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Evaluation of Medical Prescribers’ Theoretical Knowledge on Medical Imaging in the Northern Region of Burkina Faso
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作者 Some Milckisédek Judicaël Marouruana Ouedraogo Pakisba Ali +5 位作者 Tankoano Aïda Ida Savadogo Habibou Kindo Bassirou Ouedraogo Nina-Astrid Bamouni Yomboé Abel Diallo Ousseini 《Open Journal of Radiology》 2024年第2期33-41,共9页
Introduction: Medical imaging is a medical specialty that involves producing images of the human body and interpreting them for diagnostic, therapeutic purposes, and for monitoring the progress of pathologies. We aime... Introduction: Medical imaging is a medical specialty that involves producing images of the human body and interpreting them for diagnostic, therapeutic purposes, and for monitoring the progress of pathologies. We aimed to assess the theoretical knowledge of doctors and interns in medical imaging in the northern region of Burkina Faso. Methodology: This was a descriptive cross-sectional survey based on a self-administered questionnaire. Prescribers knowledge was estimated based on scores derived from questionnaire responses. Results: We collected 106 questionnaires out of 163, i.e. a participation rate of 65.03%. The average knowledge score was 81.71% for the contribution of medical imaging to patient management. It was 60.02% for the indications/counter-indications of radiological examinations and 72.56% for the risks associated with exposure to radiation during these examinations. The score was 59.83% for the methods used to select the appropriate radiological examination. As regards the completeness of the clinical and biological information on the forms requesting imaging examinations, the score was 96.65%. Specialist doctors had the highest overall level of knowledge (74.68%). Conclusion: Improved technical facilities, good initial and in-service training, and interdisciplinary collaboration will help to ensure that imaging tests are properly prescribed, leading to better patient care. 展开更多
关键词 Theoretical Knowledge Medical Imaging northern region Burkina Faso
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Study of the Spatio-Temporal Variability of Rainfall in the Northern Region of Senegal
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作者 Aichétou Dia Diop Abdoul Karim Mbodji +8 位作者 El Hadji Deme Malick Wade Mahamat Adoum Moussa Abdoulaye Bouya Diop Younousse Biaye Djiby Sarr Abdou Karim Farota Aboubakary Diakhaby Bouya Diop 《Journal of Geoscience and Environment Protection》 2023年第4期1-14,共14页
Senegal is a country of the Sahel. In this region, most of the populations live from agro-pastoral activities. The northern zone of Senegal is strongly influenced by river cultures. And the dynamics of the Senegal Riv... Senegal is a country of the Sahel. In this region, most of the populations live from agro-pastoral activities. The northern zone of Senegal is strongly influenced by river cultures. And the dynamics of the Senegal River are dependent on rainfall. The rainfall in the area is very closely linked to the dynamics of the atmosphere. The study of the spatio-temporal variability of rainfall in the northern region of Senegal requires quality rainfall observation data. It includes the Ferlo and the Senegal River valley, in particular the regions of Louga (department of Linguère included), Saint-Louis (departments of Dagana and Podor included) and Matam. These stations have been defined since Le Borgne (1988). The difficulty of having quality rain observation data can be resolved by using more accessible and good quality satellite data. Using satellite data, namely MSWEP, CRU, TAMSAT, ARC and PERSIANN, we showed the return of precipitation that appeared in 2000 and the unimodal cycle of precipitation in our study area. These data were validated using the correlation coefficient, the bias, the RMSE and the Nash index with observation data from the Regional Study Center for the Improvement of Adaptation to Drought (CERASS). The CRU data is then retained. Thus, this study made it possible to show the zonal distribution of rainfall in the northern zone of Senegal. 展开更多
关键词 Rainfall in the northern region of Senegal Variability of Rainfall Satellite Data The Zonal Distribution of Rainfall
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Field Experience Exchange Meeting for the Northern Region of National Agricultural Standardization Demonstration Area Held
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《China Standardization》 2004年第6期16-16,共1页
关键词 Field Experience Exchange Meeting for the northern region of National Agricultural Standardization Demonstration Area Held
