检索结果-南通市图书馆

Degradation of warm permafrost and talik formation on the Qinghai-Tibet Plateau in 2006-2021

在线全文

学校读者我要写书评

暂无评论

Advances in Climate Change Research 2024年第2期15卷 275-284页

作者： Qi-Hang MEI Ji CHEN You-Qian LIU Shou-Hong zhanG Jing-Yi ZHAO Tian-Chun DONG jun-Cheng WANG yao-jun ZHAO Beiluhe Observation and Research Station of Frozen Soil Engineering and Environment Key Laboratory of Cryospheric Science and Frozen Soil EngineeringNorthwest Institute of Eco-Environmental and ResourcesChinese Academy of SciencesLanzhou 730000China China Railway Qinghai-Tibet Group Co.Ltd Xining 810007China University of Chinese Academy of Sciences Beijing 100049China

Permafrost is degrading globally,particularly those with low thermal stability on the Qinghai-Tibet Plateau,owing to climate ***,the inadequacy of direct research on permafrost degradation based on in-situ monitoring limits the prediction of permafrost degradation and engineering *** study explored the processes and modes of permafrost degradation into talik by analyzing ground temperature data from five points in the hinterland of the Qinghai-Tibet Plateau from 2006 to *** results showed that the degradation of the warm permafrost layer with a geothermal gradient of zero occurred simultaneously in the top and bottom *** rate of permafrost degradation from the top down and bottom up increase during the degradation process,but the increase of the former is more drastic after the formation of thawed ***,the construction of the Qinghai-Tibet Railway changed the degradation modes of the permafrost in adjacent natural sites through horizontal heat transfer,particularly after through talik formation under the *** findings suggest that taking countermeasures before or immediately after forming thawed interlayer is more *** evaluating the thermal impact of projects in warm permafrost regions,special attention should be given to the horizontal heat transfer process that may result from the formation of a through talik.

关键词： Warm permafrost Degradation Talik Qinghai-Tibet Plateau Climate change

Ligation-assisted endoscopic submucosal resection following unroofing technique for small esophageal subepithelial lesions originating from the muscularis propria

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2024年第32期30卷 3748-3754页

作者： Quan Lu Quan-Zhou Peng jun yao Li-Sheng Wang De-Feng Li Department of Gastroenterology Shenzhen People’s HospitalShenzhen 518020Guangdong ProvinceChina Department of Pathology Shenzhen People’s HospitalShenzhen 518020Guangdong ProvinceChina Department of Gastroenterology Shenzhen People’s HospitalThe Second Clinical Medical CollegeJinan UniversityShenzhen 518020Guangdong ProvinceChina The First Affiliated Hospital Southern University of Science and TechnologyShenzhen 518020Guangdong ProvinceChina

BACKGROUND The majority of esophageal subepithelial lesions originating from the muscularis propria(SEL-MPs)are benign in nature,although a subset may exhibit malignant *** endoscopic resection techniques are time-consuming and lack efficacy for small *** To evaluate the efficacy and safety of ligation-assisted endoscopic submucosal resection(ESMR-L)following unroofing technique for small esophageal *** From January 2021 to September 2023,17 patients diagnosed with esophageal SEL-MPs underwent ESMR-L following unroofing technique at the endoscopy center of Shenzhen People’s *** of clinicopathological characteristics and clinical outcomes were collected and *** The mean age of the patients was 50.12±12.65 *** mean size of the tumors was 7.47±2.83 mm and all cases achieved en bloc resection *** average operation time was 12.2 minutes without any *** identified 2 Lesions(11.8%)as gastrointestinal stromal tumors at very low risk,12 Lesions(70.6%)as leiomyoma and 3 Lesions(17.6%)as smooth muscle *** recurrence was found during the mean follow-up duration of 14.18±9.62 *** ESMR-L following roofing technique is an effective and safe technique for management of esophageal SEL-MPs smaller than 20 mm,but it cannot ensure en bloc resection and may require further treatment.

