Amine-functionalized metal organic framework@graphene oxide as filler in PAEK-containing carboxyl group membrane for ultrafiltration with ultra-high permeability and strong fouling resistance

Achieving high fouling resistance and permeability using membrane separation technology in water treatment processes remains a challenge.In this work,a novel mixed-matrix membrane(MMM)(poly(arylene ether ketone)[PAEK]-containing carboxyl groups[PAEK-COOH]/UiO-66-NH_(2)@graphene oxide[GO])with superb fouling resistance and high permeability was prepared by the nonsolvent-induced phase separation method,by in-situ growth of UiO-66-NH_(2) on the GO layer,and by preparing hydrophilic PAEK-COOH.On the basis of the structure and performance analysis of the MMM,the maximum water flux reached 591.25 L·m^(-2)·h^(-1) for PAEK-COOH/UiO-66-NH_(2)@GO,whereas the retention rate for bovine serum albumin increased from 85.40%to 94.87%.As the loading gradually increased,the hydrophilicity of the MMMs increased,significantly enhancing their fouling resistance.The strongest anti-fouling ability observed was 94.74%,which was 2.02 times greater than that of the pure membrane.At the same time,the MMMs contained internal amide and hydrogen bonds during the preparation process,forming a cross-linked structure,which further enhanced the mechanical strength and chemical stability.In summary,the MMMs with high retention rate,strong permeability,and anti-fouling ability were successfully prepared.

Ultra-microporous Metal-organic Framework with High Concentration of Free Carboxyl Groups and Lewis Basic Sites for CO_2 Capture at Ambient Conditions

How to rationally design effective and practical CO_2 adsorbent is a great challenge. Herein, an ultra-microporous metal-organic framework(FJI-H19) with high concentration of free carboxyl groups and uncoordinated Lewis basic sites has been synthesized from a multi-dental ligand with a high proportion of polar CO_2-philic atoms. FJI-H19 displays a relatively high CO_2 volumetric uptake(120 cm^3?cm^(–3)) with high selectivity under practical atmosphere(298 K and 1 bar). Further researches demonstrate that such high adsorption results from an unusual synergistic effect from free carboxyl group and uncoordinated N atoms. This result will provide a potential strategy for developing more effective and pratical CO_2 adsorbent based on MOFs.

Synthesis of Polycaprolactone with Two Carboxyl End Groups

At 225℃. caprolactone has been polymerized in the presence of succinic acid under dry nitrogen atmosphere. Characterizations of the polymer through IR and molecular weight measurements by 1H-NMR and end group titration have shown that the polycaprolactone obtained is of two carboxyl end groups. The molecular weight of it increases with decreasing of the acid content in the reaction mixture under the same polymerization conditions. With a certain ratio of acid to caprolactone. the maximum of molecular weight of the polymer will be reached at the reaction time of 3h.

Preparation of large colored microspheres with carboxyl groups for cell surface labelling

The purpose of this experiment is to prepare a kind of large colored microspheres which can be observed under optical microscope and used for cell labelling. In the presence of organic solvent, electrolyte and dye, microspheres [styrene/acrylamide/dye (St AAm-Dye ) copolymerJ were synthesized from styrene and acrylamide by means of emulsifier-free emulsion polymerization. The carboxyl groups on the surface were derived from acrylarnide by hydrazinolysis and carboxylate reaction. The diameters of microspheres and the content of carboxyl groups on the surface were measured. The effect of the polymerization condition on microsphere size was discussed. The diam6ter of the colored microsphere was 3±0. 05μm; the content of carboxyl groups on the surface was 190. 5μmol/g (dry solids). The results indicate that it would be possible to obtain monodisperse and colored large polymer microspheres by this reported method.