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Geochemistry,geochronology and Hf isotope of granitoids in the northern Alxa region:Implications for the Late Paleozoic tectonic evolution of the Central Asian Orogenic Belt 被引量:3
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作者 Xiaochen Zhao Chiyang Liu +2 位作者 Jianqiang Wang Shaohua Zhang Yuzhao Guan 《Geoscience Frontiers》 SCIE CAS CSCD 2020年第5期1711-1725,共15页
The tectonic setting of the northern Alxa region during the Late Paleozoic is highly controversial.The key to resolve this controversy is to recognize the Late Paleozoic magmatic processes in the northern Alxa.In this... The tectonic setting of the northern Alxa region during the Late Paleozoic is highly controversial.The key to resolve this controversy is to recognize the Late Paleozoic magmatic processes in the northern Alxa.In this paper,we present new zircon U-Pb ages,Hf-isotopic compositions and whole-rock geochemical data of four granitoids along the Zhusileng-Hangwula Tectonic Belt in the northern Alxa region that could provide critical information about the tectonic evolution of this region.The zircon U-Pb data could be grouped as two phases:Late Devonian granite and diorite(ca.373-360 Ma),and Late Carboniferous granodiorite(ca.318 Ma).The Late Devonian granites and diorites are metaluminous to slightly peraluminous,with A/CNK and A/NK ratios of 0.90-1.11 and0.95-2.19,respectively.The Late Devonian diorites are characterized by high MgO,Cr and Ni contents and MgO#values,together with variableεHf(t)values from-1.0 to+1.3 and old TDM2 ages varied from 1283 Ma to 1426 Ma,indicating the primary magma was potentially derived from magma mixing of depleted mantle with Mesoproterozoic continental crust.Even though the Late Devonian granites yielded most positive and minor negative eHf(t)values between-1.1 to+5.7(three grains are negative)with two-stage model ages(TDM2)of 1003-1438 Ma,they display low MgO,Cr and Ni contents and MgO#values,suggesting that they were mainly derived from juvenile crustal materials,mixed with a small amount of ancient crust.The Late Carboniferous granitoids are metaluminous and medium-K calc-alkaline series,with A/CNK and A/NK ratios ranging from 0.88 to 0.95 and1.75 to 1.90,respectively.These rocks were potentially derived from juvenile crustal materials mixed with depleted mantle,as evidenced by their highεHf(t)values(+11.6 to+14.1)and young TDM2 ages(427 Ma to 586 Ma),as well as high Mg#values,and MgO,Ni and Cr contents.Our data,along with available sedimentary evidence and previous researches,indicate that the Late Devonian and Late Carboniferous rocks are arc-related granitoids under the subduction setting.The identification of arc-related granitoids in the northern Alxa region not only reveals the Late Paleozoic magmatic process in response to the subduction of Paleo Asian Ocean,but also provide significant constrains to the tectonic evolution of the Central Asian Orogenic Belt. 展开更多
关键词 GEOCHEMISTRY U–Pb geochronology Hf isotopic composition GRANITOIDS northern Alxa region Central Asian Orogenic Belt
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A primary study of nitrous oxide emission in agriculture region of Northern China 被引量:1
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作者 Su Weihan, Song Wenzhi, Zhang Hua, Cao Meiqiu, Lu Hongrong and Zhou QuanResearch Center for Eco-Environmental Sciences,Academia Sinica,Beijing 100083,China 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 1990年第4期85-94,共10页
Significance of nitrous oxide in atmospheric chemistry is reviewed briefly. Background concentration of N2O at Wudaoliang in Qinghai Province of Western China has been measured by collecting gas samples and analysing ... Significance of nitrous oxide in atmospheric chemistry is reviewed briefly. Background concentration of N2O at Wudaoliang in Qinghai Province of Western China has been measured by collecting gas samples and analysing them with electron capture-gas chromatography. The atmospheric concentration fluctuates in the range of 303-315 ppb with the mean value of 308 ppb. The emission rate of N2O in agriculture region of Northern China has been studied primarily. Fertilization, rain and temperature of soil appear conductible to N2O emission. The interactions between greenhouse effect and N2O emission have been discussed. The catalytic action of N2O in stratospheric ozone depletion processes and the effect of high N2O concentration on ozone depletion in stratosphere have been considered and discussed. 展开更多
关键词 nitrous oxide agriculture region greenhouse effect northern China.
