检索结果-南通市图书馆

Hydrotalcite-supported Pd-Cu catalyst for nitrate adsorption and reduction from water

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2006年第12期51卷 1431-1438页

作者： wang ying qu Jiuhui LIU Huijuan wu Rongcheng State Key Laboratory of Environmental Aquatic Chemistry Research Center for Eco-environmental Sciences Chinese Academy of Sciences Beijing 100085 China Graduate School of Chinese Academy of Sciences Beijing 100039 China

Hydrotalcite-supported Pd-Cu catalyst for nitrate adsorption and catalytic reduction from water is prepared by co-impregnation method and characterized by surface area (BET), X-ray diffraction (XRD), scanning electron microscope (SEM), trans- mission electron microscope (TEM) and X-ray pho- toelectron spectrum (XPS). The performance of ad- sorption and hydrogenation of nitrate was evaluated and compared with Al2O3, TiO2, and HZSM-supported Pd-Cu catalysts. The experimental results demon- strated that hydrotalcite-supported Pd-Cu catalyst exhibited a high surface area (185.3 m2/g) and mesopore structure (average pore diameter of 52.2 ?). The active metal clusters were homogeneously dispersed on the support, and the size of the most was less than 10 nm. Excellent adsorption for nitrate resulted from that nitrate ions were forced to enter the interlayer space when the calcined hydrotalcite re- generated layer structure in nitrate solution. The ad- sorption isotherm could be well described by the Langmuir model. The comparison between the ad- sorption and catalytic hydrogenation for nitrate using hydrogen indicated that nitrate reduction on hydro- talcite-supported Pd-Cu catalysts was a consecutive and dynamic adsorption and catalytic hydrogenation process. Compared with the Al2O3, TiO2, and HZSM- supported catalysts, hydrotalcite-supported Pd-Cu catalyst possessed higher catalytic activity and se- lectivity. The analysis on the dissolving of metals in the solution demonstrated that there was hydrolyza-tion on the surface of the hydrotalcite-supported Pd-Cu catalyst. However, the concentrations of dis- solved metals in the solution were lower than the standard executed in China. The activity of the hy- drotalcite-supported Pd-Cu catalyst for nitrate reduc- tion kept steady after repeated use.

关键词：水滑石硝酸盐吸附催化还原 XRD SEM Pd-Cu催化剂

在线全文

学校读者我要写书评

暂无评论

芋头粉对低盐巴沙鱼鱼糜凝胶特性的影响

中国调味品 2024年第8期49卷 106-112页

作者：王敬涵王舒彤戴瑞杜密英胡燕武家宇赵冬桂林旅游学院食品与健康学院广西桂林541006 广西演艺职业学院南宁530226 扬州大学旅游烹饪学院江苏扬州225127

为改善低盐巴沙鱼鱼糜的凝胶品质,分析芋头粉添加量对鱼糜凝胶蒸煮得率、保水性、色泽、质构的影响,并通过分析微观结构和蛋白质二级结构,探究其对鱼糜蛋白结构的影响。结果表明,当芋头粉添加量为0%~20%时,鱼糜的蒸煮得率、保水性显著提... 详细信息

为改善低盐巴沙鱼鱼糜的凝胶品质,分析芋头粉添加量对鱼糜凝胶蒸煮得率、保水性、色泽、质构的影响,并通过分析微观结构和蛋白质二级结构,探究其对鱼糜蛋白结构的影响。结果表明,当芋头粉添加量为0%~20%时,鱼糜的蒸煮得率、保水性显著提高;当芋头粉添加量为20%~25%时,保水性无显著性变化。芋头粉添加量对巴沙鱼鱼糜的色泽影响显著,随着芋头粉添加量的增加,巴沙鱼鱼糜的亮度和白度下降,色泽偏黄绿色;随着芋头粉添加量的增加,巴沙鱼鱼糜的凝胶强度先升高后降低,当芋头粉添加量为20%时,凝胶强度达到最大值。与空白组对比,随着芋头粉添加量的增加,凝胶肌原纤维蛋白中α-螺旋上升,β-折叠下降,说明芋头粉能降低肌原纤维蛋白中α-螺旋转变为β-折叠的程度,使其形成致密的凝胶网络结构,凝胶也更具保水性。当芋头粉添加量为20%时,鱼糜的储能模量G′达到最大值,说明鱼糜在加热形成凝胶的过程中,弹性特征更明显。芋头粉膨胀后加固了蛋白的网络结构,增强了其凝胶特性,但是芋头粉添加量为25%时,鱼糜的凝胶网络结构遭到破坏,出现空洞结构。以上结果表明,当芋头粉添加量为15%~20%时可有效改善低盐巴沙鱼鱼糜的凝胶品质,并且制备的鱼糜富含膳食纤维。

