检索结果-南通市图书馆

Differential Responses of Nitrifier and Denitrifier to Dicyandiamide in Short- and Long-Term Intensive Vegetable Cultivation Soils

引用

Journal of Integrative Agriculture 2014年第5期13卷 1090-1098页

作者： LIU Yi yang yang QIN Hong-ling ZHU Yi-jun WEI Wen-xue Key Laboratory of Agro-Ecological Processes in Subtropical Regions and Taoyuan Station of Agro-Ecology Research Institute of Subtropical Agriculture Chinese Academy of Sciences Tianjin Land & Resources & Housing Management Research Centre

Nitrification inhibitors, such as dicyandiamide （DCD）, have been shown to decrease leaching from urea- and ammoniumbased fertilizers in agricultural soils. The effect of nitrification inhibitors on nitrifier and denitrifier in short- and long-term intensive vegetable cultivation soils was poorly understood. In this study, the pot trial was conducted to investigate the differential responses of nitrifier （amoA-containing bacteria） and denitrifier （nirK-containing bacteria） to DCD in short-（soil S） and long-term （soil L） intensive vegetable cultivation soils. Quantitative polymerase chain reaction （qPCR） and terminal restriction fragment length polymorphism （T-RFLP） were employed to detect the abundance and composition of amoA- and nirK-containing communities. The results indicated that application of DCD led to a consistently higher NH4＋-N concentration during the whole incubation in soil L, while it was quickly decreased in soil S after 21 days. Furthermore, DCD induced more severe decrease of the abundance of amoA-containing bacteria in soil L than in soil S. However, the abundance of the nirK- containing community was not significantly affected by DCD in both soils. Long-term vegetable cultivation resulted in a super-dominant amoA-containing bacteria group and less divergence in soil L compared with soil S, and DCD did not cause obvious shifts of the composition of ammonia-oxidising bacteria （AOB）. On the contrary, both amoA- and nirK-containing bacterial compositions were influenced by DCD in soil S. The results suggested that long-term intensive vegetable cultivation with heavy nitrogen fertilization resulted in significant shifts of AOB community, and this community was sensitive to DCD, but denitrifiers were not clearly affected by DCD.

关键词： DCD amoA nirK vegetable soil

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Precipitation Behavior of V-N Microalloyed Steels during Normalizing

引用

Journal of Iron and Steel Research International 2015年第11期22卷 1037-1042页

作者： Tao PAN Xi-yang CHAI Jin-guang WANG Hang SU Cai-fu yang Division of Structural Steels Central Iron and Steel Research Institute Division of Equipment Construction China Sinopec Engineering Incorporation

The precipitation behavior of V-N microalloyed steel during normalizing process was studied by physicochemical phase analysis and transmission electron microscopy（TEM）. The effect of precipitation behavior on mechanical properties was investigated by theoretical calculations. The results showed that 32.9% of V（C,N） precipitates remained undissolved in the austenite during the soaking step of the normalizing process. These precipitates prevented the growth of the austenite grains. During the subsequent cooling process, the dissolved V（C,N） re-precipitated and played a role in precipitation strengthening. The undissolved V（C,N） induced intragranular ferrite nucleation and refined the ferrite grains. Consequently, compared with hot-rolled steel, the normalized steel exhibited increased grain-refining strengthening but diminished precipitation strengthening, leading to an improvement of the impact energy at the expense of about 40 MPa yield strength.

关键词： normalizing V-N microalloyed steel precipitation strengthening grain-refining strengthening

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Infrared small target detection using sparse representation

引用

Journal of Systems Engineering and Electronics 2011年第6期22卷 897-904页

作者： Jiajia Zhao ZhengyuanTang Jie yang Erqi Liu Institute of Image Processing and Pattern Recognition Shanghai Jiaotong University Shanghai 200240 P. R. China China Aerospace Science and Industry Corporation Beijing 100074 P. R. China

Sparse representation has recently been proved to be a powerful tool in image processing and object *** paper proposes a novel small target detection algorithm based on this *** modelling a small target as a linear combination of certain target samples and then solving a sparse 0-minimization problem,the proposed apporach successfully improves and optimizes the small target representation with ***,the sparsity concentration index（SCI） is creatively employed to evaluate the coefficients of each block representation and simpfy target *** the detection frame,target samples are firstly generated to constitute an over-complete dictionary matrix using Gaussian intensity model（GIM）,and then sparse model solvers are applied to finding sparse representation for each sub-image ***,SCI lexicographical evalution of the entire image incorparates with a simple threshold locate target *** effectiveness and robustness of the proposed algorithm are demonstrated by the exprimental results.

