农田地下爆破空腔使小麦增产的研究

报道了用爆破技术在土壤中形成空腔和裂隙，使小麦增产的具体方法。研究了爆破深度、装药量、孔的分布和小麦相对产量变化的规律。     

黑碳的表面化学研究进展

黑碳是生物有机体或化石燃料不完全燃烧形成的一种含芳香环的高聚产物，环境中黑碳的存在将对有机污染物产生较强的吸附作用。最新的研究表明：黑碳的表面基团和表面化学性质将极大影响其对污染物的吸附行为。以近来的活性炭表面化学的研究为参照，综述了黑碳及活性炭的表面化学的研究进展，讨论了碳表面化学与吸附性质之间的联系，进一步探讨了黑碳作工业用吸附剂的可能性。     

生物质黑碳的制备及表征

生物质黑碳的多孔结构使得它具有很强的吸附能力,其表面上的各种官能团具有活跃的化学反应活性,黑碳的多孔结构及表面吸附性能决定了它是其它环境污染物的重要载体之一,在大气环境界面化学中具有重要作用。本文以松木木屑、水稻秸秆和蜂窝煤为型燃烧源,通过采用自制的管式反应炉将不同典型燃烧源在300～500℃无氧条件下燃烧来制备黑炭样品,并对黑碳样品进行表征,获得不同典型燃烧源黑碳颗粒物的理化参数。实验结果表明:由松木屑制备得到的黑碳具有较高的碳质组分含量( 66%)和较低的无机元素含量(8%),且不含Pb、Cd等重金属组分;在300℃下制备得到的黑碳具有具有较丰富的羟基、羧基、羰基等活性基团和较高的OC/EC比值,且平均粒径小,其理化特征更接近大气气溶胶黑碳的性质,可用于模拟黑碳大气环境化学界面过程。     

聚氨酯基植物栽培基质的结构及性能

以聚氨酯为基体,与土壤复合,制备植物栽培基质,研究了聚醚多元醇、异氰酸酯、土壤、水和辛酸亚锡的含量及土壤粒径对基质结构和性能的影响。结果表明,随着土壤含量的增加,泡孔孔径分布越来越不均匀,吸水保水率和发泡倍数降低,当土壤含量为10份时,基质的吸水率达到最大,其值为690.6%;随着多元醇与异氰酸酯的比例逐渐增大,泡孔孔径逐渐减小且泡孔分布趋于均匀,吸水保水率逐渐增强,当多元醇与异氰酸酯的比例为13∶2时,基质的吸水率达到最大,其值为395.1%;随着水含量的增加,孔隙增多,孔径增大,吸水保水性增强,当水的含量为0.6份时,基质的吸水率达到最大,其值为423.9%;随着辛酸亚锡含量的增加,孔隙分布更加密集,吸水保水率缓慢增大,当辛酸亚锡含量为0.2份时,基质的吸水率达到最大,其值为355.2%。     

西安城市主干道黑碳排放特征及源解析

本文以西安不同功能区黑碳浓度为研究对象,探讨西安市城市道路交通碳排放的问题。通过AE-51型微型黑碳仪对长乐东路黑碳质量浓度进行质量检测,揭示西安市典型道路黑碳排放特征及源解析。结果表明,黑碳每日浓度在早高峰为3.70～7.57μg·m^-3及晚高峰为2.89～7.00μg·m^-3,明显大于非高峰期(2.03～5.86μg·m^-3),且工作日浓度(4.38～10.82μg·m^-3)高于休息日浓度(3.28～8.58μg·m^-3);西安市不同年份下,大气中黑碳浓度有较大变化,大致呈现出逐年下降的变化规律,最高浓度出现在2003年(16μg·m^-3);最低浓度发生在2019年(3.66μg·m^-3);与其他城市相较,西安黑碳浓度属于中等水平,黑碳排放浓度受车流量、森林覆盖率、人均生产总值等社会指标影响。可见,合理规划和适当限制机动车使用频率是缓解城市空气污染的有效途径。     

