检索结果-南通市图书馆

A novel indicator system for catalytic spectrophotometric determination and speciation of inorganic selenium species (Se(Ⅳ), Se(Ⅵ)) at trace levels in natural lake and river water samples

引用

Rare Metals 2011年第5期30卷 477-487页

作者： Ramazan Gürkan halil brahim Ulusoy Mehmet Akay Pinar Bulut Department of Chemistry Faculty of Science University of Cumhuriyet

A novel catalytic kinetic method is proposed for the determination of Se（Ⅳ）, Se（Ⅵ）, and total inorganic selenium in water based on the catalytic effect of Se（Ⅳ） on the reduction of Celestine blue by sodium sulfide at pH 7.0 phosphate buffer. The fixed-time method was adopted for the determination and speciation of inorganic selenium. Under the optimum conditions, the two calibration graphs are linear with a good correlation coefficient in the range 2-20 and 20-200 μg·L-1 of Se（Ⅳ） for the fixed-time method at 30℃. The experimental and theo- retical detection limits of the developed kinetic method were found to be 0.21 and 2.50 μg·L-1 for the fixed-time method （3 min）. All of the variables that affect the sensitivity at 645 nm were investigated, and the optimum conditions were established. The interference effect of various cations and anions on the Se（Ⅳ） determination was also studied. The selectivity of the selenium determination was greatly improved with the use of the strongly cation exchange resin such as Amberlite IR120 plus as long as chelating agents of thiourea and thiosulphate. The proposed kinetic method was validated statistically and through recovery studies in natural water samples. The relative standard deviations （RSDs） for ten replicate measurements of 2, 10, and 20 μg·L-1 of Se（Ⅳ） change between 0.35% and 5.58%, while the RSDs for ten replicate measurements of 3, 6, and 12 μg·L-1 of Se（Ⅵ） change between 0.49% and 1.61%. Analyses of a certified standard reference material （NIST SRM 1643e） for selenium using the fixed-time method showed that the proposed kinetic method has good accuracy. The Se（Ⅳ）, Se（Ⅵ）, and total inorganic selenium in lake and river water samples have been successfully determined by this method after selective reduction of Se（Ⅵ） to Se（Ⅳ）.

关键词： selenium speciation Celestine blue catalytic effect kinetic spectrophotometry natural waters

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

Synthesis and Electrochemical Properties of Carbon-Mixed LiEr_(0.02)Fe_(0.98)PO_4 Cathode Material for Lithium-ion Batteries

引用

Journal of Materials Science & Technology 2011年第9期27卷 861-864页

作者： Hüseyin Gktepe halil Sahan Ahmet lgen Saban Patat Department of Chemistry M krkǒglu Vocational High School University of Erciyes Department of Chemistry Science of Faculty University of Erciyes

LiEr0.02Fe0.98PO4/C composite cathode was synthesized by a simple solution method with polyethylene glycol （PEG） as the reductive agent and carbon source. The effect of erbium doping on the electrochemical behavior of LiFePO4 was studied in this paper. The samples were characterized by X-ray powder diffraction and scanning electron microscopy and the electrochemical properties were investigated by the charge-discharge test. An initial discharge capacity of 149 mAh.g-1 was achieved for the LiEr0.02Fe0.98PO4/C composite cathode with a rate of 0.1 C. The electronic conductivity of Er doped LiFePO4/C was measured as 10-2 ***-1. The results indicated that erbium doping did not destroy the lattice structure of LiFePO4 and enlarge the lattice volume. These changes are beneficial to the improvement of the electrochemical performance of the LiFePO4 cathode.

