among different Ga_(2)O_(3) polymorphs.In addition,the local hydrogen environments on the oxide surfaces are further explored using two-dimensional(2D)^(1)H–^(1)H homonuclear correlation spectra,revealing multiple spatially proximate Ga–H and Ga–H/–OH pairs on different Ga_(2)O_(3) polymorphs.These findings provide insights into the potential mechanism of H_(2) dissociation.Overall,this work offers new perspectives on the local structure of surface Ga–H on Ga_(2)O_(3),and the analytical approach presented here can be further extended to the study of other Ga-based catalysts and other metal hydride species.展开更多
Extracting lithium from coal measures can alleviate the shortage of strategic metal resources.However,the lattice substitution characteristics of lithium in carrier minerals and its extremely fine intercalation and en...Extracting lithium from coal measures can alleviate the shortage of strategic metal resources.However,the lattice substitution characteristics of lithium in carrier minerals and its extremely fine intercalation and entrainment behavior are the challenges that constrain the extraction efficiency of lithium from coal series.This study focuses on improving the separation efficiency between lithium-contain-ing minerals and other minerals and the release behavior of lithium in the liquid phase.First,the feasibility of extracting lithium from car-rier minerals is confirmed based on the occurrence state and the process mineralogy characterized by Bgrimm process mineralogy analyz-ing system(BPMA)and time of flight secondary ion mass spectrometry(TOF-SIMS).The optimal selective grinding behavior is achieved within 15 min,allowing Li carrier minerals,including chlorite,kaolinite,and halloysite,to deliver the best dispersion effect with other minerals.Thus,the enriched lithium carrier minerals have been preenriched through screening.The leaching efficiency of Li has reached 97.43%under 1 mol/L hydrochloric acid,15 g/L pulp density,70℃,and 20 min.Leaching kinetics studies indicate that the de-crease in apparent energy validates the impact of grinding on metal leaching,aligning with the rate-controlling step of a chemical reaction.The process proposed in this study achieves the coordinated control of size and components in coal gangue and actualizes the effective se-lective enrichment of lithium through its low energy consumption and environmentally friendly nature.展开更多
Shear strength of hydrate-bearing sediment is an essential parameter for assessing landslide potential ofhydrate reservoirs under exploration conditions. However, the characteristics and simulation of thisshear streng...Shear strength of hydrate-bearing sediment is an essential parameter for assessing landslide potential ofhydrate reservoirs under exploration conditions. However, the characteristics and simulation of thisshear strength under varying dissociation conditions have not been thoroughly investigated. To this end,a series of triaxial compression tests were first carried out on sediments with varying initial hydratesaturations along dissociation pathways. Combining measured data with microscale analysis, the underlyingmechanism for the evolution of shear strength in hydrate-bearing sediment was studied undervarying partial dissociation pathways. Moreover, a shear strength model for hydrate-bearing sedimentwas proposed, taking into account the hydrate saturation and the unhydrated water content. Apart fromthe parameters derived from the hydrate characteristic curve, only one additional model parameter isrequired. The proposed model was validated using measured data on hydrate sediments. The resultsindicate that the proposed model can effectively capture the shear strength behavior of hydrate-bearingsediment under varying dissociation paths. Finally, a sensitivity analysis of the model parameters wasconducted to characterize the proposed model.展开更多
Metal oxide catalysts are widely employed in propane dehydrogenation(PDH)for propylene synthesis,requiring sequential reduction-reaction-regeneration cycles.However,the eff ect of water present in the inlet gas or rea...Metal oxide catalysts are widely employed in propane dehydrogenation(PDH)for propylene synthesis,requiring sequential reduction-reaction-regeneration cycles.However,the eff ect of water present in the inlet gas or reactor on the catalytic per-formance of various metal oxides remains insuffi ciently understood.This study examines the infl uence of water on supported metal oxide catalysts,specifi cally CoO x/Al_(2)O_(3),VO x/Al_(2)O_(3),and an industrial analog CrO x/Al_(2)O_(3) catalyst.By combining titration experiments,in situ Fourier transform infrared spectroscopy,kinetic analysis,and isotopic techniques,we demon-strate that even trace amounts of water can markedly suppress PDH performance via dissociative adsorption on the oxide surface.Methanol pretreatment eff ectively scavenges adsorbed water,recovering Lewis acid-base sites and consequently restoring PDH activity.This work underscores the profound inhibitory role of trace water in PDH over metal oxide catalysts and illustrates the potential of methanol pretreatment as an effective strategy to mitigate this limitation.展开更多