水稻秸秆黑碳的制备与表征

本文以水稻秸秆作为原料制备环境污染物的吸附剂黑碳。首先,采用热解的方法制得黑碳的前驱体,再通过酸洗的方法去除黑碳表面的灰分等杂质,最后分析了黑碳的比表面积及孔径结构。不仅解决了农村作物秸秆的闲置问题,还为固体废物的资源化利用打下了基础。     

广州地化所在黑碳颗粒挥发性研究方面取得新进展

<正>挥发性是颗粒的一个重要物理性质,在一定程度上可以反映颗粒的老化过程。黑碳是仅次于CO_2的致暖因子,可影响云的形成过程,改变冰雪盖的熔点等,因此在气候系统中扮演着重要角色。新鲜排放的黑碳颗粒一般与其它物质以外混状态存在,在老化过程中,与二次气溶胶形成内混模式。混合状态对黑碳的光学     

原子荧光法测定土壤中汞的前处理方法优化

本文建立了用控温深孔加热板,一次性聚丙烯平底离心管消解土壤汞的前处理方法。采用控温深孔加热板作为加热装置、一次性聚丙烯平底离心管作为容器,对土壤样品进行前处理消解,并利用原子荧光光度计确认聚丙烯平底离心管空白、方法检出限、精密度和正确度。实验室结果表明,采用控温深孔加热板作为加热装置、一次性聚丙烯平底离心管作为容器,成本低、检出限低、精密度高、准确度可靠,实验操作简便,能够快速、准确完成土壤样品中汞的检测。     

并流列管反应器冷却介质的流动与均布

建立了并流列管反应器管外冷却介质流动的计算模型,对不同直径反应器分流室、集流室中流体压力分布、分布板上小孔分布以及环隙孔孔径进行了研究。结果表明:随着反应器直径增大,分流室、集流室中流体压降增大,分布板上环隙孔孔径减小。过小的环隙孔间隙成为反应器加工和装配的瓶颈。增大反应器分流室和集流室高度,对反应器中心进行不布管,可降低反应器分流室和集流室中流体压降,增大分布板上环隙孔间隙。对直径较大的反应器,可同时采用在反应器中心进行不布管以及增大反应器分流室和集流室高度的方法来降低分流室和集流室中流体压降,使分布板上环形孔间隙不致过小。     

中孔碳孔径及有序性影响因素

以表面活性剂F127为模板剂制备了有序中孔碳材料,研究了影响中孔碳孔径分布及有序性的各工艺参数,采用XRD, SEM, TEM和N2吸/脱附等手段对有序中孔碳进行了表征. 结果表明,F127用量、反应温度、搅拌时间、碳化温度和碳化升温速率等因素直接影响中孔碳结构的有序性及孔径分布. F127用量为40%、反应温度40℃、搅拌时间30 min、碳化温度800℃、升温速率1℃/min时,所得中孔碳有序性好且孔径分布比较集中.     

The effect of carbonization temperature on the morphology and adsorption of pine-shoot biomorphic porous carbon

Reactions that occur during the carbonization of pine-shoot may determine the morphology and pore structure of biomorphic porous carbon. This phenomenon has the ability to change the adsorptive performance of biomorphic porous carbon. Individual reactions were separated from the evolution of CO₂, CO, CH₄, and H₂ by using an on-line auto-sampled gas analyzer. Analysis of the structure surface morphology, and the distribution of pores of biomorphic porous carbon in three dimensions was performed through the use of XRD, SEM and polarizing microscopy. The results reveal that the morphology and pore structure of biomorphic porous carbon were significantly influenced by competitive reactions occurring at various temperatures of carbonization. High carbonization temperature favors the formation of well-ordered and penetrable pore channels. Conversely, extra high carbonization temperature may plug the pore-mouth, distort the pore-channels, and destroy the pore-structure of biomorphic porous carbon. Therefore, extra high carbonization temperatures have the ability to prevent small-size adsorbents, such as iodine, methyl blue and thiophenes, from entering into the pore channels of biomorphic porous carbon.     

