Pyrolyzed Iron Phthalocyanine-Modified Multi-Walled Carbon Nanotubes as Composite Anode in Marine Sediment Microbial Fuel Cells and Its Electrochemical Performance

Improving the performance of anode is a crucial step for increasing output power of marine sediment microbial fuel cells(MSMFCs)to drive marine monitor to work for a long term on the ocean floor.A pyrolyzed iron phthalocyanine modified multi-walled carbon nanotubes composite(FePc/MWCNTs)has been utilized as a novel nodified anode in the MSMFC.Its structure of the composite modified anode and electrochemical performance have been investigated respectively in the paper.There is a substantial improvement in electron-transfer efficiency from the bacteria biofilm to the modified anode via the pyrolyzed FePc/MWCNTs composite based on their cyclic voltammetry(CV)and Tafel curves.The electron transfer kinetic activity of the FePc/MWCNTs-modified anode is 1.86 times higher than of the unmodified anode.The maximum power density of the modified MSMFC was 572.3±14 m W m^-2,which is 2.6 times larger than the unmodified one(218.3±11 m W m^-2).The anodic structure and cell scale would be greatly minimized to obtain the same output power by the modified MSMFC,so that it will make the MSMFC to be easily deployed on the remote ocean floor.Therefore,it would have a great significance for us to design a novel and renewable long term power source.Finally,a novel molecular synergetic mechanism is proposed to elucidate its excellent electrochemical performance.

La_(0.75)Sr_(0.25)Cr_(0.5)Mn_(0.5)O_(3)-δ−Ce_(0.8)Gd_(0.2)O_(1.9) composite electrodes as anodes in LaGaO_(3)-based direct carbon solid oxide fuel cells

Direct carbon solid oxide fuel cells(DC-SOFCs)are promising,green,and efficient power-generating devices that are fueled by solid carbons and comprise all-solid-state structures.Developing suitable anode materials for DC-SOFCs is a substantial scientific challenge.Herein we investigated the use of La_(0.75)Sr_(0.25)Cr_(0.5)Mn_(0.5)O_(3)-δ−Ce_(0.8)Gd_(0.2)O_(1.9)(LSCM−GDC)composite electrodes as anodes for La_(0.9)Sr_(0.1)Ga_(0.8)Mg_(0.2)O_(3)-δelectrolyte-based DC-SOFCs,with Camellia oleifera shell char as the carbon fuel.The LSCM−GDC-anode DC-SOFC delivered a maximum power density of 221 mW/cm^(2) at 800℃ and it significantly improved to 425 mW/cm^(2) after Ni nanoparticles were introduced into the LSCM−GDC anode through wet impregnation.The microstructures of the prepared anodes were characterized,and the stability of the anode in a DC-SOFC and the influence of catalytic activity on open circuit voltage were studied.The above results indicate that LSCM–GDC anode is promising to be applied in DC-SOFCs.

Application of carbon composite iron ore hot briquette to innovative ironmaking process

As a new type of ironmaking raw materials,carbon composite iron ore hot briquette(CCB) is the product of fine iron ore and fine coal by hot briquetting process.On basis of experimental research on the manufacturing and metallurgical properties of CCB,this study focused on the application of CCB to blast furnace ironmaking and newly-developed shaft furnace smelting reduction processes.Firstly,the metallurgical properties of CCB are experimentally tested and compared with the common iron-bearing burdens.Then,the effects of charging CCB on blast furnace operation are numerically analyzed by means of multi-fluid blast furnace model,and the flowchart and pilot test of CCB-Shaft furnace smelting reduction process are briefly introduced.

CIPs@Mn_(0.8)Zn_(0.2)Fe_(2)O_(4)-CNTs复合材料低频吸波性能研究

随着5G无线通信与低频雷达侦察技术的飞速发展,低频电磁波辐射已成为当代的严重问题。目前,中高频段吸波材料的研究已趋于成熟,而设计低频段吸波材料仍面临巨大的挑战,亟待研究者们解决。基于四分之一波长相消机制,本研究设计了0.5~3 GHz低频段复合吸波材料。采用简单的一步水热法,诱导铁氧体在羰基铁粉与碳纳米管表面生长,制备出CIPs@Mn_(0.8)Zn_(0.2)Fe_(2)O_(4)-CNTs三元复合材料,对比研究了碳纳米管含量对材料吸收峰频率的影响。实验结果表明,引入碳纳米管,一方面为材料带来了界面极化、偶极极化等额外的损耗机制,增加了材料的衰减系数;另一方面基于四分之一波长相消机制,高介电与高磁导率的耦合,使材料在低频段获得良好的阻抗匹配。最终,在4 mm厚度下,样品分别在2.11与1.75 GHz处,获得了–40.8与–32.1 dB的反射损耗,–10 dB带宽分别为1.70~2.70 GHz和1.40~2.20 GHz。该复合材料制备工艺简单,低频吸收性能良好,具有很大的应用潜力,为开发更有效的低频吸波材料提供了新的思路和方法。