Synthesis and characterization functionalized poly(ether ether ketone)s with carboxylic groups

A novel type of aromatic poly（ ether ether ketone） s with carboxyl groups were prepared by polycondensation of 4,4-bis（4-hydroxyphenyl）pentanoic acid with difluoro-monomers. Their mo- lecular structures were determined by ^1H-NMR and IR, respectively. Their molecular weights were measured by gel permeation chromatography （ GPC ）, which showed that all the polymers had high molecule weights （ 〉 42 000）. Due to the long side chains of polymers, all the polymers had good solubility （soluble in NMP, DMAc, THF, etc. ）. The differential scanning calorimeter （DSC） detected their excellent glass transition temperatures （ Tg ） up to 195 ℃. The Tg increased with the content of carboxylic units in the polymer chains, because the interactions of H bonds increased with increasing content of carboxylic. The polymers could form transparent and flexible films, which make them a candidate for membrane materials.

Reliable Content Distribution in P2P Networks Based on Peer Groups

Peer-to-Peer (P2P) networks are highly dynamic systems which are very popular for content distribution in the Internet. A single peer remains in the system for an unpredictable amount of time, and the rate in which peers enter and leave the system, i.e. the churn, is often high. A user that is obtaining content from a selected peer is frequently informed that particular peer is not available anymore, and is asked to select another peer, or will have another peer assigned, often without enough checks to confirm that the content provided by the new peer presents the same quality of the previous peer. In this work we present a strategy based on group communication for transparent and robust content access in P2P networks. Instead of accessing a single peer for obtaining the desired content, a user request is received and processed by a group of peers. This group of peers, called PCG (Peer Content Group) provides reliable content access in sense that even as members of the group crash or leave the system, users continue to receive the content if at least one group member remains fault-free. Each PCG member is capable of independently serving the request. A PCG is transparent to the user, as the group interface is identical to the interface provided by a single peer. A group member is elected to serve each request. A fault monitoring component allows the detection of member crashes. If the peer is serving request crashes, another group member is elected to continue providing the service. The PCG and a P2P file sharing applications were implemented in the JXTA platform. Evaluation results are presented showing the latency of group operations and system components.

Carboxylic bacterial cellulose fiber-based hydrogel electrolyte with imidazole-type ionic liquid for dendrite-free zinc metal batteries

Aqueous zinc metal batteries are regarded as the most promising energy storage system due to their advantages of high safety,low cost,and high theoretical capacity.However,the growth of dendrites and the occurrence of side reactions hinder the development of zinc metal batteries.Despite previous attempts to design advanced hydrogel electrolytes,achieving high mechanical performance and ionic conductivity of hydrogel electrolytes has remained challenging.In this work,a hydrogel electrolyte with an ionic crosslinked network is prepared by carboxylic bacterial cellulose fiber and imidazole-type ionic liquid,following by a covalent network of polyacrylamide.The hydrogel electrolyte possesses a superior ionic conductivity of 43.76 mS cm^(−1),leading to a Zn^(2+)migration number of 0.45,and high mechanical performance with an elastic modulus of 3.48 GPa and an elongation at breaking of 38.36%.More importantly,under the anion-coordination effect of the carboxyl group in bacterial cellulose and[BF4]−in imidazole-type ionic liquid,the solvation sheath of hydrated Zn^(2+)ions and the nucleation overpotential of Zn plating are regulated.The results of cycled testing show that the growth of zinc dendrites is effectively inhibited and the generation of irreversible by-products is reduced.With the carboxylic bacterial cellulose-based hydrogel electrolyte,the Zn||Zn symmetric batteries offer good cyclability as well as Zn||Ti batteries.

ATR-FTIR Analysis on Aliphatic Hydrocarbon Bond(C-H)For­mation and Carboxyl Content during the Ageing of DC Air Plasma Treated Cotton Cellulose and Its Impact on Hydrophilicity

The surface of the cotton fabric was modified using a direct current(DC)air plasma treatment and hence enhances its hydrophilicity.The Box-Behnken approach(design expert software)was used to optimise the input process parameters.The sample prepared under optimized condition is subjected to ATR-FTIR and Field Emission Scanning Electron Microscopy(FESEM)studies in order to determine the changes in hydrogen bond energies(EH),Total Crystallinity Index(TCI),Hydrogen Bond Intensity(HBI),Lateral Order Index(LOI),functionalization,lattice parameters(a,b,c&β),degree of crystallinity(in%)and surface etching.The ageing of this sample has been studied by comparing the values of carboxyl content and AC-C/AC-O-C ratio calculated using data extracted from ATR-FTIR spectra of the sample recorded periodically for one month.

