Molecular Simulation on Competitive Adsorption Differences of Gas with Different Pore Sizes in Coal

Micropores are the primary sites for methane occurrence in coal. Studying the regularity of methane occurrence in micropores is significant for targeted displacement and other yield-increasing measures in the future. This study used simplified graphene sheets as pore walls to construct coal-structural models with pore sizes of 1 nm, 2 nm, and 4 nm. Based on the Grand Canonical Monte Carlo (GCMC) and molecular dynamics theory, we simulated the adsorption characteristics of methane in pores of different sizes. The results showed that the adsorption capacity was positively correlated with the pore size for pure gas adsorption. The adsorption capacity increased with pressure and pore size for competitive adsorption of binary mixtures in pores. As the average isosteric heat decreased, the interaction between the gas and the pore wall weakened, and the desorption amount of CH₄ decreased. In ultramicropores, the high concentration of CO₂ (50–70%) is more conducive to CH₄ desorption; however, when the CO₂ concentration is greater than 70%, the corresponding CH₄ adsorption amount is meager, and the selected adsorption coefficient S_CO2/CH4 is small. Therefore, to achieve effective desorption of methane in coal micropores, relatively low pressure (4–6 MPa) and a relatively low CO₂ concentration (50–70%) should be selected in the process of increasing methane production by CO₂ injection in later stages. These research results provide theoretical support for gas injection to promote CH₄ desorption in coal pores and to increase yield.     

Characterization and Valorization of the Agricultural Waste Obtained from Lavandula Steam Distillation for Its Reuse in the Food and Pharmaceutical Fields

The main focus of the current research was the characterization of the by-products from the steam distillation of Lavandula angustifolia Mill. (LA) and Lavandula x intermedia Emeric ex Loisel (LI) aerial parts, as they are important sources of bioactive compounds suitable for several applications in the food, cosmetic, and pharmaceutical industries. The oil-exhausted biomasses were extracted and the total polyphenol and flavonoid contents were, respectively, 19.22 ± 4.16 and 1.56 ± 0.21 mg/g for LA extract and 17.06 ± 3.31 and 1.41 ± 0.10 mg/g for LI extract. The qualitative analysis by liquid chromatography-electrospray tandem mass spectrometry (HPLC-ESI-MS) revealed that both the extracts were rich in phenolic acids and glycosylated flavonoids. The extracts exhibited radical scavenging, chelating, reducing activities, and inhibitory capacities on acetylcholinesterase and tyrosinase. The IC50 values against acetylcholinesterase and tyrosinase were, respectively, 5.35 ± 0.47 and 5.26 ± 0.02 mg/mL for LA, and 6.67 ± 0.12 and 6.56 ± 0.16 mg/mL for LI extracts. In conclusion, the oil-exhausted biomasses demonstrated to represent important sources of bioactive compounds, suitable for several applications in the food, cosmetic, and pharmaceutical industries.     

面向天基引力波探测的时间延迟干涉技术

时间延迟干涉技术(Time-delay?Interferometry,TDI)对中国引力波探测项目及其它天基激光精密测量任务具有重要的参考价值.在天基引力波探测任务中,需利用激光干涉仪对无拖曳检验质量块间实现十皮米量级的位移测量精度.其中,激光源频率噪声和时钟频率噪声是两项主要噪声.在欧洲主导的LISA(Laser?I...     

光学频率标准与光钟的实现

综述了时间频率标准的发展过程.对构成光学频率标准的四个要素,即激光冷却、激光稳频、离子捕陷和光学频率梳进行了系统的介绍.详细描述了光钟的原理与系统构成,并对光学频率标准与光钟的应用前景进行了展望.     

Superhydrophobic MoS2-based multifunctional sponge for recovery and detection of spilled oil

Oil spills are a major threat to the marine ecosystem, requiring immediate solutions to remove spilled oil from oceanic environments. In this study, we report a superhydrophobic molybdenum disulfide (MoS₂) coated polydimethylsiloxane (PDMS) sponge and demonstrate its high proficiency in spilled oil recovery and oil spill detection based on oil-water separation ability. This novel oil sorbent is fabricated by a simple dip-coating to incorporate MoS₂ flakes into PDMS sponge. The optimized MoS₂-sponge displays a water contact angle of >152°, demonstrating excellent superhydrophobicity and high oil absorption (>97 wt%) for a variety of oils, including vegetable oil and fuel waste. Moreover, the material retains excellent oil absorption capability upon repetitive compression cycles. The versatility of this novel sorbent has been extended for the real-time spontaneous detection of oils by taking advantage of electrically conductive MoS₂ layers.     

磷钼杂多化合物脱硫热力学可行性与硫磺生成机理研究

长期以来杂多化合物一直被用作特定反应的催化剂 ,尚无直接利用其氧化还原性能进行污染物治理研究的先例 [1] .由于磷和钼在我国均为丰产元素 ,相应的杂多化合物又具有稳定的化学性能 ,寻找其新的应用领域无疑具有特别重要的意义 .本文对与此相关的脱硫热力学可行性与硫磺生成机理问题进行研究 ,以期为应用开发奠定理论基础 .1　实验部分1 .1　仪器和试剂　 31 4型硫离子选择电极 (江苏电分析仪器厂 ) ;DSC- 7型微分量热仪 (美国 Perkin-Elmer公司 ) ;Finber 1 0 0 0型能谱分析仪 (配置 Pioneer KYKY2 80 0型扫描电镜 ) ;UJ33a型电位…     

仪器定量分析中几个问题的探讨

详细介绍了分析方法的评价指标,包括检出限、测定限、灵敏度、精密度、准确度、动态范围和线性范围、抗干扰能力等,单因素优化方法与加标回收实验评定测定结果准确度的可靠性,并就分析工作中遇到的一些实际问题进行了讨论.     

脱硫脱硝后V2O5/AC在含NH3气氛中的再生及硫资源化的耦合过程研究

V2O5/AC具有很好的烟气同时脱硫脱硝能力,脱硫过程包括其对烟气中SO2的吸附、吸附饱和后SO2从其上的脱附（再生）及脱附出SO2的资源化。考察了同时脱硫脱硝后的V2O5/AC在含NH3气氛中的再生和硫资源化的耦合过程。研究了NH3注入量、再生温度、再生时间和尾气循环流量对再生效率、硫回收率及二次脱硫脱硝活性的影响。结果表明,再生温度和再生时间主要影响SO2的脱附,因而影响再生效率和二次脱硫脱硝活性;NH3注入量不影响SO2的脱附,但明显影响硫回收率和二次脱硫脱硝活性;尾气循环模式是提高硫回收率的重要方法,但在研究的条件下循环流量对再生效率、硫回收率和二次脱硫脱硝活性的影响不大。     

Costas环在无线扩频定位系统中的应用技术研究

分析了扩频定位系统中载波恢复和数据解调数学模型，设计了环路中应用的Butterworth低通滤波器和产生正交两路信号的Hilbert变换滤波器，在Simulink中建立了Costas环仿真模型。结果表明：该Costas环能够准确地实现扩频定位系统的载波恢复和发送端数据解调输出，理论仿真和实际工程实验基本一致。     

鱼糜漂洗水中可溶蛋白的回收技术

对鱼糜漂洗水中可溶蛋白的综合回收技术情况进行了相关介绍, 主要包括絮凝沉淀法、等电点沉淀法、膜分离法、电阻加热法等, 这些技术的使用不仅实现了蛋白资源的再利用, 而且也减少了对环境的污染.