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Changes and spatial patterns of eco-environment in the farming-pastoral region of northern China 被引量:2
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作者 JIANG Weiguo LI Jing +2 位作者 LI Jiahong CHEN Yunhao WU Yongfeng 《Journal of Geographical Sciences》 SCIE CSCD 2005年第3期329-336,共8页
This paper firstly selects 10 kinds of indexes to reflect eco-environment background condition and builds the multi-subject spatial database by using ground meteorological data, remote sensing data and DEM. It then di... This paper firstly selects 10 kinds of indexes to reflect eco-environment background condition and builds the multi-subject spatial database by using ground meteorological data, remote sensing data and DEM. It then discusses in detail the methods about evaluating eco-environment background condition and analyzing eco-environment change. The eco-environment background conditions of 1989 and 1999 are synthetically appraised. Finally, the paper analyzes the spatial distribution, quantitative change, the trend of change, the areas of change and the dynamic spatial pattern of eco-environment. The results are as follows: (1) The eco-environment background condition becomes worse from southeast to northwest in the fanning-pastoral region of northern China. (2) The eco-environment background condition deteriorates from 1989 to 1999. (3) In the adjacent areas of Shanxi-Shaanxi-Inner Mongolia-Gansu-Ningxia, Horqin Sandy Land and its peripheries, and eastern Qinghai orovince, eco-environmental deterioration is very serious. 展开更多
关键词 fanning-pastoral region ECO-ENVIRONMENT spatial pattern northern China
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Planting Performance of Several Elephant Grass Species in Northern Guangxi Zhuang Autonomous Region
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作者 邓素媛 易显凤 +5 位作者 赖志强 姚娜 庞天德 韦锦益 史静 曹树威 《Agricultural Science & Technology》 CAS 2016年第12期2784-2787,2791,共5页
This study aimed to screen suitable species of Pennisetum purpureum for planting in northern Guangxi Zhuang Autonomous Region. During 2012-2014, a comparative field trial was carried out in Lingyun County of Baise Cit... This study aimed to screen suitable species of Pennisetum purpureum for planting in northern Guangxi Zhuang Autonomous Region. During 2012-2014, a comparative field trial was carried out in Lingyun County of Baise City in northern Guangxi to compare plant height, yield, stem-leaf ratio and nutrient composition am-ong Pennisetum purpureum Schumab cv. Purple, P. purpureum Schum cv. Guimin and P. purpureum Rich &#215; P. americana King grass cv. Reyan No.4. The results in-dicated that average annual fresh yield of P. purpureum Schumab cv. Purple reached 141.4 t/hm2, which was 2.3 t/hm^2 higher than that of P. purpureum_Rich×P. americana_King grass cv. Reyan No.4; both average annual fresh yield of these two species was lower than that of P. purpureum Schum cv. Guimin. Stem-leaf ratio of P. purpureum Schumab cv. Purple was the lowest (1.17), which was 17.8% lower compared with P. purpureum Schum cv. Guimin, with significant differences (P〈0.05), indicating that P. purpureum Schumab cv. Purple had more leaves. Crude protein content of P. purpureum_Schumab cv. Purple was slightly lower than that of P. purpureum Rich×P. americana_King grass cv. Reyan No.4, while P. purpureum Schumab cv. Purple was superior to P. purpureum Schum cv. Guimin and P. pur-pureum Rich ×P. americana_King grass cv. Reyan No.4 in other indicators. Specifi-cal y, P. purpureum Schumab cv. Purple contained 26.6% of dry matter, 39.1% of nitrogen-free extract and 2.9% of crude fat. 展开更多