文摘AIM: To investigate the therapeutic effects of simultaneous horizontal and vertical operations on dissociated vertical deviation(DVD) associated with other deviations.METHODS: Forty-five cases of DVD with horizontal and torsional strabismus underwent combined operation were collected retrospectively. All clinical records were analyzed. All patients were followed up for 6 to 24 mo. Wilcoxon signed-ranks test was performed to evaluate the changes of vertical and horizontal deviation. χ~2 test was used to evaluate the changes of binocular visual function. RESULTS: Forty-five cases included 36 patients with intermittent exotropia and binocular inferior oblique overaction(IOOA), 5 patients with concomitant esotropia and binocular IOOA, 4 patients with intermittent exotropia and monocular superior oblique palsy. The superior rectus recession(SRR) combined with horizontal rectus recession and the myectomy of inferior oblique or anterior transposition were operated simultaneously to correct all types of strabismus. There were 43 cases who achieved normal eye position in vertical direction, while 2 cases were with undercorrection of 5~Δ to 6~Δ. In patients with horizontal strabismus, 2 cases of exotropia were with overcorrection of 6~Δ to 8~Δ, 1 case of esotropia was with undercorrection of 6~Δ, and 1 case of monocular superior oblique palsy with compensatory head posture was not significantly improved. The binocular visual function of most patients recovered after operation. The difference of the binocular visual function and eye position were significant compared with that before operation(P<0.05).CONCLUSION: The simultaneous operation on DVD with horizontal and torsional strabismus is successful.
基金supported by the National Natural Science Foundation of China(Nos.11732011,11672205,and 11332007)the National Key Research and Development Program of China(No.2016YFA0401200)
文摘The high temperature gas occurs behind shock or near the wall surface of vehicle in the hypersonic flight. As the temperature exceeds 2 000 K, 4 000 K, respectively, O2 and N2 molecules are successively dissociated. Because of variable components at dif- ferent temperatures and pressures, the dissociated air is no longer a perfect gas, In this paper, a new method is developed to calculate accurate thermal physical parameters with the dissociation degree providing the thermochemical equilibrium procedure. Based on the dissociation degree, it is concluded that few numbers of equations and the solutions are easily obtained. In addition, a set of formulas relating the parameter to the dissociation degree are set up four-species, O2 molecule The thermodynamic properties of dissociated air containing and N2 molecule, O atom and N atom, are studied with the new method, and the results are consistent with those with the traditional equilibrium constant method. It is shown that this method is reliable for solving thermal physical parameters easily and directly.
基金Supported by The Natural Science Foundation of Shandong Province,No.ZR2018BH013The China Postdoctoral Science Foundation,No.2017M612214.
文摘BACKGROUND Inferior oblique anterior transposition(IOAT)has emerged as an effective surgery in the management of dissociated vertical deviation(DVD)combined with superior oblique palsy(SOP).Traditional IOAT usually provides satisfactory primary position alignment and simultaneously restricts the superior floating phenomenon.However,it also increases the risk of the anti-elevation syndrome and narrowing of the palpebral fissure in straight-ahead gaze,especially after the unilateral operation.CASE SUMMARY We report the outcomes of the modified unilateral IOAT in two patients with unilateral DVD combined with SOP.The anterior-nasal fibers of the inferior oblique muscle were attached at 9 mm posterior to the corneal limbus along the temporal board of the inferior rectus muscle,the other fibers were attached a further 5 mm temporal to the anterior-nasal fibers.Postoperatively,both hypertropia and floating were improved,and no obvious complications occurred.CONCLUSION In these cases,the modified unilateral IOAT was an effective and safe surgical method for treating DVD with SOP.
