Tannic acid/Fe^(3+)interlayer for preparation of high-permeability polyetherimide organic solvent nanofiltration membranes for organic solvent separation

Organic solvent nanofiltration(OSN)membranes have a great application prospect in organic solvent separation,but the development of OSN membranes is mainly restricted by trade-off between permeability and rejection rate.In this work,a TA/Fe^(3+)polymer was introduced into polyetherimide(PEI)ultrafiltration membranes crosslinked with hexamethylene diamine as the intermediate layer,and OSN membranes with high separation performance and solvent permeability were obtained through interfacial polymerization and solvent activation.The interlayer with high surface hydrophilicity and a fixed pore structure controlled the adsorption/diffusion of the amine monomer during interfacial polymerization,forming a smooth(average surface roughness<5.5 nm),ultra-thin(separation layer thickness reduced from 150 to 16 nm)and dense surface structure polyamide(PA)layer.The PA-Fe^(3+)_3-HDA/PEI membrane retained more than 94%of methyl blue(BS)in 0.1 g·L^(-1)BS ethanol solution at 0.6 MPa,and the ethanol permeation reached 28.56 L^(-1)·m^(-2)·h^(-1).The average flux recovery ratio(FRR)of PA-Fe^(3+)_(3)-HDA/PEI membrane was found to be 84%,which has better fouling resistance than PA-HDA/PEI membrane,and it was found to have better stability performance through different solvent immersion experiments and continuous operation in 0.1 g·L^(-1)BS ethanol solution.Compared with thin-film composite nanofiltration membranes,the PA-Fe^(3+)_(3)-HDA/PEI membrane can be manufactured from an economical and environment-friendly method and overcomes the trade-off between permeability and rejection rate,showing great application potential in organic solvent separation systems.

Bionic microchannels for step lifting transpiration

Those various cross-sectional vessels in trees transfer water to as high as 100 meters,but the traditional fabrication methods limit the manufacturing of those vessels,resulting in the non-availability of those bionic microchannels.Herein,we fabricate those bionic microchannels with various cross-sections by employing projection micro-stereolithography(PμSL)based 3D printing technique.The circumradius of bionic microchannels(pentagonal,square,triangle,and five-pointed star)can be as small as 100μm with precisely fabricated sharp corners.What's more,those bionic microchannels demonstrate marvelous microfluidic performance with strong precursor effects enabled by their sharp corners.Most significantly,those special properties of our bionic microchannels enable them outstanding step lifting performance to transport water to tens of millimeters,though the water can only be transported to at most 20 mm for a single bionic microchannel.The mimicked transpiration based on the step lifting of water from bionic microchannels is also achieved.Those precisely fabricated,low-cost,various cross-sectional bionic microchannels promise applications as microfluidic chips,long-distance unpowered water transportation,step lifting,mimicked transpiration,and so on.

Functional near-infrared spectroscopy in non-invasive neuromodulation

Non-invasive cerebral neuromodulation technologies are essential for the reorganization of cerebral neural networks,which have been widely applied in the field of central neurological diseases,such as stroke,Parkinson’s disease,and mental disorders.Although significant advances have been made in neuromodulation technologies,the identification of optimal neurostimulation paramete rs including the co rtical target,duration,and inhibition or excitation pattern is still limited due to the lack of guidance for neural circuits.Moreove r,the neural mechanism unde rlying neuromodulation for improved behavioral performance remains poorly understood.Recently,advancements in neuroimaging have provided insight into neuromodulation techniques.Functional near-infrared spectroscopy,as a novel non-invasive optical brain imaging method,can detect brain activity by measuring cerebral hemodynamics with the advantages of portability,high motion tole rance,and anti-electromagnetic interference.Coupling functional near-infra red spectroscopy with neuromodulation technologies offe rs an opportunity to monitor the cortical response,provide realtime feedbac k,and establish a closed-loop strategy integrating evaluation,feedbac k,and intervention for neurostimulation,which provides a theoretical basis for development of individualized precise neuro rehabilitation.We aimed to summarize the advantages of functional near-infra red spectroscopy and provide an ove rview of the current research on functional near-infrared spectroscopy in transcranial magnetic stimulation,transcranial electrical stimulation,neurofeedback,and braincomputer interfaces.Furthermore,the future perspectives and directions for the application of functional near-infrared spectroscopy in neuromodulation are summarized.In conclusion,functional near-infrared spectroscopy combined with neuromodulation may promote the optimization of central pellral reorganization to achieve better functional recovery form central nervous system diseases.

