Investigating the charge transfer mechanism of ZnSe QD/COF S-scheme photocatalyst for H_(2)O_(2) production by using femtosecond transient absorption spectroscopy

Hydrogen peroxide(H_(2)O_(2))has gained widespread attention as a versatile oxidant and a mild disin-fectant.Here,an electrostatic self-assembly method is applied to couple ZnSe quantum dots(QDs)with a flower-like covalent organic framework(COF)to form a step-scheme(S-scheme)photocata-lyst for H_(2)O_(2)production.The as-prepared S-scheme photocatalyst exhibits a broad light absorption range with an edge at 810 nm owing to the synergistic effect between the ZnSe QDs and COF.The S-scheme charge-carrier transfer mechanism is validated by performing Fermi level calculations and in-situ X-ray photoelectron and femtosecond transient absorption spectroscopies.Photolumi-nescence,time-resolved photoluminescence,photocurrent response,electrochemical impedance spectroscopy,and electron paramagnetic resonance results show that the S-scheme heterojunction not only promotes charge carrier separation but also boosts the redox ability,resulting in enhanced photocatalytic performance.Remarkably,a 10%-ZnSe QD/COF has excellent photocatalytic H_(2)O_(2)-production activity,and the optimal S-scheme composite with ethanol as the hole scavenger yields a H_(2)O_(2)-production rate of 1895 mol g^(-1)h^(-1).This study presents an example of a high-performance organic/inorganic S-scheme photocatalyst for H_(2)O_(2)production.

基于HPR在线监测控制SBR曝气历时实现短程脱氮

应用新型自动呼吸-滴定测量仪在线测量pH值、HPR等信号,进行了在SBR内实现短程脱氮的研究.采用SBR处理人工合成废水,COD和NH4+-N浓度分别为360,40mg/L,温度稳定在20℃,DO低于2mg/L,基于HPR在线监测控制SBR曝气历时.运行约60d后,亚硝酸盐积累率达到88%,COD和NH4+-N去除率均在90%以上,稳定实现了短程硝化反硝化.应用HPR估计硝化过程的NH4+-N浓度发现,NH4+-N实测值与基于HPR的计算值间存在良好的线性关系,相关系数为0.9722;计算值整体低于实测值,主要是由曝气初期的滴定启动滞后所致.

磁共振血管造影在胸腹部的应用

磁共振血管造影(magnetic resonance angi-ography; MRA)是继磁共振成像在临床广泛应用后发展起来的新技术。由于磁场内流体可使质子产生磁化及相位的变化,血流在图像中产生对比度而获得MRA。最近报道的MRA方法有投射采集法血管造影(Projecfion acquisition angiography)、

中科院化学研究所人工光合作用水裂解催化剂研究取得进展

利用太阳能将水裂解获得电子和质子产生氢能,被认为是解决人类社会面临的能源危机、环境污染、温室效应问题的理想途径。光合作用水裂解催化中心(又称放氧中心,简称OEC)是自然界唯一能够利用太阳能高效、安全地将水裂解,获得电子和质子,并释放出氧气的生物催化剂。该催化中心是一个不对称Mn_(4)CaO_(5)^(-)簇合物。借鉴该催化中心的结构和原理,研制仿生水裂解催化剂,不仅对认识光合作用水裂解反应的微观本质具有重要的科学意义,而且对人工光合作用利用太阳能和水获取清洁能源(氢能)具有重要应用价值,同时也是极具挑战性的科学前沿。

Effects of Fe^(2+), Co^(2+) and Ni^(2+) Ions on Biological Methane Production from Residual Heavy Oil

On the basis of single factor tests, the effect of trace elements—Fe2+, Co2+ and Ni2+ ions—on biological methane production from heavy oil was investigated by the response surface method. A three-level Box-Behnken design was employed to study the relationship between the independent variables and the dependent variable by applying initial Fe2+, Co2+ and Ni2+ concentration as the independent variables(factors) and using the methane production after 270 days of cultivation as the dependent variable(response). A prediction model of quadramatic polynomial regression equation was obtained. The results showed that the methane production could be as high as 240.69 μmol after optimization compared with 235.74 μmol obtained under un-optimized condition. Furthermore, the microbial communities before and after biodegradation were analyzed by PCR-DGGE method. The dominant bands were recovered and sequenced. Three strains were obtained; the strain T1 has 97% similarity with Bacillus thermoamylovorans, the strain H3 has 97% similarity with Bacillus thermoamylovorans and the strain H4 has 99% similarity with Bacillus vietnamensis.

