沸石类咪唑骨架材料吸附分离天然气的分子模拟

采用巨正则蒙特卡洛方法研究C₂H₆, CO₂和CH₄三种气体在两种沸石类咪唑骨架材料 (ZIF)-ZIF-2和ZIF-71中的吸附与分离性能. 考察了C₂H₆, CO₂和CH₄三种气体在ZIF-2和ZIF-71中的单组分吸附等温线、吸附热; C₂H₆-CH₄, CO₂-CH₄ 与C₂H₆-CO₂等摩尔二元混合物的分离; 以及C₂H₆-CO₂-CH₄三元体系的分离性能. 研究结果表明: 低压下不同气体的吸附量大小与其吸附热关系紧密; 而高压下因有限的孔空间, 尺寸较小的气体分子吸附量增长趋向更快; 多组分吸附分离中, 低压下能量效应通常占据主导, ZIF优先吸附作用力较强的组分; 高压下堆积效应影响显著, ZIF会优先吸附尺寸较小的组分. ZIF-2和ZIF-71对这3种二元体系的分离性能良好. 对于三元混合物吸附分离, 在常温下3000-4000kPa范围内, ZIF-2具有良好的天然气净化性能, 可有效地分离出天然气中的C₂H₆和CO₂. 关键词： 巨正则蒙特卡洛模拟 天然气分离 沸石类咪唑骨架     

注气驱替煤层气数值模拟

建立一种注气驱替煤层气的双重介质数学模型,考虑注气驱替煤层气中多组分气体渗流、吸附/解吸、扩散及孔隙度和渗透率敏感性等多物理场的耦合,用有限差分方法对数学模型数值求解,并验证模型的有效性.通过实例模拟,对比分析注入CO₂、N₂和70%N₂+30%CO₂提高采收率、产出组分动态及储层物性.计算表明:注入CO₂、N₂及其混合气体均能显著提高煤层气藏采收率,提高程度可达28%以上;N₂在注入后迅速突破产出,而CO₂突破时间较晚;注气后基质的收缩/膨胀效应在孔隙度和渗透率敏感性中起主导作用,CO₂吸附造成孔隙度和渗透率减小,而N₂吸附将增大孔隙度和渗透率.     

Adsorption and reactions of CH2I2 on Ru(001) surface

The adsorption and dissociation of CH₂I₂ were studied at 110 K with the aim of generating CH₂ species on the Ru(001) surface. The methods used included X-ray photoelectron spectroscopy (XPS), ultraviolet photoelectron spectroscopy (UPS), temperature programmed desorption (TPD), Auger electron spectroscopy (AES) and work function measurements. Adsorption of CH₂I₂ is characterized by a work function decrease (0.96 eV at monolayer), indicating that adsorbed CH₂I₂ has a positive outward dipole moment. Three adsorption states were distinguished: a multilayer (T_p=200 K), a weakly bonded state (T_p=220 K) and an irreversibly adsorbed state. A new feature is the formation of CH₃I, which desorbs with T_p=160 K. The adsorption of CH₂I₂ at 110 K is dissociative at submonolayer, but molecular at higher coverages. Dissociation of the monolayer to CH₂ and I proceeded at 198–230 K, as indicated by a shift in the I(3d_5/2) binding energy from 620.6 eV to 619.9 eV. A fraction of adsorbed CH₂ is self-hydrogenated into CH₄ (T_p=220 K), and another one is coupled to di-σ-bonded ethylene, which — instead of desorption — is converted to ethylidyne at 220–300 K. Illumination of the adsorbed CH₂I₂ initiated the dissociation of CH₂I₂ monolayer even at 110 K, and affected the reaction pathways of CH₂.     

载体结构对固态胺吸收CO2性能的影响

利用六种孔结构不同的商业无定形硅胶制备了不同四乙烯五胺（TEPA）担载量的固态胺吸收剂。吸收剂的微观结构通过BET和SEM测试;并在TGA反应器中,考察固态胺在30～80℃,CO2体积分数为1%～100%范围内的吸收性能。实验表明,固态胺吸收CO₂性能与温度、CO₂浓度以及载体结构有密切的联系。固态胺适合在低温（30～60℃）低CO₂浓度下（约10%）进行CO₂分离。载体结构通过影响最优担载量,从而影响固态胺吸收性能,孔容和孔径分别在1.211 cm³/g和13 nm附近的载体在担载量为45%时拥有最好的吸收能力（2.87 mmol/g）。     