基金supported by the National Natural Science Foundation of China (No.10774196)the Science Founda-tion Project of CQ CSTC (No.2006BB4156)Chongqing University Postgraduates’Science and Innovation Fund(No.200707A1A0030240)
文摘The extended core structure of the dissociated edge dislocation in Al, Au, Ag, Cu and Ni is determined within lattice theory of dislocation. The 2D dislocation equation governing the displacements is coupled by the restoring forces that are determined by the parameterization of the generalized stacking fault energies. The Ritz variational method is presented to solve the dislocation equation and the trial solution is constituted by two arctan-type functions with two undetermined parameters. The core widths of partial dislocations are wider than that obtained in generalized Peierls-Nabarro model due to the consideration of discreteness of crystal.
基金Project supported by the National Natural Science Foundation of China and Natural Science Foundation of Guangdong Province.
文摘Classically, ion channels are classified into 2 groups: chemical-sensitive (ligand-gated) and voltage-sensitive channels. Single ATP-sensitive K+ (K-ATP) channel currents were recorded in acutely dissociated rat neo-cortical neurons using patch clamp technique. A type of K-ATP channel has been found to be gated not only by intra-cellular ATP, but also by membrane potential ( Vm) , and proved to be a novel mechanism underlying the gating of ion channels, namely bi-gating mechanism. The results also show that the K-ATP channels possess heterogeneity and di-versity. These types of K-ATP channels have been identified in 40.12% of all patches, which are different in activa-tion-threshold and voltage-sensitivity. The present experiment studied the type-3 K-ATP channel with a unitary con-ductance of about 80 pS in detail ( n = 15). Taking account of all the available data, a variety of K-ATP channels are suggested to exist in body, and one type of them is bi-gated by both chemical substances and membrane potentials. This property of the K-ATP channels may be related to their pathophysiblogical function.
基金supported by the National Science Fund for Distinguished Young Scholars(Grant No.81025007)National Natural Science Foundation of China(Grant Nos.81100704,30973282)+4 种基金Beijing Natural Science Foundation(7131006),Ministry of Health Foundation(201202005)Beijing Nova Program(Z111107054511061)Specialized Research Fund for the Doctoral Program of Higher Education of China(20111107120004)The Capital Health Research and Development of Special(2011-1017-03)Science Foundation for High-Level Medical Talents of Beijing Health System(2009-02-007).
文摘The purpose of this study was to compare cell growth characteristics,ciliated cell differentiation,and function of human nasal epithelial cells established as explant outgrowth cultures or dissociated tissue cultures.Human nasal mucosa of the uncinate process was obtained by endoscopy and epithelial cell cultures were established by explant outgrowth or dissociated tissue culture methods.Epithelial cell growth characteristics were observed by inverted phase contrast microscopy.Ciliated cell differentiation was detected byβ-tubulin IV and ZO-1 immunocytochemistry.Basal and ATP-stimulated ciliary beat frequency(CBF)was measured using a high-speed digital microscopic imaging system.Both the explant and dissociated tissue cultures established as monolayers with tight junctions and differentiated cell composition,with both types of cultures comprising ciliated and non-ciliated epithelial cells.Fibroblasts were also frequently found in explant cultures but rarely seen in dissociated tissue cultures.In both culture systems,the highest ciliated cell density appeared at 7th–10th culture day and declined with time,with the lifespan of ciliated cells ranging from 14 to 21 days.Overall,10%of the cells in explant cultures and 20%of the cells in the dissociated tissue cultures were ciliated.These two cultures demonstrated similar ciliary beat frequency values at baseline(7.78±1.99 Hz and 7.91±2.52 Hz,respectively)and reacted equivalently following stimulation with 100μM ATP.The results of this study indicate that both the explant outgrowth and dissociated tissue culture techniques are suitable for growing well-differentiated nasal ciliated and non-ciliated cells,which have growth characteristics and ciliary activity similar to those of nasal epithelial cells in vivo.