The effect of molecular composition and structure on the development of porosity in pitch-based activated carbon fibers

Seven oligomeric fractions of well-defined composition and molecular weight distribution were generated via supercritical extraction from an isotropic petroleum pitch (M-50) and used as precursors for the production of activated carbon fibers. Both isotropic and mesophase-containing fractions were produced, so that the effects of molecular order and molecular weight could be separated. Carbonization weight loss was found to gradually decrease with increasing molecular weight (and oligomeric number), with mesophase content not being a significant factor. Similar behavior was observed for activation weight loss when the precursors were isotropic; however, even modest increases in molecular order significantly retarded the activation process and resulted in dramatic drops in specific pore volume. A 100% dimer precursor fraction with an average molecular weight of 480 Da produced activated carbon fibers with the highest (specific) pore volume, and the highest pore volume in the range desired for hydrogen adsorption (6–7 Å). Even for isotropic precursors, decreases in pore volume with increasing molecular weight were observed. The incremental pore size distribution generated from the nitrogen adsorption data consisted of discrete peaks, which is consistent with the formation of pores by the removal of short micrographene layers, with each layer being formed from an individual oligomeric molecule.     

Pore structure control of mesoporous carbon monoliths derived from mixtures of phenolic resin and ethylene glycol

Mesoporous carbon monoliths derived from phenolic resin mixtures have been prepared in the process based on polymerization-induced phase separation. The effect of the composition of resin mixtures and the resin curing temperature on the pore structure of carbon monoliths has been systematically investigated, with emphasis on controlling the apparent porosity and pore size distribution. Fractal dimensions have been introduced to evaluate the morphologies of the carbon monoliths. The results showed that mesoporous carbon monoliths with narrow pore size distribution were obtained. The pore structure of carbon monoliths could be controlled by changing the resin curing temperature and the content of ethylene glycol, curing catalyst and water in the resin mixtures. The apparent porosity of carbon monoliths varied from 54.27% to 26.83%. Carbon monoliths had narrower pore size distribution when more ethylene glycol and higher resin curing temperature were employed. The pore structure of carbon monoliths would be changed radically when the initial resin samples were prepared with excess water (9.8 wt%), i.e. porous carbon foams with sponge structure were obtained. Carbon monoliths inherit their porosity from precursing cured resins where it was formed as a result of phase separation of resin-rich and glycol-rich phases. Volume contraction had certain effect on the pore structure of carbon monoliths.     

炭化条件对多孔炭膜性能的影响

以石油沥青为原料,采用无粘结剂成型制备多孔炭膜,考察了炭化条件对炭膜的Ｈ２和Ｎ２气体渗透率和理想分离系数的影响,并用压汞法表征了炭膜的孔径分布,结果表明：炭化温度是影响炭膜性能的关键因素,制备的炭膜具有均匀性孔径分布,平均孔径为１５３ｎｍ。     

Synthesis and characterization of mesoporous electrospun carbon fibers derived from silica template

In our study, mesoporous carbon fibers were prepared by using electrospinning and physical activation. In order to develop mesoporous structure, silica was used as a physical activation agent due to meso-size of particle. The diameter of activated carbon fibers increased and surface became rougher after physical activation. Textural properties of carbon fibers were evaluated by using surface pore structure analysis apparatus. The specific surface area increased 12 times and total pore volume increased about 57 times through physical activation using silica. The development of mesoporous structure was confirmed by pore size distribution and fraction of micropore volume. From the DFT pore size distribution, it is sure that broad meso-sized porous carbon fibers were obtained from physical activation in our experiment. The fact that fractions of micropore volume are too low showing less than 2% by the results of total pore volume and HK pore volume concedes that silica activated CFs are pretty mesoporous. Eventually activated carbon fibers having broad meso-sized pores were obtained successfully.     