High adsorption and separation performance ofCO2 over N2 in azo-based (N=N) pillar[6]arene supramolecular organic frameworks

Azo-based pillar[6]arene supramolecular organic frameworks are reported for CO₂ and N₂ adsorption and separation by density functional theory and grand canonical Monte-Carlo simulation. Azo-based pillar[6]arene provides suitable environment for CO₂ adsorption and selectivity. The adsorption and selectivity results show that introducing azo groups can effectively improve CO₂ adsorption and selectivity over N₂, and both CO₂ adsorption and CO₂ selectivity over N₂ follow the sequence pillar[6]arene_N4 > pillar[6]arene_N2 > pillar[6]arene. Pillar[6]arene_N4 exhibits CO₂ adsorption capacity of ～ 1.36 mmol/g, and superior selectivity of CO₂ over N₂ of ～ 116.75 with equal molar fraction at 1 bar (1 bar=10⁵ Pa) and 298 K. Interaction analysis confirms that both the Coulomb and van der Waals interactions between CO₂ with pillar[6]arene frameworks are greater than that of N₂. The stronger affinity of CO₂ with pillar[6]arene_N4 than other structures and the larger isosteric heat differences between CO₂ and N₂ rendered pillar[6]arene_N4 to present the high CO₂ adsorption capacity and high CO₂ selectivity over N₂. Our results highlight the potential of azo-functionalization as an excellent means to improve pillar[6]arene for CO₂ capture and separation.     

二氧化碳-甲烷混合气体水合物四相区实验研究

以水合物的形式封存CO₂和置换海底的天然气（CH₄）水合物需要对CO₂-CH₄混合水合物的四相平衡状态及数据有清楚的了解。本文通过实验和模型计算对不同组分的CO₂-CH₄混合水合物的较高四相区（Q2）相平衡进行了测定和表述。实验温度范围为273.16～297 15 K,压力范围分为0～10 MPa。四相区的温度压力范围分别是283.51到287.04 K和4.74到8.37 MPa,甲烷的摩尔组份为0～0.225。结果揭示了相平衡温度和压力随着甲烷组分而变化情况以及四相区的范围和临界点,同时还给出了CO₂-CH₄混合气体水合物在四相状态下的融化开始和融化结束点。实验结果与热力学模型计算得出的CO₂-CH₄混合气体水合物相平衡结果进行比较,两者很好吻合,四相平衡区域的存在范围得以明确。     

CO2在金属有机骨架材料有机链上的吸附机理研究

金属有机骨架是一种新型的温室气体CO₂吸附材料。本文采用密度泛函理论（DFT）方法研究CO₂在MOF-5有机链上的6种不同吸附位置及其3种不同构型下的吸附行为。考虑GGA水平下三种不同泛函对计算结果的影响,对比发现GGA/PW91泛函能够较好地计算CO₂分子与有机链原子之间的弱范德华力;发现CO₂分子与苯环边相交以及与苯环上的碳原子平行是两种吸附能最大的构型;利用Br原子替代苯环上的H原子可以显著增强对CO₂分子的吸附能力,为设计具有较高CO₂吸附能力的MOFs材料提供理论依据。     