Influences of ZrO_2-SiC Composite Powder and Commercial SiC on Properties of Al_2O_3-C Refractories

In order to improve oxidation resistance and ther- mal shock resistance of Al2O3-C refractories, two groups of specimens were prepared with phenolic resin as binder, adding 0, 2 wt% , 4 wt% and 6 wt% commercial SiC or ZrO2-SiC composite powder synthesized from zircon respectively to Al2O3- C refractories, pressing at 200 MPa, drying fully at 250℃, and then carbon embedded firing at 1400℃ for 2 h. Oxidation resistance and thermal shock resistance were researched, phase composition was analyzed by XRD. The results showed that the oxidation of SiC in additives could protect carbon in specimens effectively and thus decreased the mass loss ratio and oxidation area, and improved the oxidation resistance of the specimen. Thermal shock resistance was improved owing to the micro crack toughening of ZrO2 and grain toughening of SiC. In this experiment, the specimens with 6 wt% ZrO2 -SiC composite powder or 6 wt% SiC powder had the best oxidation resistance and thermal shock resistance.

Electrocatalytic Reduction of Oxygen at Perovskite (BSCF)-MWCNT Composite Electrodes

A composite paste electrode based on Ba0.5Sr0.5Co0.8Fe0.2O3-δ (BSCF)—initially synthesized by solgel method—and multiwall carbon nanotube (MWCNT) as a cathode in fuel cells is developed. The composite pastes are prepared by the direct mixing of BSCF:MWCNT at 90:10, 80:20 and 70:30 (% w/W). These electrodes are then characterized by the x-ray diffraction (XRD), scanning electron microscopy (SEM), nitrogen adsorption-desorption isotherm, electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). The XRD and SEM confirm the inclusion and the uniform dispersal of the MWCNT within BSCF, respectively. The nitrogen adsorption isotherm study shows that the porosity of the composite paste electrode has been improved by two-fold from the BSCF electrode. The EIS and CV demonstrate that the higher ratios of MWCNT in the composites are critical in improving the electronic conductivity as well as the kinetics. It is also noticeable that the electrode has increased the catalysis of oxygen in 0.1 M KOH (pH 12.0). Cyclic voltammetric studies on the oxygen reduction reaction (ORR) suggest that the incorporation of MWCNT is vital in improving the electrode (cathode) properties of a fuel cell.

Relationship between Primary Crystal Temperature and Carbon Equivalent in Cast Iron

CE （=%C＋（1/3）x（%Si）） does not suit experiment results in many cases. In this work, the effect of alloy elements on primary crystal temperature was measured and the relationship between primary crystal temperature （Tc） and carbon equivalent （CEL） was investigated. The results show that Tc （Celsius degree） = 1650-110 × （%C） -25 × （%Si）＋3 × （%Mn） -35 × （%P） -71 × （%5）-2 × （%Ni） -7 × （%Cr）; CEL=%C ＋ 0.23×（%Si）-0.03× （%Mn）＋0.32×（%P）＋0.64×（%S） ＋0.02×（%Ni）＋0.06×（%Cr）. That is, in hypo eutectic composition, carbon equivalent should be calculated with CEL=%C＋ 0.23×（%Si）, not with CE=%C＋（1/3） x（%Si）.

