Deciphering TADF Mechanisms in Metal-Free Organic Emitters BrA-HBI:Utilizing Optimally Tuned Range-Separated Functionals for Insight

Metal-free organic emitters,characterized by their thermally activated delayed fluorescence(TADF)properties,offer considerable promise for the creation of highly efficient organic light-emitting diodes(OLEDs).Recently,Shao et al.presented a novel excited state intramolecular proton transfer(ESIPT)system BrA-HBI,demonstrating an emission quantum yield of up to 50%[Adv.Funct.Mater.32,2201256(2022)].However,many open issues cannot be answered solely by experimental means only and require detailed theoretical investigations.For instance,what causes the activation of TADF from the Keto^(*) tautomer and leads to fluorescence quenching in the Enol^(*)form?Herein,we provide a theoretical investigation on the TADF mechanism of the BrA-HBI molecule by optimally tuned range-separated functionals.Our findings reveal that ESIPT occurs in the BrA-HBI molecule.Moreover,we have disclosed the reason for the fluorescence quenching of the Enol^(*)form and determined that the T_(2)state plays a dominant role in the TADF phenomenon.In addition,double hybrid density functionals method was utilized to verify the reliability of optimally tuned range separation functionals on the calculation of the TADF mechanism in BrA-HBI.These findings not only provide a theoretical reference for development of highly efficient organic light-emitting diodes,but also demonstrate the effectiveness of the optimally tuned range-separated functionals in predicting the luminescence properties of TADF molecules.

Separate-layer balanced waterflooding development technology for thick and complex carbonate reservoirs in the Middle East

Based on the waterflooding development in carbonate reservoirs in the Middle East,in order to solve the problem of the poor development effects caused by commingled injection and production,taking the thick bioclastic limestone reservoirs of Cretaceous in Iran-Iraq as an example,this paper proposes a balanced waterflooding development technology for thick and complex carbonate reservoirs.This technology includes the fine division of development units by concealed baffles and barriers,the combination of multi well type and multi well pattern,and the construction of balanced water injection and recovery system.Thick carbonate reservoirs in Iran-Iraq are characterized by extremely vertical heterogeneity,development of multi-genesis ultra-high permeability zones,and highly concealed baffles and barriers.Based on the technologies of identification,characterization,and sealing evaluation for concealed baffles and barriers,the balanced waterflooding development technology is proposed,and three types of balanced waterflooding development modes/techniques are formed,namely,conventional stratigraphic framework,fine stratigraphic framework,and deepened stratigraphic framework.Numerical simulations show that this technology is able to realize a fine and efficient waterflooding development to recover,in a balanced manner,the reserves of thick and complex carbonate reservoirs in Iran and Iraq.The proposed technology provides a reference for the development optimization of similar reservoirs.

Optimization of Finned-Tube Heat Exchanger in a Gravity-Assisted Separated Heat Pipe

Finned-tube heat exchanger(FTHE)is often used as an evaporator in commercial products of separated heat pipe(SHP).The working conditions of FTHE in gravity-assisted SHP are significantly different from those working in refrigerators and air conditioners.Although FTHE is widely used in commercial products of SHP,previous research on its characteristics is very limited.In this paper,a mathematical model for a SHP with FTHE as the evaporator and plate heat exchanger as the condenser is established and verified with experiments.Parametric analyses are carried out to investigate the influences of evaporator design parameters:air inlet velocity,number of tube rows,tube diameter,and fin pitch.With the increasing of air velocity,number of tube rows and tube diameter,and the decreasing of fin pitch,the heat transfer rate increases,while the energy efficiency ratio(EER)decreases monotonically.Using the total cost of the ten-year life cycle as the performance index,the structure parameters of the evaporator with a given heat transfer rate are optimized by the method of orthogonal experimental design.It is found that the total cost can differ as large as nearly ten times between groups.Among the three factors investigated,the number of tube rows has a significant impact on the total cost of the evaporator.With more tube rows,the total cost will be less.The impacts of fin pitch and tube diameter are insignificant.These results are of practical importance for the engineering design of FTHE in gravity-assisted SHP.