关键词： LiFePO4 Cathode Erbium doping Lithium batteries

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

Tor topography in Giresun mountains,Türkiye

引用

Journal of Mountain Science 2023年第11期20卷 3121-3137页

作者： UZUN Ali AYLAR Faruk ZEYBEK halilİbrahim ALEMDAĞSelçuk Ondokuz Mayis University Faculty of Art and ScienceGeography DepartmentSamsun 55200Türkiye Gümüşhane University Faculty of Engineering and Natural Sciences Department of Geological EngineeringGümüşhane 29100Türkiye

Tors are mound-like rock landforms,resistant to erosion,that may sometimes reach the size of several storeys of house by *** may develop in different climate regions and different rock types,led by granitic *** this study,tors developed in granitic rocks around Yaylal?village linked to Kürtün county in Gümü?hane were *** study area is located in the eastern part of the Giresun mountain range in northeastern Turkey,2000-2300 m above sea *** aim of the study is to determine the natural environmental characteristics in tor formation and to reveal the effect of bedrock on tor *** field studies,18 tors were selected by noting location,size and structural features,and dimensions were *** sections were first made from the rock samples taken from the tors and then the mineralogical composition was investigated by modal analysis *** a result of this analysis,it was determined that the bedrock forming the tors is *** the field observations,it was determined that the intersecting vertical joints supported the formation of castle-like tors,while the horizontal joints supported the formation of pita pileshaped *** are also pseudokarstic shapes resembling kamenitza and karst *** conclusion,joint sets causing local resistance differences directed the formation of tors,while excess slope affected surface erosion and suitability of climate conditions-controlled weathering rate.

关键词： Joint sets Granite Northern Anatolian Mountains Gümü?hane Türkiye

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

Plant responses to simulated warming and drought:a comparative study of functional plasticity between congeneric mid and high elevation species

引用

Journal of Plant Ecology 2018年第3期11卷 364-374页

作者： Elena Hamann halil Kesselring Jürg Stöcklin Botanical Institute Department of Environmental SciencesSection Plant EcologyUniversity of BaselSchönbeinstrasse 64056 BaselSwitzerland

Aims Effects of climate change,especially changes in temperatures and precipitation patterns,are particularly pronounced in alpine *** response,plants may exhibit phenotypic plasticity in key functional traits allowing short-term adjustment to novel ***,little is known about the degree of pheno-typic plasticity of high elevation species relative to mid elevation *** We transplanted 14 herbaceous perennial species from high eleva-tion into two common gardens(1050 and 2000 m.a.s.l.)in the Swiss Alps,and we examined plastic responses in key functional traits to changes in temperature and soil water *** design was replicated with 14 congeneric species from mid elevation to assess if the degree of phenotypic plasticity differs between mid and high elevation *** was assessed across two growing seasons,while aboveground biomass and specific leaf area(SLA)were measured after the first growing season,and biomass alloca-tion to belowground and reproductive structures after the ***,a phenotypic plasticity index was calculated for the func-tional traits to compare the degree of plasticity between mid and high elevation *** Findings Aboveground biomass was higher in mid elevation species relative to high elevation congeners in all treatments,yet decreased for both with elevation and ***,SLA decreased with elevation and *** mass fraction(RMF)was generally higher in high ele-vation species,and decreased with drought at the lower *** increased the allocation to reproductive structures,especially when plants were grown at their elevation of ***,no differ-ence was found in the degree of phenotypic plasticity averaged across mid and high elevation species for any of the studied functional *** results indicate that phenotypic plasticity in the focal traits did not depend on the elevation of origin of the *** was not related to

关键词： biomass allocation common garden climate change perennial herbaceous species phenotypic plasticity SLA Swiss Alps transplant experiment

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

Finite element modeling of environmental effects on rigid pavement deformation

引用

Frontiers of Structural and Civil Engineering 2014年第2期8卷 101-114页

作者： Sunghwan KIM halil CEYLAN Kasthurirangan GOPALAKRISHNAN Department of CCEE Iowa State University Ames Iowa 50011 USA

In this study, finite element （FE）-based primary pavement response models are employed for investigating the early-age deformation characteristics of jointed plain concrete pavements （JPCP） under environmental effects. The FE-based ISLAB （two-and-one-half-dimensional） and EverFE （three-dimensional） software were used to conduct the response analysis. Sensitivity analyses of input parameters used in ISLAB and EverFE were conducted based on field and laboratory test data collected from instrumented pavements on highway US-34 near Burlington, Iowa. Based on the combination of input parameters and equivalent temperatures established from preliminary studies, FE analyses were performed and compared with the field measurements. Comparisons between field measured and computed deformations showed that both FE programs could produce reasonably accurate estimates of actual slab deformations due to environmental effects using the equivalent temperature difference concept.