3-Aminopropyltriethoxysilane Complexation with Iron Ion Modified Anode in Marine Sediment Microbial Fuel Cells with Enhanced Electrochemical Performance

Anode modification plays a key role in higher power output in marine sediment microbial fuel cells(MSMFCs).A low-molecular organosilicon compound(3-aminopropyltriethoxysilane)was grafted onto the surface of carbon felt using chemical method and a composite modified anode was prepared through organic ligands coordination Fe^(3+)for better electro-chemical per-formance.Results show that the biofilm resistance of the composite modified anode(2707Ω)is 1.3 times greater than that of the unmodified anode(2100Ω),and its biofilm capacitance also increases by 2.2 times,indicating that the composite modification pro-motes the growth and attachment of electroactive bacteria on the anode.Its specific capacitance(887.8 Fm^(−2))is 3.7 times higher than that of unmodified anode,generating a maximum current density of 1.5Am^(−2).In their Tafel curves,the composite modified anodic exchange current density(5.25×10^(−6)Acm^(−2))is 5.8 times bigger than that of unmodified anode,which suggests that the electro-chemical activity of redox,anti-polarization ability and electron transfer kinetic activity are significantly enhanced.The marine sediment microbial fuel cell with the composite modified anode generates the higher power densities than the blank(203.8mWm^(−2) versus 45.07mWm^(−2)),and its current also increases by 4.4 times.The free amino groups on the anode surface expands a creative idea that the modified anode ligates the natural Fe(Ⅲ)ion in sea water in the MSMFCs for its higher power output.

Effects of Multi-walled Carbon Nanotubes on the Electromagnetic Absorbing Characteristics of Composites Filled with Carbonyl Iron Particles

The electromagnetic （EM） wave absorbing property of silicone rubber filled with carbonyl iron particles （CIPs） and multi-walled carbon nanotubes （MWCNTs） was examined. Absorbents including MWCNTs and spherical/ flaky CIPs were added to silicone rubber using a two-roll mixer. The complex permittivity and complex permeability were measured over the frequency range of 1-18 GHz. The two EM parameters were verified and the uniform dispersion of MWCNTs and ClPs was confirmed by comparing the measured reflection loss （RL） with the calculated one. As the MWCNT weight percent increased, the RL of the spherical CIPs/silicone rubber composites changed insignificantly. It was attributed to the random distribution of spherical ClPs and less content of MWCNTs. On the contrary, for composites filled with flaky ClPs the absorption bandwidth increased at thickness 0.5 mm （RL value lower than -5 dB in 8-18 GHz） and the absorption ratio increased at lower frequency （minimum -35 dB at 3.5 GHz）. This effect was attributed to the oriented distribution of flaky CIPs caused by interactions between the two absorbents. Therefore, mixing MWCNTs and flaky CIPs could achieve wider-band and higher-absorption ratio absorbing materials.

铁粉/碳纤维增强树脂复合材料的制备 及脆化损伤研究

将偶联剂改性纳米铁(Fe)粉与预处理后的碳纤维混合,浸润于环氧树脂基料中,经过搅拌混合制备纳米Fe粉/碳纤维增强树脂复合材料,研究了复合材料在高温老化、水浸老化环境下的脆化损伤行为。结果表明:树脂受到高温老化和水浸泡老化后会出现脆化损伤,碳纤维和纳米Fe粉加入会对该损伤有一定抑制;加入质量分数为4.0%的纳米Fe粉后,随着高温老化时间延长,碳纤维质量分数为3.0%的纳米Fe粉/碳纤维增强复合材料的拉伸强度、断裂韧性下降幅度较小,同时脆化损伤后树脂与纳米Fe粉、碳纤维仍结合紧密;碳纤维质量分数为3.0%、纳米Fe粉质量分数为4.0%的纳米Fe粉/碳纤维增强复合材料经水浸老化后,断裂韧性仍旧保持较高水平。

Fe-Zn-Zr/分子筛复合催化剂上CO_2加氢合成异构烷烃Ⅰ.不同分子筛对催化剂性能的影响

在Fe Zn Zr/分子筛复合催化剂上考察了不同类型的分子筛对CO2 加氢反应性能的影响 .结果表明 ,不同分子筛对复合催化剂性能的影响不同 ,Fe Zn Zr/HY是合成异构烷烃有效的复合催化剂 .分子筛的酸性及酸强度对复合催化剂性能有较大的影响 ,中等强度和较高强度的酸性位有利于异构烃的生成 .