关键词： Subepithelial lesions Muscularis propria Esophagus Ligation Endoscopic submucosal resection

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

探求死亡伦理

湖南师范大学社会科学学报 2010年第2期39卷 18-21页

作者：张怀承姚站军湖南师范大学道德文化研究中心湖南长沙410081

死亡伦理研究刚刚兴起,相对而言环境伦理已较成熟,我们可以受后者的研究思路启发来探求前者,立足存在的人类在自然之思的深层价值面上便产生了环境伦理,立足在世的人类在死亡之思的深层价值面上对应有了死亡伦理。在从出生到临终的人生... 详细信息

死亡伦理研究刚刚兴起,相对而言环境伦理已较成熟,我们可以受后者的研究思路启发来探求前者,立足存在的人类在自然之思的深层价值面上便产生了环境伦理,立足在世的人类在死亡之思的深层价值面上对应有了死亡伦理。在从出生到临终的人生旅途中,我们无时不能缺少对生命的伦理关怀,甚至生命的终止(死亡)之时或死亡之后,这种伦理的关怀仍在我们关注的视域之中。

关键词：死亡伦理生命拓展生命超越生命境界

Highly dispersive tetrahedral vanadium species on pure silica ZSM-12 zeolite boosting the selective oxidation of cyclohexane into cyclohexanone

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2024年第7期67卷 2206-2214页

作者： Menglin Xie Ting Li Chao Wu Xiaoling Liu Jinling Ni Siqin yao Yu Zhou Shibo Xi jun Wang State Key Laboratory of Materials-Oriented Chemical Engineering College of Chemical EngineeringNanjing Tech UniversityNanjing 211816China Institute of Sustainability for Chemicals Energy and Environment(ISCE2)Agency for ScienceTechnology and Research(A*STAR)Singapore 627833Republic of Singapore College of Materials Science and Engineering Sichuan UniversityChengdu 610065China

The selective oxidation of cyclohexane is a promising green route for the production of KA oil(cyclohexanol and cyclohexanone),but remains a huge challenge to design high-performing heterogeneous catalysts under mild ***,a pure silica ZSM-12(MTW topology)zeolite was applied as the support to immobilize highly dispersive tetrahedrally coordinated vanadium(V)species and the constructed catalyst 1%V/SZ-12 exhibited high efficiency in the fast and selective oxidation of cyclohexane into cyclohexanone with H_(2)O_(2).The reaction completed within 30 s,affording the selectivity of 99%towards cyclohexanone and the extremely high turnover frequency(TOF)of 5,891 h^(-1).1%V/SZ-12 was facilely reused with stable activity and feasibly extended to the oxidation of various cyclohexane *** one-dimensional 12-membered ring microchannels contributed to the formation and accessibility of tetrahedrally coordinated high valent V5+species as the robust active centers,which activated H_(2)O_(2) to generate V–O–O·,the active oxygen species for the electrophilic attack on cyclohexane to produce cyclohexanone as the sole product.

关键词： zeolite metal doping cyclohexane oxidation heterogeneous catalysis

Evolution of the porous structure for phosphoric acid etching carbon as cathodes in Li–O_(2) batteries:Pyrolysis temperature-induced characteristics changes

在线全文

学校读者我要写书评

暂无评论

Carbon Energy 2024年第1期6卷 172-181页

作者： Feiyang Yang Ying yao Yunkai Xu Cong Wang Meiling Wang Jingjie Ren Cunzhong zhang Feng Wu jun Lu Beijing Key Laboratory of Environmental Science and Engineering School of Materials Science and EngineeringBeijing Institute of TechnologyBeijingChina Beijing Institute of Technology Chongqing Innovation Center ChongqingChina College of Chemical and Biological Engineering Zhejiang UniversityHangzhouChina