关键词 Forage grass Pennisetum purpureum Schumab cv. Purple YIELD Stem-leaf ratio Nutrient composition ANTHOCYANIN northern Guangxi Zhuang Autonomous region
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Relocation of the M_S≥2.0 Earthquakes in the Northern Tianshan Region, Xinjiang, Using the Double-Difference Earthquake Relocation Algorithm
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作者 Wang Haitao Li Zhihai +1 位作者 Zhao Cuiping Qu Yanjun 《Earthquake Research in China》 2007年第4期388-396,共9页
We applied the double-difference earthquake rdocation algorithm to 1348 earthquakes with Ms ≥2.0 that occurred in the northern Tianshan region, Xinjiang, from April 1988 to June 2003, using a total of 28701 P- and S-... We applied the double-difference earthquake rdocation algorithm to 1348 earthquakes with Ms ≥2.0 that occurred in the northern Tianshan region, Xinjiang, from April 1988 to June 2003, using a total of 28701 P- and S-wave arrival times recorded by 32 seismic stations in Xinjiang. Aiming to obtain most of these Ms ≥ 2.0 earthquakes relocations, and considering the requirements of the DD method and the condition of data, we added the travel time data of another 437 earthquakes with 1.5 ≤ Ms 〈 2.0. Finally, we obtained the relocation results for 1253 earthquakes with Ms ≥2.0, which account for 93 % of all the 1348 earthquakes with Ms ≥ 2.0 and includes all the Ms ≥ 3.0 earthquakes. The reason for not relocating the 95 earthquakes with 2.0 ≤ Ms 〈 3.0 is analyzed in the paper. After relocation, the RMS residual decreased from 0.83s to 0.14s, the average error is 0.993 km in E-W direction, 1.10 km in N- S direction, and 1.33 km in vertical direction. The hypocenter depths are more convergent than before and distributed from 5 km to 35 kin, with 94% being from 5km to 35 kin, 68.2% from 10 km to 25 kin. The average hypocenter depth is 19 kin. 展开更多
关键词 Double difference earthquake relocation algorithm Hypocenter parameter northern Tianshan region
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How Does the Agricultural Ecosystem Productivity Respond to Climate Fluctuations in the Northern Farming-pastoral Region?
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作者 Tesheng SUN Bo LI Xinshi ZHANG 《Asian Agricultural Research》 2013年第12期65-72,共8页
Using meteorological data and mathematical statistics analysis,we take Jungar Banner in the northern farming-pastoral region of China for example,to analyze the fluctuations in the precipitation and average temperatur... Using meteorological data and mathematical statistics analysis,we take Jungar Banner in the northern farming-pastoral region of China for example,to analyze the fluctuations in the precipitation and average temperature in Jungar Banner during the period 1961-2009.We calculate the NPP of agricultural ecosystem and climatic yield of the main crops in the region during the period 1961-2009,and expound the response of agricultural ecosystem productivity to climate fluctuations in Jungar Banner.Indubitably the climate changes impose great effects on the structure and function of regional ecosystem,and there is a need to take a number of measures to minimize the detrimental effects of climate changes on climatic yield of the main crops. 展开更多