Pharmacodynamic Experiment of Dachengqi Decoction and Separated Decoction on Incomplete Intestinal Obstruction in Rats

[Objectives]To investigate the effect and mechanism of Dachengqi Decoction and separated decoction on incomplete intestinal obstruction in rats.[Methods]80 healthy SD rats were selected to establish incomplete intestinal obstruction model by silk ligation.The dosage was 20 mL/kg for 3 d,and the damage index of ileocecal mucosa was analyzed;the morphology of ileocecal mucosa was observed by HE staining;the serum levels of IL-1α,IL-1β,IL-6,IL-18,Ach,NO,ET,IL-1,TNF-αand ultra-micro Na+-K+-ATPase were detected by ELISA.[Results]Compared with the model group,the mucosal damage index of Dachengqi Decoction and each separated decoction group decreased significantly(P<0.05);compared with the normal group and sham operation group,the serum level of IL-1,IL-6,TNF-αand other factors in the model group increased significantly(P<0.05);compared with the model group,the serum IL-1,IL-6 and TNF-αsecretion levels of rats in Dachengqi Decoction group and separated decoction group decreased(P<0.01).[Conclusions]Dachengqi Decoction and each separated decoction can effectively improve intestinal tissue pathological damage in the incomplete intestinal obstruction model rats,and reduce the inflammatory reaction in the rat body.

Separate支架在治疗胃十二指肠恶性梗阻中的应用

目的 探讨Separate支架置入术在姑息性治疗不能手术的胃肠道恶性梗阻的可行性和有效性。方法 34例患者采用经口置入Separate支架治疗不能手术的恶性胃十二指肠梗阻。梗阻的原因分别是胃癌 1 1例、胰腺癌 1 2例、转移性肿瘤 3例、胆道肿瘤 6例和十二指肠癌 2例。透视下分别将Separate支架的外层带膜支架和内层裸支架同轴重叠释放在狭窄病变处。结果 技术成功率为 97% ,未发生严重并发症。 33例患者胃肠道梗阻症状缓解或消失 ,在Separate支架置入后 ,患者进食能力评分平均从 3.8提高到 1 .2。随访期间未发现支架移位和肿瘤内生性生长等并发症 ,1例患者由于肿瘤浸润致支架近端梗阻复发 ,置入第 2枚支架。

Deep eutectic solvents for separation and purification applications in critical metal metallurgy:Recent advances and perspectives

Solvent extraction,a separation and purification technology,is crucial in critical metal metallurgy.Organic solvents commonly used in solvent extraction exhibit disadvantages,such as high volatility,high toxicity,and flammability,causing a spectrum of hazards to human health and environmental safety.Neoteric solvents have been recognized as potential alternatives to these harmful organic solvents.In the past two decades,several neoteric solvents have been proposed,including ionic liquids(ILs)and deep eutectic solvents(DESs).DESs have gradually become the focus of green solvents owing to several advantages,namely,low toxicity,degradability,and low cost.In this critical review,their classification,formation mechanisms,preparation methods,characterization technologies,and special physicochemical properties based on the most recent advancements in research have been systematically described.Subsequently,the major separation and purification applications of DESs in critical metal metallurgy were comprehensively summarized.Finally,future opportunities and challenges of DESs were explored in the current research area.In conclusion,this review provides valuable insights for improving our overall understanding of DESs,and it holds important potential for expanding separation and purification applications in critical metal metallurgy.

Structure identification for compound I separated and purified from taxoids-produced endophytic fungi (Alternaria. alternata var. taxi 1011)

Endophytic fungi are widely found in almost all kinds of plants. Many endophytic fungi can produce some physio-logical active compounds, which are same to or analog to those isolated from their hosts. Producing physiological active com-pounds through microbial fermentation can give a new way to resolve resource limitation and to find out alternative source. Through the methods of organic solvent extraction, thin layer chromatography (TLC) and column chromatography, compound I was isolated, purified from the liquid fermentation metabolites of the taxoids-produced endophytic fungi (Alternaria. alternata var. taxi 1011 Y. Xiang et LU An-guo) that was screened from the bark of Taxus. cuspidata Sieb.et Zucc.. Compound I was identified as one kind of taxoids type III, based on the analyzing results by using the methods of ultraviolet spectroscopy (UV), infrared spectroscopy (IR), mass spectrometry (MS) and nuclear magnetic resonance spectroscopy (NMR). This study provides a com-pleted method for separation and purification of the endophytic fungi as well as structure identification of its fermentation me-tabolite

强磁场条件下的spatial separated D^-心

采用 Mac Donld的对角化法研究了强磁场条件下 D-s 心的束缚态和多电子效应 .发现D-s 心有 L=0 ,-1 ,-2 ,-3 ,-4五个束缚态 ,且随着电子与 D0 心之间距离ξ值的增大 ,其束缚能存在一极大值 .并利用无规相近似讨论了长波极限 D-s 心的多电子效应 ,发现 D-s 心的本征能量随朗道能级填充因子作周期性振荡 ,且随着温度的降低振荡加剧 ;当填充因子为偶数时 ,其本征能量的绝对值最大 ,说明此时电子气对库仑势的屏蔽效应最弱 .

