Organic Melt Crystallization as a Method for Synthesis of Supramolecular Complexes

The most simple method for solventless synthesis of supramolecular complex of CMCR·2BPY·BZP, [CMCR = C-methylcalix[4]resorcinarene, BPY = 4,4'-bipyridine, BZP = benzophenone], is proposed. Although CMCR by itself is high melting point compound (above 300°C), CMCR was found to be dissolved in melt mixture of BPY and BZPeven below 120°C. In the mixture of the three components, the reaction occurs to form CMCR·2BPY·BZP supramolecular complex.

Synthesis of Single Hexagonal-Phase AlN Nanocrystallines by a Liquid-Solid Metathetical Reaction in an Organic Solution

A liquid-solid metathetical reaction method （LSMRM） of synthesizing AIN nanocrystallines is presented. AIN nanocrystallines made through LSMRM are characterized by X-ray diffractions （XRD）, X-ray photoelectron spectroscopy （XPS）, transmission electron microscopy （TEM）, Fourier transformation infrared （FT-IR） spectroscopy, and Raman spectroscopy. The results show that the samples are single hexagonal-phase AIN and the size of the AIN samples is about tens of nanometer.

Effects of long-term phosphorus fertilization and straw incorporation on phosphorus fractions in subtropical paddy soil

Study on soil phosphorus（P） fraction is an important aspect in probing the mechanisms of soil P accumulation in farmland and mitigating its losing risk to the environment. We used a sequential extraction method to evaluate the impacts of long-term fertilization and straw incorporation on inorganic, organic, and residual P（Pi, Po, and Pre） fractions in the plow layer（0–20 cm） of acidic paddy soil in southern China. The experiment comprised of six treatments：（i） no fertilizer control（CK）;（ii） straw incorporation and green manure（SG）;（iii） nitrogen and P fertilizer（NP）;（iv） NP＋SG;（v） NP＋K fertilizer（NPK）; and（vi） NPK＋SG. The results showed that, compared to the initial total soil P content（TSP, 600 mg kg^–1 in 1990）, long-term（20 years） combined continuous P fertilizer and SG significantly increased P accumulation（by 13–20%） while single fertilization（39.3 kg P ha^–1 yr^–1） could maintain soil P status at the most. The average soil P fractions comprised of extractable Pi, Po, and Pre by 51.7, 33.4, and 14.9% in total soil P, respectively. With comparison of no fertilizer addition（CK）, long-term single fertilization significantly（P〈0.05） increased the accumulation of Na HCO3^–, Na OH^–, and HCl^– extractable Pi fractions accounting for two- to three-fold, while SG increased the accumulation of Na HCO3^– and Na OH^– extractable Piand Po accounting for 12–60%. Though the mobilization of Pre fractions was not significant（P〉0.05）, our data indicate that SG may partially substitute for fertilizer P input and minimizing soil P accumulation and subsequent environmental risk in the subtropical paddy soil.

Fabrication and Properties of Aluminabased Reticulated Porous Ceramics

The primary impregnation slurry was prepared using active alumina(56.25 mass%),kaolin(15 mass%),zirconia(3.75 mass%),deionized water(25 mass%),and extra adding FS(0.2 mass%)and CMC(0.4 mass%).The effects of the active alumina particle size(d50=5.043,2.934,and 1.629μm)on the rheology and the thixotropy of the slurry were researched.It was found that the bimodal activeα-Al2O3(AMA-10)with d50=1.629μm was optimum.The secondary impregnation slurry was prepared using AMA-10,kaolin and zirconia as the main raw materials.Then the alumina-based reticulated porous ceramics were fabricated by the organic foam impregnation method combined with a secondary vacuum impregnation process.The influence of the AMA-10 content on the properties of the ceramics was studied.The residual stress of the specimens was analyzed by finite element analysis.The results show that the smaller alumina particle size and multimodal distribution are beneficial to the thixotropy of the primary impregnation slurry.The secondary vacuum impregnation technique can significantly improve the mechanical properties,the thermal shock resistance and the residual strength of the alumina-based reticulated porous ceramics.With the decrease of alumina content in the secondary impregnation slurry,the residual stress of the external layer of ceramic reinforcement gradually changes from tensile stress to compressive stress,which effectively inhibits the expansion of the surface crack,and remarkably improves the crushing strength retention ratio of alumina reticulated porous ceramics.