基金supported by the National Natural Science Foundation of China(NSFC)(No.82272743 to Xin Yue(82172812)of NSFC to Ran-yi Liu+4 种基金81871996 to Ran-yi Liu82003218 to Xuecen Wang82072029 to Zhenwei Peng and 81973174 to Xianzhang Bu)Guangdong Basic and Applied Basic Research Foundation(No.2021A1515012496 to Xin Yue and 2022A1515012221 to Xianzhang Bu)Basic Scientific Research Operation of Sun Yat-sen University(No.19ykpy192 to Xin Yue)。
文摘Radiotherapy is widely used in the management of advanced colorectal cancer(CRC).However,the clinical efficacy is limited by the safe irradiated dose.Sensitizing tumor cells to radiotherapy via interrupting DNA repair is a promising approach to conquering the limitation.The BRCA1-BARD1 complex has been demonstrated to play a critical role in homologous recombination(HR)DSB repair,and its functions may be affected by HERC2 or BAP1.Accumulated evidence illustrates that the ubiquitination-deubiquitination balance is involved in these processes;however,the precise mechanism for the cross-talk among these proteins in HR repair following radiation hasn’t been defined.Through activity-based profiling,we identified PT33 as an active entity for HR repair suppression.Subsequently,we revealed that BAP1 serves as a novel molecular target of PT33 via a CRISPR-based deubiquitinase screen.Mechanistically,pharmacological covalent inhibition of BAP1 with PT33 recruits HERC2 to compete with BARD1 for BRCA1 interaction,interrupting HR repair.Consequently,PT33 treatment can substantially enhance the sensitivity of CRC cells to radiotherapy in vitro and in vivo.Overall,these findings provide a mechanistic basis for PT33-induced HR suppression and may guide an effective strategy to improve therapeutic gain.
基金supported by National Science Fund for Distinguished Young Scholars(Grant No.52325206)National Key Research and Development Program of China(Grant No.2021YFF0500600)+3 种基金National Natural Science Foundation of China(Grant Nos.U2001220 and 52203298)Shenzhen Technical Plan Project(Grant Nos.RCJC20200714114436091,JCYJ20220530143012027,JCYJ20220818101003008,and JCYJ20220818101003007)Tsinghua Shenzhen International Graduate School-Shenzhen Pengrui Young Faculty Program of Shenzhen Pengrui Foundation(Grant No.SZPR2023006)Shenzhen Science and Technology Program(Grant No.WDZC20231126160733001).
文摘Composite solid electrolytes(CSEs)are considered among the most promising candidates for solid-state batteries.However,their practical application is hindered by low ionic conductivity and a limited lithium-ion transference number,primarily owing to the insufficient mobility of Li+.In this work,we design a heterojunc-tion nanoparticle composed of bimetallic zeolitic imidazolate frameworks(ZIFs)coupled with amorphous tita-nium oxide(TiO_(2)@Zn/Co–ZIF)as a filler to fabricate a composite solid-state electrolyte(PVZT).The amor-phous TiO_(2) coating facilitates salt dissociation through Lewis acid–base interactions with the anions of the lithium salt.Meanwhile,the Zn/Co–ZIF framework not only provides additional selective pathways for Li+transport but also effectively restricts anion migration through its confined pore size.The synergistic effect results in a high room-temperature ionic conductivity(8.8×10^(-4) S·cm^(-1))and a lithium-ion transference number of 0.47 for PVZT.A symmetrical cell using PVZT demonstrates stable Li+deposition/stripping for over 1100 h at a current density of 0.1 mA·cm^(-2).Additionally,a LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)/Li full cell using PVZT retains 75.0%of its capacity after 1200 cycles at a 2 C rate.This work offers valuable insights into the design of func-tional fillers for CSEs with highly efficient ion transport.