CO2在气体水合物结构特性的固体核磁共振波谱与拉曼光谱实验研究

天然气水合物是蕴含着巨大能源潜力的非常规能源,2017年和2020年两次我国南海探索性试采的成功,加快了天然气水合物项目的进展。二氧化碳置换开采法,既能开发CH₄,又能封存CO₂。同时水合物法分离烟气中CO₂具有很好的应用前景,而CO₂在气体水合物的微观结构和特性尚不明确,实际应用存在一定的未知影响。为了考察其特性,利用13C固体核磁技术（NMR）和拉曼光谱（Raman）进行CO₂置换CH₄水合物、合成13CO₂-H₂-CP混合水合物实验表征,讨论CO₂在水合物中的定量问题,研究CO₂分子在笼型结构中的分布,探讨CO₂分子在气体水合物中的结构类型和特性。结果表明：（1）利用Raman费米低频共振1 277.5 cm-1峰积分得到CO₂在I型大笼（51262笼）的占有率为0.978 2,CH₄在Ⅰ型小笼（512笼）和大笼（51262笼）的占有率为0.059 3和0.009 5,水合数7.61,Raman费米高频共振1 381.3 m-1峰积分得到CO₂在51262笼的占有率为0.984 3,CH₄在512笼和51262笼的占有率为0.023 7和0.003 3,水合数7.70,CO₂几乎占满了大笼,CO₂气体的加入会导致水合物中,CH₄的大、小笼占有率均大幅度降低,置换后水合数略低于纯甲烷水合物,未标记的CO₂水合物在核磁中较难测出信号,CO₂气体置换后CH₄在小笼的占有率仅0.097 5,大笼占有率为0.317 2,两种方法差异主要原因为核磁的CO₂未出峰。（2）利用拉曼费米低频共振1 273.4 cm-1峰积分得到H₂、CO₂在512笼、CP在51262的占有率分别为0.124 8,0.304 2和0.997 8,水合数9.16;Raman费米高频共振1 380.6 cm-1峰积分得到H₂、CO₂在512笼、CP在51262的占有率分别为0.123 6,0.577 1和0.985 1,水合数7.12。13C标记CO₂分子在水合物中达到较好的固体核磁分辨率,首次确认CO₂在Ⅱ型小笼中的化学位移为124.8 ppm,计算得到CO₂的小笼占有率为0.783 1,CP的大笼占有率为0.971 8,水合数6.70,Raman高频频费米共振峰（1 380.6 cm-1）定量计算与13C NMR结果更接近。（3）对CO₂的13C NMR化学位移进行了归属,并结合Raman与13C NMR的对比分析,为CO₂水合物的13C NMR研究和拉曼定量提供参考。     

液体火箭推力室面板发汗冷却与燃烧耦合数值模拟

对推力室的喷嘴多孔面板的发汗冷却和燃烧室内的燃料燃烧过程进行了耦合数值计算,建立了一个带燃烧的三维、真实气体、变物性的推力室CFD计算模型。利用UDF编写了CH₄、O₂、CO₂、H₂O气体的实际气体状态方程,并根据NIST物性数据拟合了不同温度和压力下各气体的比热容、扩散系数、黏性系数和导热系数等物性多项式。基于EDC模型建立了甲烷-氧燃烧的多步反应机理。计算了三种厚度的面板和多种燃料进口工况下的推力室内的发汗冷却和燃烧过程,研究了面板厚度、冷却剂进出条件等因素对发汗冷却和燃烧过程的影响规律。     

Adsorption of oxygen and carbon dioxide on cesium-reconstructed Ag(1 1 0) surface

The adsorption of oxygen and carbon dioxide on cesium-reconstructed Ag(1 1 0) surface has been studied with scanning tunneling microscopy (STM) and temperature programmed desorption (TPD). At 0.1 ML Cs coverage the whole surface exhibits a mixture of (1 × 2) and (1 × 3) reconstructed structures, indicating that Cs atoms exert a cooperative effect on the surface structures. Real-time STM observation shows that silver atoms on the Cs-covered surface are highly mobile on the nanometer scale at 300 K. The Cs-reconstructed Ag(1 1 0) surface alters the structure formed by dissociative adsorption of oxygen from p(2 × 1) or c(6 × 2) to a p(3 × 5) structure which incorporates 1/3 ML Ag atoms, resulting in the formation of nanometer-sized (10–20 nm) islands. The Cs-induced reconstruction facilitates the adsorption of CO₂, which does not adsorb on unreconstructed, clean Ag(1 1 0). CO₂ adsorption leads to the formation of locally ordered (2 × 1) structures and linear (2 × 2) structures distributed inhomogeneously on the surface. Adsorbed CO₂ desorbs from the Cs-covered surface without accompanied O₂ desorption, ruling out carbonate as an intermediate. As a possible alternative, an oxalate-type surface complex [OOC–COO] is suggested, supported by the occurrence of extensive isotope exchange between oxygen atoms among CO₂(a). Direct interaction between CO₂ and Cs may become significant at higher Cs coverage (>0.3 ML).     

Cao吸附CO2系统能耗分析及热集成系统研究

本文以通用流程模拟软件Aspen为平台,对一个600 MW电厂排放的CO₂吸收过程进行了模拟,分析了关键参数对吸收系统性能影响。研究了采用余热锅炉回收系统热量后对整个电厂性能的影响规律,比较了采用25MPa,566/566℃;28MPa,580/580℃和30 MPa,600/600℃三种不同蒸汽参数时整个电厂性能。研究结果表明,采用钙法回收电厂CO₂并合理利用余热后系统效率下降约5个百分点。本文研究成果为基于火电站脱除CO₂提供有益的参考。     

Effects of potassium on the adsorption and dissociation of CH3Cl on Pd(100)