Upsilon Photo-Production off Proton in QCD Inspired Model

Based on the generalized vector meson dominance model in QCD, we study photoproduction of vector meson T off the proton by use of the QCD inspired model in which the contributions from quark-quark, gluon-gluon, and quark-gluon interference term to observable are taken into consideration. Calculations are performed for total cross section σtot, differential cross section dσ/dt, ratio of the real part to imaginary part of forward scattering amplitude ρ, and nuclear slop parameter function β. The mediators of interactions between projectiles （the quark and antiquark pair fluctuated from the real the photon） and the proton target （three-quark system） are the tensor Glueball and Odderon instead of using the usual Pomeron exchange. The theoretical predictions for σtot （s） are consistent with the experimental data within error bars of the data. The data for dσ/dt, ρ, and β are urgently needed.

Adsorption of Heavy Metal Ions,Dyes and Proteins by Chitosan Composites and Derivatives-A Review

Chitosan composites and derivatives have gained wide attentions as effective biosorbents due to their low costs and high contents of amino and hydroxyl functional groups.They have showed significant potentials of removing metal ions,dyes and proteins from various media.Chemical modifications that lead to the formation of the chitosan derivatives and chitosan composites have been extensively studied and widely reported in literatures.The aims of this review were to summarize the important information of the bioactivities of chitosan,highlight the various preparation methods of chitosan-based active biosorbents,and outline its potential applications in the adsorption of heavy metal ions,dyes and proteins from wastewater and aqueous solutions.

Evaluation of the Production, Quality of Three Cultivars of Rhodes Grass （Chloris Gayana） and Viability of Seeds, Introduced in the Pampas

This paper describes how a research was carried out about Chloris gayana Kunth. The objective of the work was to agronomical characterize the best sowing date, establishment efficiency, first year management, persistence strategies, biomass production and seeds. The parameter evaluated was： morphological, quality and production of seeds of three commercial cultivars （Santana, Finecut and Recleimer）. Trial duration is December 2012 to December 2016 （33o S, 61o W） Argentina. Design three random blocks with three repetitions, plot 5 × 5 meter. The results were analyzed by ANOVA （Analysis of Variance）, and there was used Tukey Test （p 〈 0.05） for comparison of averages, to determine significant differences between the different ones that will be sown. It was determined that the ends of spring dates ensure better establishment. Although the data of morphology of the first year （length of pod, length of blade and number of leaves/plant） presented differences between the cv, they did not mark a tendency that ensures the best development of one. Recleimer with 598 and 1,026 accumulated degree days present the highest values in both measurements. The accumulation of biomass over the years shows that commercial cv show a very similar performance （12,000 kg DM （Dry Matter） per hectare per year）. The annual accumulation of DM would not vary significantly as monthly cuts are applied during the growing season or total accumulation without cuts would be allowed. In relation to quality parameters （gross protein, neutral detergent fiber and acid detergent fiber）, Recleimer has the lowest values. Santana and Finecut were best in quality. Production of the seed was highest in May for all cvs. However, viability was limited in all date but Finecut and Recleimer showed best performance. As expected, in the megathermal species, seed production being one of the critical points.

Effect of Guazuma Leaves （Guazuma ulmifolia） Inclusion as Protein Source on Growing Calves

The present work was undertaken in a cattle ranch of the north of Puebla state, Mexico. The aim was to incorporate Guazuma leaves （Guazuma ulmifolia） in the diet of growing calves and evaluate its effect on weight gain. Twenty-four Cebu × Swiss calves （approximately live weight 250 kg） were used during all the experimental period （64 d）. They were assigned to a completely randomized design under two treatments （n = 12 for each treatment）： control （T1） consisted of commercial feed based on 15% crude protein （CP） ＋ cut Taiwan grass and the treatment （T2） consisted of a formulated diet containing 14.7% CP including Guazuma. The composition of the formulated diet consisted of： Guazuma （60%）, rolled corn （12%）, ground sorghum （9%）, oats in grain （7%）, wheat bran （9%） and vitamins and minerals. The feed was offered twice a day at a rate of 3% of live weight for 64 d. The mean daily gain for T1 and T2 was 1.15 g/animal and 1.52 g/animal, respectively （p 〈 0.05）. Results indicate that Guazuma-based supplements resulted in greater productive yield in growing calves.

Charged Top-Pion Production at Hadron Colliders

We studied the charged top-pion in the topcolor assisted technicolor model(TC2).If the charged top-pionsare heavy,m_(πt)>m_t+m_b,they will decay mainly via the channel π_t^+→tb^-.We also calculated the production of chargedtop-pion at the Tevatron and LHC.The cross section can reach to 100 fb at the Tevatron and dozens of pb at the LHCdepending on the mass of the top-pion.