Synthesis and characterization of mesoporous carbon with narrow pore size distribution derived from rare earth–macromolecule complexes

Mesoporous carbon with narrow pore size distribution was novelly derived from rare earth–macromolecule complexes, which were formed by the coordination between grafted novolac‐type phenolic resin and rare earth ions (Ce³⁺). The as‐made resins or carbons were characterized by infrared spectrum, thermogravimetry, carbon tetrachloride adsorption, nitrogen adsorption, and scanning electron microscope. The results showed that the rare earth–macromolecule complexes were formed successfully, which could promote the dispersion of rare earth elements in the precursor and further control the pore structure and pore size distribution of as‐made mesoporous carbon during steam‐activation process. The as‐made mesoporous carbon exhibited typical mesoporous structure and relatively narrow pore size distribution, and the mesoporosity of it was up to 88%. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

炭化条件对分子筛型活性炭孔结构的影响

以木屑及宁夏太西煤混合物为原料,以木焦油为粘结剂,经压力成型,制备柱状分子筛型活性炭,考察了炭化条件对活性炭孔径分布及其性能的影响。结果表明,炭化温度是影响分子筛型活性炭性能的关键因素,制备的活性炭具有均匀的孔径分布, <0 9nm(9 A)的孔占活性炭总孔容的 80%以上。     

炭黑分散法制备双重孔分布的γ-Al2O3载体

采用表面活性剂分散炭黑的方法对γ-Al2O3进行扩孔,制备出孔径较大且孔分布集中的γ-Al2O3载体。主要考察了炭黑类型、炭黑用量及炭黑分散性,如分散剂类型、用量、超声时间等对γ-Al2O3孔径分布的影响。结果表明,传统的炭黑扩孔法存在用量大的缺点,采用分散剂结合超声处理的方法可在较低炭黑用量下(<10%)取得良好的扩孔效果,制备出孔径分布集中于6 nm和10～20 nm(或20～30 nm)的γ-Al2O3载体。     

Regulation of pore cell structures of coal-based carbon foams based on the nucleation mechanism of microcellular polymer

It is widely accepted that the performance of carbon foams can be regulated by the tailoring of pore cell structures to meet the requirements of various applications. However, no theory has been used to date for guiding such regulation. In this work, carbon foams were prepared by saturating vitrinite concentrate with nitrogen gas under high pressure. The influence of key factors on the pore cell structure of carbon foams was investigated systematically. The results showed that the mean cell diameter and the bulk density of carbon foams can be regulated, respectively, in the ranges 140–440?µm and 0.29–0.75?g/cm³, which indicates that vitrinite concentrate separated from fat coal is highly suitable for the preparation of carbon foams. The variation trends of the pore cell structures were well explained by combining the homogeneous nucleation mechanism of microcellular polymer with the viscosity of the fusant formed from vitrinite concentrate. The inherent reason for all the variation trends is related to the gas nuclei density and viscosity of the fusant. More importantly, a strategy is suggested to successfully accomplish the design and regulation of the pore structure of carbon foams by taking into account the homogeneous nucleation mechanism and viscosity of the fusant.     

溶胶-凝胶法碳源对多孔炭材料孔隙结构的影响

以正硅酸乙酯(TEOS)为模板硅源,β-环状糊精和可溶性淀粉分别为碳前驱体,运用溶胶-凝胶法制备了多孔炭材料。利用低温N2等温吸脱附、X射线衍射、高倍扫描电子显微镜等对所得炭材料的结构进行了测试与表征,结果表明,β-环糊精为碳源的样品主要孔径分布在2~3 nm;以可溶性淀粉为碳源的样品孔径呈双峰分布,即孔径集中在3.7 nm和5~20 nm,但由于炭化温度较低,所得的炭材料仍为无定形结构。