The effects of potassium on the adsorption and dissociation of CH₃Cl on a Pd(100) surface has been investigated by ultraviolet photoelectron spectroscopy (UPS), Auger electron spectroscopy (AES), electron energy loss spectroscopy (in the electronic range EELS), temperature-programmed desorption (TPD) and work function change. In contrast to the clean surface, the adsorption of CH₃Cl caused a significant work function increase, 0.9-1.4 eV, of potassium-dosed Pd. Preadsorbed K enhanced the binding energy of CH₃C1 to the surface and induced the dissociation of adsorbed molecules. The extent of the dissociation increased almost linearly with the potassium content. The appearance of a new emission in the UPS spectrum at 9.2 eV, attributed to adsorbed CH₃ species, and the low-temperature formation of ethane suggest that a fraction of adsorbed CH₃Cl dissociates even at 115–125 K on potassium-dosed Pd(100). At the same time, a significant part of adsorbed CH₃ radical is stabilized, the reaction of which occurs only at 250–300 K. By means of TPD measurements, H₂, CH₄, C₂H₆, C₂H₄, KCl and K were detected in the desorbing gases. The results are interpreted by assuming a through-metal electronic interaction at low potassium coverage and by a direct interaction of the Cl in the adsorbed CH₃Cl with potassium at high potassium coverage. The latter proposal is supported by the electron excited Auger fine structure of the Cl signal and by the formation of KCl in the desorbing gases.     

多孔介质水合物中储存二氧化碳的实验研究

为了研究多孔介质中CO₂水合物的生成速率和储气量,利用1.8 L的水合反应釜研究了孔隙为13.8 nm和26.7nm的石英砂中CO₂水合物的生成过程,结果表明:孔径为26.7 nm石英砂中,1 m³的石英砂可以储存64.4 m³标准状况的二氧化碳气体,平均生成速率为0.001703 mol/min;孔径为13.8 nm石英砂中,1 m³的石英砂可以储存118.8m³标准状况的二氧化碳气体,平均生成速率为0.001803 mol/min;在多孔介质孔径范围为13.8 nm至26.7 nm之间时,粒径越小,储气量越大。     

Glycine on Pt(111): a TDS and XPS study

The adsorption and desorption of in situ deposited glycine on Pt(111) were investigated with thermal desorption spectroscopy (TDS) and X-ray photoelectron spectroscopy (XPS). Glycine adsorbs intact on Pt(111) at all coverages at temperatures below 250 K. The collected results suggest that the glycine molecules adsorb predominantly in the zwitterionic state both in the first monolayer and in multilayers. Upon heating, intact molecules start to desorb from multilayers around 325 K. The second (and possibly third) layer(s) are somewhat more strongly bound than the subsequent layers. The multilayer desorption follows zero order kinetics with an activation energy of 0.87 eV molecule⁻¹. From the first saturated monolayer approximately half of the molecules desorbs intact with a desorption peak at 360 K, while the other half dissociates before desorption. Below 0.25 monolayer all molecules dissociate upon heating. The dissociation reactions lead to H₂, CO₂, and H₂O desorption around 375 K and CO desorption around 450 K. This is well below the reported gas phase decomposition temperature of glycine, but well above the thermal desorption temperatures of the individual H₂, CO₂, and H₂O species on Pt(111), i.e. the dissociation is catalyzed by the surface and H₂, CO₂, and H₂O immediately desorb upon dissociation. For temperatures above 500 K the remaining residues of the dissociated molecules undergo a series of reactions leading to desorption of, for example, H₂CN, N₂ and C₂N₂, leaving only carbon left on the surface at 900 K. Comparison with previously reported studies of this system show substantial agreement but also distinct differences.     

LEED studies of the adsorption of CO2 on thin epitaxial NaCl(100) films

The adsorption of CO₂ on the NaCl(100) surface was studied with a high-resolution LEED-system. Measurements without charging up at low electron energies and without damage by the e-beam could be performed by using ultrathin epitaxial films on a conducting Ge(100) substrate. The adsorption behavior was recorded as a function of time and pressure at constant substrate temperatures of 78 and 83 K and CO₂ partial pressures from 4 × 10⁻⁸−2 × 10⁻³ Pa. The adsorption system shows a first-order two-dimensional phase transition to a (2 × 1) superstructure including glide planes (herringbone-like structure) at p = 7.2 × 10⁻⁸Pa (T = 78 K). The condensation of the CO₂ solid is starting at p = 1.5 × 10⁻⁴ Pa (T = 78 K). The LEED-pattern shows in this c(2 × 2) superstructure, which corresponds to the pyrite-like structure of the CO₂ solid. Both observed superstructures are commensurable with the NaCl(100) surface. Observation of island growth shows that the domains of the (2 × 1) superstructures have already at coverage of 5% of a monolayer an average lateral size of at least 200 A.     