Some aspects of excellent marine source rock formation:implications on enrichment regularity of organic matter in continental margin basins

Through the analysis of ocean organisms, the distribution characteristics and enrichment of organic matters in modern marine sediments and ancient marine strata, this paper shows that the main factors influencing the formation of excellent marine source rocks are the paleoclimate, biologic productivity, terrestrial organic matter, oxidation–reduction environment, sedimentation rate, and the type of the basin. In addition to those factors,high biologic productivity or high content of terrestrial organic matter input is a requirement for the enrichment of the organic matter in a marine environment. Reducing environment was favorable for organic matter accumulation and preservation in depositing and early diagenesis stage, which is an important element for the formation of high-quality marine source rocks. Paleoclimate also influences the marine source rocks formation, as humid subtropical and tropical climates are the most favorable regimes for the formation of marine source rocks. Wind transports some vascular plant materials into the marine environment. Furthermore, upwellings driven by steady wind can cause high biologic productivity, thus formingorganic-C-rich mud. Suitable sedimentation rate is beneficial for marine organic matter accumulation. Moreover, the type of the basin also plays an important role in the development of marine source rocks. Silled basins with a positive water balance often act as nutrient traps, thus enhancing both productivity and organic matter preservations, while in open oceans, organic matter enrichment in sediments has just been found in the oxygen minimum layers.

Superb VOCs capture engineering carbon adsorbent derived from shaddock peel owning uncompromising thermal-stability and adsorption property

High applied thermal-stability and superior structural property for activated carbon adsorbent are extremely promising,which also is the determining short slab in volatile organic compounds(VOCs)adsorption applications.Herein,we develop the outstanding engineering carbon adsorbents from waste shaddock peel which affords greatly-enhanced thermal-stability and super structural property(S_(Lang)=4962.6 m2·g^(-1),Vmicro=1.67 cm^(3)·g^(-1)).Such character endows the obtained adsorbent with ultrahigh adsorption capture performance of VOCs specific to benzene(16.58 mmol·g^(-1))and toluene(15.50 mmol·g^(-1),far beyond traditional zeolite and activated carbon even MOFs materials.The structural expression characters were accurately correlated with excellent adsorption efficiency of VOCs by studying synthetic factor-controlling comparative samples.Ulteriorly,adsorption selectivity prediction at different relative humidity was demonstrated through DIH(difference of the isosteric heats),exceedingly highlighting great superiority(nearly sixfold)in selective adsorption of toluene compared to volatile benzene.Our findings provide the possibility for practical industrial application and fabrication of waste biomass-derived outstanding biochar adsorbent in the environmental treatment of threatening VOCs pollutants.

Application of eDNA Metabarcoding for Detecting Anura in North China

eDNA metabarcoding is an advanced method formonitoring biodiversityproposed in recent years.By analyzing DNA in water,soil and sediment samples,the technology obtains species distribution and population quantity information.It was found that macrobarcode technology is more accurate than the traditional method in measuring the species richness of some groups.In Europe,America and South America,the relia bility of this technology in monitoring amphibian diversity in the wild was studied,and it was found to be better than traditional biodiversity monitoring methods in detecting species diversity.At present,amphibian monitoring mainly depends on various traditional methods,such as transects,drift fence traps,artificial shelters and mark-recapture.These monitoring techniques have many shortcomings,such as low accuracy and strong subjectivity of study results.These technologies have poor effects on rare,invasive and endangered species with strong concealment ability,low density and strong seasonality and are difficult to implement in sites inaccessible to people.Traditional monitoring technology also requires considerable investment of human and material resources,and the economic cost is relatively high,while eDNA metabarcoding ismore efficient and less costly,so it is important to use eDNA meta barcoding in amphibian monitoring in China.In this study,the eDNA meta barcoding and traditional line transect method(TLTM)were used to study the characteristics of the two methods in the Beijing-Tianjin-Hebeiregion.Repeated samplingwas conducted on 58 waterbodies in July 2019 and June 2020.After sequencing the samples using highthroughput sequencing technology,the differences between metabarcoding and commonly used TLTM surveys in detecting the diversity of four amphibians in North China were assessed.Our results showed that eDNA meta barcoding is more sensitive to the detection of the four amphibian species in the sampling area,and the combined use of eDNA metabarcoding and TLTM can improve the survey results of amphibians in the survey area to the greatest extent.In addition,in the process of species classification and identification of metabarcoding results,7 species of reptiles were detected,indicating that eDNA metabarcoding is also useful to detect reptiles.The results of this study indicate that metabarcoding in combination with TLTM can accurately estimate the diversityof amphibians in a short-term survey in North China and is also useful in reptile species detection.

