检索结果-南通市图书馆

Journal of Environmental Sciences 2007年第6期19卷 647-651页

作者： zhang Shu-jun PENG Yong-zhen WANG Shu-ying ZHENG Shu-wen GUO Jin College of Environmental and Energy Engineering Beijing University of Technology Beijing 100022 China

An UASB＋Anoxic/Oxic （A/O） system was introduced to treat a mature landfill leachate with low carbon-to-nitrogen ratio and high ammonia concentration. To make the best use of the biodegradable COD in the leaehate, the denitrifieation of NOx^--N in the reeireulation effluent from the elarifier was carried out in the UASB. The results showed that most biodegradable organic matters were removed by the denitrifieation in the UASB. The NH4^＋-N loading rate （ALR） of A/O reactor and operational temperature was 0.28- 0.60 kg NH4^＋-N/（m^3-d） and 17-29℃ during experimental period, respectively. The short-cut nitrification with nitrite accumulation efficiency of 90%-99% was stabilized during the whole experiment. The NH4^＋-N removal efficiency varied between 90% and 100%. When ALR was less than 0.45 kg NH4^＋-N/（m^3.d）, the NH4^＋-N removal efficiency was more than 98%. With the influent NH4^＋-N of 1200-1800 mg/L, the effluent NH4^＋-N was less than 15 mg/L. The shortcut nitrification and denitrifieation can save 40% carbon source, with a highly efficient denitrifieation taking place in the UASB. When the ratio of the feed COD to feed NH4^＋-N was only 2-3, the total inorganic nitrogen （TIN） removal efficiency attained 67%-80%. Besides, the sludge samples from A/O reactor were analyzed using FISH. The FISH analysis revealed that ammonia oxidation bacteria （AOB） accounted for 4% of the total eubaeterial population, whereas nitrite oxidation bacteria （NOB） accounted only for 0.2% of the total eubaeterial population.

关键词： mature landfill leachate UASB+A/O shortcut nitrification carbon source

Cooling Efficiency of Laminar Cooling System for Plate Mill

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2008年第5期15卷 24-28页

作者： zhang Dian-hua WANG Bing-xing ZHOU Na YU Ming WANG jun State Key Laboratory of Rolling and Automation Northeastern University Shenyang 110004 Liaoning China

Heat transfer was researched from a perspective of the industry application. On the basis of the first law of thermodynamics, the cooling efficiency was deduced from the change of enthalpy inside hot plate. The relationship between the cooling efficiency and its influencing parameters was regressed from plenty of data collected from the worksite and discussed in detail. The temperature profiles resulting from the online model and the model modified by regressed formulas were presented and compared. The results indicated that the control accuracy of the modified model was increased obviously.

关键词： hot rolled plate laminar cooling cooling efficiency temperature profile

Propagation characteristics of laser-generated like-Rayleigh waves in viscoelastic adhesive coating/substrate structures

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Acoustics 2016年第4期35卷 516-529页

作者： guan Yijun SUN Hongxiang YUAN Shouqi zhang Shuyi GE Yong Faculty of Science Research Center of Fluid Machinery Engineering and TechnologyJiangsu University Laboratory of Modern Acoustics Institute of AcousticsNanjing University State Key Laboratory of Acoustics Institute of AcousticsChinese Academy of Sciences

The propagation characteristics of laser-generated like-Rayleigh waves in viscoelastic adhesive coating/substrate structures were *** the viscoelasticity of the coating and substrate,we have established the finite element models in frequency domain for the laser-generated like-Rayleigh waves in the epoxy coating/aluminum substrate,epoxy coating/brass substrate,and epoxy coating/foam substrate structures,*** addition,we have investigated the waveform and propagation characteristics of the like-Rayleigh waves and studied the influences of the coating transparency,coating thickness,coating viscoelasticity,and substrate viscoelasticity on the propagation characteristics of the like-Rayleigh ***,we have verified the results by the theoretical phase velocity and attenuation *** results show that the coating viscoelasticity induces the attenuation characteristics of the higher frequencies of the like-Rayleigh waves,but has little effect on the lower frequencies,and the substrate viscoelasticity has the influences on both the higher and lower frequencies of the like-Rayleigh waves,especially the lower ***,the mode and dispersive characteristics of the like-Rayleigh waves are closely related to the *** study provides a useful theoretical basis for inverting mechanical parameters and evaluating the adhesive quality of the viscoelastic adhesive coating/substrate structures.

关键词： Propagation characteristics of laser-generated like-Rayleigh waves in viscoelastic adhesive coating/substrate structures

A new benzophenone glycoside from the leaves of Psidium guajava L.

