《宣室志》作者張讀墓誌考

張讀著《宣室志》是唐後期重要的志怪小説集，以往對他的家世生平瞭解甚少，僅知他是張薦孫，牛僧孺的外孫，大中間登進士第，該書撰成時比較年輕。僖宗時追隨入蜀，官至禮部侍郎。今根據西安碑林新入藏徐彦若撰其墓誌，得以完整瞭解他的生平履歷。知道他是唐初著名小説家張文成的四世孫；其父張希復是《酉陽雜俎》作者段成式的好友，雖因早亡未有著作存世，但段書中許多次提到他對於新奇事物的興趣。其母爲牛僧孺女，叙述其父母婚姻的部分也提示他文學來源的另一綫索。墓誌罕見地爲此小説世家保存了珍貴記録。而對存世《宣室志》遺文的截止時間，以及苗台符曾爲撰序，基本可認爲該書譔寫於他二十歲左右。此後他進士及第，宦海浮沉，雖與文學活動漸遠，但足以瞭解他完整履歷，足稱珍貴

Signal enhancement with stacked magnets for high-resolution radio frequency glow discharge mass spectrometry

A method for signal enhancement utilizing stacked magnets was introduced into high-resolution radio frequency glow discharge-mass spectrometry (rf-GD-MS) for significantly improved analysis of inorganic materials. Compared to the block magnet, the stacked magnets method was able to achieve 50−59% signal enhancement for typical elements in Y2O3, BSO, and BTN samples. The results indicated that signal was enhanced as the increase of discharge pressure from 1.3 to 8.0 mPa, the increase of rf-power from 10 to 50 W with a frequency of 13.56 MHz, the decrease of sample thickness, and the increase of number of stacked magnets. The possible mechanism for the signal enhancement was further probed using the software “Mechanical APDL (ANSYS) 14.0”. It was found that the distinct oscillated magnetic field distribution from the stacked magnets was responsible for signal enhancement, which could extend the movement trajectories of electrons and increase the collisions between the electrons and neutral particles to increase the ionization efficiency. Two NIST samples were used for the validation of the method, and the results suggested that relative errors were within 13% and detection limit for six transverse stacked magnets could reach as low as 0.0082 μg g−1. Additionally, the stability of the method was also studied. RSD within 15% of the elements in three nonconducting samples could be obtained during the sputtering process. Together, the results showed that the signal enhancement method with stacked magnets could offer great promises in providing a sensitive, stable, and facile solution for analyzing the nonconducting materials

李杜齊名之形成

中國詩歌史發展到盛唐，無疑達到巔峰之成就，而站在峰頂的人物，當然是被譽爲雙子星座的李白與杜甫。李白生前就已經取得舉世公認的地位，而比他年幼十二歲的杜甫則成名過程要複雜得多。今人根據通行的幾種唐人選唐詩没有收録杜甫詩歌，因此而認爲杜甫在唐代詩人中地位不高，影響不大，實在是皮相之見。本文則力圖根據第一手文獻，證明李杜齊名在杜甫生前已經爲部分人所認可，其最終獲得舉世公認，則在杜甫生後三五十年間完成。李杜地位的確定，是中古詩學史上的重大事件，也是引導唐宋詩歌轉型的關鍵所在

A semianalytical model of fractured horizontal well with hydraulic fracture network in shale gas reservoir for pressure transient analysis

Accurate construction of a seepage model for a multifractured horizontal well in a shale gas reservoir is essential to realizing the forecast of gas well production, the pressure transient analysis, and the inversion of the postfracturing parameters. This study introduces a method for determining the fracture control region to characterize the flow area of the matrix within the hydraulic fracture network, distinguishing the differences in the flow range of the matrix system between the internal and external regions caused by the hydraulic fracture network structure. The corresponding derivation and solution methods of the semi-analytical seepage model for fractured shale gas well are provided, followed by the application of case studies, model validation, and sensitivity analysis of parameters. The results indicate that the proposed model yields computational results that closely align with numerical simulations. It is observed that disregarding the differentiation of matrix flow area between the internal and external regions of the fracture network led to an overestimation of the estimated ultimate recovery, and the boundary-controlled flow period in typical well testing curves will appear earlier. Because hydraulic fracture conductivity can be influenced by multiple factors simultaneously, conducting a sensitivity analysis using combined parameters could lead to inaccurate results in the inversion of fracture parameters.Document Type: Original articleCited as: Cui, Q., Zhao, Y., Zhang, L., Chen, M., Gao, S., Chen, Z. A semianalytical model of fractured horizontal well with hydraulic fracture network in shale gas reservoir for pressure transient analysis. Advances in Geo-Energy Research, 2023, 8(3): 193-205. https://doi.org/10.46690/ager.2023.06.0