Variations in Composition and Water Use Efficiency of Plant Functional Groups Based on Their Water Ecological Groups in the Xilin River Basin

Major plant species in the Xilin River Basin were grouped into six plant functional groups (PFGs) based on their water ecological groups: xerophytes, mesoxerophytes, xeromesophytes, mesophytes, hygromesophytes and hygrophytes. We surveyed the composition, delta(13)C values and proline concentration of PFGs in eight different plant communities along a soil moisture gradient. Results show that: (1) PFGs occurred variously in eight steppe communities with different soil moisture status. In wetter habitats, hygromesophytes and hygrophytes were more abundant and accounted for the majority of aboveground biomass, whereas xerophytes and mesoxerophytes became more conspicuous in dryer habitats; (2) the numerical order of the mean delta(13)C values of PFGs is as follows: xerophytes (-26.38parts per thousand) = mesoxerophytes (-26.51parts per thousand) > xeromesophytes (-27.02parts per thousand) > mesophytes (-27.56parts per thousand) = hygromesophytes and hygrophytes (-27.80parts per thousand); (3) xerophytes maintained relative higher delta(13)C values and water use efficiency (WUE) in habitats of different water availability, whereas delta(13)C values of xeromesophytes were more sensitive to change in soil water availability; (4) From xerophytes to hygrophytes, their proline content markedly increased. Significantly positive correlations existed between proline and biomass or delta(13)C values of different water ecological groups.

Synthesis, Structure and Properties of a Strontium(Ⅱ) Complex with 2, 3-Pyrazinedicarboxylic Acid

Complex [Sr2（pdc）2（H2O）7]·H2O （1, H2pdc = 2,3-pyrazinedicarboxylic acid） has been synthesized and characterized by single-crystal X-ray diffraction studies and FT-IR. Structural determination reveals that there are two crystallographically independent strontium ions in 1. The coordination geometry of Sr（1） is a nine-coordinated distorted monocapped tetragonal antiprism, while Sr（2） is a nine-coordinated distorted monocapped tetragonal prism. The ligand pdc2- takes two different connecting modes and links St（If） centers to generate a 2D layer structure. The 2D layers are linked through O-H...O and O-H...N hydrogen bonds to form a 3D framework structure. Thermal stability and luminescent properties of complex 1 are investigated. 1 belongs to the monoclinic system, space group P21/n with a = 10.7182（10）, b = 7.0377（6）, c = 29.225（3） A, β = 95.7170（10）°, Z = 4, V = 2193.5（3） A3, Mr = 651.56, Dc = 1.973 g/cm3, F（000） = 1296,μ = 4.951 mm-1, the final R = 0.0318 and wR = 0.0726 for 3938 observed reflections with I 〉 2σ（/）.

Synthesis, Structure and Properties of a Two-dimensional Samarium(Ⅲ) Complex of 1,3-Benzenedicarboxylic Acid and 1,10-Phenanthrolin