关键词： target detection sparse representation orthogonal matching pursuit(OMP).

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Dynamic response to a moving load of a Timoshenko beam resting on a nonlinear viscoelastic foundation

引用

Acta Mechanica Sinica 2013年第5期29卷 718-727页

作者： Yan yang Hu Ding Li-Qun Chen Shanghai Institute of Applied Mathematics and Mechanics Shanghai Key Laboratory of Mechanics in Energy EngineeringShanghai University Department of Mechanics Shanghai University

The present paper investigates the dynamic response of finite Timoshenko beams resting on a sixparameter foundation subjected to a moving load. It is for the first time that the Galerkin method and its convergence are studied for the response of a Timoshenko beam supported by a nonlinear foundation. The nonlinear Pasternak foundation is assumed to be cubic. Therefore, the effects of the shear deformable beams and the shear deformation of foundations are considered at the same time. The Galerkin method is utilized for discretizing the nonlinear partial dif- ferential governing equations of the forced vibration. The dynamic responses of Timoshenko beams are determined via the fourth-order Runge-Kutta method. Moreover, the effects of different truncation terms on the dynamic responses of a Timoshenko beam resting on a complex foundation are discussed. The numerical investigations shows that the dynamic response of Timoshenko beams supported by elastic foundations needs super high-order modes. Furthermore, the system parameters are compared to determine the dependence of the convergences of the Galerkin method.

关键词： Nonlinear Timoshenko beam Pasternak foun- dation Galerkin method Convergence

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Thermal Analysis of a Volumetric Solar Receiver

引用

Journal of Thermal Science 2019年第6期28卷 1176-1185页

作者： CHEN Longfei yang Ming LI Jinping BAI Yakai LI Xiaoxia TANG Wenxue yang Nancong WANG Zhifeng Lanzhou University of Technology Lanzhou 730050China Key Laboratory of Solar Thermal Energy and Photovoltaic Systems Chinese Academy of SciencesBeijing 100190China Institute of Electrical Engineering Chinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China Beijing Engineering Research Center of Solar Thermal Power Beijing 100190China Beijing CSP International Cooperation Centre Beijing 100190China Joint Laboratory Institute of Electrical EngineeringChinese Academy of Sciences and Guangdong Five Star Solar Energy Co.Ltd.Beijing 100190China Guangdong 5 Star Solar Energy CO.LTD Dongguan 523051China

The volumetric receiver has received wide attention due to its high thermal efficiency. This paper studied a new type of a solid-liquid composite volumetric receiver. The heat transfer in a solid-liquid composite volumetric solar receiver was analyzed using a one-dimensional unsteady simulation model of the solid-liquid receiver. The model included absorption of the incident solar radiation by the glass window, the silicon carbide porous ceramic heat absorber panel and the water. The results were verified against experimental data for a volumetric receiver and the error did not exceed 10%. It can be used to predict the heat transfer in solid-liquid composite volumetric receivers.