Evidence for bicarbonate formation on vacuum annealed TiO2(110) resulting from a precursor-mediated interaction between CO2 and H2O

The reaction of CO₂ and H₂O to form bicarbonate (HCO⁻₃) was examined on the nearly perfect and vacuum annealed surfaces of TiO₂(110) with temperature programmed desorption (TPD), static secondary ion mass spectrometry (SSIMS) and high resolution electron energy loss spectrometry (HREELS). The vacuum annealed TiO₂(110) surface possesses oxygen vacancy sites that are manifested in electronic EELS by a loss feature at 0.75 V. These oxygen vacancy sites bind CO₂ only slightly more strongly (TPD peak at 166 K) than do the five-coordinated Ti⁴⁺ sites (TPD peak at 137 K) typical of the nearly perfect TiO₂(110) surface. Vibrational HREELS indicates that CO₂ is linearly bound at the latter sites with a ν_a(OCO) frequency similar to the gas phase value. In contrast, oxygen vacancies dissociate H₂O to bridging OH groups which recombine to liberate H₂O in TPD at 490 K. No evidence for a reaction between CO₂ and H₂O is detected on the nearly perfect surface. In sequentially dosed experiments on the vacuum annealed surface at 110 K, CO₂ adsorption is blocked by the presence of preadsorbed H₂O, adsorbed CO₂ is displaced by postdosed H₂O, and there is little or no evidence for bicarbonate formation in either case. However, when CO₂ and H₂O are simultaneously dosed, a new CO₂ TPD state is observed at 213 K, and the 166 K state associated with CO₂ at the vacancies is absent. SSIMS was used to tentatively assign the 213 K CO₂ TPD state to a bicarbonate species. The 213 K CO₂ TPD state is not formed if the vacancy sites are filled with OH groups prior to simultaneous CO₂+H₂O exposure. Sticking coefficient measurements suggest that CO₂ adsorption at 110 K is precursor-mediated, as is known to be the case for H₂O adsorption on TiO₂(110). A model explaining the circumstances under which the proposed bicarbonate species is formed involves the surface catalyzed conversion of a precursor-bound H₂O–CO₂ van der Waals complex to carbonic acid, which then reacts at unoccupied oxygen vacancies to generate bicarbonate, but falls apart to CO₂ and H₂O in the absence of these sites. This model is consistent with the conditions under which bicarbonate is formed on powdered TiO₂, and is similar to the mechanism by which water catalyzes carbonic acid formation in aqueous solution.     

基于离轴腔增强吸收光谱双组分CH4/H2O高灵敏度探测研究

H₂O和CH₄在气候变化过程中起着关键作用,实时在线测量H₂O和CH₄浓度一直都是国内外学者研究的热点问题之一。利用1.653 μm可调谐半导体激光器作光源,结合反射率为99.997 6%的两片高反射镜组成离轴腔增强吸收光谱装置,开展了H₂O和CH₄的高灵敏度测量研究。离轴腔增强系统的有效吸收光程通过吸收面积-浓度关系法来标定,吸收面积-浓度关系法的可行性首先通过已知光程的光学吸收池进行验证,确定有效后用于标定离轴腔增强系统的有效光程。结果表明,基长为21 cm的离轴腔增强系统的有效吸收光程达到了8 626.3 m。当谐振腔内压力为5.06 kPa时,利用7组不同浓度的CH₄标准气体（0.2～1.4 μmol·mol-1）对系统进行了线性响应标定测试,得到了CH₄吸收的积分面积与浓度拟合关系曲线。系统的稳定性、可实现的最小探测灵敏度等信息通过Allan方差进行分析,结果表明系统对探测CH₄的最佳平均时间为100 s,最小可探测浓度极限为7.5 nmol·mol-1;系统对探测H₂O的最佳平均时间为200 s,最小可探测浓度极限为55 μmol·mol-1。对提高系统测量精度的数据处理方法也进行了分析研究,结果表明相比于多次平均方法,Kalman滤波能显著的提高测量精度,而且缩短了系统的响应时间。最后,利用搭建的离轴腔增强实验系统结合Kalman滤波数据处理方法对实际大气中CH₄和H₂O浓度进行了连续两天的测量,CH₄每天平均的浓度分别为2.1和2.08 μmol·mol-1,H₂O每天平均的浓度分别为11 515.6和11 628.6 μmol·mol-1,由此可知建立的离轴腔增强吸收光谱装置能够用于大气CH₄和H₂O的测量,另外建立的系统也可用于相关工业领域的高灵敏度CH₄和H₂O监测。     