白口铸铁/碳钢液-固复合铸造研究

利用只受内压的厚壁圆筒应力计算公式 ,计算出液 固复合铸造时金属预制件被包覆部位的最大允许尺寸。白口铸铁 /碳钢复合铸造试验及生产实践都表明 ,计算结果对控制包覆层内表面裂纹的产生具有一定的实用价值。关于硅、磷含量对白口铸铁包覆层内表面裂纹的影响 ,也作了一定的探讨。

Fe-Cr-C系高碳耐磨堆焊合金组织及性能

研究了Fe Cr C高碳耐磨堆焊合金的显微组织及其性能 ,对含碳量为 3 .3 4 %、4 .1 1 %、5 .1 6 %、6 .5 %的四种耐磨堆焊层微观组织及初生碳化物的形态进行了研究 ,分析了碳对微观组织和力学性能的影响。试验结果表明 ,对Fe Cr C耐磨堆焊合金 ,随含碳量的增加 ,初生碳化物数量越来越多且单个碳化物颗粒的体积也变大 ;堆焊层宏观硬度一直持续增加 ;当含碳量 <5 .1 6 %时 ,耐磨性随碳含量的增加而提高 ,但当含碳量到达一定程度时 ,耐磨性反而降低。碳对耐磨堆焊层的组织及性能起着重要作用 ;从理论上分析了湿砂磨损后耐磨面上的孔洞可能就是初生碳化物上的空洞

SCSC-S/Fe复合系统脱氮除磷途径及微生物群落特性

为提升再生水品质,以玉米芯耦合硫铁填料构造出固相纤维素碳源+硫铁填料复合脱氮除磷系统(简称SCSC-S/Fe复合系统),基于填料生物膜Miseq高通量测序构建了16S rRNA基因克隆文库,结合系统沉积物的X射线衍射(XRD)分析,探讨了该系统对模拟城市污水处理厂低C/N比尾水深度脱氮同步除磷特性及作用途径.结果表明,随温度升高,TN去除率逐渐增大,TP去除率增加不明显,在温度为30℃和水力停留时间HRT=9h时,NO_3^--N、TN、TP平均去除率分别为99.86%、92.70%和89.15%.固相纤维素碳源反硝化脱氮单元内具有降解纤维素类和反硝化作用类细菌分别占细菌总数的41.37%和54.02%,硫铁复合填料脱氮除磷单元内异养反硝化、硫自养反硝化和氬自养反硝化的细菌占细菌总数的91.53%;XRD结果表明,水中的PO_4^(3-)主要以FeP0_4、Fe_3(P0_4)_2·χH_20和Fe_3(P0_4)_3(0H)_2等物质形式去除.因此,复合系统脱氮以异养反硝化作用为主,协同硫自养反硝化和氢自养反硝化作用;复合系统具有"化学+生物"双重除磷作用,以化学除磷作用为主.SCSC-S/Fe复合系统实现了低C/N比城市污水处理厂尾水深度脱氮同步除磷的目的.

氮化硅-氧氮化硅复合粉对Al2O3-SiC-C铁沟料性能的影响

为了进一步提高Al 2O3-SiC-C出铁沟浇注料的性能并降低其生产成本,在其中加入质量分数分别为0、2%、4%、6%、8%的氮化硅-氧氮化硅复合粉等量替代其中的碳化硅粉,加水搅拌均匀后,检测料浆的流动性,再经浇注成型、养护、烘干、不同温度(800、1100和1450℃)热处理等程序制成浇注料试样,然后检测浇注料试样的线变化率、显气孔率、体积密度、常温抗折强度、热态抗折强度和抗渣性,并采用XRD分析浇注料试样的物相组成。结果表明:1、加入氮化硅-氧氮化硅复合粉后,Al 2O3-SiC-C出铁沟浇注料的初始流动值减小,烧后线变化率、显气孔率、体积密度、常温抗折强度和热态抗折强度变化不大,抗高炉渣侵蚀性提高。2、综合考虑,氮化硅-氧氮化硅复合粉的最佳加入量为4%(w)。

复合抗氧化剂加入量对Al_2O_3-SiC-C浇注料性能的影响

以电熔棕刚玉为骨料，电熔棕刚玉粉、活性α-Al2O3微粉、黑碳化硅粉、球状沥青、SiO2微粉、纯铝酸钙水泥等为基质料，配以质量分数为2％、2．3％、2．6％、2．9％的复合抗氧化剂，搅拌均匀制备成Al2O3-SiC—C质浇注料。外加5％（埘）的水搅拌3～5min后，检测浇注料的流动性；经振动成型、养护、脱模、干燥后，于1500℃空气气氛中热处理3h，测定热处理后试样的质量损失率、体积密度、显气孔率、常温耐压强度、常温抗折强度和抗热震性。结果表明：随着复合抗氧化剂加入量（W）从2％增加到2．9％，浇注料的流动性变化不大并且保持较高的水平，显气孔率、体积密度和常温强度变化不大，质量损失率从1．14％减小到0．35％，氧化层厚度逐渐减小；复合抗氧化剂加入量为2．9％（W）的试样热震后耐压强度仍保持在70MPa左右，具有较好的抗热震性。