Research on Ruin Probability of Risk Model Based on AR(1)Time Series

The insurance industry typically exploits ruin theory on collected data to gain more profits.However,state-of-art approaches fail to consider the dependency of the intensity of claim numbers,resulting in the loss of accuracy.In this work,we establish a new risk model based on traditional AR(1)time series,and propose a fine-gained insurance model which has a dependent data structure.We leverage Newton iteration method to figure out the adjustment coefficient and evaluate the exponential upper bound of the ruin probability.We claim that our model significantly improves the precision of insurance model and explores an interesting direction for future research.

Isolation of a Microorganic Strain for the High Volume Degradation of Aniline Blue and Its Application in Natural Sewage Treatment

Aniline blue, one of the triphenylmethane dyes, is the most commonly produced and used of these dyes yet it is also the most dangerous and the most serious cause of pollution amongst them. An exploration of aniline blue degradation is likely to facilitate an understanding of the degradation mechanism for a range of related dyes. In this study, we managed to isolate a particular strain of microorganism, identified to be Lysinibacillus fusiformis N019a, which showed a significant capacity for aniline blue degradation in both laboratory tests and natural sewage treatment. In analysis aided by a UV-Visible spectrophotometer, we found that 96.7% of aniline blue had degraded within 24 hours under laboratory conditions. When treating natural sewage, 80.1% of the aniline blue was removed after just 16 hours. Further analysis has shown that Lysinibacillus fusiformis N019a has a strong resistance to Cu2+, Mn2+, Zn2+, and Pb2+. We also found that the degradation product of aniline blue by Lysinibacillus fusiformis N019a was of reduced toxicity to plants and microbes.

Screening and Application of Phthalic Acid Degrading Bacteria

O-phthalic acid is a kind of important pollutant, which accumulates in the environment with the extensive use of plastics and other products. Meanwhile, phthalic acid is one of the high content of allelopathic autotoxic substances secreted by tobacco. The accumulation of phthalic acid in soil is an important cause of tobacco continuous cropping effect. In order to degrade phthalic acid accumulated in environment, the barrier effect of tobacco continuous cropping caused by phthalic acid accumulation in soil can be removed. A strain capable of degrading phthalic acid was isolated from sludge of sewage treatment plant and compared with 16 s DNA. The homology between this strain and Enterobacter sp. is 99%. The optimum growth conditions are as follows: pH7 at 30°C, 500 mg/L of o-phthalic acid, inoculation concentration ≥ 1.2% and its highest degradation rate of o-phthalic acid is 74%. The results of pot experiment showed that the degradation efficiency of o-phthalic acid in soil was about 40%, which alleviated the inhibitory effect of o-phthalic acid accumulation on tobacco growth.

定容弹内柴油/丁醇混合燃料燃烧特性研究

In this paper,the spray and combustion characteristics of diesel/butanol-blended fuels were studied within a high-temperature and high-pressure constant volume chamber equipped with a single-hole injector.Two blends with 80%diesel/20%butanol and 60%diesel/40%butanol mixed by volume were tested in this study.The pure diesel B0 was also tested here as a reference.The spray penetration,flame lift-off length,and soot optical thickness were obtained through high-speed schlieren imaging,OH*chemiluminescence,and diffused back-illumination extinction imaging technique,respectively.The thermogravimetric curves of different fuels were obtained through a thermogravimetric analyzer.The results showed that butanol/diesel blends presented a longer ignition delay(ID)and flame lift-off length compared with pure diesel,and such finding was mainly caused by the lower cetane number and higher latent heat of vaporization of n-butanol.With the increase in the n-butanol ratio,soot production in the combustion process decreased significantly.Given the shorter ID period,the soot distribution of pure diesel reached a steady state earlier than the blends.