关键词： jointed plain concrete pavements (JPCP) curling and warping sensitivity analyses rigid pavement analysis anddesign finite element analysis (FEA)

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

Effects of moisture damage on asphalt mixtures

引用

Journal of Traffic and Transportation Engineering(English Edition) 2020年第5期7卷 600-628页

作者： Hend Ali Omar Nur Izzi MdYusoff Muhammad Mubaraki halil Ceylan Department of Civil Engineering University of TripoliTripoliLibya Department of Civil Engineering Universiti Kebangsaan MalaysiaBangi 43600Malaysia Faculty of Engineering Jazan UniversityJazanKingdom of Saudi Arabia Department of Civil Construction and Environmental EngineeringIowa State UniversityAmesIA 50011USA

The reduction in the ability of bitumen to bond with the aggregate surface due to the infiltration of moisture has been recognised for years, and this deterioration phenomenon is called moisture damage. In general, the loss of bonding between bitumen and aggregate shortens the service life of the top layer of the pavement. Many investigations have been conducted to understand the mechanisms of moisture damage due to the loss of bonding strength between bitumen and aggregate and to find ways to improve and strengthen the bond to mitigate the effect of moisture. This paper reviews the extensive literature on the loss of bitumen-aggregate bonding strength due to moisture damage in asphalt *** general description of the theories and mechanisms that explain the effect of the thermodynamic, chemical, physical and mechanical characteristics of the bitumen and aggregate on the bonding phenomenon are discussed in this paper. In addition, the causes of and contributing factors to moisture damage and methods to improve the bond between bitumen and aggregates are also discussed. Moreover, a description of the test methods that can be used to evaluate moisture damage in poorly bonded and compacted mixtures are also presented. Special attention is given to a well-known method, known as the pulloff test, which has been successfully used to evaluate aggregate-binder bond strength, both for laboratory and in-situ tests. This includes the test methods, the factors that affect the bonding strength results and their correlation with other test method. A review of the failure mode of bitumen under the pull-off loading test is discussed in the final section of this paper.

关键词： Road engineering Bitumen Aggregate Asphalt mixture Moisture damage

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

Significance of defecography and the role of rectocele in constipated patients

引用

Open Journal of Gastroenterology 2012年第2期2卷 40-44页

作者： Mehmet Abdussamet bozkurt Ahmet Sürek Murat Gonenc Mustafa Uygar Kalayci halil Alis Department of General Surgery Bakırkoy Dr. Sadi Konuk Training and Research Hospital İstanbul Turkey

Backround: Chronic constipation is a common, chronic and frequent problem of the general population. The aim of this study is to assess the efficacy of defecography in diagnosing the etiology of constipation and the relation between constipation and rectocele. Material-method: We have investigated 250 patients who have been admitted to our general surgery out-patient clinic with complaint of constipation using Rome III criteria and diagnostic defecography. Results: Out of 250 patients who were evaluated with defecography only 24 had normal findings. 136 patients were found to have rectocele. Conclusion: We propose that rectocele is an important etiology of constipation, and defecography should be considered early in the diagnosis of rectocele.

