检索结果-南通市图书馆

Rh/SiO_2催化剂上甲烷部分氧化制合成气的反应机理

在线全文

学校读者我要写书评

暂无评论

催化学报 2012年第7期33卷 1183-1190页

作者：温在恭李虎翁维正夏文生黄传敬万惠霖厦门大学固体表面物理化学国家重点实验室醇醚酯化工清洁生产国家工程实验室化学化工学院化学系福建厦门361005

采用原位Raman光谱技术,在原料气中的O2未完全耗尽的条件下,对CH4部分氧化制合成气反应的Rh/SiO2催化剂床层前部贵金属物种的化学态以及由CH4解离所生成的碳物种进行了表征.在此基础上采用脉冲反应和同位素示踪技术,比较了CH4的部分氧... 详细信息

采用原位Raman光谱技术,在原料气中的O2未完全耗尽的条件下,对CH4部分氧化制合成气反应的Rh/SiO2催化剂床层前部贵金属物种的化学态以及由CH4解离所生成的碳物种进行了表征.在此基础上采用脉冲反应和同位素示踪技术,比较了CH4的部分氧化及其与H2O和CO2的重整等反应对催化剂床层氧化区内CO和H2生成的相对贡献,并将实验结果与Ra-man光谱表征结果进行了关联.结果表明,在600°C下将还原后的4%Rh/SiO2催化剂切入CH4:O2:Ar=2:1:45原料气,催化剂床层前部未检测到铑氧化物的Raman谱峰,但可清晰检测到源于CH4解离的碳物种;在700°C和接触时间小于1ms的条件下,催化剂床层的氧化区内已有大量CO和H2生成,在相同的实验条件下,CH4与H2O或CO2重整反应对氧化区内合成气生成的贡献则很小;以CH4:16O2:H218O:He=2:1:2:95为原料气的同位素示踪实验结果表明,在原料气中16O2未完全耗尽的情况下,反应产物中C16O的含量占CO生成总量的92.3%,表明CO主要来自CH4的部分氧化反应.上述结果均表明,在O2存在下Rh/SiO2催化剂上CO和H2可以通过CH4直接解离和部分氧化机理生成.

关键词：铑甲烷部分氧化合成气脉冲反应原位拉曼光谱同位素示踪

锆促进纳米氧化镍催化剂的制备及其对乙烷氧化脱氢制乙烯的催化性能

在线全文

学校读者我要写书评

暂无评论

催化学报 2005年第2期26卷 148-152页

作者：操小栋陈铜吴瑛张晋芬翁维正万惠霖厦门大学化学系物理化学研究所固体表面物理化学国家重点实验室福建厦门361005

用尿素均匀沉淀法制备了不同含量锆促进的纳米氧化镍催化剂 ,并考察了其对乙烷氧化脱氢制乙烯的催化性能 .结果表明 ,纯纳米氧化镍在优化条件下的最高乙烯收率为 2 1 7% ;而锆促进的纳米氧化镍催化剂对乙烯选择性和高温抗乙烷裂解性能... 详细信息

用尿素均匀沉淀法制备了不同含量锆促进的纳米氧化镍催化剂 ,并考察了其对乙烷氧化脱氢制乙烯的催化性能 .结果表明 ,纯纳米氧化镍在优化条件下的最高乙烯收率为 2 1 7% ;而锆促进的纳米氧化镍催化剂对乙烯选择性和高温抗乙烷裂解性能都有明显改善 .15 %ZrO2 NiO表现出最佳的催化性能 ,在 4 10℃下 ,乙烷转化率为 6 1 5 % ,乙烯选择性为 6 8 6 % ,乙烯收率为 4 2 2 % ;该催化剂在 4 2 0℃经 36h反应 ,乙烯收率仅下降约 4 % ,粒子没有发生明显的团聚 ,表现出较好的稳定性 .XRD结果表明 ,锆促进的纳米氧化镍粒子较纯纳米氧化镍粒子小 ,平均粒径为 5～ 7nm ;助剂锆以无定形的ZrO2 形式存在 .O2 TPD MS结果表明 ,锆的加入提高了催化剂中较高温度下脱附的氧物种量 ,降低了较低温度下脱附的氧物种量 .H2 TPR结果显示 ,锆促进的纳米氧化镍催化剂较纯纳米氧化镍难以完全还原 .

关键词：乙烷氧化脱氢乙烯锆促进纳米氧化镍催化剂尿素均匀沉淀法

Provably secure attribute-based authenticated encryption with keyword search from ideal lattices

在线全文

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2024年第1期67卷 308-309页

作者： Lisha YAO Lin HOU Jian weng Feixiang ZHAO College of Cyber Security Jinan University

A public-key authenticated encryption with keyword search(PAEKS)[1, 2] system overcomes the problem of an inside adversary forging searchable ciphertexts and guessing the keyword information from the given token. This system allows the sender to encrypt and authenticate a ***, traditional PAEKS schemes require the sender to specify the intended receiver in advance, losing much flexibility.

