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Geochemistry and tectonic significance of Early Cretaceous granites in Highland 1248 of Daxing'anling 被引量:1
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作者 YANG Naifeng YANG Liting WANG Chunguang 《Global Geology》 2014年第2期86-98,共13页
The Early Cretaceous granitic complex in Highland 1248 of Daxing'anling successively consists of intruded granodiorite,monzonite granite and syenite granite. Through test analysis on the major,trace and rare earth... The Early Cretaceous granitic complex in Highland 1248 of Daxing'anling successively consists of intruded granodiorite,monzonite granite and syenite granite. Through test analysis on the major,trace and rare earth elements of the intrusive complex,this study focuses on the source characteristics and tectonic environment of the original magma of intrusive complex. The results show that the intrusive rocks in Highland 1248 are meta-aluminous-peraluminous rocks in calc-alkaline series with homologous characteristics in δEu negative anomalies; the complex is enriched in LILE( Rb,Cs and K) and depleted in HFSE( lanthanide,Sc,Y,U,Nb and Ta),displaying the geochemical characteristics of I-type granites in active continental-margin subduction zones. The complex also has the characteristics of granites after the collision of plate with rich aluminum and high potassium,but significantly depleted Nb,Ta,Ti,P and other elements,i. e. in the orogenic evolutionary stage. The zircon U-Pb SHRIMP isotopic apparent age of the complex in Highland 1248 is 140. 0--141. 0Ma,and the formation time is in Early Cretaceous. 展开更多
关键词 complex rock mass GEOCHEMISTRY tectonic setting daxing'anling
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Classification,metallogenesis and exploration of silver deposits in Daxing’anling of Inner Mongolia and its adjacent areas
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作者 Biao Jiang Deng-hong Wang +12 位作者 Yu-chuan Chen Tong Zhang Xiu-lang Pu Wen-wen Ma Yan Wang Guang Wu Li-wen Wu Tong Zhang Xue-jiao Li Jie Yan Yu-shan Zuo Hong-jun Sun Zhi-yuan Li 《China Geology》 CAS 2022年第4期595-613,共19页
By the end of 2020,83 silver deposits(or ore occurrences),including four super-large-scale deposits,nine large-scale deposits,33 medium-scale deposits and 37 small-scale deposits or ore occurrences,have been proved.Th... By the end of 2020,83 silver deposits(or ore occurrences),including four super-large-scale deposits,nine large-scale deposits,33 medium-scale deposits and 37 small-scale deposits or ore occurrences,have been proved.The amount of silver metal exceeds 86000 t with average grade of 100 g/t,which makes Daxing’anling region one of the the most important silver ore belt in China.However,the metallogenic characteristics and metallogenesis need to be clarified.The silver deposits in the study area are classified into three main types,which are magmatic hydrothermal vein type,continental volcano-subvolcanic type and skarn type,respectively.The supergiant deposits include the Shuangjianzishan deposit(silver metal amount of 15214 t with average grade of 138 g/t),the Baiyinchagandongshan deposit(silver metal amount of 9446 t with average grade of 187 g/t),the Huaobaote deposit(silver metal amount of 6852 t with average grade of 170 g/t),and the Fuxingtun deposit(silver metal amount of 5240 t with average grade of 196 g/t).The silver deposits are mainly distributed in the central and south of the Daxing’anling area,and mainly formed in the Yanshanian period.The silver polymetallic deposits in the Daxinganling area are significantly controlled by regional faults and the junction zone of volcanic rock basins and their margins.The north-east trending deep faults are the most important ore-controlling structures in this area.The distribution of silver polymetallic deposits along the main faults is obvious,and the intersection area of multiple groups of faults often form important mine catchments.The Permian is the most important ore-bearing formation in this area,but some important silver