济南市钢铁集聚区大气细颗粒物中碳组分污染特征

为分析钢铁集聚区大气细颗粒物(PM_(2.5))中碳组分的污染特征,对济南市钢铁集聚区和市区秋季(2020年10月15日至2020年10月24日)、冬季(2020年12月18日至2021年1月7日)和春季(2021年4月23日至5月2日)环境空气中PM_(2.5)进行手工采样,利用热光碳分析仪测定了PM_(2.5)中有机碳(OC)和元素碳(EC)的含量.结果表明,钢铁集聚区秋季OC和EC质量浓度范围分别为5.79—12.56μg·m^(−3)和1.34—3.44μg·m^(−3);冬季OC和EC质量浓度范围分别为3.92—55.54μg·m^(−3)和0.38—11.39μg·m^(−3);春季OC和EC质量浓度范围分别为2.14—4.70μg·m^(−3)和0.19—1.33μg·m^(−3),呈现显著的季节变化,表现为冬季>秋季>春季.钢铁集聚区冬季PM_(2.5)中OC和EC占比最高,分别为28.11%和5.36%,春季OC和EC占比最低,分别为9.82%和1.76%.钢铁集聚区秋季和冬季OC(EC)质量浓度均高于市区,分别是市区的2.12(2.68)、2.27(4.27)倍,表明钢铁集聚区秋冬季PM_(2.5)的污染状况比较严峻.在以PM_(2.5)为首要污染物的不同污染等级下,均为碳组分OC4和EC1的占比最高,分别占PM_(2.5)的9.0%和7.5%,是碳组分的主要贡献组分.钢铁集聚区春季、秋季和冬季SOC的浓度分别为1.09、1.79、10.80μg·m^(−3),分别占OC质量浓度的35.39%、19.02%和37.00%,表明钢铁集聚区冬季比其他季节二次有机污染较严重.由因子分析可知,钢铁集聚区碳组分主要来源于钢铁工业烧结等工序燃煤和柴油车尾气排放.研究成果为济南市钢铁集聚区周围环境空气质量改善措施的制定提供技术支撑.

固-液复合铸造锤头的组织与性能

研究高铬铸铁-碳钢固-液复合铸造锤头的组织及硬度分布特征。结果表明,固-液复合铸造高铬铸铁锤头部分具有较高的硬度,远离复合面高铬铸铁硬度增加,碳钢硬度降低。远离复合面高铬铸铁组织为M7C3型碳化物+回火马氏体+残余奥氏体,固-液复合铸造高铬铸铁组织中碳化物有定向分布的趋势,有利于提高锤头的耐磨性;远离复合面碳钢部分的组织为珠光体和较多的铁素体,复合面附近碳钢组织珠光体数量明显增加,铁素体数量明显减小,高铬铸铁中的碳通过复合界面向碳钢进行扩散。

活性炭-纳米铁复合材料处理含镍废水研究

为拓展活性炭的资源化利用,以过50目的活性炭作为载体,硫酸亚铁为铁源,采用液相还原法制备活性炭-纳米铁复合材料。用XRD对其进行结构表征,并就其对模拟的含镍废水进行还原去除研究。实验结果表明:m(活性炭)∶m(硫酸亚铁)为1∶2所制备的活性炭-纳米铁复合材料负载的粒子主要是α-Fe,具有较强的还原性,对含镍废水具有较好的去除作用,可在重金属废水处理中推广使用。

(Al_2O_3-C)/Fe反应对铁中碳和铝含量影响的热力学分析

研究了在埋炭条件下,不同碳素材料的Al_2O_3-C耐火材料与铁液之间的反应及对铁液碳含量和铝含量的影响。对实验后金属试样的碳含量和铝含量进行了分析;对实验条件下Al_2O_3-C耐火材料与铁液之间的反应及对铁液中[Al]和[C]含量进行了热力学分析。结果表明,在埋炭气氛下,氧化铝的碳热还原反应受到一定程度的抑制,实验后铁液中铝含量较低;同时,Al_2O_3-C耐火材料中的碳会溶入铁液中,增加铁液中的碳含量,这个过程不受反应体系中CO分压变化的影响。