关键词 AGRICULTURAL ECOSYSTEM PRODUCTIVITY CLIMATIC yield
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Study on potential evapotranspiration and wet-dry condition in the seasonal frozen soil region of northern Tibetan Plateau 被引量:1
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作者 HuiGen He ZeYong Hu +4 位作者 XueYi Xun Jun Sun Li Hao LiJiao Xu Wen Peng 《Research in Cold and Arid Regions》 2011年第2期172-178,共7页
This study was based on the CEOP/CAMP-Tibet observed data at AWS (Automatic Weather Station) of MS3478 in the seasonal frozen soil region of northern Tibetan Plateau from March 2007 to February 2008. The variation c... This study was based on the CEOP/CAMP-Tibet observed data at AWS (Automatic Weather Station) of MS3478 in the seasonal frozen soil region of northern Tibetan Plateau from March 2007 to February 2008. The variation characteristics of PE (potential evapotransph'ation) were analyzed based on the Penman-Monteith method recommended by FAO (the Food and Agriculture Organization of the United Na- lions). The contributions of dynamic, thermal and water factors to PE were discussed, and the wet-dry condition of the plateau region was further studied. The results indicated that daily PE was between 0.52 mm and 6.46 mm for the whole year. Monthly PE was over 107 mm from May to September, but decreased to less than 41 mm from November to February. Annual PE was 1,037.8mm. In the summer, thermal PE was significantly more than dynamic PE, but conversely in the winter. Annual variation of thermal PE was of sine wave pattern. In addition, drought and semi-drought climate lasted for a long time while semi-humid climate was short. The effect of water and dynamic factors on PE varied considerably with the seasons. Annual variation of thermal PE was of sine wave pattern. 展开更多
关键词 northern Tibetan Plateau seasonal frozen soil region potential evapolranspimtion dynamic and thermal effects water factor wet -dry condition
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玉米秸秆堆腐还田对黑土区土壤性状的影响 被引量:1
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作者 原韬 安琦 +4 位作者 牛彦波 孟利强 吴皓琼 樊川 曹亚彬 《中国农学通报》 2024年第5期47-52,共6页
本研究针对东北地区秋冬季节气候寒冷特点和秸秆堆腐还田的实际操作需求,开展秸秆堆腐还田试验。在秋季玉米收获之后进行田间堆腐试验,期间连续监测环境温度、降水、秸秆堆温度、秸秆失重率等指标。离田玉米秸秆经过腐熟后作为肥料还田... 本研究针对东北地区秋冬季节气候寒冷特点和秸秆堆腐还田的实际操作需求,开展秸秆堆腐还田试验。在秋季玉米收获之后进行田间堆腐试验,期间连续监测环境温度、降水、秸秆堆温度、秸秆失重率等指标。离田玉米秸秆经过腐熟后作为肥料还田,连续施用3年,检测土壤有机质、碱解氮、速效磷、速效钾、土壤孔隙度、土壤容重等指标。在基本农田和棚室保护地进行为期2年的应用试验。结果表明:120 d秸秆失重率达到31.53%。施用腐熟秸秆3年,土壤有机质提高了4.06~6.31 g/kg、土壤中碱解氮提高了15.08~27.35 mg/kg、速效磷提高了18.11~21.95 mg/kg、速效钾提高63.97~89.93 mg/kg;土壤容重降低了0.10~0.14 g/cm^(3)、土壤田间持水量提高了7.51%~9.24%(V/V)、土壤孔隙度提高了3.69%~5.27%(V/V),且差异显著(P≤0.05)。基本农田和棚室保护地应用试验中,速效养分与有机质有所增长,土壤容重与田间持水量变化显著。逐年施用腐熟秸秆对于提高土壤有机质含量、速效养分具有显著作用。同时,施用腐熟秸秆能够降低土壤容重,提高土壤孔隙度与田间持水量,改善土壤板结问题。腐熟秸秆在改良与保育黑土性质方面具有良好的作用。 展开更多
关键词 玉米秸秆 堆腐 北方寒地 还田 黑土保护 土壤性状
