Prediction of Henry's constant in polymer solutions using PCOR equation of state coupled with an activity coefficient model

In this paper,the polymer chain of rotator(PCOR) equation of state(EOS) was used together with an EOS/G^E mixing rule(MHV1) and the Wilson's equation as an excess-Gibbs-energy model in the proposed approach to extend the capability and improve the accuracy of the PCOR EOS for predicting the Henry's constant of solutions containing polymers.The results of the proposed method compared with two equation of state(van der Waals and GC-Flory) and three activity coefficient models(UNIFAC,UNIFAC-FV and Entropic-FV) indicated that the PCOR EOS/Wilson's equation provided more accurate results.The interaction parameters of Wilson's equation were fitted with Henry's constant experimental data and the property parameters of PCOR,a and b,were fitted with experimental volume data(Tait equation).As a result,the present work provided a simple and useful model for prediction of Henry's constant for polymer solutions.

Correlation of the mean activity coefficient of aqueous electrolyte solutions using an equation of state

Accurate calculation of thermodynamic properties of electrolyte solution is essential in the design and optimization of many processes in chemical industries. A new electrolyte equation of state is developed for aqueous electrolyte solutions. The Carnahan-Starling repulsive model and an attractive term based on square-well potential are adopted to represent the short range interaction of ionic and molecular species in the new electrolyte EOS. The long range interaction of ionic species is expressed by a simplified version of Mean Spherical Approximation theory （MSA）. The new equation of state also contains a Born term for charging free energy of ions. Three adjustable parameters of new eEOS per each electrolyte solution are size parameter, square-well potential depth and square-well potential interaction range. The new eEOS is applied for correlation of mean activity coefficient and prediction of osmotic coefficient of various strong aqueous electrolyte solutions at 25℃ and 0.1 MPa. In addition, the extension of the new eEOS for correlation of mean activity coefficient and solution density of a few aqueous electrolytes at temperature range of 0 to 100℃ is carried out.

Ag3PO4 Microcrystals Synthesized by Room-Temperature Solid State Reaction:Enhanced Photocatalytic Activity and Photoelectronchemistry Performance

Ag3PO4 microcrystals with highly enhanced visible light photocatalytic activity are prepared by a facile and simple solid state reaction at room temperature. The composition, morphology and optical properties of the asprepared Ag3PO4 microcrystMs are characterized by x-ray diffraction, scanning electron microscopy and UV-vis diffuse reflectance spectra. The photocatalytie properties of Ag3PO4 are investigated by the degradation of both methylene blue and methyl orange dyes under visible light irradiation. The as-prepared Ag3PO4 microcrystals possess high photocatalytic oxygen production with the rate of 673μmolh-1g-1. Moreover, the as-prepared Ag3PO4 microcrystals show an enhanced photoelectrochemistry performance under irradiation of visible light.

Research on the Relationship Between Learning Motivation and Neural Activity in the Learning Process of Instructional Video:A NIRS Study

As the intrinsic driving force to promote learner’s learning,learning motivation is one of the key factors that affect learning engagement and efficiency.In terms of optimizing instructional videos and strengthening learning effects,it is particularly important to understand the cognitive neural mechanism and influencing factors of the changes of learning motivation.By using the near-infrared spectrometer technology,the paper has collected the state of neural activity while learners were learning different instructional videos,and has analyzed the relationship between the learning motivation of instructional videos and the state of neural activity in the learning process from the angle of cognitive neuroscience.It is found that both the intrinsic and extrinsic learning motivation of instructional videos will affect the state of neural activity in the learning process;the learning process will also affect the intensity of learning motivation,while the preparation of fine instructional videos will also cause the transfer of learning motivation.

H_∞ drift control of time-delayed seismic structures

In this paper, an optimal H∞ control algorithm was applied to the design of an active tendon system installed at the first story of a multi-story building to reduce its interstory drift due to earthquake excitations. To achieve optimal control performance and to guarantee the stability of the control system, an optimum strategy to select control parameters γ and α was developed. Analytical expressions of the upper and the lower bounds of γ and α were obtained for a single degree-of-freedom system with state feedback control. The selection ranges for both γ and α are graphically defined so that the controlled system is always stable and the control performance is better than by the conventional LQR control algorithm. Numerical results from a controlled three-story building under real earthquake excitations demonstrate that the peak first interstory drift can be significantly reduced with maximum control force around 10% of the building weight. An optimum design flow chart was provided. In addition, for a time-delayed structure, this study gave explicit formulae to calculate the critical values of γ and a. The system stability and control performance can thus be guaranteed even with time delay.