新型冠状病毒疫苗设计原理与研究进展

新型冠状病毒肺炎(COVID-19)已在全球范围内呈大流行趋势,为全球社会带来重大损失。其致病病原体新型冠状病毒(SARS-CoV-2)具有较强传染率和一定的致死率,为疾病治疗带来挑战。疫苗接种是预防传染病的重要手段,目前全球多家研究机构已经启动了新冠疫苗的研发工作。本文介绍了新冠疫苗研发的原理以及国内外最新的疫苗研究进展,希望有助于理解新冠疫苗的研发。

Study of limits to the rotation function in the SA-RC turbulence model

The Rotation and Curvature(RC)correction is an important turbulence model modifi-cation approach,and the Spalart-Allmaras model with the RC correction(SA-RC)has been exten-sively studied and used.As a multiplier of the modelling equation’s production term,the rotation function f_(r1)should have a cautiously designed value range,but its limit varies in different models and flow solvers.Therefore,the need of restriction is discussed theoretically,and the common range of f_(r1)is explored in Burgers vortexes.Afterwards,the SA-RC model with different limits is tested numerically.Negative f_(r1)always appears in the SA-RC model,and the difference between simula-tion results brought by the limits is not negligible.A lower limit of 0 enhances turbulence produc-tion,and therefore the vortex structures are dissipated faster and shrink in size,while an upper limit plays an opposite role.Considering that the lower limit of 0 usually promotes the simulation accu-racy and fixes the numerical defect,whereas the upper limit worsens the predictive performance in most cases,it is recommended to limit f_(r1)non-negative while utilizing the SA-RC model.In addi-tion,the RC-corrected model has a better prediction of the attached flow near curved walls,while the SA-Helicity model largely improves the simulation accuracy of three-dimensional large-scale vortices.The model combining both corrections has the potential to become more adaptive and more accurate.

Study on Optimizing Nutrition and Fermentation Conditions for Compound <i>Bacillus spp.</i>

In order to improve the spore yield of compound Bacillus spp. (B. amyloliquefaciens, B. laterosporus and B. megaterium), the effects of nutrient conditions including carbon source, nitrogen source, mineral salt and fermentation conditions including the inoculum age, inoculation amount, loading volume of liquid and initial pH on the spore yield were studied. The results indicated that the optimized medium was glucoses 20 g/L, soybean meal 30.0 g/L, K2HPO4 1.0 g/L;fermentation temperature is 37&#8451;, the inoculum age 12 h, initial pH 7.0, 2% inoculation amount, loading volume of liquid 20 mL/250 mL. Under the optimized conditions of culture medium and fermentation for compound Bacillus spp., spore yield was 10.24 times more than the initial medium, and the spore formation rate reached more than 90%.

Increase Data Characters to Construct the Molecular Phylogeny of the <i>Drosophila auraria</i>Species Complex

Previous phylogenetic analyses of the auraria species complex have led to conflicting hypotheses concerning their relationship;therefore the addition of new sequence data is necessary to discover the phylogeny of this species complex. Here we present new data derived from 22 genes to reconstruct the phylogeny of the auraria species complex. A variety of statistical tests, as well as maximum likelihood mapping analysis, were performed to estimate data quality, suggesting that all genes had a high degree of contribution to resolve the phylogeny. Individual locus was analyzed using maximum likelihood (ML), and the concatenated dataset (21,882 bp) were analyzed using partitioned maximum likelihood (ML) and Bayesian analyses. Separated analysis produced various phylogenetic relationships. Phylogenetic topologies from ML and Bayesian analysis based on concatenated dataset show that D. subauraria was well supported as the first species by separated analysis, concatenated dataset analysis, and some previous analysis, then followed by D. auraria and D. biauraria, D. quadraria and D. triauraria. The close relationships of D. quadraria and D. triauraria were consistent with most previous studies. The phylogenetic position of the D. auraria and D. biauraria will be resolved by more data sets.