关键词：巴沙鱼鱼糜芋头粉凝胶特性蛋白结构

维普期刊数据库博看期刊

新工科背景下提高教学类仪器设备利用率的探索与实践——以吉林大学工程训练中心为例

在线全文

学校读者我要写书评

暂无评论

实验技术与管理 2024年第8期41卷 244-250页

作者：丁连涛吴彤刘思含杨洋刘鹏王云艺曲晓海吉林大学机械与航空航天工程学院吉林长春130022

实践教学能够帮助学生巩固理论知识、提高实践创新能力、培养劳动精神,在新工科背景下卓越工程师的培养过程中发挥着重要作用。教学类仪器设备是实践教学的基础,提高其利用率、挖掘最大可用价值,是当前各高校亟待解决的问题。为探索更... 详细信息

实践教学能够帮助学生巩固理论知识、提高实践创新能力、培养劳动精神,在新工科背景下卓越工程师的培养过程中发挥着重要作用。教学类仪器设备是实践教学的基础,提高其利用率、挖掘最大可用价值,是当前各高校亟待解决的问题。为探索更加贴合基层教学单位的仪器设备利用率提高路径,该文以某高校工程训练中心为例,从微、小、中、大型仪器设备的角度出发,通过课内改革打造共享空间、课外扩展建设共享平台,以及发挥社会服务协同作用的方法,达到强化仪器设备管理、推动实践教学改革、提升人才培养质量的目的。

关键词：新工科实践教学仪器设备利用率

Power optimization for maximum channel capacity in MIMO relay system

在线全文

学校读者我要写书评

暂无评论

The Journal of China Universities of Posts and Telecommunications 2007年第3期14卷 10-15页

作者： wang ying SHEN Xiao-dong wu tong LIU Bao-ling Key Laboratory of Ubiquitous Wireless Communication Ministry ofEducation Beijing University of Posts and TelecommunicationsBeijing 100876 China

Introducing multiple-input multiple-output（MIMO） relay channel could offer significant capacity gain. And it is of great importance to develop effective power allocation strategies to achieve power efficiency and improve channel capacity in amplify-and-forward relay system. This article investigates a two-hop MIMO relay system with multiple antennas in relay node （RN） and receiver （RX）. Maximizing capacity with antenna selection（MCAS） and maximizing capacity with eigen-decomposition （MCED） schemes are proposed to efficiently allocate power among antennas in RN under first and second hop limited scenarios. The analysis and simulation results show that both MCED and MCAS can improve the channel capacity compared with uniform power allocation （UPA） scheme in most of the studied areas. The MCAS bears comparison with MCED with an acceptable capacity loss, but lowers the complexity by saving channel state information （CSI） feedback to the transmitter （TX）. Moreover, when the RN is close to RX, the performance of UPA is also close to the upper bound as the performance of first hop is limited.