基金supported by the National Key R&D Program of China(2022YFA1604100)the National Natural Science Foundation of China(22302220,22372187,1972157,21972160,22402218)+2 种基金the National Science Fund for Distinguished Young Scholars of China(22225206)the Fundamental Research Program of Shanxi Province(202203021222403)the Youth Innovation Promotion Association CAS(2020179)。
文摘Carbon nanotube formation exemplifies atomically precise self-assembly,where atomic interactions dynamically engineer nanoscale architectures with emergent properties that transcend classical material boundaries.However,elucidating the transient molecular intermediates remains a critical mechanistic frontier.This study investigates the atomic-scale nucleation process of single-walled carbon nanotubes(SWCNTs)from acetylene on iron(Fe)clusters,utilizing GFN(-x)TB-based nanoreactor molecular dynamics simulations.The simulations reveal a consistent nucleation pathway,regardless of iron cluster size(Fe_(13),Fe_(38),Fe_(55)),where the chemisorption and dissociation of acetylene molecules on the Fe clusters lead to the formation of C_(2)H and C_(2)intermediates.These species then undergo oligomerization,initiating the growth of carbon chains.As the chains cross-link and cyclize,five-membered carbon rings are preferentially formed,which eventually evolve into six-membered rings and more complex sp2-hybridized carbon networks,resembling the cap structures of nascent SWCNTs.Although the nucleation mechanism remains similar across all cluster sizes,larger clusters show enhanced catalytic activity,leading to higher molecular weight hydrocarbons and more extensive carbocyclic networks due to their higher density of active sites per reacting molecule.Crucially,the study highlights the role of C_(2)H as the key active species in the carbon network formation process.These findings offer critical insights into the initial stages of SWCNT nucleation,contributing to a deeper understanding of the mechanisms driving SWCNT growth and guiding the development of optimized synthetic strategies.
基金Supported by NSFC (Nos.12171089,12271235)NSF of Jiangsu (No.BK20190919)NSF of Fujian (No.2021J02048)。
文摘For a simple graph G,let A(G)and D(G)be the adjacency matrix and the diagonal degree matrix of G,respectively.[Appl.Anal.Discrete Math.,2017,11(1):81-107]defined the matrix A_(α)(G)of G as A_(α)(G)=αD(G)(1-α)A(G),α∈[0,1].The Aa-spectral radius is the largest eigenvalue of A_(α)(G).Let G_(n,β) be the set graphs with order n and dissociation numberβ.In this paper,we identify the b with maximal A_(α)-spectral radius among all graphs in G_(n,β).
基金supported by the National Natural Science Foundation of China(No.22122308)Beijing National Laboratory for Molecular Sciences(BNLMS).Hong Gao is also partially supported by the Innovation Capability Support Program of Shaanxi Province(2023-CX-TD-49)supported by the China Postdoctoral Science Foundation(No.2020TQ0324).
文摘The dicarbon(C_(2))molecule is an important molecular species observed in many carbon-containing gaseous environments.The spectroscopic and dissociative studies of C_(2)have attracted great attention for a long time for understanding its electronic characters as well as the evolution and cycling of carbon in the universe.In this study,the lifetimes of C_(2)populated at the three high-lying electronic states of(2-4)^(3)Δ_(g) in the vacuum ultraviolet(VUV)region have been experimentally measured using a time-of-flight mass spectrometer and the VUV-pump-UV-probe photoionization scheme.The measurements showed that all the rovibronic levels in the 2(g)^(3)Δ_(g) state exhibit shorter lifetimes than the dynamical limit of the experimental method,consistent with the theoretically predicted radiative lifetimes.Dependence of the lifetime on the vibrational level was observed in the 3^(3)Δ_(g) state,and a marginal rotational dependence was noticed in the vʹ=1 vibrational level.For the 4^(3)Δ_(g) state,the rotationally resolved lifetimes in the vʹ=1 vibrational level were found to be slightly longer than those in the vʹ=0 and 2 vibrational levels.Such a complicated dependence of the lifetime on the rovibronic level makes further experimental and theoretical investigations highly desired for understanding the dynamics in the high-lying excited states of C_(2).
基金supported by the Key Research and Development Program of Shaanxi Province(No.2024SF-YBXM-567)the National Natural Science Foundation of China(Nos.21976045,22076112)the China Scholarship Council(CSC)Scholarship(No.202308610123).