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Analysis of the influence of exploiting water closing to the river on the regional environment in northern suburb water resource of Zhengzhou
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《Global Geology》 1998年第1期104-104,共1页
关键词 Analysis of the influence of exploiting water closing to the river on the regional environment in northern suburb water resource of Zhengzhou
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北方寒冷地区温度场作用下公路路表形变规律分析
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作者 纪伦 张红菊 +3 位作者 郭宏斌 邹勇 赵振国 谭忆秋 《哈尔滨工业大学学报》 EI CAS CSCD 北大核心 2024年第9期113-123,共11页
为了更加具体、深入地理解寒区道路,研究其病害发生、发展规律,提高对道路结构在时间和空间上的认知,开展了北方寒冷地区路表形变规律的研究。通过选取典型公路路段,建立10个监测段落,对路基的冻胀、融沉变形持续进行现场高程监测。分... 为了更加具体、深入地理解寒区道路,研究其病害发生、发展规律,提高对道路结构在时间和空间上的认知,开展了北方寒冷地区路表形变规律的研究。通过选取典型公路路段,建立10个监测段落,对路基的冻胀、融沉变形持续进行现场高程监测。分析温度场作用下路表形变特征和响应机制,分析公路在自然条件下的时域形变特点、动态形变特征及差异性。分析周期监测数据,构建竖向相对形变、竖向相对形变速率、横断面间形变速率最大倍数等参数,比较不同段落、不同横断面和监测点间的形变及其差异。研究北方寒冷地区路表形变与温度场协调规律,结果表明:北方寒冷地区基于温度场的路表形变具有典型的周期特性。对比分析填、挖方路段纵横方向形变的差异特征,形变极值分布规律,以及结合热胀、冻胀、融沉阶段的相对形变规律及形变速率差异特点,结果发现:挖方路段形变速率是填方路段的10余倍;8月份至10月份的热胀速率大于10月份至11月份的热胀速率;融沉主要发生在3月份至5月份;而冻胀速率较为稳定,对于填方路段,11月份至次年1月份的冻胀大于1月份至2月份的冻胀,而挖方路段则相反。给出了寒冷地区路表形变的温度场时域响应规律、特点,为开展寒区路基、路面结构和材料研究,以及道路病害等研究提供了依据。 展开更多
关键词 北方寒冷地区 路表形变 路基 冻胀 融沉 形变规律
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先秦时期北方地区民族交错地带的变迁及特点
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作者 李春梅 《内蒙古社会科学》 北大核心 2024年第1期130-136,共7页
先秦时期,长城以南、黄河中下游以北地区是北方各族与华夏民族交往交流交融的主要发生地。这一区域具有开放包容、丰富多元的文化样态及其文化积淀,并呈现出局部稳定和整体波动的变迁过程。近两千年的交往互动,使各民族及其文化发展都... 先秦时期,长城以南、黄河中下游以北地区是北方各族与华夏民族交往交流交融的主要发生地。这一区域具有开放包容、丰富多元的文化样态及其文化积淀,并呈现出局部稳定和整体波动的变迁过程。近两千年的交往互动,使各民族及其文化发展都得到了相应的回报,为更大规模、更大范围、更多民族的融合奠定了深厚的经济、政治、人文基础。到战国中后期,秦赵燕长城修筑后,该区域皆被纳入中原王朝的管辖范围。 展开更多
关键词 先秦 北方地区 民族交错地带
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Petrology of Spinel-Lherzolite Xenoliths from Mazéléand Others Northen Xenoliths Localities of Cameroon Volcanic Line: Exchange Reactions and Equilibrium State
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作者 Nguihdama Dagwai Kamgang Pierre +2 位作者 Mbowou Gbambié Isaac Bertrand Chazot Gilles Ngounouno Ismaïla 《Open Journal of Geology》 CAS 2024年第5期629-653,共25页
The alkaline volcanism of the Cameroon Volcanic Line in its northern domain has raised many fresh enclaves of peridotites. The samples selected come from five (05) different localities (Liri, in the plateau of Kapsiki... The alkaline volcanism of the Cameroon Volcanic Line in its northern domain has raised many fresh enclaves of peridotites. The samples selected come from five (05) different localities (Liri, in the plateau of Kapsiki, Mazélé in the NE of Ngaoundéré, Tello and Ganguiré in the SE of Ngaoundéré and Likok, locality located in the west of Ngaoundé). The peridotite enclaves of the above localities show restricted mineralogical variation. Most are four-phase spinel-lherzolites, indicating that this is the main lithology that forms the lithospheric mantle below the shallow zone. No traces of garnet or primary plagioclase were detected, which strongly limits the depth range from which the rock fragments were sampled. The textures and the wide equilibrium temperatures (884˚C - 1115˚C) indicate also entrainment of lherzolite xenoliths from shallow depths within the lithosphere