关键词：

CSCO guidelines for colorectal cancer version 2024:Updates and discussions

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Cancer Research 2024年第3期36卷 233-239页

作者： Liubo Chen Hanguang Hu Ying Yuan Shanshan weng Department of Medical Oncology(Key Laboratory of Cancer Prevention and Intervention China National Ministry of EducationKey Laboratory of Molecular Biology in Medical SciencesZhejiang ProvinceChina)the Second Affiliated HospitalZhejiang University School of MedicineHangzhou 310009China Zhejiang Provincial Clinical Research Center for CANCER Hangzhou 310009China Cancer Center Zhejiang UniversityHangzhou 310058China

According to the latest global cancer statistics,colorectal cancer(CRC)is the most common malignancy of the digestive system and the second most lethal among all cancer types(1).In China,CRC is the second most prevalent cancer,following only after lung cancer(2).The first version of the Chinese Society of Clinical Oncology(CSCO)guideline was launched in 2017 and has been updated annually based on the latest findings of clinical research,drug accessibility and expert consensus(3-8).Here,we present the main updates of the 2024 version compared to the 2023 version.

关键词： CSCO colorectal cancer

Biomineralization of soil with crude soybean urease using different calcium salts

在线全文

学校读者我要写书评

暂无评论

Journal of Rock Mechanics and Geotechnical Engineering 2024年第5期16卷 1788-1798页

作者： Yajie weng Junjie Zheng Hanjiang Lai Mingjuan Cui Xingzhi Ding School of Civil and Hydraulic Engineering Huazhong University of Science and TechnologyWuhan430074China Zijin School of Geology and Mining Fuzhou UniversityFuzhou350108China College of Civil Engineering Fuzhou UniversityFuzhou350116China

Calcium salt is an important contributing factor for calcium-based *** study the effect of calcium salt on soil biomineralization using crude soybean urease,the calcium salts,including the calcium chloride (CaCl_(2)),calcium acetate ((CH_(3)COO)_(2)Ca) and calcium nitrate (Ca(NO_(3))_(2)),were used to prepare the biotreatment solution to carry out the biomineralization tests in this *** series of biomineralization tests in solution and sand column,respectively,were *** electron microscopy (SEM) and X-ray diffraction (XRD) were performed to determine the microscopic characteristics of the precipitated calcium carbonate (CaCO_(3)) *** experimental results indicate that the biomineralization effect is the best for the CaCl2 case,followed by (CH_(3)COO)_(2)Ca,and worst for Ca(NO_(3))_(2) under the test conditions of this study (i.e.1 mol/L of calcium salt-urea).The mechanism for the effect of the calcium salt on the biomineralization of crude soybean urease mainly involves: (1) inhibition of urease activity,and (2) influence on the crystal size and morphology of CaCO_(3).Besides Ca^(2+) ,the anions in solution can inhibit the activity of crude soybean urease,and NO_(3)− has a stronger inhibitory effect on the urease activity compared with both CH_(3)COO^(−) and Cl^(−) .The co-inhibition of Ca^(2+) and NO_(3)− on the activity of urease is the key reason for the worst biomineralization of the Ca(NO_(3))_(2) case in this *** difference in biomineralization between the CaCl_(2) and (CH_(3)COO)_(2) Ca cases is strongly correlated with the crystal morphology of the precipitated CaCO_(3).

关键词： Biomineralization Crude soybean urease Calcium salt Influence mechanism

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

介孔Ni基催化剂上乙烷氧化脱氢制乙烯

催化学报 2009年第8期30卷 714-716页

作者：李建辉李仁贵汪彩彩黄传敬翁维正万惠霖厦门大学化学化工学院化学系固体表面物理化学国家重点实验室福建厦门361005

以十二烷基硫酸钠为模板剂,尿素为沉淀剂制备了介孔氧化镍,并将该方法成功拓展至介孔NiMgO催化剂的合成.考察了这两种催化剂以及采用溶胶-凝胶法制备的纳米氧化镍催化剂对乙烷氧化脱氢反应的催化性能.结果表明,介孔氧化镍较纳米氧化镍... 详细信息

以十二烷基硫酸钠为模板剂,尿素为沉淀剂制备了介孔氧化镍,并将该方法成功拓展至介孔NiMgO催化剂的合成.考察了这两种催化剂以及采用溶胶-凝胶法制备的纳米氧化镍催化剂对乙烷氧化脱氢反应的催化性能.结果表明,介孔氧化镍较纳米氧化镍在相同乙烷转化率条件下乙烯选择性更高,且前者反应温区大为扩展,因而乙烯收率更高.介孔氧化镍经Mg调变后,其催化性能进一步提高,在450oC,C2H6:O2:N2=1:1:4和GHSV=18000ml/(g·h)条件下,介孔NiMgO催化剂上乙烷转化率和乙烯收率分别为56.6%和30.1%,其乙烯收率远高于纳米氧化镍(15.9%)和介孔氧化镍(22.5%).