文摘As antibiotic pollutants cannot be incompletely removed by conventional wastewater treatment plants,ultraviolet(UV)based advanced oxidation processes(AOPs)such as UV/persulfate(UV/PS)and UV/chlorine are increasingly concerned for the effective removal of antibiotics from wastewaters.However,the specific mechanisms involving degradation kinetics and transformation mechanisms are not well elucidated.Here we report a detailed examination of SO_(4)•−/Cl•-mediated degradation kinetics,products,and toxicities of sulfathiazole(ST),sarafloxacin(SAR),and lomefloxacin(LOM)in the two processes.Both SO_(4)•−/Cl•-mediated transformation kinetics were found to be dependent on pH(P<0.05),which was attributed to the disparate reactivities of their individual dissociated forms.Based on competition kinetic experiments and matrix calculations,the cationic forms(H_(2)ST^(+),H_(2)SAR^(+),and H_(2)LOM^(+))were more highly reactive towards SO_(4)•−in most cases,while the neutral forms(e.g.,HSAR^(0)and HLOM^(0))reacted the fastest with Cl•for the most of the antibiotics tested.Based on the identification of 31 key intermediates using tandem mass spectrometry,these reactions generated different products,of which the majority still retained the core chemical structure of the parent compounds.The corresponding diverse transformation pathways were proposed,involving S−N breaking,hydroxylation,defluorination,and chlorination reactions.Furthermore,the toxicity changes of their reaction solutions as well as the toxicity of each intermediate were evaluated by the vibrio fischeri and ECOSAR model,respectively.Many primary by-products were proven to be more toxic than the parent chemicals,raising the wider issue of extended potency for these compounds with regards to their ecotoxicity.These results have implications for assessing the degradative fate and risk of these chemicals during the AOPs.
文摘BACKGROUND Left colon cancer surgery relies on laparoscopic hemicolectomy,with digestive tract reconstruction critical.End-to-side anastomosis(ESA)and side-to-side anastomosis(SSA)anastomoses are common,but their comparative outcomes,especially in splenic flexure handling and efficacy,need clarification.This study compares ESA and SSA to guide surgical practice.AIM To compare the clinical outcomes of laparoscopically assisted left hemicolectomy with ESA and SSA.METHODS A total of 334 patients were included,with 105 patients from the First Affiliated Hospital of Xiamen University and 229 patients from the First Affiliated Hospital of Fujian Medical University,between January 1,2012,and May 31,2020.The patients were divided into two groups:146 cases in the ESA group and 188 cases in the SSA group.Clinical data from both groups were compared,and the survival prognosis was followed up.RESULTS The operation time for the ESA group was significantly shorter than that of the SSA group(197.1±57.7 minutes vs 218.6±67.5 minutes,χ2=4.298,P=0.039).There were no significant differences between the two groups in intraoperative blood loss,postoperative pain score at 48 hours,time to first bowel movement,number of lymph nodes dissected,or postoperative complications such as anastomotic leakage,bleeding,stenosis.and adhesive intestinal obstruction at 6 months,12 months,and 24 months(P>0.05).Specifically,the incidence of complications like anastomotic leakage was 2.1%in the ESA group vs 4.3%in the SSA group(P=0.264).The 5-year disease-free survival(DFS)rate was 66.4%for the ESA group and 63.9%for the SSA group(P=0.693).There were no significant differences in the overall survival rate between the two groups.The incidence of splenic laceration was significantly higher in the SSA group(3.7%vs 0.7%,P=0.018).Overall,the 5-year DFS was 66.4%for ESA and 63.9%for SSA,with no significant difference in survival between the groups(P=0.693).CONCLUSION Both laparoscopically assisted left hemicolectomy with ESA and SSA are feasible and offer comparable long-term outcomes.ESA may reduce the need for splenic flexure dissociation,particularly when the tumor is located at the descending colon or its junction with the sigmoid colon,and especially in obese patients,elderly individuals with multiple complications,or those with severe adhesions in the splenic flexure of the surgical field.
文摘Even if dissociation has various facets,it is clear that knowledge of dissociative psychosis and a dissociative schizophrenia-based viewpoint may provide new perspectives on mental disorders.Many researchers screening for comorbid symptoms of“childhood traumatic experiences”and“dissociation”,where specific characteristics are significant to the presence of psychosis and schizophrenia,may lead to an acceptable definition.In recent years,researchers have also reported crucial advances in the understanding of dissociative psychosis and dissociative schizophrenia.Although clinical studies in this area have been ongoing for a long time,research has not demonstrated that a clear and valid relationship exists between dissociation,childhood traumatic experiences,and schizophrenia or psychotic spectrum disorders.However,some results of statistical comparisons have supported the existence of the clinical manifestation known as dissociative psychosis and dissociative schizophrenia.Dissociation,childhood traumatic experiences,and positive psychotic symptoms may be a prominent part of dissociative psychosis and schizophrenia.The intense presence of negative symptoms may indicate classical schizophrenia.In research and clinical practice,researchers and clinicians may use psychometric tests to detect symptoms of dissociative psychosis.Psychotic persons with traumatic experiences likely benefit from treatment focused on trauma symptomatolgy.