关键词： MIMO-relay MCAS MCED UPA maximum channel capacity

On the MAC-BC duality of multiuser non-regenerative MIMO relay systems

在线全文

学校读者我要写书评

暂无评论

The Journal of China Universities of Posts and Telecommunications 2011年第1期18卷 1-8页

作者： LI Gen wang ying GONG Feng wu tong ZHANG Ping Wireless Technology Innovation Institute Beijing University of Posts and Telecommunications Beijing 100876 China Key Laboratory of Universal Wireless Communications Ministry of Education Beijing University of Posts and Telecommunications Beijing 100876 China

Multiple input multiple output （MIMO） relaying techniques can greatly improve the spectral efficiency and extend network coverage for future wireless systems. This article investigates a multiuser MIMO relay channel, where a base station （BS） with multiple antennas communicates with multiple mobile stations （MS） via a relay station （RS） with multiple antennas. The RS applies linear processing to the received signal and then forwards the processed signal. The dual channel conditions between MIMO relay multiple access channel （MAC） and broadcast channel （BC） are first developed for single-relay scenario with white Gaussian noise. Then the MAC-BC duality for MIMO relay systems is established by proving that the capacity region of MIMO relay MAC is equal to that of dual MIMO relay BC under the same total network transmit power constraint. In addition, the duality is also extended to multi-relay scenario with arbitrary noise. Finally, several simple general numerical examples are provided to better illustrate the effectiveness of the MIMO relay MAC-BC duality.

关键词： M1MO relay multiuser duality multiple access channel broadcast channel

Preparation of dry flowable formulations of Clonostachys rosea by spray drying and application for Sclerotinia sclerotiorum control

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Agriculture 2018年第3期17卷 613-620页

作者： wu Hong-qu SUN Li-li LIU Fang wang Zhi-ying CAO Chuan-wang College of Forestry Northeast Forestry University Harbin 150040 P.R.China Hubei Biopesticide Engineering Research Centre Wuhan 430064 P.R.China

A dry flowable formulation of Clonostachys rosea with fungicidal activity against Sclerotinia sclerotiorum was prepared by spray drying. The formulation was optimized by a four-factor, three-level orthogonal experiment to screen inert ingredients and spray-drying conditions. The optimal dry flowable formulation of C. rosea included 30% C. rosea （ratio of conidia powder and its fermentation broth is 1：3）, 3% Morwet EFW, 4% K12, 10% Morwet D425, 9% sodium salt of polynaphthalene sulphonic acid （NNO）, 5% croscarmellose sodium, 5% （NH4）2SO4, 0.5% carboxymethyl cellulose sodium （CMC-Na）, 1% oxalic acid and palygorskite （carrier） up to 100%. The formulation exhibited good physical characteristics, such as high dispersibility, viability and a long shelf life. Plate antagonism tests and pot trials indicated that the dry flowable formulation was very effective against S. sclerotiorum, with control efficiency of up to 88.30%. This dry flowable formulation of C. rosea is a new potential commercial fungicide for spray drying to control S. sclerotiorum.

关键词： Clonostachys rosea dry flowable formulation Sclerotinia sclerofiorum spray drying

Corrosion resistance properties of colored zirconium conversion coating and powder coating on cold-rolled steel

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2023年第3期42卷 1005-1010页

作者： Ai-Hua wu Yao-Zu wang tong-Kuan Xu Zhi Li Sheng-Ji Luan Feng-Zuo qu Shenzhen Key Laboratory of Environment Simulation and Pollution Control PKU-HKUST Shenzhen-HongKong InstitutionShenzhen 518057China Faculty of Light Industry and Chemical Engineering Dalian Polytechnic UniversityDalian 116034China

Jiuhe Corporation developed a new surface pretreatment for producing a phosphate-free and colored zirconium conversion coating on cold-rolled steel(CRS).Scanning electron microscopy(SEM)and energy-dispersive spectroscopy(EDS)were applied to study the surface morphology and elemental composition of the golden yellow-colored conversion *** trochemic al impedance spectroscopy(EIS)was used to investigate the electrochemical performance of the conversion coatings with different *** corrosion resistance properties of the powder coatings were characterized using the neutral salt spray test(NSS)and the tape adhesion *** EIS and NSS results demonstrate that the colored zirconium conversion coatings exhibit excellent corrosion resistance properties compared with the bare *** golden yellow-colored conversion coating has a maximum EIS value(748Ω·cm^(2))and achieves 0 mm degree of corrosion,as stipulated by EN ISO *** paper proposes a hypothesis concerning the ZrO_(2)-(β-FeOOH)-polymer conversion reaction to explain the color changes.

