壳聚糖在4种咪唑型离子液体中溶解性的研究

研究、比较了壳聚糖在4种咪唑型离子液体氯化1-丁基-3-甲基咪唑([BMIM]Cl)、1-丁基-3-甲基咪唑醋酸盐([ BMIM] Ac)、1-乙基-3-甲基咪唑醋酸盐([EMIM] Ac)和氯化1-烯丙基-3-甲基咪唑([AMIM] Cl)中的溶解性,提出了可能的溶解机理,并利用红外光谱(FTIR)、热重分析(TGA...     

弱碱性离子交换树脂D301分离低浓度甲酸的研究

采用D301弱碱性离子交换树脂对水溶液中低浓度甲酸进行分离。静态条件下考察了时间、温度、振荡速率和树脂用量对分离效果的影响,获得了交换等温线;动态条件下考察了不同高径比、流速、温度、浓度下动态穿透曲线;研究了树脂再生效果与稳定性。初始浓度573mg/L的甲酸废水,在树脂用量2.5g/L、温度35℃、振荡速率160r/min条件下,最大交换量为154.16mg/g;其交换等温线符合Langmuir方程,热力学平衡方程计算得G<0,H=10.25kJ/mol,S>0,表明该吸附过程是自发的、吸热、熵增加的过程。交换过程中颗粒扩散是离子交换的主要速率控制步骤,表观活化能与反应级数分别为5.983kJ/mol和0.378。     

Treatment of anionic dye aqueous solution using Ti,HDTMA and Al/Fe pillared bentonite. Essay to regenerate the adsorbent

In this study, the adsorption removal of an anionic dye (Congo red) by a local bentonite before and after modification was studied. The modification of the bentonite was made by organophilisation using surfactant (HDTMA) and by pillaring process to obtain a bentonite with Ti pillars and with mixed pillars of Fe/Al. The various synthesized materials are characterized by different techniques such as DRX, MET, N₂ adsorption-desorption, Zeta potential measurement. Results show the development of the texture and the structure of the bentonite after modification. The various adsorbents synthesized show an increase in the adsorption capacity of Congo Red compared to the initial bentonite. Adsorption isotherms are described by the Langmuir model in all cases except that for Ti pillared bentonite, the Freundlich model is more suitable. Pseudo-second order is better for describing the adsorption process. Also, regeneration of the adsorbent is approached in this study by photochemical way and the results show a total regeneration of the adsorbent.     

Phenylboronic acid immunoaffinity reactor coupled with flow injection chemiluminescence for determination of α-fetoprotein

A reusable and sensitive immunoassay based on phenylboronic acid immunoaffinity reactor in combination with flow injection chemiluminescence (CL) for determination of glycoprotein was described. The reactor was fabricated by immobilizing 3-aminophenylboronic acid (APBA) on glass microbeads with γ-glycidoxypropyltrimethoxysilane (GPMS) as linkage. The α-fetoprotein (AFP) could be easily immobilized on the APBA coated beads through sugar-boronic interaction. After an off-line incubation, the mixture of the analyte AFP with horseradish peroxidase-labeled AFP antibody (HRP-anti-AFP) was injected into the reactor. This led the trapping of free HRP-anti-AFP by the surface coated AFP on glass beads. The trapped HRP-anti-AFP was detected by chemiluminescence due to its sensitizing effect on the reaction of luminol and hydrogen peroxide. Under optimal conditions, the chemiluminescent signal was proportional to AFP concentration in the range of 10-100 ng mL⁻¹. The whole assay process including regeneration of the reactor could be completed within 31 min. The proposed system showed acceptable detection and fabrication reproducibility, and the results obtained with the present method were in acceptable agreement with those from parallel single-analyte test of practical clinical sera. The described method enabled a low-cost, time saving and was potential to detect the serum AFP level in clinical diagnosis.     