基金supported by the National Natural Science Foundation of China(No.U22A20253)。
文摘Electrochemical reduction of nitrate(NO_(3^(-)))serves as an eco-friendly friendly alternative to the conventional Haber-Bosch ammonia(NH_(3))synthesis process.The Cu electrocatalyst is widely recognized for its strong adsorption capacity towards nitrate,but its limited H adsorption and slow hydrogenation of oxynitride intermediates hinder the efficiency of converting NO_(3^(-))into NH_(3).Herein,a series of nanocomposite catalysts composed of CuO nanostructure with low NiO content that grow in-situ on carbon paper(Cu O/Ni O_(x)-CP)were synthesized via hydrothermal method and calcination for enhanced nitrate electroreduction utilizing the strong nitrate adsorption capacity of copper and excellent water dissociation ability of NiO to supply hydrogen free radicals(·H).In-situ Raman spectroscopy reveals dynamic reconstruction of Cu/NiO_(x)during the electrochemical nitrate reduction process from Cu O/NiO_(x).Due to the synergistic effect of Cu and NiO,a high Faradaic efficiency(FE,~97.9%)and yield rate(YR,391.5μmol h^(-1)cm^(-2))of ammonia are achieved on CuO/NiO_(2.3%)-CP.Electron paramagnetic resonance(EPR)proves that the presence of Ni O enhances the generation of·H,which can be rapidly consumed during nitrate reduction process.Density functional theory(DFT)calculations indicate that the activation energy of Ni O(0.57 eV)is much lower than Cu(0.84 e V)for water splitting to generate·H,thus facilitating*NO hydrogenations.This drives us to create more effective catalysts for nitrate reduction under neutral conditions by promoting H2O dissociation.
基金financially supported by the National Key R&D Program of China(No.2021YFA1502803)the National Natural Science Foundation of China(Nos.22325405,22372160,22432005 and 22321002)Dalian Science and Technology Talent Innovation Program(No.2024RG009).
文摘As a highly reactive reaction intermediate,surface gallium hydride(Ga–H)has garnered significant attention due to its critical role in various catalytic reactions.However,the detailed experimental characterization of this unique species remains challenging.Recently,we have demonstrated that solid-state NMR can be an effective tool for studying surface Ga–H.In this work,we report a comparative solid-state NMR study on H_(2) activation over different Ga_(2)O_(3) polymorphs,specificallyα-,β-andγ-Ga_(2)O_(3).^(1)H solid-state NMR enabled the identification of Ga–H species formed on all the three samples following high-temperature H_(2) treatment.The characteristic ^(1)H NMR signals of Ga–H species are resolved using J-coupling-based double-resonance NMR methods,revealing highly similar lineshapes of Ga–H for all the Ga_(2)O_(3) samples.This suggests potentially similar surface Ga–H configurations among different Ga_(2)O_(3) polymorphs.In addition,the local hydrogen environments on the oxide surfaces are further explored using two-dimensional(2D)^(1)H–^(1)H homonuclear correlation spectra,revealing multiple spatially proximate Ga–H and Ga–H/–OH pairs on different Ga_(2)O_(3) polymorphs.These findings provide insights into the potential mechanism of H_(2) dissociation.Overall,this work offers new perspectives on the local structure of surface Ga–H on Ga_(2)O_(3),and the analytical approach presented here can be further extended to the study of other Ga-based catalysts and other metal hydride species.
基金supported by the National Key R&D Program of China(No.2023YFC2907701)This work was also supported by the Fundamental Research Program of Shanxi Province,China(No.202103021223045)+4 种基金the Shanxi Scholarship Council of China(No.2022-062)the Scientific and Technological Innovation Programs of Higher Education Institutions in Shanxi,China(No.2021L064)This study was also funded by Open Foundation of State Key Laboratory of Mineral Processing(No.BGRIMM-KJSKL-2025-26)This work was supported by the National Natural Science Foundation of China(No.52104260)This work was supported by Young Elite Scientists Sponsorship Program by CAST(No.2022QNRC001).