关键词：镍基催化剂介孔材料镁乙烷氧化脱氢乙烯

Functional thermal fluids and their applications in battery thermal management:A comprehensive review

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2024年第7期94卷 78-101页

作者： Xinyue Xu Keyu weng Xitao Lu Yuanqiang Zhang Shuyan Zhu Deqiu Zou Faculty of Maritime and Transportation Ningbo UniversityNingbo 315211ZhejiangChina

With the increasing requirements for fast charging and discharging,higher requirements have been put forward for the thermal management of power ***,there is an urgent need to develop efficient heat transfer *** a new type of heat transfer fluids,functional thermal fluids mainly includ-ing nanofluids(NFs)and phase change fluids(PCFs),have the advantages of high heat carrying density,high heat transfer rate,and broad operational temperature ***,challenges that hinder their practical applications *** this paper,we firstly overview the classification,thermophysical prop-erties,drawbacks,and corresponding modifications of functional thermal *** NFs,the high ther-mal conductivity and high convective heat transfer performance were mainly elaborated,while the stability and viscosity issues were also *** then for PCFs,the high heat carrying density was mainly elaborated,while the problems of supercooling,stability,and viscosity were also *** this basis,the composite fluids combined NFs and PCFs technology,has been ***,the thermal properties of traditional fluids,NFs,PCFs,and composite fluids are compared,which proves that functional thermal fluids are a good choice to replace traditional fluids as ***,battery thermal management system(BTMS)based on functional thermal fluids is summarized in detail,and the thermal management effects and pump consumption are compared with that of water-based ***,the current technical challenges that parameters optimization of functional thermal fluids and structures optimization of BTMS systematically are *** the future,it is necessary to pay more attention to using machine learning to predict thermophysical properties of functional thermal fluids and their applications for BTMS under actual vehicle conditions.

关键词： Functionalthermal fluids Nanofluids Phase change fluids Battery thermal management system Thermophysical properties

KH550-SiO_(2)/polyimide insulating paper preparation and characterisation

在线全文

学校读者我要写书评

暂无评论

High Voltage 2024年第2期9卷 466-473页

作者： Minghe Chi Xue Sun Xiaorui Zhang Jiahao Shi Ling weng Yang Yu School of Electrical and Electronic Engineering Harbin University of Science and TechnologyHarbinChina Key Laboratory of Engineering Dielectrics and Its Application Ministry of EducationHarbin University of Science and TechnologyHarbinChina School of Materials Science and Engineering Harbin University of Science and TechnologyHarbinChina

Oil-paper insulation material is an essential component for oil-filled transformers,and polyimide(PI)insulation paper is a novel material in the field of *** improvement of insulation class for insulation paper has gained significant attention in recent *** this study,SiO_(2)nanoparticles were modified with a silane coupling agent(KH550),and the KH550-SiO_(2)was added to the fibre membrane through in situ *** chemical composition and microcosmic characteristics of the PI porous fibre membrane were characterised using FT-IR and SEM FT-IR and ***-quently,the dielectric constant of the composite paper was reduced to 2.3 upon adding 3 wt%of KH550-SiO_(2),and the dielectric strength reached its maximum value of 85 kV/*** results demonstrate that the insulation performance of the KH550-SiO_(2)/PI composite was significantly improved due to the incorporation of nano-SiO_(2).This establishes an efficient approach for achieving excellent electrical and thermal properties in practical applications using the KH550-SiO_(2)/PI fibre membrane.

关键词： composite insulation fibre

When Glanzmann thrombasthenia encounters antithrombin defi ciency: how do we balance the risk and benefi t of antithrombotic therapy?

维普期刊数据库评论

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 Emergency Medicine 2024年第1期15卷 67-69页

作者： Yu Wang Zhihao Liu Haoyu weng Jianping Li Department of Endocrinology Peking University First HospitalBeijing 100034China Department of Cardiology Peking University First HospitalBeijing 100034China Key Laboratory of Molecular Cardiovascular Sciences of Ministry of Education Health Science CenterPeking UniversityBeijing 100034China

Glanzmann’s thrombasthenia(GT)is an inherited autosomal recessive bleeding disorder,resulting from mutations in the ITGA2B and ITGB3 genes,that lead to a defect in the platelet membrane integrinαIIbβ3.[1]As integrinαIIbβ3 plays an important role in thrombus formation,the clinical manifestation of GT includes bleeding(mostly mucocutaneous)and *** this reason,patients with GT are typically thought to be unlikely to suffer from thromboembolic *** is an anticoagulant that inhibits thrombin and is activated factor X and other serine proteases in the coagulation cascade.[2]Antithrombin deficiency is an autosomal dominant hereditary disease with an approximate prevalence of 1/500 in the overall population.[3]In contrast to the hemorrhagic tendency of GT,patients with antithrombin deficiency are at increased risk of thromboembolism,especially in the venous ***,we describe a rare case of GT and antithrombin deficiency coexisting in a single *** was used for the treatment of pulmonary embolism(PE)and deep vein thrombosis(DVT).

关键词： thrombin throm bleeding