关键词： solar receiver solid-liquid composite absorber silicon carbide porous ceramic volumetric solar collector

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Treatment of coke plant wastewater by SND fixed biofilm hybrid system

引用

Journal of Environmental Sciences 2007年第2期19卷 153-159页

作者： QI Rong yang Kun YU Zhao-xiang Department of Chemistry Tongji University Shanghai 200092 China

In this article, coke plant wastewater was treated by a simultaneous nitrifying and denitrifying （SND） fixed biofilm hybrid system. The results showed that suitable parameters of the system were important for the performance of the bio-degradation system. The chemical oxygen demand （COD） removal efficiency in this system was satisfactory, higher than 94%, and ammonia nitrogen was higher than 95%. The effluent COD concentration could meet the discharge standard, except for very few situations. The results showed that a sufficient carbon source was important for making ammonia nitrogen concentration meet the discharge standard. Then the TiN removal efficiency in this system can be brought higher than 94%. Dissolved oxygen （DO） is very important to the performance of the SND bio-degradation system, and the suitable DO is about 3.5-4.0 mg/L at the forepart of reactor. In addition, the performance of the system was almost not affected by pH value. The results show that the system is feasible to treat coke plant wastewater.

关键词： coke plant wastewater SND fixed biofilm ammonia nitrogen COD carbon source

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Preparation and desulfurization activity of nano-CeO_2/γ-Al_2O_3 catalysts

引用

Rare Metals 2018年第7期37卷 554-560页

作者： Qi yang Hui Hu Shan-Shan Wang School of Environment Science and Engineering Huazhong University of Science and Technology Department of Urban Construction Wuchang Shouyi University Wuhan Zuoling New Town Development and Investment Co. Ltd.

γ-A12O3-supported CeO2 catalysts were pre- pared by microemulsion and impregnation methods and characterized by X-ray diffraction （XRD） and scanning electron microscope （SEM） techniques. At the same time, the desulfurization activity of catalysts was investigated. The results show that nanoscale active substances and a high desulfurization effect are achieved by microemulsion, exhibiting a significant dominance compared with traditional impregnation method. The optimal preparation condition is temperature of 30 ℃ and ratio of [H20]/[surface active agent] of 7 with slow demulsification. The activated catalysts still keep high and stable desulfurization activity during a wide temperature range of 450-600 ℃. Among a series of prepared catalysts, the desulfurization rate of 6CeOz/γ-A1203 is the highest, reaching up to 80 % when temperature is higher than 550℃. The catalytic reduction mechanism of SO2 over nano-CeOz/γ-A1203 follows redox mechanism.

关键词： Nano-CeO2/γ-Al2O3 Microemulsion Catalyst Desulfurization

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Design and Performance Study of an Ultrasonic Bone Scalpel with Composite Horn Structure

引用

Nanomanufacturing and Metrology 2023年第1期6卷 24-35页

作者： Jieping Wu Yong yang Zhao yang Cong Chen Shuai Huang College of Mechanical and Vehicle Engineering Hunan UniversityChangsha 410082China National Engineering Research Center For High Efficiency Grinding Hunan UniversityChangsha 410082China

The ultrasonic bone scalpel was often used in all kinds of clinical orthopedic surgery as a new type of medical *** on the working theory of the ultrasonic bone scalpel and combined with the design method of a quarter wavelength transducer and horn,this study proposed an optimization design method for the ultrasonic bone scalpel with a composite horn *** structure of the ultrasonic bone scalpel was simplified,and its length was *** element analysis,modal analysis,and harmonic response analysis were used to optimize the design of the ultrasonic bone *** performance of the ultrasonic bone scalpel was explored through impedance analysis,amplitude measurement,temperature measurement,and cutting tests,and the feasibility of the design was verified through torque *** results showed that when the torque force was 4.0 N,the resonance frequency of the ultrasonic bone scalpel was 30,540 Hz,and the maximum amplitude of the ultrasonic bone scalpel could reach 62μ*** spray cooling,the maximum surface temperature of the rear end cover was reduced from 51.8 to 36.3℃,the maximum surface temperature of the composite horn was reduced from 71 to 45.3℃,and the maximum surface temperature of the cutter head was reduced from 101 to 46.1℃,demonstrating a good cooling *** 89 Voltage,the optimal cutting force for cutting chicken leg bones was 0.1 N,the optimal cutting force for cutting pork ribs was 0.3 N,and the cutting process showed tissue selectivity.