Critical process parameter identification of manufacturing processes of Astragali Radix extract with a weighted determination coeffcient method

Objective:Critical process parameters(CPPs)identification is an important step of the implementation of quality by design(Qb D)concept.There are many CPP identification methods,such as risk analysis method,sensitivity analysis method,multiple linear regression method,standard partial regression coefficient(SPRC)method,and so on.The SPRC method can consider multiple process critical quality attributes(CQAs)simultaneously,but the determination of CPP number is subjective.Therefore,new CPP identification method is still required.Methods:The manufacturing process of Astragali Radix extract,which contained water reflux extraction,concentration,and ethanol precipitation,was used as an example.First,the multiple process CQAs were determined to be the yield of pigment,dry matter,sugars,and active ingredients.Second,the potential CPPs were determined by a knowledge organization method.Plackett-Burman designed experiments were then performed.A weighted determination coefficient(R2 w)method was presented to identify CPPs.In this method,the importance of different CQAs was considered.Process parameters were removed one-by-one according to their importance index.The decrease in R2 wwas used to characterize the importance of the removed parameter.If the decrease of R2 wwas less than a preset threshold,the removed parameter was not a CPP.Results:During the manufacturing process of Astragali Radix extract,the potential CPPs determined by the knowledge organization method were water consumption,reflux extraction time,extraction frequency,ethanol content,ethanol consumption,and concentration endpoint.Reflux extraction time,the first ethanol consumption,the second ethanol consumption,and the second ethanol precipitation refrigeration temperature were found to be CPPs using the weighted determination coefficient method with the threshold of 10%.Conclusion:Using the weighted determination coefficient method,CPPs can be determined with all the CQAs considered based on their importance.The determination of CPP number is more objective compared with the SPRC method.

Bulk heterojunction thin film formation by single and dual feed ultrasonic spray method for application in organic solar cells

We here present a way of preparing the polymer： fullerene BHJ using dual feed method which can lead to formation of pure phases. In this report, we present results of our initial experiments in this direction.The effect of process parameters on the thickness and surface roughness of the active layer has been discussed.The structural and optical properties have been studied using the optical microscope, UV–visible spectroscopy and photoluminescence spectroscopy. Significant PL quenching indicates efficient charge separation in the BHJ formed using this technique. We have also compared the BHJ thin films prepared with this dual feed ultrasonic technique with the single feed spray method. The BHJ formed using this technique has been used as an active layer in OSC.

Experimental study using the dilution incubation method to assess water biostability

Water biostability is of particular concern to water supply as a major limiting factor for heterotrophic bacterial growth in water distribution systems. This study focused on bacterial growth dynamics in the series dilution of water samples with TOC（total organic carbon） values determined beforehand. The results showed that the specific growth rate of Pseudomonas fluorescens P17 varied dramatically and irregularly with TOC value when TOC concentrations were low enough during the initial periods of incubation under given conditions. According to this relationship between bacterial growth rate and TOC, a dilution incubation method was designed for the study of water biostability. With the method under a given condition, a turning-point TOC value was found at a relatively fixed point in the curve between bacterial growth rate and TOC of water sample, and the variation of growth rate had different characteristics below the turning-point TOC value relative to that over this value. A turning-point TOC value similarly existed in all experiments not only with tap water, but also with acetate and mixed solutions. And in the dilution incubation method study, the affections were analyzed by condition factors such as inoculum amount,incubation time and nature of the organic carbon source. In very low organic carbon water environments, the variation characteristics of bacterial growth rate will be useful to further understand the meaning of water biostability.

An effective method for the hydrodehalogenation of organic halides

THE reduction of organic halides to the corresponding hydrocarbons plays an important role inorganic synthesis and environmental decontamination.It is one of the earliest reactions de-scribed in the organic chemical literature.A number of successful approaches have been report-ed hitherto,but the hydrodehalogenation of chloroarenes and organic fluorides is still a

The reaction of perfluoroalkanesulfonyl halides Ⅷ. A mild method for introducing BrCF_2 group to organic molecules

BrCF_2SO_2Br, prepared from sulfinatodehalogenation of CF_2Br_2 followed by bromination of the intermediate BrCF_2SO_2Na, was shown to be a mild and efficient bromodifluoromethylating agent.

Ultrathin Ni/V-layered double hydroxide nanosheets for efficient visible-light-driven photocatalytic nitrogen reduction to ammonia

Ammonia is important for industrial development and human life.The traditional Haber Bosch method converts nitrogen into ammonia gas at high temperatures and pressures,causing serious pollution and greenhouse gas emissions.These problems prompt the nitrogen fixation method to proceed in a sustainable way.Ultrathin Ni/V-layered double hydroxides(Ni/V-LDHs)nanosheets with different proportions were prepared successfully for photocatalystic reduction of nitrogen to ammonia,through aqueous miscible organic solvent method(AMO)to achieve the higher surface area and rich oxygen vacancies,containing more carriers and active sites to enhance nitrogen reduction.And the optimal catalyst of Ni/V-LDHs 11 AMO possesses the highest photocatalytic efficiency(176μmol·g^(-1)·h^(-1)),indicating its potential application prospects in catalyst fields.Consequently,this work achieves an environmentally friendly,low-cost and efficient conversion method for nitrogen reduction to ammonia through solar energy.