Components of Liquid Media on the Production of High Spore Concentrations of Lecanicillium lecanii （Zimm.） Gams and Zare

Two Lecanicillium lecanii isolates, ATCC26854 and V3, were evaluated for spore production in liquid media. Both isolates have interesting known properties for the production of high concentrations of chitinases （ATCC26854）, and an outstanding pathogenic activity against the green cabbage aphid, Brevicorine brassiacae （L.）. The isolates were grown on thirteen different liquid media, which had been used to produce other entomopathogenic Hyphomycetes. Experiments were carried out at 27 -4- 1 ℃ with a 12：12 photoperiod using shake flasks. The production of spores was quantified during a seven days period, and the effects of the media were evaluated by determining spore concentration and morphology. Submerged conidia yields were higher with ATCC26854 than with V3 in all thirteen media, while higher concentrations （5.3×10^9, 4.6 ×10^9 and 3.4 ×10^9 conidia/mL） were found with ATCC26854 isolate in the Camaron, Minerales and Jenkins-Prior medium, respectively; lower yields （2.3 ×10^8, 2.2 ×10^8 and 2.3 ×10^8 conidia/mL） were found with the V3 isolate in Catroux, TKI and Camaron media, respectively. Spore production curves were adjusted to different sigmoid models. The process was better explained by the Richards model （r^2 = 0.99）. Concerning conidia morphology, submerged conidia seemed to look like aerial conidia, but they were different in size （ATCC26854 2.73-6.99 μm and V3 5.28-14.29 μm）; however, the dimensions fall within the ranges reported for L. lecanii. The analysis of shake flask cultures with the Richards model allowed selecting two low-cost liquid medium, Camaron and Jenkins-Prior, for scaling up conidia production for use in aphid biological control programs.

The Impact of Land Fragmentation in the Qualitative and Quantitative Aspect of Seeds and Their Production

Due to the pedo-climate conditions in the region of Korca, this area is considered to be one of the most favorable regions for cultivating various kinds of plants such as cereals, vegetables, wood-trees, vineyards, etc. All the factors such as rain, temperature, the impact of sunlight, and the pathological structure of the land, make this region one of the most productive and qualitative among the others. Changing the political systems in Albania during the last decades in Albania had its own impact even in the agricultural aspect. Shifting from communism into a modem, capitalist economy built a huge barrier for farmers in their way to intensifying the agricultural production. Dividing the land according to the law number 7,501, was accompanied by a severe fragmentation of the plot, reducing the degree of mechanization and chemical process. In this paper, the authors will try to analyze the effect of law fragmentation in the regional farmers working process in the region of Korea, and other municipalities such as Bilisht and Maliq, nearby Korea. There were randomly interviewed 150 farmers, from which 30 from the municipality of Bilisht, 22 from Korca municipality and 15 from Maliqi. From each farmer, these were the variables taken into consideration： Total land area, irrigated land, the number of plots, the area planted with wheat, corn, vegetables, fruit, vineyards, and forages. All the data that were gathered and translated into figures have indicated statistic elements such as the average value of each variable, deviation or standard deviation, coefficient of variation, correlation and regression. For instance in the municipality of Bilisht, it has been concluded that between the total variable area and number of plots, the related correlation value of the correlation coefficient is r = ＋ 0.73 and the value of regression coefficient is R = 2.71. In this municipality, correlative links between the variable and the total area planted with wheat area, are of medium category, with a value of the correlation coefficient of r = ＋ 0.52 and the regression coefficient is R = 0.89. Regarding the studies in the municipality of Maliq, it has been a correlation link between the weak variable category： in the surface of the irrigated area and the land planted with vegetables and corn, the value of the correlation coefficient is r = ＋ 0.24 and the regression coefficient R = 2.11. In the municipality of Korea, among the variable of irrigated area and the surface of the land planted with vegetables, there is a weak correlative link with a value of the correlation coefficient r = ＋ 0.17 and the regression coefficient R = 0.58.

Exploring the Feasibility of Producing Superheavy Nuclei in the Proton Evaporation Channel

The feasibility of producing superheavy nuclei in proton evaporation channels was systematically studied within the dinuclear system(DNS)model.Due to the Z=114 proton-shell,one can synthesize Fl isotopes in proton evaporation channels.We only considered the case of evaporating one proton first and then n neutrons in this work,other cases were ignored due to the small cross-section.The production cross sections of unknown isotopes ^(290,291)Fl in ^(38)S+^(255)Es reaction are the highest compared with ^(50)Ti+^(243)Np and ^(54)Cr+^(239)Pa reactions,and the maximum cross sections are 1.1 and 15.1 pb,respectively.^(42)S+^(254)Es is a promising candidate to approach the island of stability as the radioactive beam facilities are upgraded in the future,and the production cross sections of ^(291−294)Fl in that reaction are estimated to be 3.2,6.0,4.0,and 0.1 pb,respectively.

