检索结果-南通市图书馆

Marine ciliate community in relation to eutrophication of coastal waters in the Yellow Sea

Chinese Journal of Oceanology and Limnology 2011年第1期29卷 118-127页

作者：徐奎栋 choi joong ki 类彦立 YANG Eun Jin Institute of Oceanology Chinese Academy of Sciences Department of Oceanography Inha University Korea Polar Research Institute

We assessed the potential of marine ciliate community as an indicator to coastal water quality using water samples collected from four stations in thc Yellow Sea in the summer 2000. The four stations were characterized by different levels of pollution. The ciliate communities consisted primarily of tintinnids and aloricate ciliates that were 〈30 um. A total of 78 species were classified： 55 species at Station 2, 51 species each at Stations l and 4, and 47 species at Station 3. The mean number of species at each site was 29.2±2.0 （Station 1）, 28.5±2.9 （Station 2）, 27.8±1.7 （Station 3）, and 24.5±2.3 （Station 4）. The abundance was highly variable： 19 331±11 187 ind./L at Station 1, 7 960±5 639 ind./L at Station 2, 29 015±12 999 ind./L at Station 3, and 8 190±4 658 ind./L at Station 4. Our results suggest that neither the simple chemical analysis （e.g. chemical oxygen demand, dissolved inorganic nitrogen, and phosphate） nor the eutrophication/pollution index adequately described the water quality at the four stations. The same was true of the number of species and their abundance, both of which had no correlation with the chemical indices. In contrast, Margalef＇s diversity index values （3.12 at Station 2, 2.89 at Station 1, and 2.64 at Stations 3 and 4） generally discriminated the water quality status of the four stations. The difference in water quality among the stations was strongly supported by the pattern of species richness （i.e. the total number of species） of ciliates at each station. Our evaluation was consistent with the results of long-term water quality monitoring at the four stations. With increasing eutrophication, we observed also a compositional and functional shift in the ciliate assemblages from algivorous oligotrich/choreotrich to nonselective-omnivorous gymnostomatids to bacterivorous-detrivorous scuticociliatids. Thus, eiliates may be used to indicate the coastal water quality status of a given site.

关键词： biomonitoring chemical evaluation ciliates community structure eutrophication marine pollution

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

Temporal population dynamics of dinoflagellate Prorocentrum minimum in a semi-enclosed mariculture pond and its relationship to environmental factors and protozoan grazers

引用

Chinese Journal of Oceanology and Limnology 2010年第1期28卷 75-81页

作者：许恒龙 MIN Gi-Sik choi joong-ki 朱明壮姜勇 AL-RASHEID Khaled A.S. Laboratory of Protozoology KLMOcean University of China Department of Biological Sciences Inha University Department of Oceanography Inha University Zoology Department King Saud University

The ecological processes and interrelationships between protists,either autotrophic or heterotrophic,and environmental factors in mariculture ponds are largely *** study investigated the temporal dynamics of potentially harmful dinoflagellate,Prorocentrum minimum (Pavillard) Schiller,and its relationship to physico-chemical factors and protozoan grazers over a complete cycle in a semi-enclosed shrimp-farming pond near Qingdao,Northern *** occurred frequently in low numbers from June to August,followed by a sharp increase from the middle of August,reaching a single maximum peak value of 2.2×105 cells L-1 in *** variation in abundance was positively correlated with dissolved nitrogen,but showed a significant inverse relationship to abundance of the dominant ciliates,Tintinnopsis lohmanni and Askenasia *** results provide statistical evidence that the number of *** increased with increasing nitrogen,and the suppression or shortening of algal bloom may be associated with protozoan grazers,such as Tintinnopsis lohmanni,in mariculture ponds.