关键词： Defecography Rectocele Chronic Constipation

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

The predictive value of triglyceride-glucose index for in-hospital and one-year mortality in elderly non-diabetic patients with ST-segment elevation myocardial infarction

引用

Journal of Geriatric Cardiology 2022年第8期19卷 610-617页

作者： FaysalŞaylık TufanÇınar Murat Selçuk İbrahim halil Tanboğa Department of Cardiology Van Training and Research HospitalVanTurkey Department of Cardiology Sultan II.Abdülhamid Han Training and Research HospitalIstanbulTurkey Department of Cardiology and Biostatistics Nisantasi University Medical SchoolIstanbulTurkey

BACKGROUND Triglyceride-glucose(TyG)index,a reliable marker of insulin resistance,was associated with cardiovascular morbidity and *** study aimed to evaluate the predictive value of TyG index for mortality in elderly non-diabetic pa-tients with ST-segment elevation myocardial infarction(STEMI).METHODS In total,430 non-diabetic patients aged over 65 years with STEMI were consecutively *** TyG index was calculated by using the following formula:TyG index=ln(fasting triglyceride×fasting glucose/2).The 5-item modified frailty index score was utilized to determine *** were divided into three groups based on TyG index *** Patients included into high TyG index tertile were male and had higher body mass index,glucose,triglyceride,low-density lipoprotein cholesterol,5-item modified frailty index and GRACE risk score;and had low systolic blood pressure,estim-ated glomerular filtration rate and left ventricular ejection fraction.A one-unit increase in TyG index was associated with 3.03 ex-tra cases per 1000 person-day for in-hospital mortality and 0.29 extra cases per 1000 person-day for long-term *** was a non-linear relationship between TyG index and the risk of mortality with an increased risk above 8.5 for TyG ***-Meier survival curves revealed that patients in high TyG index tertile had higher in-hospital and long-term mortality rates than those in low TyG index *** This was the first study to demonstrate that the TyG index could predict in-hospital and long-term mortality in elderly non-diabetic STEMI patients.

关键词： patients mortality diabetic

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

Migrated endoclip and stone formation after cholecystectomy:A new danger of acute pancreatitis

引用

World Journal of Gastroenterology 2007年第47期13卷 6446-6448页

作者： Kemal Dolay halil Alis Aliye Soylu Gulum Altaca Ersan Aygun Department of General Surgery1 and Gastroenterology 2 Endoscopy UnitBakirkoy Research and Training HospitalBakirkoyIstanbulTurkey

Endoclip migration into the common bile duct following laparoscopic cholecystectomy (LC) is an extremely rare complication. Migrated endoclip into the common bile duct can cause obstruction,serve as a nidus for stone formation,and cause cholangitis. We report a case of obstructive jaundice and acute biliary pancreatitis due to choledocholithiasis caused by a migrated endoclip 6 mo after LC. The patient underwent early endoscopic retrog-rade cholangiopancreatography (ERCP) with endoscopic sphincterotomy and stone extraction.

关键词： Laparoscopic cholecystectomy Endoclip migration Biliary pancreatitis Endoscopic retrograde cholangiopancreatography

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

Effect of purification,dehydration,and coagulation processes on the optical parameters of biological tissues

引用

Chinese Optics Letters 2021年第1期19卷 69-74页

作者： halil Arslan Bahar Pehlivanoz Faculty of Technology Electrical and Electronics Engineering DepartmentSakarya University of Applied SciencesSakaryaTurkey

In this study,the effects of purification,dehydration,and coagulation processes on the absorption and reduced scattering coefficients of chicken liver tissues have been investigated by using a single integrating sphere *** purification process performed on the tissue samples to remove blood residue has been found to cause a slight change in the optical *** the dehydration process brings about an increase in the absorption coefficient due to the water loss,no direct relationship has been observed between the reduced scattering coefficient and the dehydration level of the *** addition,it has been observed that there was a relatively small increase in the absorption coefficient and a significant increase in the reduced scattering coefficient after the coagulation ***,it can be said that the optical penetration depth decreased significantly after dehydration and coagulation processes unlike blood ***,fluence rate distributions inside the fresh,blood purified,dehydrated,and coagulated tissue models have been investigated by using the Monte Carlo modeling of photon transport in multilayered tissues simulation code.

关键词： optical properties dehydration coagulation integrating sphere IAD

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

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：