文摘Extracting lithium from coal measures can alleviate the shortage of strategic metal resources.However,the lattice substitution characteristics of lithium in carrier minerals and its extremely fine intercalation and entrainment behavior are the challenges that constrain the extraction efficiency of lithium from coal series.This study focuses on improving the separation efficiency between lithium-contain-ing minerals and other minerals and the release behavior of lithium in the liquid phase.First,the feasibility of extracting lithium from car-rier minerals is confirmed based on the occurrence state and the process mineralogy characterized by Bgrimm process mineralogy analyz-ing system(BPMA)and time of flight secondary ion mass spectrometry(TOF-SIMS).The optimal selective grinding behavior is achieved within 15 min,allowing Li carrier minerals,including chlorite,kaolinite,and halloysite,to deliver the best dispersion effect with other minerals.Thus,the enriched lithium carrier minerals have been preenriched through screening.The leaching efficiency of Li has reached 97.43%under 1 mol/L hydrochloric acid,15 g/L pulp density,70℃,and 20 min.Leaching kinetics studies indicate that the de-crease in apparent energy validates the impact of grinding on metal leaching,aligning with the rate-controlling step of a chemical reaction.The process proposed in this study achieves the coordinated control of size and components in coal gangue and actualizes the effective se-lective enrichment of lithium through its low energy consumption and environmentally friendly nature.
基金supported by the National Natural Science Foundation of China(Grant No.51939011)the Science and Technology Program of CNOOC Research Institute(Grant No.2023OTKK03)supported by the program of the Youth Innovation Promotion Association,Chinese Academy of Sciences(Grant No.2020326).
文摘Shear strength of hydrate-bearing sediment is an essential parameter for assessing landslide potential ofhydrate reservoirs under exploration conditions. However, the characteristics and simulation of thisshear strength under varying dissociation conditions have not been thoroughly investigated. To this end,a series of triaxial compression tests were first carried out on sediments with varying initial hydratesaturations along dissociation pathways. Combining measured data with microscale analysis, the underlyingmechanism for the evolution of shear strength in hydrate-bearing sediment was studied undervarying partial dissociation pathways. Moreover, a shear strength model for hydrate-bearing sedimentwas proposed, taking into account the hydrate saturation and the unhydrated water content. Apart fromthe parameters derived from the hydrate characteristic curve, only one additional model parameter isrequired. The proposed model was validated using measured data on hydrate sediments. The resultsindicate that the proposed model can effectively capture the shear strength behavior of hydrate-bearingsediment under varying dissociation paths. Finally, a sensitivity analysis of the model parameters wasconducted to characterize the proposed model.
基金supported by the National Key R&D Program of China(No.2023YFA1507800)the National Science Foundation of China(Nos.22121004,22122808,22478279,and 22108201)+1 种基金the Haihe Laboratory of Sustainable Chemical Trans-formations,the Program of Introducing Talents of Discipline to Uni-versities(No.BP0618007)the XPLORER PRIZE.
文摘Metal oxide catalysts are widely employed in propane dehydrogenation(PDH)for propylene synthesis,requiring sequential reduction-reaction-regeneration cycles.However,the eff ect of water present in the inlet gas or reactor on the catalytic per-formance of various metal oxides remains insuffi ciently understood.This study examines the infl uence of water on supported metal oxide catalysts,specifi cally CoO x/Al_(2)O_(3),VO x/Al_(2)O_(3),and an industrial analog CrO x/Al_(2)O_(3) catalyst.By combining titration experiments,in situ Fourier transform infrared spectroscopy,kinetic analysis,and isotopic techniques,we demon-strate that even trace amounts of water can markedly suppress PDH performance via dissociative adsorption on the oxide surface.Methanol pretreatment eff ectively scavenges adsorbed water,recovering Lewis acid-base sites and consequently restoring PDH activity.This work underscores the profound inhibitory role of trace water in PDH over metal oxide catalysts and illustrates the potential of methanol pretreatment as an effective strategy to mitigate this limitation.