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2011年第2期22卷 178-180页

作者： Hui Zheng Fu Jing Zhi Yang Chuang jun Li Dong Ming zhang Institute of Materia Medica Chinese Academy of Medical Sciences and Peking Union Medical College(Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal MedicineMinistry of Education)Beijing 100050China

A new benzophenone glycoside,2,6-dihydroxy-4-O-β-D-glucopyranosylbenzophenone（1）,was isolated from the leaves of guajava *** structure was elucidated by spectral and chemical methods.1 showed significant activities... 详细信息

关键词： Psidium guajava L. Benzophenone glycoside 2,6-Dihydroxy-4-O-β-D-glucopyranosylbenzophenone NO

Analysis of spudcan-footprint interaction in a single soil with nonlinear FEM

在线全文

学校读者我要写书评

暂无评论

Petroleum Science 2015年第1期12卷 148-156页

作者： Dong-Feng Mao Ming-Hui zhang Yang Yu Meng-Lan Duan jun Zhao College of Mechanical and Transportation Engineering China University of Petroleum

The footprints that remain on the seabed after offshore jack-up platforms completed operations and moved out provide a significant risk for any futurej ack-up installation at that site. Detrimental horizontal and/or rotational loads will be induced on the base cone of the jack-up platform leg （spudcan） in the preloading process where only vertical loads are normally expected. However, there are no specific guidelines on design of spudcan re-installation very close to or partially overlapping existing footprints. This paper presents a rational design approach for assessing spudcan-footprint interaction and the failure process of foundation in a single layer based on nonlinear finite element method. The rela- tionship between the distance between the spudcan and the footprint and the horizontal sliding force has been obtained. Comparisons of simulation and experimental results show that the model in this paper can deal well with the combined problems of sliding friction contact, fluid-solid coupling, and convergence difficulty. The analytical results may be useful to jack-up installation workovers close to existing footprints.

关键词： Jack-up Existing footprint Spudcan-footprint interaction Numerical simulation Nonlinearity

Study on photocatalytic activity of MoS2/ZnO composite in visible light

在线全文

学校读者我要写书评

暂无评论

Optoelectronics Letters 2020年第6期16卷 446-450页

作者： TANG Chun-mei zhang Hong-yan zhang jun School of Physical Science and Technology Xinjiang UniversityUrumqi 830046China

A series of MoS_2/ZnO compound photocatalysts with different mass ratios were successfully prepared by hydrothermal method. The X-ray diffraction(XRD), X-ray photoelectron spectroscopy(XPS), scanning electron microscope(SEM) and UV-vis absorption were used to characterize the prepared MoS_2/ZnO photocatalysts. It was proved that the combination of Mo S2 and Zn O can increase the content of oxygen vacancies on surface of Zn O, thus improving the light absorption capacity in visible light region and reducing the band gap of Zn O. And the photocatalytic performance of Zn O was improved. Experimental results show that the MoS_2/ZnO(3 wt%) compound has the highest degradation rate for methylene blue(MB) under visible light, which means that it has the best photocatalytic activity among all the prepared samples.

关键词： XPS XRD Study on photocatalytic activity of MoS_2/ZnO composite in visible light ZnO

Ultra-small Co/CoO_(x) nanoparticles dispersed on N-doped carbon nanosheets for highly efficient electrocatalytic oxygen evolution reaction

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2021年第4期30卷 345-354页

作者： Chen Chen Zhuojun Yang Wei Liang Hao Yan Yongxiao Tuo Yanpeng Li Yan Zhou jun zhang College of Materials Science and Engineering China University of Petroleum(East China)Qingdao 266580ShandongChina College of Chemical Engineering China University of Petroleum(East China)Qingdao 266580ShandongChina

In this paper,we report a facile strategy to synthesize Co-BDC-NH2 material,which is used as a precursor towards an excellent OER electrocatalyst by thermal annealing in ***-small Co/Co Oxnanoparticles were uniformly dispersed on the rhombus N-doped carbon(NC)*** electron microscopic,X-ray diffraction spectrometric,and X-ray photoelectron spectroscopic analyses revealed the coexistence of metallic Co and Co oxides *** was found that Co/CoO_(x)@NC obtained at 500℃ annealing temperature exhibited the highest electrocatalytic OER activity,with 307 and375 m V overpotential to achieve 10 and 100 m A cm^(-2) current ***,thanks to the in-situ annealing process,Co/CoO_(x)@NC showed excellent catalytic stability with 97.4%current density retention after 24 h electrolysis at 1.66 V *** electrode *** investigations revealed that the ultrasmall Co/Co Oxnanoparticles distributed on N-doped carbon template contribute significantly towards OER electrocatalysis through enlarging the activity surface areas and enhancing the intrinsic electrochemical activity due to the presence of metallic Co.

关键词： Co/CoO_(x)nanoparticle Metal-organic framework In-situ annealing Nitrogen-doped porous carbon Oxygen evolution reaction Electrocatalysis

Fenton-like oxidation of azo dye in aqueous solution using magnetic Fe3O4-MnO2 nanocomposites as catalysts

在线全文

学校读者我要写书评

暂无评论

Water Science and Engineering 2017年第4期10卷 326-333页

作者： Zhen-dong Fang Kai zhang Jie Liu jun-yu Fan Zhi-wei Zhao Department of National Defense Architecture Planning and Environmental Engineering Logistical Engineering UniversityChongqing 401311China