Although biomass-derived carbon(biochar)has been widely used in the energy field,the relation between the carbonization condition and the physical/chemical property of the product remains ***,we revealed the carbonization condition's effect on the morphology,surface property,and electrochemical performance of the obtained *** open slit pore structure with shower-puff-like nanoparticles can be obtained by finely tuning the carbonization temperature,and its unique pore structure and surface properties enable the Li–O_(2) battery with cycling longevity(221 cycles with 99.8%Coulombic efficiency at 0.2 mA cm^(−2) and controlled discharge–charge depths of 500 mAh g^(−1))and high capacity(16,334 mAh g^(−1) at 0.02 mA cm^(−2)).This work provides a greater understanding of the mechanism of the biochar carbonization procedure under various pyrolysis conditions,paving the way for future study of energy storage devices.

关键词： biomass Li-O_(2) battery oxygen catalysts porous carbon temperature parameters

Dynamic interwell connectivity analysis of multi-layer waterflooding reservoirs based on an improved graph neural network

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Petroleum Science 2024年第2期21卷 1062-1080页

作者： Zhao-Qin Huang Zhao-Xu Wang Hui-Fang Hu Shi-Ming zhang Yong-Xing Liang Qi Guo jun yao School of Petroleum Engineering China University of Petroleum(East China)Qingdao266580ShandongChina Exploration and Development Research Institute Shengli OilfieldSINOPECDongying257015ShandongChina

The analysis of interwell connectivity plays an important role in the formulation of oilfield development plans and the description of residual oil distribution. In fact, sandstone reservoirs in China's onshore oilfields generally have the characteristics of thin and many layers, so multi-layer joint production is usually adopted. It remains a challenge to ensure the accuracy of splitting and dynamic connectivity in each layer of the injection-production wells with limited field data. The three-dimensional well pattern of multi-layer reservoir and the relationship between injection-production wells can be equivalent to a directional heterogeneous graph. In this paper, an improved graph neural network is proposed to construct an interacting process mimics the real interwell flow regularity. In detail, this method is used to split injection and production rates by combining permeability, porosity and effective thickness, and to invert the dynamic connectivity in each layer of the injection-production wells by attention *** on the material balance and physical information, the overall connectivity from the injection wells,through the water injection layers to the production layers and the output of final production wells is established. Meanwhile, the change of well pattern caused by perforation, plugging and switching of wells at different times is achieved by updated graph structure in spatial and temporal ways. The effectiveness of the method is verified by a combination of reservoir numerical simulation examples and field example. The method corresponds to the actual situation of the reservoir, has wide adaptability and low cost, has good practical value, and provides a reference for adjusting the injection-production relationship of the reservoir and the development of the remaining oil.

关键词： Graph neural network Dynamic interwell connectivity Production-injection splitting Attention mechanism Multi-layer reservoir

Illuminating spin-crossover octanuclear metal-organic cages

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2024年第4期67卷 1208-1215页

作者： Zhi-Kun Liu Alyona A.Starikova Yu-Xia Li Ke Sun Meng Yu Zi-Shuo yao jun Tao Key Laboratory of Cluster Science of Ministry of Education School of Chemistry and Chemical EngineeringLiangxiang CampusBeijing Institute of TechnologyBeijing 102488China Institute of Physical and Organic Chemistry Southern Federal UniversityRostov-on-Don 344090Russia

Spin-crossover(SCO)materials that reversibly switch between high-and low-spin states have potential for the storage of spin state-relative information,and have gained much attention incorporating secondary physical properties,such as fluorescence and magneto-optical *** this study,we synthesized three octanuclear metal-organic cages(MOCs)using tetraphenylethylene-based luminophores,aldehydes,and Fe^(Ⅱ)salts,by subcomponent self-assembly approach,namely[Fe1]-[Fe3].By controlling the ligand-field strength and guest encapsulation,we finely tuned their SCO *** them,MOC[Fe2]displayed nearly complete SCO behavior in the solid state,which is rare for high-nuclearity *** also demonstrated the coupling of SCO with fluorescence emission in these MOCs by using isostructural Zn^(Ⅱ)complexes([Zn1]-[Zn3])as control experiments,for the first *** calculations revealed the energy-transfer mechanism between fluorophores and SCOactive centers,which emphasizes the significant contribution of d-d transitions in the interplay between the occurrence of SCO and fluorescence emission.

