Microwave irradiation-induced alterations in physicochemical properties and methane adsorption capability of coals:An experimental study using carbon molecular sieve

In order to comprehend the applicability of microwave irradiation for recovering coalbed methane,it is necessary to evaluate the microwave irradiation-induced alterations in coals with varying levels of metamorphism.In this work,the carbon molecular sieve combined with KMnO_(4)oxidation was selected to fabricate carbon molecular sieve with diverse oxidation degrees,which can serve as model substances toward coals.Afterwards,the microwave irradiation dependences of pores,functional groups,and highpressure methane adsorption characteristics of model substances were studied.The results indicated that microwave irradiation causes rearrangement of oxygen-containing functional groups,which could block the micropores with a size of 0.40-0.60 nm in carbon molecular sieve;meanwhile,naphthalene and phenanthrene generated by macro-molecular structure pyrolysis due to microwave irradiation could block the micropores with a size of 0.70-0.90 nm.These alterations in micropore structure weaken the saturated methane adsorption capacity of oxidized carbon molecular sieve by 2.91%-23.28%,suggesting that microwave irradiation could promote methane desorption.Moreover,the increased mesopores found for oxidized carbon molecular sieve after microwave irradiation could benefit CH4 diffusion.In summary,the oxidized carbon molecular sieve can act as model substances toward coals with different ranks.Additionally,microwave irradiation is a promising technology to enhance coalbed methane recovery.

Behavior of phenol adsorption on thermal modified activated carbon

Adsorption process is acknowledged as an effective option for phenolic wastewater treatment. In this work, the activated carbon(AC) samples after thermal modification were prepared by using muffle furnace. The phenol adsorption kinetics and equilibrium measurements were carried out under static conditions at temperature ranging from 25 to 55 °C. The test results show that the thermal modification can enhance phenol adsorption on AC samples. The porous structure and surface chemistry analyses indicate that the decay in pore morphology and decrease of total oxygen-containing functional groups are found for the thermal modified AC samples. Thus, it can be further inferred that the decrease of total oxygen-containing functional groups on the modified AC samples is the main reason for the enhanced phenol adsorption capacity. For both the raw sample and the optimum modified AC sample at 900 °C, the pseudo-second order kinetics and Langmuir models are found to fit the experimental data very well. The maximum phenol adsorption capacity of the optimum modified AC sample can reach144.93 mg·g-1which is higher than that of the raw sample, i.e. 119.53 mg·g-1. Adsorption thermodynamics analysis confirms that the phenol adsorption on the optimum modified AC sample is an exothermic process and mainly via physical adsorption.

Robust H_∞ guaranteed cost satisfactory fault-tolerant control for discrete-time systems with quadratic D stabilizability

The problem of robust H∞ guaranteed cost satisfactory fault-tolerant control with quadratic D stabilizability against actuator failures is investigated for a class of discrete-time systems with value-bounded uncertainties existing in both the state and control input matrices.Based on a more practical and general model of actuator continuous gain failures,taking the transient property,robust behaviour on H∞ performance and quadratic cost performance requirements into consideration,sufficient conditions for the existence of satisfactory fault-tolerant controller are given and the effective design steps with constraints of multiple performance indices are provided.Meanwhile,the consistency of the regional pole index,H∞ norm-bound constraint and cost performance indices is set up for fault-tolerant control.A simulation example shows the effectiveness of the proposed method.

Interactions of dynamic supercritical CO_(2) fluid with different rank moisture-equilibrated coals: Implications for CO_(2) sequestration in coal seams

The interactions between CO_(2) and coals during CO_(2)-ECBM(CO_(2) sequestration in deep coal seams with enhanced coal-bed methane recovery)could change pore morphology and chemistry property of coals,thereby affecting adsorption,diffusion and flow capability of CO_(2) and CH_(4) within coal reservoirs.To simulate CO_(2)-ECBM process more practically,the dynamic interactions of supercritical CO_(2)(sc CO_(2))and moisture-equilibrated coals were performed at temperature of 318.15 K,pressure of 12.00 MPa,and duration of 12.00 h.The impacts of the interactions on physicochemical properties of coals were investigated.Results indicate that sc CO_(2)/H_(2)O exposure shows minor effect on micropores of coals.However,the exposure significantly decreases the mesopore surface area of bituminous coals,while increases that of anthracites.The mesopore volume and the average mesopore diameter of all the coals after sc CO_(2)/H_(2)O exposure decrease.The multi-fractal analysis verifies that the sc CO_(2) exposure can enhance the pore connectivity of various rank coals.Apart from the pore morphology,the exposure of sc CO_(2)/H_(2)O also affects the oxygenic functional groups on coal surface.Particularly,the exposure of sc CO_(2)/H_(2)O reduces the content of CAO and C@O of coals.The content of COOH of low rank coals including Hehua-M2#coal,Zhongqiang-4#coal,Buliangou-9#coal and Tashan-5#coal decreases,while the high rank Laochang^(-1)1#coal and Kaiyuan-9#coal witness a growth in COOH.The content of total oxygenic functional groups of all coals after interaction with sc CO_(2)/H_(2)O decreases;on the contrary,that of CAC/CAH of all coals after sc CO_(2)/H_(2)O exposure increases.In summary,the interaction with sc CO_(2)/H_(2)O significantly changes the pore system and oxygenic functional groups of various rank coals,which needs further attention regarding CO_(2)-ECBM.

