乙烯基封端型氧化石墨烯和碳纳米管复合聚氨酯UV固化树脂的合成与性能

为提高聚氨酯紫外光固化涂料的力学性能和导电性,基于聚氨酯化学反应,采用异佛尔酮二异氰酸酯(IPDI)和甲基丙烯酸羟乙酯(HEMA)对氧化石墨烯(GO)实现了化学接枝,制备出新型氧化石墨烯(HEMA@GO)。探讨了HEMA@GO和多壁碳纳米管(MWCNTs)协同复合对聚氨酯基UV固化涂层的机械强度和导电性的影响。结果表明:化学接枝型氧化石墨烯的层间距由接枝前的0.89 nm扩大到2.10 nm,改善了GO在聚氨酯基体中的分散能力和界面相互作用;当HEMA@GO和MWCNTs的添加量分别为1.0%、3.0%时,聚氨酯膜的拉伸强度和涂层硬度达到了最佳,分别为13.6 MPa和6H。此外,HEMA@GO和MWCNTs的协同作用,显著降低了聚氨酯涂层的方块电阻,从空白涂层的1012 kΩ/□降至7.1 kΩ/□,展现出优异的导电性和力学性能提升效果。

Preparation and Swelling Kinetic Analysis of Poly (HPMC-co-AA-co-AM) Super Absorbent Resin

Super absorbent resin(SAR)is prepared by aqueous high temperature polymerization using hydroxypropyl methylcellulose(HPMC)as monomer backbone material,acrylic acid(AA)and acrylamide(AM)as the graft copolymer monomer,potassium persulfate(KPS)as the initiator to generate free radicals,and N,N`-methylenebisacrylamide(MBA)as cross-linking agent for cross-linking reaction.Simutaneously,the influence of individual factors on the water absorption is investigated,and these factors are mainly AA,AM,KPS,MBA,HPMC,and reaction temperature.The optimized conditions are obtained by the experiment repeating for several times.The water absorption multiplicity and salt absorption multiplicity under the conditions are 782.4 and 132.5 g/g,respectivity.Furthermore,the effects of different temperatures and salt concentrations on its water absorption,as well as the swelling kinetics of SAR are studied.It is indicated the water-absorbing swelling process is mainly caused by the difference in water osmotic pressure and Na+concentration inside and outside the cross-linked molecular structure of the resin,which is not only consistent with the quasi-secondary kinetic model,but also with the Fick diffusion model.

Effect of the presence of trace sulfur dioxide on piperazine-based amine absorbents for carbon dioxide capture

The effect of the presence of trace SO_(2)in industrial flue gas on the amine-scrubbing-based absorption process for CO_(2)capture has been a matter of concern.This study aimed to investigate the effect of trace SO_(2)on the CO_(2)capture process using piperazine-based amine absorbents,focusing on SO_(2)-resistance capability,SO_(2)/CO_(2)absorption selectivity,and cyclic stability.The presence of trace SO_(2)not only restrains CO_(2)absorption,but also promotes the formation of carbamate within the piperazine-based amine absorbents.Remarkably,the incorporation of aminoethyl group in piperazine-based amine absorbents can enhance the SO_(2)-resistance capability by promoting the formation of carbamate,while piperazine-based amine absorbents with hydroxyethyl group can promote the formation of bicarbonate to reduce the SO_(2)-resistance capability.The work offers valuable insights into the efficient application of novel amine absorbents for CO_(2)capture from practical industrial flue gas.

UV/Fe(Ⅲ)工艺对络合态重金属的去除效果及机理

UV/Fe(Ⅲ)工艺是一种处理络合态重金属的新型组合工艺,该工艺先通过Fe(Ⅲ)的置换作用释放游离重金属离子,然后通过UV辐照对有机配体进行降解,最后通过碱性沉淀去除络合态重金属。以Cu(Ⅱ)-EDTA、Ni(Ⅱ)-EDTA为目标污染物,采用UV/Fe(Ⅲ)工艺对其进行去除,通过去除效果对比和机理分析,对组合工艺去除效果差异的内部机理进行阐述,并提出相应的优化方案。结果表明,UV/Fe(Ⅲ)工艺对Cu(Ⅱ)-EDTA、Ni(Ⅱ)-EDTA的去除效果存在较大差异,对两种络合态重金属中Cu、Ni的去除率分别为70%和41%。通过高效液相色谱(HPLC)、分光光度法、苯甲酸(BA)探针实验,确定Cu(Ⅱ)-EDTA、Ni(Ⅱ)-EDTA去除效果差异的主要原因是Fe(Ⅲ)对Cu(Ⅱ)、Ni(Ⅱ)的置换效果有明显差异,置换率分别是85%、22%。对Ni(Ⅱ)-EDTA置换过程分别进行Fe(Ⅲ)投加量和反应温度优化,结果表明,反应温度优化可以显著提升Fe(Ⅲ)对Ni(Ⅱ)-EDTA的置换效率。将反应温度提升至35℃,Ni去除率从41%提升至60%。反应温度在UV/Fe(Ⅲ)工艺中对Ni(Ⅱ)-EDTA的去除至关重要,适当升温有助于提高置换率,进而提升去除率。