The title complex [Sm2（bdc）3（phen）2]n （1, H2bdc = 1,3-benzenedicarboxylic acid, phen = 1,10-phenanthrolin）, a new samarium（III） complex based on ligand H2bdc and 1,10-phen- anthrolin, has been hydrothermally synthesized and characterized by elemental analysis, FT-IR, and single-crystal X-ray diffraction. The crystal structure reveals that the Sm（1） centre adopts an eight-coordinated distorted square anti-prism coordination geometry, while the Sm（2） centre adopts a nine-coordinated distorted monocapped square prism coordination geometry. The ligand bdc2- takes two different connecting modes and links the Sm（llI） centers to give rise to a 2D network structure. Further, 2D layers of 1 are connected together to form a 3D structure through C-H-O hydrogen bonding interactions. The luminescent property and thermal stability of complex 1 are studied. 1 belongs to the triclinic system, space group P1 with a = 10.7367（5）, b = 14.3750（7）, c = 13.7505（3）A, a = 92.8840（10）, β = 104.4010（10）, ）, = 98.1400（10）°, Z= 2, V= 2143.44（18） A3, Mr = 1153.44, Dc = 1.787 g/cm3, F（000） = 1128,μ= 2.784 mm-1, the final R = 0.0279 and wR = 0.0720 for 8226 observed reflections with 1 〉 2σ（I）.

Expression of high mobility group protein B1 in the lungs of rats with sepsis

BACKGROUND： Vibrio vulnifi cus inside the body could activate the NF-!B signaling pathwayand initiate the inflammatory cascade. The lung is one of the earliest organs affected by sepsisassociated with acute lung injury. High mobility group protein B1 （HMGB1） is an important late-actingpro-infl ammatory cytokine involving in the pathophysiology of sepsis. It is also involved in the injuryprocess in the lung, liver and intestine. There has been no report on the involvement of HMGB1 inVibrio vulnifi cus sepsis-induced lung injury.METHODS： Sixty rats were randomly divided into a normal control group （group A, n=10） anda Vibrio vulnificus sepsis group （group B, n=50）. Sepsis was induced in the rats by subcutaneousinjection of Vibrio vulnificus （concentration 6×108 cfu/mL, volume 0.1 mL/100g）） into the left lowerlimbs. The rats in group B were sacrifi ced separately 1, 6, 12, 24, and 48 hours after the infection.Their lungs were stored as specimens, lung water content was measured, and lung pathology wasobserved under a light microscope. The expressions of the HMGB1 gene and protein in the lungswere detected by RT-PCR and Western blot. Data were analyzed with one-way analysis of variance（ANOVA） and the LSD method for pair-wise comparison between the two groups. P〈0.05 wasconsidered statistically signifi cant.RESULTS： Compared to group A （0.652±0.177）, HMGB1 mRNA expression in the lungs ofgroup B was signifi cantly higher at 0 hour （1.161±0.358, P=0.013）, 24 hours （1.679±0.235, P=0.000）,and 48 hours （1.258±0.274, P=0.004） （P〈0.05）, and peaked at 24 hours. Compared to group A（0.594±0.190）, HMGB1 protein expression at 6 hours （1.408±0.567, P=0.026） after infection wassignificantly increased （P〈0. 05）, and peaked at 24 hours （2.415±1.064, P=0.000） after infection.Compared to group A （0.699±0.054）, lung water content was significantly increased at 6 hours（0.759±0.030, P=0.001）,12 hours （0.767±0.023, P=0.000）, 24 hours （0.771±0.043, P=0.000） and 48hours （0.789±0.137, P=0.000） after infection （P〈0.05）. Compared to group A, pathological changesat 12 hours in group B indicate marked pulmonary vascular congestion, interstitial edema andinfl ammatory infi ltration. Alveolar cavity collapse and boundaries of the alveolar septum could not beclearly identifi ed.CONCLUSION： Vibrio vulnifi cus sepsis can lead to injury in rat lungs, and increased HMGB1expression in lung tissue may be one of the mechanisms for injury from Vibrio vulnifi cus sepsis.

Effects of Phenyl Content and Molecular Structure on the Refractive Index of Organic Silicon Polymer

The effects of phenyl content and group distribution on the refractive index of phenyl silicone oil were investigated by synthesis and characterization of silicone oils of different molecular structures.A group contribution function model was established to predict the refractive index. The results showed that refractive index of phenyl silicone oil increased as its phenyl content increased. A linear equation had been established to describe the quantitative relationship between the refractive index and phenyl content.Refractive index values from the group contribution function model showed good consistency with experimental results.