关键词： dinoflagellate harmful algae Prorocentrum minimum shrimp-farming

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

Temporal dynamics of phytoplankton communities in a semi-enclosed mariculture pond and their responses to environmental factors

引用

Chinese Journal of Oceanology and Limnology 2010年第2期28卷 295-303页

作者：许恒龙 MIN Gi-Sik choi joong-ki AL-RASHEID Khaled A. S. 林晓凤朱明壮 Laboratory of Protozoology KLM Ocean University of China Department of Biological Sciences Inha University Department of Oceanography Inha University Zoology Department King Saud University Laboratory of Protozoology Key Laboratory of Ecology and Environmental Science in Guangdong Higher Education South China Normal University

Variations in physical-chemical factors, species composition, abundance and biomass of nano-and micro-phytoplankton assemblages, as well as their responses to environmental factors, were investigated over a complete cycle (6 months) in a semi-enclosed shrimp-farming pond near Qingdao, northern China. The aim was to establish the temporal patterns of phytoplankton communities and to evaluate protists as suitable bioindicators to water quality in mariculture systems. A total of 34 taxa with nine dominant species were identified, belonging to six taxonomic groups (dinoflagellates, diatoms, cryptophyceans, chlorophyceans, euglenophyceans and chrysophyceans). A single peak of protist abundance occurred in October, mainly due to chlorophyceans, diatoms and chrysophyceans. Two biomass peaks in July and October were primarily due to dinoflagellates and diatoms. Temporal patterns of the phytoplankton communities significantly correlated with the changes in nutrients, temperature and pH, especially phosphate, either alone or in combination with NO3-N and NH3-N. Species diversity, evenness and richness indices were clearly correlated with water temperature and/or salinity, whereas the biomass/abundance ratio showed a significant correlation with NO3-N. The results suggest that phytoplankton are potentially useful bioindicators to water quality in semi-enclosed mariculture systems.

关键词： bioindicator phytoplankton environmental stress microbial ecology shrimp-fanning temporal variations

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

Effect of drawing speed on microstructure distribution and drawability in twinning-induced plasticity steel during wire drawing

引用

Journal of Iron and Steel Research International 2020年第5期27卷 577-587页

作者： joong-ki Hwang School of Mechanical Engineering Tongmyong UniversityBusan 48520Republic of Korea

The effect of drawing speed on temperature rise and microstructure distribution in twinning-induced plasticity(TWIP)steel during wire drawing has been investigated to improve drawability for wire rod *** wire drawing process is performed at room temperature,heat is generated due to the plastic deformation and friction at the wire-die *** steel wires subjected to the low drawing speed(LD)of 0.5 m/min and the high drawing speed(HD)of 5.0 m/min were analyzed using the numerical simulation and electron backscatter diffraction ***,the specimens subjected to the HD had a higher drawability by about 18%compared to the LD,which is totally different from the general behavior of plain carbon pearlitic *** LD wire had uniform temperature distribution along the radial direction during wire *** contrast,the HD wire had a temperature gradient along the radial direction due to the higher frictional effect at surface:the minimum temperature of 58℃ at center area and the maximum temperature of 143 C at surface *** higher stacking fault energy of HD wire at the surface area due to the high temperature rise retarded twinning rate,resulting in the prevention of fast exhaustion in ductility in comparison with the LD wires since the earlier depletion of twins at surface area is known as the main reason for the fracture of TWIP steel during wire ***,HD process delayed the fracture strain of wire and increased the uniformity of microstructure and mechanical properties along the radial direction.

关键词： Twinning-induced plasticity steel Wire drawing Deformation twin Drawing speed Temperature rise

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

Strain hardening rate dependency of deformation shape,strain distribution,and contact pressure during wire flat rolling

引用

Journal of Iron and Steel Research International 2023年第3期30卷 475-486页

作者： joong-ki Hwang School of Mechatronics Engineering Korea University of Technology and EducationCheonan 31253Republic of Korea

The effect of the strain hardening exponent(n)of a material on the changes in shape,strain inhomogeneity,and contact pressure was investigated during wire flat rolling to understand its effect on the deformation behavior of a flat-rolled wire and to determine the optimal working conditions with *** deformation behaviors of wires with various n values were systematically compared using finite element *** shape of the deformed wire was found to depend on the n value of the *** the contact width and lateral spreading of the wire decrease with increasing n,resulting in a large reduction in area with the n *** strain homogeneity of the wire increases with the n value of the *** improvement in the strain homogeneity with the n value is attributable to two factors:a lower strain concentration in the central region and a higher overall elongation as n *** addition,the average effective strain of the wire cross section decreases with the n value of a material during wire flat *** contact pressure distribution on the surface of the wire differs significantly depending on the n *** materials with a low n value,the contact pressure exhibits a higher value at the entry and edge zones of the contact *** contrast,materials with high n values exhibit a higher contact pressure at the exit *** behavior can be explained by the strain hardening behavior of the material during wire flat rolling.