Femtosecond mode-locking and soliton molecule generation based on a GaAs saturable absorber

In the last few years,research on advanced ultrafast photonic devices has attracted great interest from laser physicists.As a semiconductor material with excellent nonlinear saturation absorption characteristics,Ga As has been used in solidstate and fiber lasers as a mode-locker.However,the pulse widths that have been reported in the searchable published literature are all long and the shortest is tens of picoseconds.Femtosecond pulse widths,desired for a variety of applications,have not yet been reported in Ga As-based pulsed lasers.In this work,we further explore the nonlinear characteristics of Ga As that has been magnetron sputtered onto the surface of a tapered fiber and its application in the generation of femtosecond lasing via effective dispersion optimization and nonlinearity management.With the enhanced interaction between evanescent waves and Ga As nanosheets,mode-locked soliton pulses as short as 830 fs are generated at repetition rates of 4.64 MHz.As far as we know,this is the first time that femtosecond-level pulses have been generated with a Ga As-based saturable absorber.In addition,soliton molecules,including in the dual-pulse state,are also realized under stronger pumping.This work demonstrates that Ga As-based photonic devices have good application prospects in effective polymorphous ultrashort pulsed laser generation.

Effects of Super Absorbent Polymers on Yield and Water-saving and Drought-escaping Mechanism in Spring Maize

The effects of super absorbent polymers （SAP） on yield as well as water-saving and drought-escaping mechanism in spring maize in the seasonal drought region were studied. As shown by the results, during the seasonal drought in southern China, SAP treatment promoted the soil moisture, improved the capability of absorption and transportation of roots, promoted physiological and biochemical functions, increased the chlorophyll content, photosynthetic rate and intercellular CO2 concentration, and reduced the stomatal conductance and transplre.tion rate. As a result, the economic characters of spring maize were improved, and the yield was increased.

UV-C照射对鲜切豇豆的保鲜效果研究

为探究短波紫外线(UV-C)照射对鲜切豇豆的保鲜效果,在预试验结果的基础上,分别采用0、0.5 kJ/m^(2)的UV-C处理豇豆,然后将其置于4℃条件下贮藏,定期测定相关指标。结果表明:采用0.5 kJ/m^(2)UV-C照射可以维持鲜切豇豆较高的VC、可溶性固形物、可溶性蛋白和叶绿素含量,减少鲜切豇豆丙二醛(MDA)的积累,同时还能保持鲜切豇豆较高的总酚、类黄酮含量,并提高抗氧化酶的活性,包括过氧化物酶(POD)、过氧化氢酶(CAT)、抗坏血酸过氧化物酶(APX),一定程度上稳定多酚氧化酶(PPO)的活性。综合来说,0.5 kJ/m^(2)UV-C处理可用于鲜切豇豆的贮藏保鲜。

装饰用UV延迟固化环保型胶粘剂制备及性能分析

针对传统热固化技术中效率低、材料强度低等问题,制备一种UV延迟固化胶粘剂,并对其工艺进行优化,研究其强度、热稳定性、耐化学性等。试验结果表明,选择25%EP3作为活性稀释剂,1%TR-PAG-20101作为阳离子光引发剂,光固化时间为10 s;试验制备的25%EP3UV延迟固化胶粘剂的粘接强度为(3.52±0.16)MPa,拉伸剪切强度为3.6 MPa,固化反应时间在5 min之内,热分解温度在300℃以上;材料在沸水和酸性溶液(pH=2)环境下,强度依然较好,其中,酸性溶液浸泡后强度为(3.36±0.40)MPa。因此,试验制备的UV延迟固化胶粘剂具备良好的力学性能。

超声耦合TiO_(2)/UV光催化处理对玉米秸秆组分影响研究

本文采用超声耦合Ti O_(2)/UV光催化处理玉米秸秆,探究处理条件对玉米秸秆组分及结构的影响。研究结果表明,在Ti O_(2)投加量为0.25g·L^(-1)、pH值为8.25、超声强度为0.625W·m L^(-1)、处理1h的条件下,玉米秸秆中木质素和半纤维素含量分别由未处理前的26.06%、20.58%降低到22.85%、18.39%,纤维素含量由37.67%增加到40.39%。超声耦合Ti O_(2)/UV光催化处理可以破坏玉米秸秆的结构,玉米秸秆断裂破碎成细小碎片,表面粗糙有褶皱。本研究可为超声耦合Ti O_(2)/UV光催化技术在玉米秸秆预处理中的应用提供技术参考。