关键词： metal-organic cages spin crossover fluorescence switching materials DFT calculation

Efficient removal of Cr(VI) by polydopamine-modified lignin from aqueous solution: Batch and XAFS studies

在线全文

学校读者我要写书评

暂无评论

Water Science and Engineering 2024年第1期17卷 51-61页

作者： Xiao-jie Guo Wei-kang Fu Jing-yuan Ma Bo-jun Xi Chen Wang Meng-yao Guan College of Materials and Environmental Engineering Hangzhou Dianzi UniversityHangzhou 310018China College of Textile and Garment Shaoxing UniversityShaoxing 312000China Shanghai Synchrotron Radiation Facility Shanghai Advanced Research InstituteChinese Academy of SciencesShanghai 201204China

Lignocellulose has the potential to become a bio-based adsorbent due to its biodegradability and *** this study,a novel polydopamine functionalized-lignin(lignin@PDA),prepared via self-polymerization of dopamine(PDA)on lignin,was used as a bio-based adsorbent for rapid scavenging of hexavalent chromium(Cr(VI)).The morphology,functional groups,crystalline structure,and chemical composition of lignin@PDA were characterized with a scanning electron microscope-energy dispersive spectrometer,Fourier transform infrared spectroscopy,X-ray diffraction,and X-ray photoelectron *** Cr(VI)adsorption process of lignin@PDA was studied using batch experiments as a function of pH,ionic strength,adsorbent dose,and contact time at room *** adsorption rate of lignin@PDA was five times greater than that of the unmodified lignin,with a maximum adsorption capacity of 102.6 mg/g in an acidic *** adsorption of Cr(VI)on lignin@PDA fit the pseudo-secondorder equation and the Freundlich model,indicating that the adsorption process was mainly dominated by chemisorption and surface *** thermodynamic parameters showed that adsorption of Cr(VI)on lignin@PDA was an endothermic and spontaneous *** X-ray absorption fine structure results showed that sorption and reduction of Cr(VI)into Cr(II)occurred simultaneously on ***,PDA coating not only improved the reactivity of lignin but also promoted the complete reduction of Cr(VI)by *** to these results,polydopamine functionalized-lignin is a promising bio-based adsorbent for immobilization of Cr(VI)from wastewater.

关键词： Lignin Polydopamine Hexavalent chromium EXAFS Adsorption mechanism

不同浸提剂大蒜根浸提液对番茄晚疫病菌的化感作用

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

广东农业科学 2012年第1期39卷 72-73,81页

作者：杨玉锋姚战军安阳工学院生物与食品工程学院河南安阳455000

利用生长速率法研究了不同浸提剂的大蒜根浸提液对番茄晚疫病病菌的化感作用。结果表明,不同浸提剂的大蒜根浸提液对番茄晚疫病菌均有一定的化感作用。大蒜根乙酸乙酯和乙醇浸提液各浓度均表现为化感抑制作用,但是对于大蒜根水浸提液来... 详细信息

利用生长速率法研究了不同浸提剂的大蒜根浸提液对番茄晚疫病病菌的化感作用。结果表明,不同浸提剂的大蒜根浸提液对番茄晚疫病菌均有一定的化感作用。大蒜根乙酸乙酯和乙醇浸提液各浓度均表现为化感抑制作用,但是对于大蒜根水浸提液来说,高浓度表现的为化感抑制作用,低浓度表现为化感促进作用,3种浸提液中化感抑制效果最强的是乙酸乙酯,抑制率达到50.00%,其次是乙醇浸提液,为34.29%,最弱是水浸提液,为29.12%。不同浸提剂的大蒜根浸提液70%浓度处理为化感抑制作用临界值。

关键词：大蒜根浸提液番茄晚疫病病菌化感作用