and the presence of mantle diapirism. The exchange reactions and equilibrium state established in this work make it possible to characterize the chemical composition of the upper mantle of each region and test the equilibrium state of the phases between them. Variations of major oxides and incompatible elemental concentrations in clinopyroxene indicate a primary control by partial melting. The absence of typical “metasomatic” minerals, low equilibration temperatures and enriched LREE patterns indicate that the upper mantle below septentrional crust of Cameroun underwent an event of cryptic metasomatic enrichment prior to partial melting. The distinctive chemical features, LREE enrichment, strong U, Ce and Pr, depletion relative to Ba, Nb, La, Pb, and T, fractionation of Zr and Hf and therefore ligh high Zr/Hf ratio, low La/Yb, Nb/La and Ti/Eu are all results of interaction of refractory peridotite residues with carbonatite melts. 展开更多
关键词 XENOLITHS Upper Mantle northern region Adamawa Cameroon Volcanic Line Exchange Reaction
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Comparative analysis on microbial community associated with different gastrointestinal regions of wild northern snakehead Channa argus Cantor, 1842 被引量:1
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作者 MIAO Shuyan ZHAO Chenze +1 位作者 ZHU Jinyu PAN Mingzhu 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2018年第2期450-456,共7页
Microbial communities in different gastrointestinal regions (stomach, foregut, midgut, and hindgut) of the northern snakehead Channa argus (Cantor, 1842) were compared by polymerase chain reaction and partial 16S ... Microbial communities in different gastrointestinal regions (stomach, foregut, midgut, and hindgut) of the northern snakehead Channa argus (Cantor, 1842) were compared by polymerase chain reaction and partial 16S rDNA sequencing. A total of 194, 140, 212, and 122 OTUs were detected in the stomach, foregut, midgut, and hindgut, respectively. Significant differences were found in the Sobs, ACE, Shannon, and Simpson indices among samples (P〈0.05). The gastrointestinal microbial community of C. argus consisted predominantly of Proteobacteria with either Halomonas, Shewanella, Plesiomonas, or Sphingomonas. Fusobacteria, Firm!cutes, and Bacteroidetes also existed in the gastrointestinal tracts. However, significant'differences were found in the compositions of microbial community among the four regions (P〈0.05). Cyanobacteria and Spirochetes were significantly higher in the midgut and hindgut (P〈0.05). Fusobacteria and Firmicutes were dominant in the hindgut and foregut, respectively (P〈0.05). Proteobacteria was the lowest in the hindgut (P〈0.05). At genus level, Cetobacterium and Plesiomonas were significantly higher in the hindgut than in the other three samples (P〈0.05). Clostridium and Prevotella were the highest in the midgut (P〈0.05). Halomonas, Shewanella, and Sphingomonas were the highest in the foregut (P〈0.05). Paracoccus and Vibrio were the highest in the stomach. Several genera were only detected in certain regions, as follows: stomach, Paracoccus and Hbrio; foregut, Halomonas, Shewanella, and Sphingomonas; midgut, Clostridium and Prevotella; and hindgut, Cetobacterium and Plesiomonas (P〈0.05). At