UV平板打印技术在核电DCS成套中的研究与应用

随着核电技术的快速发展,核电DCS成套设备对标识、标记等工艺要求不断提高,传统的标识方法已难以满足高精度、高效率的需求。本文深入研究了UV平板打印技术,探讨了其在核电DCS成套设备中的应用,并对其优势进行了详细分析。实验结果表明,UV平板打印技术能够显著提高标识的清晰度和效率,为核电DCS成套设备的制造和维护提供了有力的技术支持。

UV-B照射时长对酿酒葡萄果实品质及类黄酮代谢产物的影响

为探明UV-B照射时长对赤霞珠酿酒葡萄果实品质及类黄酮物质的影响,试验设立UV-B每天分别照射2、4、6、8 h共4个梯度,以不进行UV-B照射为对照(CK),对不同UV-B照射时长葡萄果实品质及类黄酮物质进行检测分析。结果表明,短时间的UV-B照射会增加果实中可溶性糖含量,UV-B不同照射时长处理的总酚、单宁、总类黄酮、黄烷-3-醇和总花色苷含量均增加;UV-B不同照射时长对酿酒葡萄果皮中的类黄酮代谢产物影响显著,筛选出差异代谢物13个,其中5种物质显著上调、8种物质显著下调;在类黄酮和次生代谢产物合成通路上分别富集了7个差异代谢物,占代谢物总数的77.78%。利用主成分对果实品质和果皮类黄酮产物测定值进行综合评价,得分从高到低依次为UV-B照射2 h>UV-B照射8 h>UV-B照射4 h>UV-B照射6 h>CK。UV-B照射酿酒葡萄赤霞珠2 h时,果实品质和类黄酮代谢产物表现最佳。

Simultaneous desulfurization and denitrification of sintering flue gas via composite absorbent

Experiments on simultaneous absorption of SO_2 and NO_X from sintering flue gas via a composite absorbent NaClO_2/NaClO were carried out. The effects of various operating parameters such as NaClO_2 concentration(ms), NaClO concentration(mp), molar ratio of NaClO_2/NaClO(M), solution temperature(TR), initial solution pH, gas flow(Vg) and inlet concentration of SO_2(CS) and NO(CN) on the removal efficiencies of SO_2 and NO were discussed. The optimal experimental conditions were determined to be initial solution pH = 6, TR=55 °C and M = 1.3 under which the average efficiencies of desulfurization and denitrification could reach99.7% and 90.8%, respectively. Moreover, according to the analysis of reaction products, it was found that adding NaClO to NaClO_2 aqueous solution is favorable for the generation of ClO_2 and Cl_2 which have significant effect on desulfurization and denitrification. Finally, engineering experiments were performed and obtained good results demonstrating that this method is practicable and promising.

CO_2 absorption into a phase change absorbent: Water-lean potassium prolinate/ethanol solution

Phase change solvents are attractive energy-efficient absorbents for carbon dioxide(CO_2) capture due to CO_2-rich phase formation. Potassium prolinate + water + ethanol(ProK/W/Eth) solution has shown good capture characteristics as a promising one in our previous work. In this work, absorption rate of CO_2, solubility of N2 O,and heat of absorption for ProK/W/Eth solution were investigated using a stirred cell reactor and a CPA201 reaction calorimeter and these results were also compared with the aqueous ProK and 30 mass% MEA solutions.Using ethanol as a solvent can substantially increase the CO_2 physical solubility and the absorption rate of CO_2 in ProK/W/Eth solutions is far higher than that in aqueous 30 mass% MEA solutions especially at a low CO_2 loading range. Solid precipitation, obtained from the liquid-to-solid phase change absorption, was analyzed by13 C NMR and DSC-TGA. The enthalpy change for ProK/W/Eth solutions at various CO_2 loading was also discussed.

Promoting effect of super absorbent polymer on hydrate formation

The effect of super absorbent polymer（SAP） on the formation of tetrahydrofuran（THF） hydrate was studied by the successional cooling method.It was found that THF solution samples with 0.004 wt% and 0.03 wt% of SAP formed THF hydrate completely during the same cooling process.The corresponding induction time was 16-29 min,14-31 min,respectively,which was obviously shorter than that of THF solution samples without SAP（25-62 min）.It indicated that SAP accelerated the formation of THF hydrate.At the same time,the pictures of hydrate formation with and without SAP had been compared.It was found that SAP did not change the morphology of the hydrate.Finally,the mechanism of SAP promoting effect on the formation of THF hydrate was suggested.