SEPARATED FRAMES

In this paper we shall offer a separation axiom for frames inspired by the Hausdorff separation axiom for topological spaces. We call it separated condition. This is a condition on topology OX equivalent to the T O space X being Hausdorff. The class of separated frames includes that of strong Hausdorff frames and that of S frames. We shall show that the class of separated frames is a class closed under the formation of coproducts and subspaces, and the space Fil( L ) is Hausdorff for any separated frame L . Therefore there is a contravariant adjunction between the category TOP 2 of Hausdorff topological spaces and the category FRAM 2 of separated frames.

一个改进的Separate算法及其应用

关联规则的挖掘是一个重要的数据挖掘问题,在关联规则的挖掘过程中加入约束条件,是实现用户参与挖掘的一种方式,这样得到的规则是用户所真正关心的,而Separate算法便是这类算法的代表.先对Separate算法进行了改进,从而进一步提高其性能,然后用改进后的算法挖掘实际应用中的一个实例,最后对挖掘结果给出相关决策解释.

Exchange Bias Effect in Phase Separated La0.33Pr0.34Ca0.33MnO3 Thin Films

Exchange bias effect is observed in the phase separated La0.33Pr0.34Ca0.33MnO3 thin films. High exchange bias field of about 1 kOe is achieved at 4 K. The exchange bias effect in La0.33Pr0.34Ca0.33MnO3 thin films might originate from the intrinsic phase separation of the La0.33Pr0.34Ca0.33MnO3 or surface effect. The dependence of exchange bias effect on temperature, cooling field, and thickness is also investigated. This work would open an avenue to the application in the magnetic memory devices based on the phase separated manganites.

A continuous and high-efficiency process to separate coal bed methane with porous ZIF-8 slurry:Experimental study and mathematical modelling

Coal bed methane has been considered as an important energy resource.One major difficulty of purifying coal bed methane comes from the similar physical properties of CH_4 and N_2.The ZIF-8/water-glycol slurry was used as a medium to separate coal bed methane by fluidifying the solid adsorbent material.The sorption equilibrium experiment of binary mixture(CH_4/N_2)and slurry was conducted.The selectivity of CH_4 to N_2 is within the range of 2-6,which proved the feasibility of the slurry separation method.The modified Langmuir equation was used to describe the gas-slurry phase equilibrium behavior,and the calculated results were in good agreement with the experimental data.A continuous absorption-adsorption and desorption process on the separation of CH_4/N_2 in slurry is proposed and its mathematical model is also developed.Sensitivity analysis is conducted to determine the operation conditions and the energy performance of the proposed process was also evaluated.Feed gas contains 30 mol%of methane and the methane concentration in product gas is 95.46 mol%with the methane recovery ratio of 90.74%.The total energy consumption for per unit volume of product gas is determined as 1.846 kWh Nm^(-3).Experimental results and process simulation provide basic data for the design and operation of pilot and industrial plant.

Comparative assessment of SAS and DES turbulence modeling for massively separated flows

Numerical studies of the flow past a circular cylinder at Reynolds number 1.4 × 105 and NACA0021 airfoil at the angle of attack 60° have been carried out by scale-adaptive simulation （SAS） and detached eddy simu- lation （DES）, in comparison with the existing experimental data. The new version of the model developed by Egorov and Menter is assessed, and advantages and disadvantages of the SAS simulation are analyzed in detail to provide guidance for industrial application in the future. Moreover, the mechanism of the scale-adaptive characteristics in separated regions is discussed, which is obscure in previous analyses. It is con- cluded that： the mean flow properties satisfactorily agree with the experimental results for the SAS simulation, although the prediction of the second order turbulent statistics in the near wake region is just reasonable. The SAS model can produce a larger magnitude of the turbulent kinetic energy in the recir- culation bubble, and, consequently, a smaller recirculation region and a more rapid recovery of the mean velocity out- side the recirculation region than the DES approach with the same grid resolution. The vortex shedding is slightly less irregular with the SAS model than with the DES approach, probably due to the higher dissipation of the SAS simulation under the condition of the coarse mesh.

Optimal design of the separate type heat pipe heat exchanger

Separate type heat pipe heat exchangers are often used for large-scale heat exchanging. The arrangement of such a heat exchanger conveniently allows heat input to and output from the heat exchanger at remote locations. The traditional method of designing an ordinary HPHE (heat pipe heat exchanger) is commonly applied in the separate type exchanger design, but the calculations have to be carried out separately, which makes it very complicated. In this work, the ε-NTU (effectiveness-Number of Transfer Units) method was applied for optimization analysis of single- or multi-level separate type heat pipe heat exchangers. An optimizing formula for single-level separate type heat pipe heat exchangers was obtained. The optimizing principles of effec- tiveness-NTU and heat transfer rate by the equal distribution method for multi-level separate type heat pipe heat exchanger are presented. The design of separate type heat pipe heat exchangers by the optimizing method is more convenient and faster than by the traditional method.