关键词： Strain hardening exponent Wire flat rolling Shape change Strain inhomogeneity Contact pressure

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 reduction in area per pass on strain distribution and microstructure during caliber rolling in twinning-induced plasticity steel

引用

Journal of Iron and Steel Research International 2020年第1期27卷 62-74页

作者： joong-ki Hwang Sung Jin kim School of Mechanical Engineering Tongmyong UniversityBusan 48520Republic of Korea Department of Advanced Materials Engineering Sunchon National UniversitySuncheon 57922Republic of Korea

The effects of reduction in area(RA)per pass during caliber rolling on microstructure and strain distribution of twinninginduced plasticity steel have been investigated to find solutions to make a more homogeneous material along the radial direction for wire rod *** steel wires subjected to an average RA per pass of 2.5%(skin pass caliber rolling)and 10.0%(conventional caliber rolling)were *** skin pass caliber-rolled wire was characterized as a duplex fiber texture of majorand minor.and the textures were almost same at/between center and surface area,which is totally different from those of conventional caliber rolling and wire *** skin pass caliber rolling led to more homogeneous microstructure and mechanical properties along the radial direction in comparison with the conventional caliber rolling and wire drawing due to the more homogeneous Hall-Petch hardening,dislocation hardening,and texture behavior with area,resulting in higher formability.

关键词： Twinning-induced plasticity steel Caliber rolling Deformation twin Reduction in area Skin pass

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

Evaluation of Mechanical Properties According to Nb Content of High Strength Steel Manufactured in VIM

引用

Journal of Materials Science & Technology 2008年第5期24卷 793-796页

作者： Byung-Hui choi Byung-ki choi Department of Mechanical Engineering Graduate SchoolChosun UniversityKorea Department of Mechanical Engineering Chosun UniversityGwang-ju 501-750Korea

As the aircraft and aerospace industry and the automobile industry are developed, the demand of reliable materials with high strength and high toughness is steadily increased. The grain miniature method which improves the ductility and the toughness simultaneously under high strength is the miniature of the casting microstructure. In this paper, the Nb which affects the austenite grain miniature is added by 0.00%, 0.03% and 0.06% in this steel and the ingot is manufactured in a vacuum induction melting furnace （VIM）. The casting microstructure and the mechanical property of the maraging steel according to Nb contents are analyzed by conducting the solution annealing and the age hardening after hot rolling. In this result, a specimen containing 0.03% Nb is most miniature. When it does the long time age hardening, the precipitation estimated as the carbide is appeared. The mechanical properties are excellent if a specimen containing 0.06% Nb does the age hardening during 8 h in 482℃.

关键词： High strength steel Maraging steel Nb Vacuum induction melting furnace (VIM)

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

Gastric cancer occurring in a patient with Plummer-Vinson syndrome: A case report

引用

World Journal of Gastroenterology 2005年第44期11卷 7048-7050页

作者： ki-Han kim Min-Chan kim Ghap-joong Jung Department of Surgery

Plummer-Vinson syndrome (sideropenic dysphagia) is characterized by dysphagia due to an upper esophageal or hypopharyngeal web in patients with chronic iron deficiency anemia. The main cause of dysphagia is the presence of the web in the cervical esophagus,and abnormal motility of the pharynx or esophagus is also found to play a significant role in this *** syndrome is thought to be precancerous because squamous cell carcinoma of hypopharynx, oral cavity or esophagus takes place in 10% of those patients suffering from this malady, but it is even more unusual that Plummer-Vinson syndrome should be accompanied by gastric cancer. We have reported here a case of a43-year-old woman with Plummer-Vinson syndrome who developed stomach cancer and recovered after a radical total gastrectomy with D2 nodal dissection.