the species level, Acinetobacter rhizosphaerae was only detected in the stomach. Prevotella copri and Clostridium perfring were not detected in the foregut and midgut, respectively, whereas Prevotella copri and Faecalibacterium pra were not detected in the hindgut. These findings provide valuable information on the microbial community in each gastrointestinal region of C. argus. Moreover, this study indicated that microbial community was not only related to rearing environment but also to the physico-chemical characteristics of each gastrointestinal region. 展开更多
关键词 northern snakehead (Channa argus Cantor 1842) 16S rDNA microbial community gastrointestinal region physico-chemical characteristic
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清代北方地区粟米的生产、流通及价格
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作者 朱琳 《古今农业》 2024年第3期33-47,共15页
粟是北方地区一种重要的粮食作物。清代伴随着社会经济的发展,其种植面积有所下降,但仍为许多地区居民的主要食物来源,清中期粟谷年产量估计可达1亿余石;每年参与流通的数量为9600余万石。就整体价格而言,清代粟米价格接近小麦价格;从... 粟是北方地区一种重要的粮食作物。清代伴随着社会经济的发展,其种植面积有所下降,但仍为许多地区居民的主要食物来源,清中期粟谷年产量估计可达1亿余石;每年参与流通的数量为9600余万石。就整体价格而言,清代粟米价格接近小麦价格;从价格长期变动趋势来看,其涨幅低于麦价,这与粟米商品化程度更低有关。通过对粟米市场整合的考察可知,北方各省粟价变动的同步性达到了相当的水平,说明从余粮区向缺粮区有着频繁的米粮输出,市场效率比较高;这也反映出清代粮食市场的发育达到了一个较高的程度。 展开更多
关键词 北方地区 粟米 流通量 价格 市场整合
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供水工程影响下中国北方地区耕地后备资源开发潜力 被引量:2
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作者 李溦 何国华 +4 位作者 赵勇 姚园 何凡 李海红 王浩 《农业工程学报》 EI CAS CSCD 北大核心 2024年第5期264-274,共11页
灌溉水源是北方地区耕地后备资源能否有效开发的关键。当前,中国正在推动国家水网工程规划建设,为北方地区耕地后备资源开发提供了新的机遇。在以往研究基础上,该研究考虑北方地区已建、在建及规划的供水工程,基于自然适宜、利用高效、... 灌溉水源是北方地区耕地后备资源能否有效开发的关键。当前,中国正在推动国家水网工程规划建设,为北方地区耕地后备资源开发提供了新的机遇。在以往研究基础上,该研究考虑北方地区已建、在建及规划的供水工程,基于自然适宜、利用高效、发展稳定三方面评价准则,结合三维魔方空间分类方法,开展了雨养情景和供水灌溉情景下耕地后备资源开发潜力分析。结果表明:雨养农业情景下,北方地区勉强适宜(Ⅱ级)、中度(Ⅲ级)和高度(Ⅳ级)适宜的耕地后备资源面积分别为2.9万、1.0万和0.6万km^(2)。灌溉农业情景下,耕地后备资源面积明显增加,勉强适宜(Ⅱ级)、中度(Ⅲ级)和高度(Ⅳ级)适宜的耕地后备资源面积将分别达到5.4万、7.6万和6.5万km^(2),主要集中于新疆、内蒙古和甘肃3省(自治区)。该研究结果可为中国耕地后备资源开发利用及国家水网工程效益发挥提供参考。 展开更多
关键词 灌溉 土地利用 北方地区 耕地后备资源 供水工程 雨养
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1980—2016年中国北方风蚀气候侵蚀力的变化
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作者 刘伟 邹学勇 +2 位作者 刘博 王汝幸 王祖正 《地理科学》 CSCD 北大核心 2024年第4期703-710,共8页
随着修订风蚀方程(RWEQ)的提出,采用增加了冻结因子的气候因子(WF)表达风蚀气候侵蚀力更具有科学性和必要性。基于中国北方风蚀区157个气象站1980—2016年的观测数据,逐月计算了各站点气候因子,并探讨了气候因子时空分布变化特征及影响... 随着修订风蚀方程(RWEQ)的提出,采用增加了冻结因子的气候因子(WF)表达风蚀气候侵蚀力更具有科学性和必要性。基于中国北方风蚀区157个气象站1980—2016年的观测数据,逐月计算了各站点气候因子,并探讨了气候因子时空分布变化特征及影响因素。结果表明:①1980—1997年,年气候因子值表现为快速下降,从940.46 kg/m下降到273.03 kg/m;而1998—2016年,年气候因子值表现相对稳定,在139.81~398.85 kg/m范围内波动。②春季气候因子值约占全年63%,其变化也显著高于其它季节,这也是土壤风蚀发生在春季的主要原因。③气候因子的高值区分布在新疆东部、青海西部、40°N以北的内蒙古中西部,这与气压中心和高大山体地形分布有关。 展开更多
关键词 气候因子 土壤风蚀 全球变暖 北方风蚀区
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山西北部高层建筑分布特征
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作者 程紫燕 郑树平 《江西科学》 2024年第4期737-741,767,共6页
随着城市化进程加速和城市建设用地的压力增大,高层建筑在城市中扮演着重要角色。然而,高层建筑的抗震性能一直是人们关注的焦点。基于对山西北部地区高层建筑的调查研究,分析了其分布情况、结构特点和抗震能力。利用遥感技术了解了该... 随着城市化进程加速和城市建设用地的压力增大,高层建筑在城市中扮演着重要角色。然而,高层建筑的抗震性能一直是人们关注的焦点。基于对山西北部地区高层建筑的调查研究,分析了其分布情况、结构特点和抗震能力。利用遥感技术了解了该区域高层建筑分布情况,采用抽样调查的方法了解了该区域高层建筑的结构类型、基础特征、混凝土强度等对结构抗震有影响的关键指标,并进行了统计和分析,发现山西北部地区高层建筑多采取筏板基础、剪力墙结构体系,整体抗震性能较好。通过该研究,旨在为建立自然灾害防治体系和提高地震防灾能力提供数据支持和科学依据。 展开更多
关键词 山西北部地区 高层建筑 区域特征
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