Solving mKdV-sinh-Gordon equation by a modified variable separated ordinary differential equation method

By introducing a more general auxiliary ordinary differential equation （ODE）, a modified variable separated ODE method is developed for solving the mKdV-sinh-Gordon equation. As a result, many explicit and exact solutions including some new formal solutions are successfully picked up for the mKdV-sinh-Gordon equation by this approach.

Research on data assimilation strategy of turbulent separated flow over airfoil

In order to increase the accuracy of turbulence field reconstruction,this paper combines experimental observation and numerical simulation to develop and establish a data assimilation framework,and apply it to the study of S809 low-speed and high-angle airfoil flow.The method is based on the ensemble transform Kalman filter(ETKF)algorithm,which improves the disturbance strategy of the ensemble members and enhances the richness of the initial members by screening high flow field sensitivity constants,increasing the constant disturbance dimensions and designing a fine disturbance interval.The results show that the pressure distribution on the airfoil surface after assimilation is closer to the experimental value than that of the standard Spalart-Allmaras(S-A)model.The separated vortex estimated by filtering is fuller,and the eddy viscosity field information is more abundant,which is physically consistent with the observation information.Therefore,the data assimilation method based on the improved ensemble strategy can more accurately and effectively describe complex turbulence phenomena.

SYNTHESIS AND CHARACTERIZATION OF AMPHIPHILIC GRAFT COPOLYMER CONTAINING MICROPHASE SEPARATED AND LONG POLY(ETHYLENE OXIDE) SIDE CHAIN STRUCTURES

Acryloyl terminated Poly (ethyleneoxide)macromonomers (PEO-A) with different PEO chain lengths have been prepared by deactivation of PEO alkoxide with acryloyl chloride. A new kind of amphiphilic polystyrene-g-poly (ethylene oxide)graft copolymer containing both microphase separated and PEO side chain structures has been synthesized from radical copolymerization of PEO-A macromonomer with styrene. After careful purification by a newly-developed method called 'selective dissolution', the well-defined structure of the purified copolymers was confirmed by IR, ~1H-NMR and GPC. Various experimental parameters controlling the copolymerization were studied in detail. The results indicated that the feed ratio of styrene to macromonomer(S/M) was the most important determining factor for the composition of the copolymers. A detailed 'comb- model' was proposed to describe the molecular structure of the graft copolymers. Finally, this amphiphilic graft copolymers may readily form microphase separated structures as clearly indicated by transmission electron microscopy.

Maneuvering target state estimation based on separate model-ing of target trajectory shape and dynamic characteristics

The state estimation of a maneuvering target,of which the trajectory shape is independent on dynamic characteristics,is studied.The conventional motion models in Cartesian coordinates imply that the trajectory of a target is completely determined by its dynamic characteristics.However,this is not true in the applications of road-target,sea-route-target or flight route-target tracking,where target trajectory shape is uncoupled with target velocity properties.In this paper,a new estimation algorithm based on separate modeling of target trajectory shape and dynamic characteristics is proposed.The trajectory of a target over a sliding window is described by a linear function of the arc length.To determine the unknown target trajectory,an augmented system is derived by denoting the unknown coefficients of the function as states in mileage coordinates.At every estimation cycle except the first one,the interaction(mixing)stage of the proposed algorithm starts from the latest estimated base state and a recalculated parameter vector,which is determined by the least squares(LS).Numerical experiments are conducted to assess the performance of the proposed algorithm.Simulation results show that the proposed algorithm can achieve better performance than the conventional coupled model-based algorithms in the presence of target maneuvers.

T_2 Separation Subsets and T_2 Separateness in L-fuzzy Topological Spaces

The concept of α-CT2 separation L-fuzzy subsets in L-fuzzy topological spaces is presented by taking the stratiform structure of L-fuzzy subsets as the point of departure,and its basic characterizations and some topological properties are discussed,and the relation between it and other separateness is exposed,and the action is studied of α-CT2 separateness in N-compact spaces and N-paracompact spaces.

Applications of URANS on predicting unsteady turbulent separated flows

Accurate prediction of unsteady separated turbulent flows remains one of the toughest tasks and a practi cal challenge for turbulence modeling. In this paper, a 2D flow past a circular cylinder at Reynolds number 3,900 is numerically investigated by using the technique of unsteady RANS （URANS）. Some typical linear and nonlinear eddy viscosity turbulence models （LEVM and NLEVM） and a quadratic explicit algebraic stress model （EASM） are evaluated. Numerical results have shown that a high-performance cubic NLEVM, such as CLS, are superior to the others in simulating turbulent separated flows with unsteady vortex shedding.