Preparation and Characterization of Super Absorbent Resin from Natural Cellulose

The grafting polyacrylamide onto wood pulp cellulose (cell g PAM) was performed with cerous ammonium nitrate as the initiator and hydrolyzed to produce the super absorbent resin. The FTIR shows that the polyacrylamide is grafted on the cellulose. After hydrolyzation, part of acrylamino groups are transformed into carboxyl groups. The XRD analysis shows that the graft polymerization occurred at the amorphous section and the surface of the crystal section of cellulose. The SEM graph reveals that there is a layer of polymer on the surface of cellulose fiber and the fibril structure of the cellulose surface is covered. After hydrolyzation, the surface of the product is different from that of cell g PAM's and the surface is scraggy. The technical conditions to prepare high water absorbent resin were confirmed. Through the radical graft copolymerization, the high water absorbent resin can be produced from wood pulp cellulose.

HPLC-UV法同时测定赤血康脉胶囊中五种成分

本研究旨在建立HPLC-UV法同时测定赤血康脉胶囊中芍药苷、毛蕊异黄酮葡萄糖苷、β-蜕皮甾酮、阿魏酸和党参炔苷的含量。采用DiamonsilR C_(18)(250 mm×4.6 mm,5μm)色谱柱;流动相为乙腈-0.1%磷酸(梯度洗脱);流速为1.0 mL/min;柱温为35℃;检测波长为268 nm,进行分析。结果显示,5种化学成分在各自范围内线性关系良好(r>0.9995);精密度、稳定性、重复性试验结果的RSD均小于2.0%,平均加样回收率99.35%~101.59%,RSD 0.95%~2.69%。该含量测定方法简单可靠、重复性好,操作便捷,适用于同时测定赤血康脉胶囊中五种成分的含量。

UV接枝聚硅氧烷-TiO_(2)复合棉织物的制备及性能

通过紫外辐射3-(异丁烯酰氧)丙基三甲氧基硅烷对棉织物进行接枝聚合改性,然后与钛酸四丁酯共水解,形成Si—O—Ti化学键,通过化学键合的形式引入TiO_(2)层。由于Si元素位于棉织物和二氧化钛之间,阻断TiO_(2)光催化降解棉织物。化学键合TiO_(2)与棉织物的结合强度高,提高了耐久性。TiO_(2)对棉织物的整体结构未造成改变,但棉织物的抗紫外线能力显著提升,禁带宽度变小,光催化自清洁能力增强。

基于HPLC-UV-QDa检测不同剂型中噻唑膦和吡虫啉

建立了高效液相色谱-紫外检测器-质谱(HPLC-UV-QDa)测定5种不同剂型产品中噻唑膦和吡虫啉含量的分析方法。样品以乙腈+水(0.05%甲酸)为流动相,采用C18色谱柱进行梯度洗脱,结合紫外和质谱串联检测器进行定性和定量分析。研究结果显示,在质量浓度0.05~50 mg/L,噻唑膦、吡虫啉的线性关系良好,R2分别为0.9992~0.9999和0.9991~0.9996。在0.5、50、500 mg/kg等3个添加水平下,噻唑膦、吡虫啉的平均回收率分别为90.2%~103.9%和94.7%~104.1%,相对标准偏差(RSD)分别为1.04%~6.69%和1.27%~5.88%。噻唑膦和吡虫啉在5种基质中无明显基质效应,检出限分别为0.005和0.01 mg/L,定量限分别为0.02和0.04 mg/kg。方法灵敏度高、稳定性好、准确度高,适用于不同剂型产品中噻唑膦和吡虫啉的分析。

Influence of absorbent on electromagnetic wave absorbing property of porous concrete

Influences of ferrite content and iron ore powder content on electromagnetic wave absorbing property of porous concrete are studied.The radar cross section(RSC)of samples was tested in a microwave anechoic chamber.Results show that the optimum content of ferrite is 15%,and the minimum,maximum and average reflectivity of the sample is-46.60 dB,-10.84 dB and-23.75 dB,respectively.And the sample's improved bandwidth is 8.2 GHz.The optimum content of iron ore powder is 20%,and the minimum,maximum and average reflectivity of the sample is-34.69 dB,-9.25 dB and-20.69 dB,respectively.And the sample's improved bandwidth is 6 GHz.In conclusion,appropriate ferrite and iron ore powder can improve wave absorbing property and widen wave absorption bandwidth of porous concrete.

A New CMC-AA Resin/Inorganic-gel Super Absorbent Material

A super absorbent material was prepared with the super absorbent resin （ SAR ） and inorganic gel. The SAR of the carboxymethyl cellulose grafting acrylic acid （ CMC-AA ） was copolymer synthesized using the method of inverse-phase suspension polymerization. The influences of the monomer concentration, neutralization degree, the initiator, dispersion agent, cross-linking agent, reaction and drying temperature on the grafting copolymer properties were examined. Meanwhlie, its properties was investigated and the model for absorption mechanism of this absorbent composite was proposed.