关键词： Ultrasonic bone scalpel Transducer Horn Modal analysis Harmonic response analysis

来源：

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

Resilience assessment framework toward interdependent bus-rail transit network:Structure,critical components,and coupling mechanism

引用

Communications in Transportation Research 2023年第1期3卷 118-129页

作者： Bing Liu Xiaoyue Liu yang yang Xi Chen Xiaolei Ma School of Transportation Science and Engineering Beihang UniversityBeijing100191China Department of Civil&Environmental Engineering University of UtahSalt Lake CityUT84112USA School of Computer Science and Engineering Beihang UniversityBeijing100191China Key Laboratory of Intelligent Transportation Technology and System Ministry of EducationBeijing100191China

Understanding the interdependent nature of multimodal public transit networks(PTNs)is vital for ensuring the resilience and robustness of transportation ***,previous studies have predominantly focused on assessing the vulnerability and characteristics of single-mode PTNs,neglecting the impacts of heterogeneous disturbances and shifts in travel behavior within multimodal ***,this study introduces a novel resilience assessment framework that comprehensively analyzes the coupling mechanism,structural and functional characteristics of bus-rail transit networks(BRTNs).In this framework,a network performance metric is proposed by considering the passengers’travel behaviors under various ***,stations and subnetworks are classified using the k-means algorithm and resilience metric by simulating various disturbances occurring at each station or *** proposed framework is validated via a case study of a BRTN in Beijing,*** indicate that the rail transit network(RTN)plays a crucial role in maintaining network function and resisting external disturbances in the interdependent ***,the coupling interactions between the RTN and bus transit network(BTN)exhibit distinct characteristics under infrastructure component disruption and functional *** findings provide valuable insights into emergency management for PTNs and understanding the coupling relationship between BTN and RTN.

关键词： Complex network Bus-rail transit network Resilience analysis Interdependent coupling relationship Classification analysis

来源：

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

Transarterial chemoembolization vs. liver resection as initial treatment for hepatocellular carcinoma occurring exclusively in caudate lobe: A retrospective propensity matching analysis

引用

Oncology Research 2022年第1期30卷 23-33页

作者： BIAO yang MINLAN YUAN TING yang ZHENGYIN LIAO HAO WU Department of Abdominal Oncology West China HospitalSichuan UniversityChengduChina Department of Psychiatry West China HospitalSichuan UniversityChengduChina Department of Gastroentology West China HospitalSichuan UniversityChengduChina

Treatment of hepatocellular carcinoma(HCC)in the caudate lobe is technically *** retrospective study was designed to evaluate the clinical outcome of both superselective transcatheter arterial chemoembolization(TACE)and liver resection(LR)for HCC occurring exclusively in the caudate *** January 2008 to September 2021,a total of 129 patients were diagnosed with HCC of the caudate *** Cox proportional hazard model was used to analyze the potential clinical factors and established prognostic nomograms with interval *** the total number of patients,78 received TACE and 51 received *** overall survival(OS)rates(TACE ***)at 1,2,3,4,and 5 years were 83.9%vs.71.0%;74.2%vs.61.3%;58.1%vs.48.4%;45.2%vs.45.2%;and 32.3%vs.25.0%,***,subgroup analysis revealed that TACE was superior to LR for treating patients with stage IIb Chinese liver cancer(CNLC-IIb)in the entire cohort(p=0.002).Interestingly,no difference was found between TACE and LR in the treatment outcomes of CNLC-IIa HCC(p=0.6).Based on Child-Pugh A and B calculations,TACE tended to lead to a better OS than LR(p=0.081 and 0.16,respectively).Multivariate analysis showed that Child-Pugh score,CNLC stage,ascites,alpha fetoprotein(AFP),tumor size,and anti-HCV are related to *** nomograms for 1,2,and 3 years were *** on this study,TACE may provide a longer OS than liver resection for patients with CNLC-IIb HCC of the caudate *** this suggestion is limited by the study design and relatively small sample size,additional randomized controlled trials are needed.

关键词： Transarterial chemoembolization Liver resection Hepatocellular carcinoma Caudate lobe

来源：

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

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：