Boosting chiral carboxylic acid hydrogenation by tuning metal-MO_(x)-support interaction in Pt-ReO_(x)/TiO_(2) catalysts

Engineering the surface microenvironment by tuning the binary interactions between a supported metal with a secondary metal oxide(MO_(x))or support has been a common method for improving the catalytic performance of supported metal catalysts.However,few studies have investigated the ternary interactions among the metal,MO_(x),and support.Here,we report for the first time the formation of metal-MO_(x)-support interaction(MMSI)in reducible TiO_(2)-supported PtReO_(x) catalysts,affording 87% yield and 100% ee in the tandem hydrogenation of an aqueous chiral cyclohexane-1,2-dicarboxylic acid into the corresponding diol;the catalytic activity is eight times higher than that obtained with non-reducible support counterparts in the same reaction via traditional batch synthesis with multiple steps and unfriendly reagents.Detailed experimental and computational studies suggest that the TiO_(2) crystalline phase-dependent density of the oxygen vacancies induces different Pt-ReO_(x)-TiO_(2) interactions,which dominate the electron transfer therein and tune the adsorption strength of the carbonyl moiety of the substrate/intermediate,thus promoting the hydrogenation activity and selectivity.In addition,the strong MMSI endows the optimal rutile TiO_(2) supported PtReO_(x) catalyst with an outstanding lifetime of 400 h in a fixed-bed reactor under acidic aqueous conditions and ensures efficient applications in the selective hydrogenation of aliphatic dicarboxylic acids and functional carboxylic acids.This work provides a promising strategy for the development of efficient and stable supported catalysts for the selective hydrogenation of diverse C-O and C=O bonds.

Decentralized content sharing in mobile ad-hoc networks:A survey

The evolution of smart mobile devices has significantly impacted the way we generate and share contents and introduced a huge volume of Internet traffic.To address this issue and take advantage of the short-range communication capabilities of smart mobile devices,the decentralized content sharing approach has emerged as a suitable and promising alternative.Decentralized content sharing uses a peer-to-peer network among colocated smart mobile device users to fulfil content requests.Several articles have been published to date to address its different aspects including group management,interest extraction,message forwarding,participation incentive,and content replication.This survey paper summarizes and critically analyzes recent advancements in decentralized content sharing and highlights potential research issues that need further consideration.

dCACH: Content Aware Clustered and Hierarchical Distributed Deduplication

In deduplication, index-lookup disk bottleneck is a major obstacle which limits the throughput of backup processes. One way to minimize the effect of this issue and boost speed is to use very high course-grained chunks for deduplication at a cost of low storage saving and limited scalability. Another way is to distribute the deduplication process among multiple nodes but this approach introduces storage node island effect and also incurs high communication cost. In this paper, we explore dCACH, a content-aware clustered and hierarchical deduplication system, which implements a hybrid of inline course grained and offline fine-grained distributed deduplication where routing decisions are made for a set of files instead of single files. It utilizes bloom filters for detecting similarity between a data stream and previous data streams and performs stateful routing which solves the storage node island problem. Moreover, it exploits the negligibly small amount of content shared among chunks from different file types to create groups of files and deduplicate each group in their own fingerprint index space. It implements hierarchical deduplication to reduce the size of fingerprint indexes at the global level, where only files and big sized segments are deduplicated. Locality is created and exploited first using the big sized segments deduplicated at the global level and second by routing a set of consecutive files together to one storage node. Furthermore, the use of bloom filter for similarity detection between streams has low communication and computation cost while it enables to achieve duplicate elimination performance comparable to single node deduplication. dCACH is evaluated using a prototype deployed on a server environment distributed over four separate machines. It is shown to have 10× the speed of Extreme_Binn with a minimal communication overhead, while its duplicate elimination effectiveness is on a par with a single node deduplication system.