CO吸附和加氢反应过程的原位高压MAS NMR研究

应用原位变温高压MAS核磁共振技术,对比研究了CO在不同Rh基催化剂上的吸附和加氢反应过程. ²⁹Si MAS NMR研究结果表明：Rh基催化剂中加入金属助剂后,载体Silicate-1上的表面硅羟基减少,助剂金属与硅羟基作用锚锭在载体表面.¹³C MAS NMR研究结果表明：当引入CO/H2混合气后,在Rh/Silicate-1催化剂上只能观测到气相CO、线式吸附CO和孪式吸附CO的快速交换信号;而在Rh-Mn/Silicate-1和Rh-Mn-Li/Silicate-1催化剂上,还观测到了倾斜式吸附的CO共振信号,表明助剂Mn或Mn-Li的加入促进了CO的吸附. 随着反应温度升高,CO/H₂在Rh/Silicate-1催化剂上转化生成CO_²,进一步升高温度会有CH₄生成;而CO/H₂在RhMnLi/Silicate-1催化剂上反应活性更高,在较低的温度下就会转化生成CO₂,但未观测到甲烷的生成. ¹H MAS NMR 谱显示,反应后载体Silicate-1上硅羟基的量会减少,表明CO与载体部分表面硅羟基反应生成了CO₂.     

FTIR和Raman技术在煤结构分析中的应用研究

为明确不同煤种大分子结构特征的异同,采用傅里叶变换红外光谱(FTIR)和拉曼光谱(Raman)分析技术,对五种烟煤（HY,HJ,BL,DJ和HK）进行系统表征,为后续煤及类煤材料结构和性能的研究提供可靠指导。在FTIR光谱特征曲线上,波数3 200~3 600 cm-1范围有明显的吸收区,其中样品HJ相较于其他4种样品更明显,主要是由于-OH官能团和N-H结构振动引起,但该波段容易受到自由水或结晶水的影响,从而造成判断误差。在2 923 cm-1处可以观察到CH₂反对称伸缩振动峰值都明显高于其对称伸缩振动,产生这一现象的原因是烟煤中存在大量脂肪族CH₂碳链结构,后续将其液化加工再应用的潜力较大。而在1 000~1 800 cm-1的含氧官能团波数范围内,主要包含了羟基（醇羟基和酚羟基）、羧基、羰基等。为了更清晰的表征煤结构,定量分析了煤的表观芳香度fa(FTIR),(R/C)_u,H_al/H,A_ar/A_al和H/C原子比之间的关系,可以看出随着煤质水平的提高,煤中芳香族氢含量增加,脂肪族氢含量降低。另外比较了各个结构参数发现fa(FTIR),(R/C)_u和H/C原子比之间存在线性关系,能够更加准确的表征煤阶。Raman光谱特征曲线通过Origin 2018进行分峰拟合,采用去卷积方法将频谱划分为十个峰,分别为G,G_R,V_L,V_R,D,S,G_L,S_L,S_R和R。对比不同波段峰面积比例及主峰半高宽和H/C原子比的关系,发现随着H/C原子比的增加,A_D/A_G值总体呈下降趋势。从而说明煤样基本结构中单元核的芳香环数量随着煤化作用及其石墨化程度的增加而增加,该结果与FTIR光谱分析一致。通过上述研究结果的对比可证明FTIR和Raman光谱技术是煤中大分子结构特征研究的可靠方法。最后基于两种分析技术提供的结构参数,建立了简单的煤分子模型,为煤化学研究中基础分子构建提供参考。     

Characterization and frequency measurement of a new far infrared laser line from CHin2Fin2

We present the discovery and frequency measurement of a new FIR laser line from CH₂F₂ optically pumped by a waveguide CO₂ laser. This new line has the same CO₂ laser pump line (9R32), offset (+5 MHz) and relative polarization of the strongest FIR laser line of CH₂F₂, namely the 184.3μm. The frequency is only 19,454 MHz apart from that of this line. We got a frequency measurement of 1,646,196.6 (10) MHz, which corresponds to a wavelength of 182.112 μm.