In order to overcome the drawback of the low degree of separation from an aqueous solution of MnO_2, Fe_3 O_4-MnO_2 core-shell nanocomposites were used as heterogeneous Fenton-like catalysts for the removal of acid orange 7. On the basis of the catalyst characterization, the catalytic ability of the as-synthesized nanocomposites was examined. The results showed that Fe304-Mn02 core-shell nanocomposites had greater catalytic ability than Fe_3 O_4 or MnO_2 used alone. Meanwhile, the catalyst dosage, H_2 O_2 dosage, temperature, and initial pH had significant effects on the removal of acid orange 7. A high degree of stability and reusability were exhibited by Fe_3 O_4-MnO_2 core-shell nanocomposites. Both HO· and HO_2· were generated in the reaction and HO· was the main radical for the removal of acid orange 7. A mechanism for H_2 O_2 catalytic decomposition using Fe_3 O_4-MnO_2 core-shell nanocomposites to produce HO·is proposed.

关键词： Heterogeneous catalysts Fenton reaction Core-shell structure Magnetic separation Acid orange 7

Surgical treatment of mixed cervical spondylosis with spontaneous cerebrospinal fluid leakage: A case report

在线全文

学校读者我要写书评

暂无评论

World Journal of Clinical Cases 2023年第29期11卷 7242-7247页

作者： Zhong Yu Hao-Fu-Zi zhang Yan-jun Wang Department of Emergency Honghui HospitalXi’an Jiaotong UniversityXi’an 710032Shaanxi ProvinceChina Department of Neurosurgery Xijing HospitalFourth Military Medical UniversityXi’an 710032Shaanxi ProvinceChina

BACKGROUND Spontaneous cerebrospinal fluid(CSF)leaks associated with cervical spondylosis are *** our knowledge,only a few cases have been reported in which treatment is challenging and varies from case to ***,we review the literature and describe the surgical treatment of a 70-year-old woman who presented with a CSF leak due to a cervical spine *** SUMMARY A 70-year-old female patient who was treated for a cerebral infarction,presented with complains of weakness in the right lower extremity and a feeling of stepping on *** patient underwent regular neck massage and presented with neck and right shoulder pain radiating to the right upper extremity one-month *** resonance imaging showed a strip of leaking cerebrospinal fluid posterior to the C1-4 vertebrae,and computed tomography showed a“sickleshaped”disc prolapse with calcification in C4/*** chose to perform an anterior cervical *** the prolapsed C4/5 disc was scraped,clear fluid leakage was observed,and exploration revealed a 1 mm diameter rupture in the anterior aspect of the dura mater,which was compressed continuously with cotton patties,with no significant cerebrospinal fluid leakage after 1 *** Three months after surgery,the patient was asymptomatic and follow-up imaging demonstrated complete resolution.

关键词： Cerebrospinal fluid leak Degenerative spine pathology Cervical spine Surgical treatment Case report

Gene expression in rats with Barrett's esophagus and esophageal adenocarcinoma induced by gastroduodenoesophageal reflux

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 Gastroenterology 2005年第33期11卷 5117-5122页

作者： Peng Cheng jun Gong Tao Wang Jie Chen Gui-Sheng Liu Ru zhang Department of Gastroenterology the Second HospitalXi'an Jiaotong University Xi'an 710004 Shaanxi Province China

AIM: To study the different gene expression profiles in rats with Barrett's esophagus (BE) and esophageal adenocarcinoma (EA) induced by gastro-duodenoesophageal ***: Esophagoduodenostomy was performed in 8-wk old Sprague-Dawley rats to induce gastro-duodenoesophageal reflux, and a group of rats that received sham operation served as control. Esophageal epithelial pathological tissues were dissected and frozen in liquid nitrogen immediately. The expression profiles of 4 096genes in EA and BE tissues were compared to normal esophagus epithelium in normal control (NC) by cDNA ***: Four hundred and forty-eight genes in BE were more than three times different from those in NC, including 312 upregulated and 136 downregulated genes. Three hundred and seventy-seven genes in EA were more than three times different from those in NC, including 255upregulated and 142 downregulated genes. Compared to BE, there were 122 upregulated and 156 downregulated genes in EA. In the present study, the interested genes were those involved in carcinogenesis. Among them, the upregulated genes included cathepsin C, aminopeptidase M, arachidonic acid epoxygenase, tryptophan-2,3-dioxygenase, ubiquitin-conjugating enzyme, cyclic GMP-stimulated phosphodiesterase, tissue inhibitor of metalloproteinase-1, betaine-homocysteine methyltransferase, lysozyme, complement 4b binding protein,complement 9 protein, insulin-like growth factor binding protein, UDP-glucuronosyltransferase, tissue inhibitor of metalloproteinase-3, aldolase B, retinoid X receptor gamma, carboxylesterase and testicular cell adhesion molecule 1. The downregulated genes included glutathione synthetase, lecithin-cholesterol acyltransferase, p55CDC,heart fatty acid binding protein, cell adhesion regulator and endothelial cell selectin ***: Esophageal epithelium exposed excessively to harmful ingredients of duodenal and gastric reflux may develop into BE and even EA gradually. The gene expression

关键词： Gastroduodenoesophageal reflux Barrett'sesophagus Esophageal adenocarcinoma Gene expression