Relationship between ESIPT properties and antioxidant activities of 5-hydroxyflavone derivates

It is of great significance to study the relationship between the excited state intramolecular proton transfer(ESIPT)properties and antioxidant activities of compounds in the field of life sciences.In this work,two novel compounds 5HF-OMe and 5HF-NH2 are designed through introducing a methoxy-and amino-group into the structure of 5-hydroxyflavone(5HF)respectively.The relationship between the ESIPT reaction and antioxidant activities of the three compounds is studied via the density functional theory(DFT)and time-dependent DFT(TD-DFT)methods.The calculated potential energy curves suggest that the rate of ESIPT reaction will gradually slow down from 5HF to 5HF-OMe and 5HF-NH2.In addition,the antioxidant activities of the three compounds gradually enhance from 5HF to 5HF-OMe and 5HF-NH2,which can be seen from the calculated energy gaps and ionization potential values.Interestingly,the above results imply that the rate of ESIPT reaction has a negative relationship with the antioxidant activities of the compounds,i.e.,the slower rate of ESIPT reaction will reflect the higher antioxidant activity of the compound,which will provide valuable reference for detecting the antioxidant activity of compound via the photophysical method.

Influence of Pressure and Discharge Voltage on Spectral Intensities in a Pulsed Nitrogen Discharge Supersonic Free-Jet

The effects of the pressure and discharge voltage on the spectral intensities of the second positive and first negative systems were studied in a pulsed nitrogen discharge supersonic flee-jet. The results show that a stabilized discharge condition was reached when the vacuum chamber pressure increased to 100 Pa. Both N2（C^3∏u） and N＋（B^2∑u^＋） states were highly populated at a pressure of 100 Pa to 130 Pa. The active state N2（C^3∏u）could be selectively populated at a low pressure of 10 Pa and a discharge voltage of 4500 V. Different populating mechanisms under the experimental conditions for N2（C^3∏u） and N＋（B^2∑u^＋） states were proposed to account for the experimental results.

New protocols for non-orthogonal quantum key distribution

Combining the passive decoy-state idea with the active decoy-state idea, a non-orthogonal （SARG04） decoy-state protocol with one vacuum and two weak decoy states is introduced based on a heralded pair coherent state photon source for quantum key distribution. Two special cases of this protocol are deduced, i.e., a one-vacuum-and-one-weak-decoy-state protocol and a one-weak-decoy-state protocol. In these protocols, the sender prepares decoy states actively, which avoids the crude estimation of parameters in the SARG04 passive decoy-state method. With the passive decoy-state idea, the detection events on Bob＇s side that are non-triggered on Alice＇s side are not discarded, but used to estimate the fractions of single-photon and two-photon pulses, which offsets the limitation of the detector＇s low efficiency and overcomes the shortcoming that the performance of the active decoy-state protocol critically depends on the efficiency of detector. The simulation results show that the combination of the active and passive decoy-state ideas increases the key generation rate. With a one-vacuum-and-two-weak-decoy-state protocol, one can achieve a key generation rate that is close to the theoretical limit of an infinite decoy-state protocol. The performance of the other two protocols is a little less than with the former, but the implementation is easier. Under the same condition of implementation, higher key rates can be obtained with our protocols than with existing methods.

Theoretical Study on the C-H Activation in Decarbonylation of Acetaldehyde by NiL_2(L=SO_3CH_3) Using Density Functional Theory

Density functional theory calculations were carried out to explore the potential energy surface（PES） associated with the gas-phase reaction of Ni L2（L=SO3CH3） with acetone. The geometries and energies of the reactants, intermediates, products and transition states of the triplet ground potential energy surfaces of [Ni, O, C2, H4] were obtained at the B3LYP/6-311＋＋G（d,p） levels in C,H,O atoms and B3LYP/ Lanl2 dz in Ni atom. It was found through our calculations that the decabonylation of acetaldehyde contains four steps including encounter complexation, C-C activation, aldehyde H-shift and nonreactive dissociation. The results revealed that C-C activation induced by Ni L2（L=SO3CH3） led to the decarbonylation of acetaldehyde.

Online Observability-Constrained Motion Suggestion via Efficient Motion Primitive-Based Observability Analysis

An active perception methodology is proposed to locally predict the observability condition in a reasonable horizon and suggest an observability-constrained motion direction for the next step to ensure an accurate and consistent state estimation performance of vision-based navigation systems. The methodology leverages an efficient EOG-based observability analysis and a motion primitive-based path sampling technique to realize the local observability prediction with a real-time performance. The observability conditions of potential motion trajectories are evaluated,and an informed motion direction is selected to ensure the observability efficiency for the state estimation system. The proposed approach is specialized to a representative optimizationbased monocular vision-based state estimation formulation and demonstrated through simulation and experiments to evaluate the ability of estimation degradation prediction and efficacy of motion direction suggestion.