羧基化柚子皮吸附Cd^(2+)的性能与机制

为探索利用食品加工废弃物柚子皮制备一种重金属离子吸附材料的可行性,通过NaOH将柚子皮中甲酯化的羧基水解成羧酸,再利用TEMPO/次氯酸钠/溴化钠体系将柚子皮中C-6位伯羟基氧化成羧酸,制备出一种羧基化柚子皮吸附材料,同时采用FTIR、SEM-EDS和XPS对柚子皮和吸附Cd^(2+)前后的羧基化柚子皮进行表征,研究其吸附机制。结果表明羧基化柚子皮中羧基含量为2.34 mmol/g,是改性前的10.64倍,且可以有效地去除水溶液中Cd^(2+)。羧基化柚子皮吸附Cd^(2+)更符合Langmuir和伪二阶动力学模型,属于单层化学吸附,对Cd^(2+)的最大吸附量为76.16 mg/g,是改性前的5.81倍。羧基化柚子皮中羧基(-COO^(-))是吸附Cd^(2+)的功能性基团,吸附后形成羧酸镉,其中镉以Cd^(2+)的形式存在,与-COO^(-)的配位方式主要是双齿桥式,该吸附过程是一个阳离子(Na^(+)和Cd^(2+))交换的过程。

羧基化吸附材料的制备及其对重金属离子的吸附

以玉米芯为原料,利用原子转移自由基聚合(atomic transfer radical polymerization,ATRP)技术在其表面引发丙烯酸甲酯发生聚合反应,再利用NaOH将嫁接在玉米芯表面的聚丙烯酸甲酯水解成聚丙烯酸钠,得到羧基化玉米芯吸附材料(C-C-A)。通过单因素试验和正交试验优化得到C-C-A最佳制备条件,同时采用FTIR、SEM-EDS和XPS对C-C-A进行表征,结果表明其表面凹凸不平,存在大量羧基。C-C-A对Pb^(2+)、Cd^(2+)、Cu^(2+)和Ni^(2+)的去除率均可达到98%以上,说明其可以有效去除重金属离子。C-C-A吸附重金属离子的过程既符合Pseudo-second-order动力学模型,又符合Langmuir等温线模型,属于单分子层化学吸附,且吸附较快。

聚酰胺纳滤膜表面羧基密度调控及其抗污染性能

采用均苯三甲酰氯(TMC)、对苯二甲酰氯(IPC)与哌嗪进行界面聚合反应,制备了不同羧基密度的聚酰胺纳滤膜.研究了羧基密度对膜污染的影响,并对纳滤膜的镁-锂分离选择效果进行评估.结果表明,TMC纳滤膜的羧基密度是IPC纳滤膜的3倍,水通量分别为81.9 L/(m^(2)·h·MPa)和56.5 L/(m^(2)·h·MPa).TMC纳滤膜对硫酸镁、氯化钠的截留效果优于IPC纳滤膜,对卤水镁的截留率达82.66%,对锂的截留率为-27.82%,具有较好的镁-锂分离选择效果.膜污染结果显示,TMC纳滤膜的不可逆通量衰减指数是IPC纳滤膜的3倍,抗污染能力与膜面羧基密度成反比.结果证实了膜面羧基官能团在膜污染中的关键作用,为制备具备抗污染性和高镁-锂分离比的纳滤膜提供了新思路.

43个玉米自交系遗传多样性分析及其杂种优势群划分

利用SSR标记对43个玉米自交系进行遗传多样性分析,从100对SSR引物中筛选20对扩增带清晰且具有稳定多态性的引物。结果表明,20对引物在供试材料中共检测出71个等位基因变异,平均每对引物检测到等位基因数3.55个,变幅在2~5个之间;每个标记位点的多态性信息含量(PIC)变幅为0.335~0.796,平均多态性信息量为0.533;表明43个自交系具有较为丰富的遗传多样性。43个自交系之间的遗传相似系数变幅为0.441~0.938。UPGMA聚类分析结果表明,43个自交系被划分为四大类群,聚类结果与系谱分析基本一致。