High-mobility air-stable n-type field-effect transistors based on large-area solution-processed organic single- crystal arrays

Solution-processed n-type organic semiconductor micro/nanocrystals （OSMCs） are fundamental elements for developing low-cost, large-area, and all organic logic/complementary circuits. However, the development of air-stable, highly aligned n-channel OSMC arrays for realizing high-performance devices lags far behind their p-channel counterparts. Herein, we present a simple one-step slope-coating method for the large-scale, solution-processed fabrication of highly aligned, air-stable, n-channel ribbon-shaped single-crystalline N,N＇-bis（2- phenylethyl）-perylene-3,4：9,10-tetracarboxylic diimide （BPE-PTCDI） arrays. The slope and pattemed photoresist （PR） stripes on the substrate are found to be crucial for the formation of large-area submicron ribbon arrays. The width and thickness of the BPE-PTCDI submicron ribbons can be finely tuned by controlling the solution concentration as well as the slope angle. The resulting BPE-PTCDI submicron ribbon arrays possess an optimum electron mobility up to 2.67 cm2.V-l.s-1 （with an average mobility of 1.13 cm2.V-l-s-1）, which is remarkably higher than that of thin film counterparts and better than the performance reported previously for single-crystalline BPE-PTCDI-based devices. Moreover, the devices exhibit robust air stability and remain stable after exposing in air over 50 days. Our study facilitates the development of air-stable, n-channel organic field-effect transistors （OFETs） and paves the way towards the fabrication of high-performance, organic single crystal-based integrated circuits.

Enhanced catalytic complete oxidation of 1,2-dichloroethane over mesoporous transition metal-doped γ-Al_2O_3

High-surface-area mesoprous powders of γ-Al2O3 doped with Cu^2＋, Cr^3＋, and V^3＋ ions were prepared uia a modified sol-gel method and were investigated as catalysts for the oxidation of chlorinated organic compounds. The composites retained high surface areas and pore volumes comparable with those of undoped γ-Al2O3 and the presence of the transition metal ions enhanced their surface acidic properties. The catalytic activity of the prepared catalysts in the oxidation of 1,2-dichloroethane （DCE） was studied in the temperature range of 250-400℃. The catalytic activity and product selectivity were strongly dependent on the presence and the type of dopant ion. While Cu^2＋- and Cr^3＋-containing catalysts showed 100% conversion at 300℃ and 350℃, V3＋-containing catalyst showed considerably lower conversion. Furthermore, while the major products of the reactions over γ-alumina were vinyl chloride （C2H3Cl） and hydrogen chloride （HCl） at all temperatures, Cu- and Cr-doped catalysts showed siguiticantly stronger capability for deep oxidation to CO2.

Missing in total OH reactivity of VOCs from gasoline evaporation

Gasoline evaporation is an important anthropogenic source of atmospheric volatile organic compounds（VOCs）. Total OH reactivity for gasoline vapor was measured from 4 kinds of gasoline for the first time by comparative reactivity method（CRM） using proton transfer reaction mass spectrometer（PTR-MS）.Compositions of 56 PAMS（photochemical assessment monitoring station） nonmethane hydrocarbons（NMHCs） were measured for both liquid and headspace of gasoline. We found high abundance of alkenes and aromatics in gasoline. The calculated OH reactivity derived from quantified NMHCs speciation accounted for only 57 ？ 4% of total reactivity obtained from CRM method. N-Alkenes, only 6 wt% in liquid gasoline, contributed to 70% of calculated reactivity. We assume that the undetected branched alkenes are the possible reason for the missing reactivity. We suggest that the priority of gasoline quality improvement is to reduce alkenes content in gasoline in term of reactivity-based control.

Morphology Control over the Organic Nanoparticles of 1,3-Diphenyl-5-(9-anthryl)-2-pyrazoline

The organic nanoparticles of a blue-light-emitting molecule,1,3-diphenyl-5-(9-anthryl)-2-pyrazoline,were prepared by reprecipitation method using acetonitrile as the solvent for the molecular precursor. Three morphologies,spherical,doughnut-shaped and cubic,could be observed on the silicon substrate for the nanoparticles by the volume-controlled addition of acetonitrile. The evolution of particle morphology as a function of acetonitrile addition was attributed to the variation of the growth habits of the particles in the different environment. The nanoparticles exhibit the novel photoluminescence spectra as compared to those of monomer and the bulk crystals.