关键词： Plummer-Vinson syndrome Gastric cancer Esophageal web

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

Two climate factors in May that affect Korean rainfall in September

引用

Acta Oceanologica Sinica 2013年第1期32卷 32-47页

作者： choi ki-Seon MOON Il-Ju National Typhoon Center Korea Meteorological Administration College of Ocean Science/Ocean and Environment Research Institute Jeju National University

This study revealed a high positive correlation between rainfall in Korea during September and the trade wind （TW）/Arctic Oscillation （AO） index in May that combines two climate factors, low-level TWs and the AO. This correlation was identified on the basis of the difference in the 850 hPa streamline analysis between the positive and negative phases selected using the combined TW/AO index. In May, the spatial pattern of the anomalous pressure systems is similar to that in the positive AO phase. These anomalous pressure sys- tems continue in June to August （JJA） and September, but the overall spatial distribution shifts a little to the south. Particularly in September, a huge anomalous anticyclone centered over the southeast seas of Japan strengthens in most of the western north Pacific region and supplies a large volume of warm and humid air to the region near Korea. This characteristic is confirmed by the facts that during the positive TW/AO phase, the subtropical western north Pacific high （SWNPH） is more developed to the north and that the continu- ous positioning of the upper troposphere jet over Korea from May to September strengthens the anomalous upward flow, bringing warm and humid air to all layers. These factors contribute to increasing September rainfall in Korea during the positive TW/AO phase. Because the SWNPH develops more to the north in the positive phase, tropical cyclones tend to make landfall in Korea frequently, which also plays a positive role in increasing September rainfall in *** above features are also reflected by the differences in average rainfall between the six years that had the highest May Nifio 3.4 indices （El Niflo phase） and the six years that had the lowest May Niflo 3.4 indices （La Nifia phase）.

关键词： anomalous pressure Arctic Oscillation Korea low-level trade wind rainfall tropical cyclone

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

Epidural blood patch for spontaneous intracranial hypotension with subdural hematoma: A case report and review of literature

引用

World Journal of Clinical Cases 2022年第1期10卷 388-396页

作者： Se Hee choi Youn Young Lee Won-joong kim Anesthesiology and Pain Medicine Ewha Womans University Mokdong HospitalSeoul 07985South Korea Anesthesiology and Pain Medicine School of MedicineEwha Womans UniversitySeoul 07985South Korea

BACKGROUND Cerebrospinal fluid(CSF)leakage at C1/2 in spontaneous intracranial hypotension(SIH)is *** hematoma(SDH),a serious complication of SIH,may lead to neurological *** report presents a case of SDH after spontaneous C1/2 CSF leakage,which was treated with a targeted epidural blood patch(EBP).CASE SUMMARY A 60-year-old man with no history of trauma was admitted to our hospital with orthostatic headache,nausea,and *** computed tomography imaging revealed bilateral,subacute to chronic *** magnetic resonance imaging(MRI)findings were SDH with dural enhancement in the bilateral cerebral convexity and posterior fossa and mild sagging,suggesting *** the patient underwent burr hole trephination,the patient’s orthostatic headache was *** myelography led to a suspicion of CSF leakage at C1/***,we performed a targeted cervical EBP using an epidural catheter under fluoroscopic *** 5 d after EBP,a follow-up MR myelography revealed a decrease in the interval size of the CSF *** his symptoms improved,the patient still complained of headaches;therefore,we repeated the targeted cervical EBP 6 d after the initial ***,his headache had almost disappeared on the 8th day after the repeated *** Targeted EBP is an effective treatment for SDH in patients with SIH due to CSF leakage at C1/2.

关键词： Cerebrospinal fluid Chronic subdural hematoma Epidural blood patch Myelography Spontaneous intracranial hypotension Case report

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：