不可逆费米奥托制冷循环性能分析

基于回热式不可逆奥托制冷循环和理想费米气体的状态方程,导出以费米气体为工质的奥托制冷循环的输入功、制冷量、制冷系数等重要性能参数的表达式,以此讨论费米气体的量子简并性、回热及内不可逆性对循环性能的影响,给出以理想费米气体为工质的回热式不可逆奥托制冷循环的性能特征。所得结果有助于进一步了解经典气体奥托制冷循环与量子气体奥托制冷循环的区别和联系。     

Regenerating Spent Solutions of Vanadium‐containing Heteropoly Acids in the Presence of Additives

Vanadium‐containing heteropoly acid solutions of Keggin H_3+xPMo_12–xV_xO₄₀ and modified H_aP_zMo_yV_xO_b types (P‐Mo‐V HPAs) are promising nanosized inorganic metal‐oxygen cluster compounds with the property of reversible oxidability (V^V ↔ V^IV). The oxidation of reduced P‐Mo‐V HPAs at a temperature of 130–170 °C and an oxygen pressure of 4 atm is a convenient method for their regeneration, but results in regeneration degree of only 75–88 %. Various materials with electron transfer or oxidative properties, such as nitrogen doped carbon nanofibers (N‐CNFs), Sibunit‐4, HNO₃, and MoO₂, were investigated as additives to facilitate and accelerate the regeneration of HPA solutions. Among the studied additives HNO₃ was found to show the best efficiency, resulting in regeneration degree of higher 95 %. Rapid and efficient regeneration of spent HPA catalysts is an important criterion for achieving high productivity and sustainability of oxidative processes on their basis.     

Electrochemical immunoassay for α-fetoprotein through a phenylboronic acid monolayer on gold

A novel reusable electrochemical immunosensor for α-fetoprotein (AFP) based on phenylboronic acid monolayer on gold was proposed. The sensor was fabricated by immobilizing of 3-aminophenylboronic acid (APBA) conjugated thiol-mixed monolayer on gold through 2-(5-norbornene-2,3-dicarboximido)-1,1,3,3-tetramethyluronium tetrafluoroborate (TNTU) as linkage. AFP and enzyme-conjugated antibody were further trapped to the modified electrode surface through sugar-boronic acid and immunoaffinity interactions, respectively. The attached enzyme-conjugated antibody on the electrode surface could catalyze the reduction of hydrogen peroxide in the presence of thionine, which can be used to detect AFP in human serum by a competitive mechanism. Cyclic voltammetric, electrochemical impedance studies and photometric activity assays were used to probe the assembly and regeneration process of the immunosensor. The influences of the competitive ratio of antigen and antibody, pH value of the measuring solution, incubation temperature and time were explored for optimizing the analytical performance. The whole assay process including incubation, detection and regeneration of the electrode could be completed in 35 min. The detection of AFP in five serum samples provided from clinically diagnosed patients with liver cancer showed acceptable accuracy. The proposed immunosensor enabled fast, low-cost and would be valuable for clinical diagnosis.     

Long-term results of recurrent laryngeal nerve resection for adductor spasmodic dysphonia

From a total of 43 adductor spasmodic patients over a 10-year period, 11 underwent resection of a portion of the recurrent laryngeal nerve on one side. The initial results were excellent but a varying degree of recurrence took place in 8 patients. In 4, a reoperation was done. At the final follow-up, 2–8 years after the primary operation, 4 patients were no longer suffering from spasmodic dysphonia, another 5 were better off than before surgery, and 1 remained unchanged. Only 1 was worse off. Electromyographic findings indicated that the recurrence of symptoms was due to regeneration of the nerve fibers.     

砷中毒商业V2O5-WO3/TiO2催化剂再生研究

采用FeCl3和2, 4, 6-三巯基三嗪（TMT）溶液分别清洗再生砷（As）中毒商业V2O5-WO3/TiO2催化剂,通过BET、XRD、XRF、in situ DRIFTS以及H2-TPR等表征方法对清洗再生前后催化剂理化性质进行分析。研究发现,清洗后催化剂脱硝活性有极大地恢复,20 mg/ml FeCl3和0.5%TMT溶液再生30 min时最佳As去除率分别为83.67%和94.57%。清洗后,阻塞在催化剂微孔和中孔中的AsOx被清除,因此再生后催化剂比表面积和孔体积均有所增大而平均孔径略有减小。同时,FeCl3和2,4,6-TMT溶液清洗再生后催化剂表面Br?nsted和Lewis酸强度均有所增加,这可能是再生催化剂催化性能提高的主要原因。