Structure-Property Relationship of Conjugated Polymers Utilizing Isomerized Fused Benzothiadiazole-Based Building Blocks

Only a few fused benzothiadizole(BTz)based conjugated polymers have been applied in organic field-effect transistors(OFETs),and their performances were low,mainly due to the lack of available building blocks and in-depth study of the relationship between structure and performance.Herein,we report two isomeric fused BTz-based building blocks(M1 and M2)and their copolymers PBTzVBTz-T and PBTzVBTz-TT,PTVT-T and PTVT-TT.DFT study showed all polymers had nearly planar backbone geometries,and PBTzVBTz-TT exhibited the most linear backbone.PTVT-T and PTVT-TT exhibited red-shift absorption spectra and deeper LUMO level than those of PBTzVBTz-T and PBTzVBTz-TT.Thin film microstructure study demonstrated PBTzVBTz-TT and PTVT-TT had edge-on molecular orientation,while the others had the mixed molecular orientation of edge-on and face-on.Furthermore,PBTzVBTz-TT had the longest coherence length in thin film.All these features of PBTzVBTz-TT resulted in its highest carrier mobility of 0.1 cm^(2)·V^(–1)·s^(–1) among these polymers.

Interactivemedical image segmentation with self-adaptive confidence calibration

Interactive medical image segmentation based on human-in-the-loop machine learning is a novel paradigm that draws on human expert knowledge to assist medical image segmentation.However,existing methods often fall into what we call interactive misunderstanding,the essence of which is the dilemma in trading off short-and long-term interaction information.To better use the interaction information at various timescales,we propose an interactive segmentation framework,called interactive MEdical image segmentation with self-adaptive Confidence CAlibration(MECCA),which combines action-based confidence learning and multi-agent reinforcement learning.A novel confidence network is learned by predicting the alignment level of the action with short-term interaction information.A confidence-based reward-shaping mechanism is then proposed to explicitly incorporate confidence in the policy gradient calculation,thus directly correcting the model’s interactive misunderstanding.MECCA also enables user-friendly interactions by reducing the interaction intensity and difficulty via label generation and interaction guidance,respectively.Numerical experiments on different segmentation tasks show that MECCA can significantly improve short-and long-term interaction information utilization efficiency with remarkably fewer labeled samples.The demo video is available at https://bit.ly/mecca-demo-video.

Effect of substituents on self-assembling behaviors and charge transport properties of nonplanar heterocycloarenes

(Hetero)cycloarenes possessing rigid molecular skeletons and largeπ-systems are the potential active materials in various electronic devices.However,the development of their organic electronics still lags far behind the synthetic chemistry.Herein,in order to bridge this gap,we reported the study of organic semiconductor materials based on heterocycloarenes in detail about the relationship between structure,properties,and device performance.Three varying straight alkyl chain substituted butterflyshaped heterocycloarenes PTZs were strategically synthesized.Compared with bulky aryl(mesityl)substituted PTZ1,PTZs show additional self-assembly behavior.Concentration-dependent^(1)H NMR spectra indicated that the self-assembly behavior can be modulated by the alkyl chain length.Medium alkyl chain length substituted heterocycloarene PTZ-C6 showed the strongest association constants of 490 M^(–1)in solution,and a similar trend was also observed in solid state by thin film absorption spectra.Remarkably,despite the nonplanar conjugated backbones,solution-processing thin film transistor based on PTZ-C6 exhibits hole mobility up to 0.13 cm^(2)V^(–1)s^(–1)and considerable current on/off ratio of 10^(5).Our study demonstrates that substituent engineering of heterocycloarenes is a powerful strategy for modulating self-assembling structures and promoting transistor device performance.