Basic science of water： Challenges and current status towards a molecular picture

Rapid developments in both fundamental science and modern technology that target water-related problems, including the physical nature of our planet and environment, the origin of life, energy production via water splitting, and water purification, all call for a molecular-level understanding of water. This invokes relentless efforts to further our understanding of the basic science of water. Current challenges to achieve a molecular picture of the peculiar properties and behavior of water are discussed herein, with a particular focus on the structure and dynamics of bulk and surface water, the molecular mechanisms of water wetting and splitting, application-oriented research on water decontamination and desalination, and the development of complementary techniques for probing water at the nanoscale.

Associated Production of a Photon with Dark Matter Pair at the ILC within the Littlest Higgs Model with T-parity

Within the context of the Littlest Higgs model with T-parity, the heavy photon （AH） is supposed to be an ideM dark matter （DM） candidate. One direct proof of validity of the model is to produce the heavy photon at collider. In this paper, we investigate the associated production of a photon with heavy photon pair at the planned international e＋ e- linear collider （ILC）, i.e., e＋e- → AHAHγ and show the distributions of the transverse momenta of the photon. The numerical results indicate that the heavy photon production rate could reach severaL fb at the low mass parameter space and the characteristic signal is a single high energetic photon and missing energy, carried by the heavy photons. All in a/l, it can be a good chance to observe the heavy photon via this process with the high yearly luminosity of the ILC.

Influence of coalescence parameters on the production of protons and Helium-3 fragments

The time evolution of protons and 3He fragments from Au＋Au/Pb＋Pb reactions at 0.25, 2, and 20 GeV/nucleon is investigated with the potential version of the Ultrarelativistic Quantum Molecular Dynamics （UrQMD） model combined with the traditional coalescence afterburner. In the coalescence process, the relative distance R0 and relative momentum P0 are surveyed in the range of 3-4 fm and 0.25-0.35 GeV/c, respectively. For both clusters, a strong reversed correlation between R0 and Po is seen and it is time-dependent as well. For protons, the accepted （R0, P0） bands lie in the time interval 30-60 fm/c, while for 3He, a longer time evolution （at about 60-90 fm/c） is needed. Otherwise, much smaller R0 and P0 values should be chosen. If we further look at the rapidity distributions from both central and semi-central collisions, it is found that the accepted [tout, （R0, P0）] assemble can provide consistent results for proton yield and collective flows especially at mid-rapdities, while for 3He, the consistency is destroyed at both middle and projectile-target rapidities.

Determination of quantitative structure-property and structure-process relationships for graphene production in water

A scalable method for graphene and few-layer graphene （FLG） production by graphite delamination in aqueous solutions of the nonionic surfactant TWEEN 80 （TW80） using stirred-media mills is presented. Delaminated product analysis using statistical Raman spectroscopy yielded extensive processing-structure-property relationships that revealed how stress intensity and specific energy input, i.e., the process parameters, govern the yield of graphene production and defect formation. The dispersed carbon concentration increased but the content and the quality of the FLG product decreased sharply with higher specific energy input. The FLG content of the product was up to 90%, especially for low specific energy input. Moreover, Raman analyses revealed that stress intensities greater than about I nJ were related to significant defect formation in the product particles. Another key parameter for graphene production is solvent viscosity. The FLG concentration in the product increased by a factor of 10 when the solvent＇s viscosity was increased from 1 to 6 mPa-s because shear- and friction-induced delamination was enhanced and in-plane fracture was reduced due to dampening of bead motion. Based on the processing-structure-property relationships found, we propose that the delamination process can be designed in such way that the product consists, almost totally, of FLG and that single-layer graphene is produced. The scalability of graphene production by stirred-media delamination was demonstrated when an increase in the batch size from 0.2 to 2 L had no significant effect on product quality.

Laser generation of iron-doped silver nanotruffles with magnetic and plasmonic properties

A frontier topic in nanotechnology is the realization of multifunctional nanoparticles （NPs） via the appropriate combination of different elements of the periodic table. The coexistence of Fe and Ag in the same nanostructure, for instance, is interesting for nanophotonics, nanomedicine, and catalysis. However, alloying of Fe and Ag is inhibited for thermodynamic reasons. Here, we describe the synthesis of Fe-doped Ag NPs via laser ablation in liquid solution, bypassing thermodynamics constraints. These NPs have an innovative structure consisting of a scaffold of face-centered cubic metal Ag alternating with disordered Ag-Fe alloy domains, all arranged in a truffle-like morphology. The Fe-Ag NPs exhibit the plasmonic properties of Ag and the magnetic response of Fe-containing phases, and the surface of the Fe-Ag NPs can be functionalized in one step with thiolated molecules. Taking advantage of the multiple properties of Fe-Ag NPs, the magnetophoretic amplification of plasmonic properties is demonstrated with proof-of-concept surface-enhanced Raman scattering and photothermal heating experiments. The synthetic approach is of general applicability and virtually permits the preparation of a large variety of multi-element NPs in one step.