Defining activation states of microglia in human brain tissue: an unresolved issue for Alzheimer's disease

The development of concepts concerning the role of microglia in different brain diseases has relied on studies of animal models or human brain tissue,which primarily use antibodies and immunohistochemistry techniques to make observations.Since initial studies defined increased expression of the major histocompatibility complexⅡprotein human leukocyte antigen-DR as a means of identifying reactive,and therefore by implication,damage-causing microglia in Alzheimer's disease(AD)or Parkinson's disease(PD),understanding and describing their activation states has evolved to an unexpected complexity.It is still difficult to ascertain the specific functions of individual microglia,particularly those associated with pathological structures,using a narrow range of antigenic markers.As many approaches to developing treatments for AD or PD are focused on anti-inflammatory strategies,a more refined understanding of microglial function is needed.In recent years,gene expression studies of human and rodent microglia have attempted to add clarity to the issue by sub-classification of messenger RNA expression of cell-sorted microglia to identify disease-associated profiles from homeostatic functions.Ultimately all newly identified markers will need to be studied in situ in human brain tissue.This review will consider the gaps in knowledge between using traditional immunohistochemistry approaches with small groups of markers that can be defined with antibodies,and the findings from cell-sorted and single-cell RNA sequencing transcription profiles.There have been three approaches to studying microglia in tissue samples:using antigenic markers identified from studies of peripheral macrophages,studying proteins associated with altered genetic risk factors for disease,and studying microglial proteins identified from mRNA expression analyses from cell-sorting and gene profiling.The technical aspects of studying microglia in human brain samples,inherent issues of working with antibodies,and findings of a range of different functional microglial markers will be reviewed.In particular,we will consider markers of microglia with expression profiles that do not definitively fall into the pro-inflammatory or anti-inflammatory classification.These additional markers include triggering receptor expressed on myeloid cells-2,CD33 and progranulin,identified from genetic findings,colony stimulating factor-1 receptor,purinergic receptor P2RY12,CD68 and Toll-like receptors.Further directions will be considered for addressing crucial issues.

Altered relationship between thickness and intrinsic activity amplitude in generalized tonic–clonic seizures

A thinner cortex has higher potential for binding GABA receptor A which is associated with larger amplitudes of intrinsic brain activity(i BA). However, the relationship between cortical thickness and i BA is unknown in intact and epileptic brains. To this end, we investigated the relationship between cortical thickness measured by highresolution MRI and surface-based i BA derived from resting-state functional MRI in normal controls(n = 82) andpatients with generalized tonic–clonic seizures(GTCS)only(n = 82). We demonstrated that the spatial distribution of cortical thickness negatively correlated with surface-based i BA amplitude at both whole-brain and within independent brain functional networks. In GTCS patients,spatial coupling between thickness and i BA amplitude decreased in the default mode, dorsal attention, and somatomotor networks. In addition, the vertex-wise acrosssubject thickness–i BA amplitude correspondence altered in the frontal and temporal lobes as well as in the precuneus in GTCS patients. The relationship between these two modalities can serve as a brain-based marker for detecting epileptogenic changes.

Biochemical and microbial soil functioning after application of the insecticide imidacloprid

Imidacloprid is one of the most commonly used insecticides in agricultural practice, and its application poses a potential risk for soil microorganisms. The objective of this study was to assess whether changes in the structure of the soil microbial community after imidacloprid application at the field rate（FR, 1 mg/kg soil） and 10 times the FR（10 × FR, 10 mg/kg soil）may also have an impact on biochemical and microbial soil functioning. The obtained data showed a negative effect by imidacloprid applied at the FR dosage for substrate-induced respiration（SIR）, the number of total bacteria, dehydrogenase（DHA）, both phosphatases（PHOS-H and PHOS-OH）, and urease（URE） at the beginning of the experiment. In 10 × FR treated soil, decreased activity of SIR, DHA, PHOS-OH and PHOS-H was observed over the experimental period. Nitrifying and N2-fixing bacteria were the most sensitive to imidacloprid. The concentration of NO3-decreased in both imidacloprid-treated soils,whereas the concentration of NH4＋in soil with 10 × FR was higher than in the control.Analysis of the bacterial growth strategy revealed that imidacloprid affected the r- or K-type bacterial classes as indicated also by the decreased eco-physiological（EP） index.Imidacloprid affected the physiological state of culturable bacteria and caused a reduction in the rate of colony formation as well as a prolonged time for growth. Principal component analysis showed that imidacloprid application significantly shifted the measured parameters, and the application of imidacloprid may pose a potential risk to the biochemical and microbial activity of soils.

Activation in the initial stage of oxygen permeation in SrCo_(0.9)Ta_(0.1)O_(3-δ)

Mixed conducting perovskite oxide SrCo_（0.9）Ta_（0.1）O_（3-δ）（SCT） is synthesized by solid-state reaction method.The activation in the initial stage of oxygen permeation through the SCT membrane is investigated.The results show that the activation in the initial stage of oxygen permeation has activate-memory,the first activation can only help to reduce active time of the next cycles,but it is helpless to increase the final oxygen permeation flux.XRD characterization shows that the imperfect perovskite phase structure is gradually improved and the crystal lattice has made some self-adjustment under the permeation conditions,therefore,the oxygen permeation flux of SCT disk membrane increases gradually and till it reaches a steady state.