Oximation reaction induced reduced graphene oxide gas sensor for formaldehyde detection

High-performance gas sensors can offer great potentials for monitoring and detection ofvolatile organic compounds (VOCs) in both domestic and industrial environment. In the presentwork, a new HCHO gas sensor was constructed with reduced graphene oxide (RGO) induced bythe oximation reaction. The gas-sensing performance test results suggested that the RGO hydrox-ylamine hydrochloride (RGO/HA-HCl) sensor presented a high response of 75% at 16 ppm HCHOat room temperature, and a high selectivity for HCHO suffering little interference with high concen-trations of volatile organic compounds, including methanol, ethanol, and methylbenzene, dichlor-omethane and water. Additionally, the RGO/HA-HCl sensor also showed a good long-termstability with RSD of 5.83% for a 15-day continuous sensing test, and the detection limit (DL)could reach 0.023 ppm under ambient conditions. Moreover, the mechanism for the high sensitivityand selectivity of formaldehyde was further established by in-situ gas chromatography mass spec-trometry (GC–MS). This work would provide a reliable new HCHO gas sensor which could be usedfor monitoring and forewarning the emission of HCHO for a better protection and improvement ofour environment

Unleash electron transfer in C-H functionalization by mesoporous carbon-supported palladium interstitial catalysts

The functionalization of otherwise unreactive C–H bonds adds a new dimension to synthetic chemistry, yielding useful molecules for a range of applications. Arylation has emerged as an increasingly viable strategy for functionalization of heteroarenes which constitute an important class of structural moieties for organic materials. However, direct bisarylation of heteroarenes to enable aryl-heteroaryl-aryl bond formation remains a formidable challenge, due to the strong coordination between heteroatom of N or S and transitional metals. Here we report Pd interstitial nanocatalysts supported on ordered mesoporous carbon as catalysts for a direct and highly efficient bisarylation method for five-membered heteroarenes that allows for green and mild reaction conditions. Notably, in the absence of any base, ligands and phase transfer agents, high activity (turn-over frequency, TOF, up to 107 h−1) and selectivity (>99%) for the 2,5-bisarylation of five-membered heteroarenes are achieved in water. A combination of characterization reveals that the remarkable catalytic reactivity here is attributable to the parallel adsorption of heteroarene over Pd clusters, which breaks the barrier to electron transfer in traditional homogenous catalysis and creates dual electrophilic sites for aryl radicals and adsorbate at C2 and C5 positions. The d-band filling at Pd sites shows a linear relationship with activation entropy and catalytic activity. The ordered mesopores facilitate the absence of a mass transfer effect. These findings suggest alternative synthesis pathways for the design, synthesis and understanding of a large number of organic chemicals by ordered mesoporous carbon supported palladium catalysts.publishedVersio

Larmor precession: observation and utilization for boosting the signal intensity of radio frequency glow discharge mass spectrometry

A novel magnet array system was constructed to use Larmor precession for boosting the signal intensity of rf-GD-MS. The enhancement mechanism with four magnet array devices of single block magnet and 2×2, 3×2, and 3×4 magnet arrays was simulated and studied by COMSOL Multiphysics Software 5.4.0 (COMSOL) to determine if the electrons in the discharge plasma could perform Larmor precession along the direction perpendicular to the magnetic field. Induced by Larmor precession, inelastic collisions between the primary electrons and sample produced numerous secondary electrons and further improved the ionization efficiency. Moreover, the fuzzy synthetic evaluation result predicted that the device with 3×2 magnet array would display the greatest enhancement effect among the four devices. Based on these theoretical studies, a magnet array system with four magnet array devices was fabricated and utilized for studies of two scintillation crystals BGO and PWO. The observations indicated that the signal intensities obtained for 209Bi and 208Pb with the magnet array system were 630-3600 times of that obtained without magnet, and were enhanced by a factor of 1.5-2.8 compared with a previously reported stacked magnetic device. Two NIST samples were used to validate the method, and the results suggested that relative errors were less than 10% and the lowest detection limit for the 3×2 magnet array could reach 0.0032μg•g−1. Furthermore, the magnet array enhancement system with Larmor precession offers an efficient and sensitive approach for the direct analysis of non-conducting materials