关键词： Surface pretreatment Colored conversion coating Zirconium oxide Powder coating Corrosion protection

MoS_(2)/八面体Fe_(3)O_(4)复合界面催化电化学海水提铀的性能与机理研究

在线全文

学校读者我要写书评

暂无评论

核化学与放射化学 2024年第4期46卷 334-344,I0002页

作者：吕莹童刘旺朱波明程儒吴旭东刘欢欢何嵘西南科技大学国防科技学院四川绵阳621010

电化学海水提铀是一种可持续补充核燃料的有效策略,但由于海洋中铀的浓度极低(铀质量分数为3.3×10^(-9))与复杂的环境干扰,高活性电催化剂的合理设计仍然是一个挑战。本工作提出界面键合策略,通过简单水热法制备MoS_(2)/八面体Fe_(3)O_... 详细信息

电化学海水提铀是一种可持续补充核燃料的有效策略,但由于海洋中铀的浓度极低(铀质量分数为3.3×10^(-9))与复杂的环境干扰,高活性电催化剂的合理设计仍然是一个挑战。本工作提出界面键合策略,通过简单水热法制备MoS_(2)/八面体Fe_(3)O_(4)复合材料,通过X射线光电子能谱(XPS)、高分辨透射电镜(HRTEM)等一系列表征,表明成功将八面体Fe_(3)O_(4)的{2 2 2}晶面与MoS_(2)的{0 0 2}晶面进行键合。在模拟溶液中,经过7 h的电化学提取,铀提取效率可以达到96%。同时,共存离子下的铀提取实验结果表明,MoS_(2)/Fe_(3)O_(4)对铀具有良好的选择性和对共存离子的抗干扰性。在10 L天然海水中进行电化学提取,提取到27.2μg的铀,提取容量为5.44 mg/g。通过对催化剂与提铀性能之间构效关系的研究,验证了界面键合面向电化学海水提铀的可行性。机理探究揭示了界面键合策略对降低Fe_(3)O_(4)的电荷转移电阻、提高电子在界面处的转移速率与Fe_(3)O_(4)的循环稳定性的促进作用,对电化学海水提铀的催化剂设计与开发提供了思路。

关键词：电化学海水提铀界面

不同年限梅花鹿干扰对亚热带森林土壤和植物生物量的影响

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

生态学报 2024年第17期44卷 7786-7796页

作者：杜芳芳童根平何影王旭池叶正钱吴家森傅伟军浙江农林大学环境与资源学院杭州311300 浙江清凉峰国家级自然保护区管理局临安311321

有蹄类动物的采食、践踏、排泄等行为会影响森林土壤理化特性与植物群落特征。选取浙江清凉峰国家级自然保护区典型亚热带针阔混交林地,设置4个华南梅花鹿干扰处理(禁养,圈养10、15、20 a),以探讨华南梅花鹿圈养对亚热带林地土壤和植被... 详细信息

有蹄类动物的采食、践踏、排泄等行为会影响森林土壤理化特性与植物群落特征。选取浙江清凉峰国家级自然保护区典型亚热带针阔混交林地,设置4个华南梅花鹿干扰处理(禁养,圈养10、15、20 a),以探讨华南梅花鹿圈养对亚热带林地土壤和植被功能的影响。结果表明:(1)随着华南梅花鹿圈养年限的增加,土壤pH、含水率、毛管孔隙度、有机质和阳离子交换量呈现降低的趋势,土壤容重、碱解氮、有效磷和速效钾呈现升高的趋势。(2)华南梅花鹿圈养对0—40 cm土层土壤容重、含水率、毛管孔隙度、有机质、阳离子交换量以及0—20 cm土层碱解氮和有效磷的影响显著,均为圈养20 a处理与对照处理之间差异性达到显著水平(P<0.05)。(3)华南梅花鹿干扰能显著降低林下植被的地上生物量(P<0.05)。研究结果揭示亚热带森林土壤-植被对梅花鹿干扰的响应特征,为探讨森林蹄类动物栖息地退化机制和优化区域生态恢复模式提供科学的数据与理论基础。

关键词：华南梅花鹿圈养年限土壤理化性质地上生物量亚热带针阔混交林