光/蒸气协同构建交联多孔聚合物复合结构基超稳定高速阻变存储器

有机阻变存储器由两个电极及夹在其间的阻变聚合物层组成,具有湿法制备和功能可调的优点.然而,该类存储器还存在结构稳定性差、开关速度慢和图案化困难等问题.在本文中,我们利用光/蒸汽协同方法制备了一种具有交联多孔复合结构的非晶态聚合物薄膜,并将其作为阻变活性材料构建了一种具有高稳定性和高读取速度特征的存储阵列.所制备的聚合物二极管表现出非易失性的FLASH存储特性,具有高开关比、长维持时间以及快速信息写入(70 ns)和擦除(845 ns)等特征.令人印象深刻的是,该存储器件能够承受紫外辐射和极端温度等恶劣环境的考验.通过将存储阵列和特定传感器集成,构建了能模拟视觉/热感知和记忆功能的人造感知记忆系统,表明该系统在仿生神经形态电子领域具有巨大的应用潜力.该工作为制备具有高稳定性和高读取速度特征的聚合物存储阵列提供了一种可靠的策略.

Fine Mapping of RppP25, a Southern Rust Resistance Gene in Maize

Southern rust （Puccinia polysora Underw.） is a major disease that can cause severe yield losses in maize （Zea mays L.）. In our previous study, a major gene RppP25 that confers resistance to southern rust was identified in inbred line P25. Here, we report the fine mapping and candidate gene analysis of RppP25 from the near-isogenic line F939, which harbors RppP25 in the genetic background of the susceptible inbred line F349. The inheritance of resistance to southern rust was investigated in the BC1F1 and BC3F1 populations, which were derived from a cross between F939 and F349 （as the recurrent parent）. The 1：1 segregation ratio of resistance to susceptible plants in these two populations indicated that the resistance is controlled by a single dominant gene. Ten markers, including three simple sequence repeat （SSR） markers and seven insertion/deletion （InDel） markers, were developed in the RppP25 region. RppP25 was delimited to an interval between P091 and M271, with an estimated length of 40 kb based on the physical map of B73. In this region, a candidate gene was identified that was predicted to encode a putative nucleotide-binding site leucine-rich repeat （NBS-LRR） protein. Two co-segregated markers will aid in pyramiding diverse southern rust resistance alleles into elite materials, and thereby improve southern rust resistance worldwide.

Overexpression of the maize GRF10, an endogenous truncated growth-regulating factor protein, leads to reduction in leaf size and plant height

It has long been thought that growth‐regulating factors（GRFs） gene family members act as transcriptional activators to play important roles in multiple plant developmental processes. However, the recent characterization of Arabidopsis GRF7 showed that it functions as a transcriptional repressor of osmotic stress‐responsive genes. This highlights the complex and diverse mechanisms by which different GRF members use to take action. In this study, the maize（Zea mays L.） GRF10 was functionally characterized to improve this concept. The deduced ZmGRF10 protein retains the N‐terminal QLQ and WRC domains, the characteristic regions as protein‐interacting and DNA‐binding domains, respectively. However,it lacks nearly the entire C‐terminal domain, the regions executing transactivation activity. Consistently, ZmGRF10 protein maintains the ability to interact with GRF‐interacting factors（GIFs） proteins, but lacks transactivation activity.Overexpression of ZmGRF10 in maize led to a reduction in leaf size and plant height through decreasing cell proliferation,whereas the yield‐related traits were not affected. Transcriptome analysis revealed that multiple biological pathways were affected by ZmGRF10 overexpression, including a few transcriptional regulatory genes, which have been demonstrated to have important roles in controlling plant growth and development. We propose that ZmGRF10 aids in fine‐tuning the homeostasis of the GRF‐GIF complex in the regulation of cell proliferation.