Efficient and selective recovery of Gd(Ⅲ)via polyethyleneimine modification of lanthanum-based metal-organic frameworks

With the development of the economy and the increasing demand for environmental protection,the efficient and selective recovery of Gd(Ⅲ)from actual wastewater is of critical importance.In this work,lanthanum-based metal-organic framework(LaBDC)materials were prepared by a hydrothermal method,and then polyethyleneimine(PEI)and LaBDC were combined by an impregnation method to form a novel LaBDC@xPEI composite.The prepared materials were characterized using Fourier transfo rm infrared spectroscopy(FTIR),X-ray diffraction(XRD),scanning electron microscopy(SEM),energy dispersive X-ray spectroscopy(EDX),B runauer-Emmett-Teller(BET),thermogravimetric analysis(TGA)and X-ray photoelectron spectroscopy(XPS).Experiments show that LaBDC@50%PEI has the highest adsorption capacity(181.77 mg/g)among lanthanum-based MOFs with different PEI loadings at pH=5.5,which is about 5.1 times that of bare LaBDC.The adsorption isotherm analysis shows that LaBDC@50%PEI follows the Langmuir model.In addition,the adsorption kinetics of LaBDC@50%PEI follows a pseudo-second-order kinetic model,indicating that the adsorption process is chemical adsorption.It is worth noting that LaBDC@50%PEI maintains good adsorption performance and stability after three recycling tests,and exhibits excellent selectivity in cation interference experiments.Overall,the LaBDC@50%PEI composites possess good stability and hold great promises in rapid recovery of Gd(Ⅲ)from practical aqueous environments.

Ultrathin organic solvent nanofiltration membrane with polydopamine-HKUST-1 interlayer for organic solvent separation

Polydopamine(PDA)and metal-organic skeleton HKUST-1 were co-deposited on the base membrane of hexamethylenediamine(HDA)-crosslinked polyetherimide(PEI)ultrafiltration membrane as the interlayer,and high-throughput organic solvent nanofiltration membrane(OSN)was prepared by interfacial polymerization and solvent activation reaction.The polyamide(PA)layer surface roughness from 28.4 nm in PA/PEI to 78.3 nm in PA/PDA-HKUST-10.6/PEI membrane,reduced the thickness of the separation layer from 79 to 14 nm,and significantly improved the hydrophilic,thermal and mechanical properties.The flux of the PA/PDA-HKUST-10.6/PEI membrane in a 0.1 g/L Congo Red(CR)ethanol solution at 0.6 MPa test pressure reached 21.8 L/(m^(2)·hr)and the rejection of CR was 92.8%.Solvent adsorption test,N,N-dimethylformamide(DMF)immersion experiment,and long-term operation test in ethanol showed that the membranes had high solvent tolerance.The solvent flux test demonstrated that,under the test pressure of 0.6 MPa,the flux of different solvents ranked as follows:methanol(56.9 L/(m^(2)·hr))>DMF(39.6 L/(m^(2)·hr))>ethanol(31.2 L/(m^(2)·hr))>IPA(4.5 L/(m^(2)·hr))>N-hexane(1.9 L/(m^(2)·hr)).The ability of the membranes to retain dyes in IPA/water dyes solution was also evaluated.The flux of the membrane was 30.4 L/(m^(2)·hr)and the rejection of CR was 91.6%when the IPA concentration reached 50%.This OSN membrane-making strategy is economical,environment-friendly and efficient,and has a great application prospect in organic solvent separation systems.

Targeted delivery of hyaluronic acid nanomicelles to hepatic stellate cells in hepatic fibrosis rats

Hepatic fibrosis is one kind of liver diseases with a high mortality rate and incidence.The activation and proliferation of hepatic stellate cells(HSCs)is the most fundamental reason of hepatic fibrosis.There are no specific and effective drug delivery carriers for the treatment of hepatic fibrosis at present.We found that when hepatic fibrosis occurs,the expression of CD44 receptors on the surface of HSCs is significantly increased.Based on this finding,we designed silibinin-loaded hyaluronic acid(SLB-HA)micelles to achieve the treatment of hepatic fibrosis.Meanwhile,we constructed liver fibrosis rat model using Sprague-Dawley rats.We demonstrated that HA micelles had specific uptake to HSCs in vitro while avoiding the distribution in normal liver cells and the phagocytosis of macrophages.Importantly,HA micelles showed a significant liver targeting effect in vivo,especially in fibrotic liver which highly expressed CD44 receptors.In addition,SLB-HA micelles could selectively kill activated HSCs,having an excellent anti-hepatic fibrosis effect in vivo and a significant sustained release effect,and also had a good biological safety and biocompatibility.Overall,HA micelles represented a novel nanomicelle system which showed great potentiality in anti-hepatic fibrosis drugs delivery.