Sources of nitrate in a heavily nitrogen pollution bay in Beibu Gulf, as identified using stable isotopes

Eutrophication, mainly caused by the oversupply of inorganic nitrogen and phosphate, has increased and become a serious environmental problem in the coastal bays of Beibu Gulf, a newly developing industry and port in South China. However, the sources of nitrate are poorly understood in the gulf. In this study, nitrate dual isotopes (δ15N-NO3- and δ18O-NO3-) and ammonium isotopes (δ15N-NH4+) were measured during the rainy season to identify the nitrate sources and elucidate their biogeochemical processes in Xi Bay, a semi-enclosed bay that is strongly affected by human activities in the Beibu Gulf. The results showed that a high dissolved inorganic nitrogen (DIN, 10.24-99.09 µmol L-1) was observed in Xi Bay, particularly in the bay mouth. The concentrations of DIN in the bay were 1.5 times higher than that in Qinzhou Bay and 1.7 times than that in Tieshangang Bay, which mainly influenced by the intensive human activities (i.e., industrial and port activities). In addition, lower values of δ15N-NO3- and δ18O-NO3- and higher values of δ15N-NH4+ were observed in the upper bay, suggesting that microbial nitrification occurs in the upper bay, which was the dominant nitrate source in the upper bay (39%). In addition to nitrification, external sources, including sewage and manure (33%), soil N (15%) and fertilizer (11%), contributed to the higher nutrients in the upper bay. In the lower bay, severe nitrogen pollution led to a weaker impact of biological processes on isotopic fractionation, although a high Chl a level (average of 7.47 µg L-1) was found in this region. The heavy nitrate pollution in the lower bay mainly originated from sewage and manure (54%), followed by soil N (26%) and fertilizer (17%). The contribution of the nitrate source from atmospheric deposition was relatively low in the bay (<3%). This study suggests that biogeochemical processes have little impact on nitrate dual isotopes under heavy nitrogen pollution, and isotopes are an ideal proxy for tracing nitrogen sources

CTAB Enhanced Room-Temperature Detection of NO2 Based on MoS2-Reduced Graphene Oxide Nanohybrid

A new NO2 nanohybrid of a gas sensor (CTAB-MoS2 /rGO) was constructed for sensitive room-temperature detection of NO2 by 3D molybdenum disulfide (MoS2 ) and reduced graphene oxide (rGO), assisted with hexadecyl trimethyl ammonium bromide (CTAB). In comparison with MoS2 and MoS2 /rGO, the BET and SEM characterization results depicted the three-dimensional structure of the CTAB-MoS2 /rGO nanohybrid, which possessed a larger specific surface area to provide more active reaction sites to boost its gas-sensing performance. Observations of the gas-sensing properties indicated that the CTAB-MoS2 /rGO sensor performed a high response of 45.5% for 17.5 ppm NO2, a remarkable selectivity of NO2, an ultra-low detection limit of 26.55 ppb and long-term stability for a 30-day measurement. In addition, the response obtained for the CTAB-MoS2 /rGO sensor was about two to four times that obtained for the MoS2 /rGO sensor and the MoS2 sensor toward 8 ppm NO2, which correlated with the heterojunction between MoS2 and rGO, and the improvement in surface area and conductivity correlated with the introduction of CTAB and rGO. The excellent performance of the CTAB-MoS2 /rGO sensor further suggested the advantage of CTAB in assisting a reliable detection of trace NO2 and an alternative method for highly efficiently detecting NO2 in the environment