polymetallic deposits occur in Mesozoic volcanic basins or pre-Mesozoic strata.The magmatic rocks related to mineralization are mainly intermediate acidic or acidic intrusions,intermediate acidic lavas,pyroclastic rocks,and small intrusions of ultra-shallow or shallow facies of the Yanshanian Period.The mineralization element combination is mainly determined by the elemental geochemical background of surrounding rocks or source layers.In addition,the type of deposit,the distance from the mineralization center,and the degree of differentiation of ore-forming rock mass are also important influence factors.The article analyzes the prospecting prospects of each silver deposit type in the study area,discusses the relationship between mineralization center and deep prospecting,and proposes that porphyry silver deposits should be paid attention to.In the prospecting and exploration of silver deposits,comprehensive evaluation and multi-target prospecting need to be strengthened because silver can coexist or be associated with a variety of metals. 展开更多
关键词 Silver deposit Deposit type Porphyry silver deposit Supergiant silver deposit METALLOGENESIS Mineral exploration engineering Prospecting direction daxinganling Inner Mongolia
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Daxing'anling Prefecture:unspoiled Land and a Green Source
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《China Today》 2001年第4期72-77,共6页
关键词 daxinganling Prefecture:unspoiled Land and a Green Source
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Anle138b对oAβ_(1-42)诱导大鼠海马神经元线粒体功能损伤的影响
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作者 张丽 刘欣宇 马泽刚 《青岛大学学报(医学版)》 CAS 2024年第3期337-340,共4页
目的探究Anle138b对慢性β淀粉样蛋白(Aβ)诱导的海马神经元线粒体功能损伤的影响。方法取出生24 h以内的SD乳鼠,原代培养海马神经元,待细胞成熟将其分为对照组(不进行任何处理)、oAβ_(1-42)组(100 nmol/L oAβ_(1-42)处理7 d)、oAβ_(... 目的探究Anle138b对慢性β淀粉样蛋白(Aβ)诱导的海马神经元线粒体功能损伤的影响。方法取出生24 h以内的SD乳鼠,原代培养海马神经元,待细胞成熟将其分为对照组(不进行任何处理)、oAβ_(1-42)组(100 nmol/L oAβ_(1-42)处理7 d)、oAβ_(1-42)+Anle138b组(100 nmol/L oAβ_(1-42)+100 nmol/L Anle138b共处理7 d)、Anle138b组(100 nmol/L Anle138b处理7 d)。各组处理结束后,应用流式细胞术检测活性氧(ROS)和线粒体膜电位(Δψm)阳性细胞的变化。结果析因设计的方差分析显示,oAβ_(1-42)和Anle138b的主效应明显(F_(oAβ1-42)=14.149、38.209,F_(Anle138b)=1.942、24.871,P<0.01),oAβ_(1-42)和Anle138b之间有交互性作用(F_(交互)=18.425、21.904,P<0.01)。单独效应分析显示,用oAβ_(1-42)处理时,Anle138b的处理效应明显(F=16.483、19.148,P<0.01);不用Anle138b处理时,oAβ_(1-42)的处理效应明显(F=14.149、38.209,P<0.01)。结论Anle138b可以减轻oAβ_(1-42)引起的海马神经元氧化应激和线粒体损伤,抑制oAβ_(1-42)对海马神经元的损伤。 展开更多
关键词 阿尔茨海默病 淀粉样β肽类 anle138b 海马 神经元 氧化应激 大鼠 SPRAGUE-DAWLEY
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固定化脂肪酶ANL-MARE催化酸解合成1-油酸-2-棕榈酸-3-亚油酸甘油三酯
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作者 康梦 何家强 +7 位作者 冯孔龙 黄早成 李一峰 苗建银 符姜燕 朱泽榕 刘果 曹庸 《现代食品科技》 CAS 北大核心 2024年第2期109-119,共11页
1-油酸-2-棕榈酸-3-亚油酸甘油三酯(OPL)是人乳中主要的脂质组成,为满足婴幼儿配方食品母乳化需求,该试验探究了新型固定化脂肪酶ANL-MARE催化制备OPL的方法。试验成功制备和表征了固定化酶ANLMARE,并以ANL-MARE为生物催化剂,建立了一... 1-油酸-2-棕榈酸-3-亚油酸甘油三酯(OPL)是人乳中主要的脂质组成,为满足婴幼儿配方食品母乳化需求,该试验探究了新型固定化脂肪酶ANL-MARE催化制备OPL的方法。试验成功制备和表征了固定化酶ANLMARE,并以ANL-MARE为生物催化剂,建立了一种用三棕榈酸甘油三酯(PPP)、油酸(OA)和亚油酸(LA)高效酶催化制备富含OPL结构脂的方法。经单因素和响应面试验优化,获得OPL最优合成工艺为:PPP与总脂肪酸的摩尔比1:14.27,OA与LA摩尔比为1:0.76,脂肪酶添加量12.70%,反应温度50℃,反应4 h,此条件下产物中OPL相对含量为47.93%,2位棕榈酸(sn-2 PA)占总棕榈酸(PA)的质量分数(sn-2 PA相对含量)为71.69%。此外,固定化酶ANL-MARE与商业脂肪酶相比,表现出较好的催化合成OPL的活性。综上所述,固定化酶ANL-MARE具有催化制备OPL结构脂的重大潜力,为人乳脂替代脂的高效制备提供了新策略和理论基础。 展开更多
关键词 1-油酸-2-棕榈酸-3-亚油酸甘油三酯 酶促酸解法 固定化脂肪酶 anl-MARE 工艺优化
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Landscape change on burned blanks in Daxing'an Mountains 被引量:5
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作者 孔繁花 李秀珍 尹海伟 《Journal of Forestry Research》 SCIE CAS CSCD 2004年第1期33-38,J002,共7页
Daxing抋n Mountains was one of the most important forest areas in China, but it was also an area which was prone to suffering forest fire. The catastrophic forest fire that occurred in Daxing抋n Mountains on May 6, 19... Daxing抋n Mountains was one of the most important forest areas in China, but it was also an area which was prone to suffering forest fire. The catastrophic forest fire that occurred in Daxing抋n Mountains on May 6, 1987 devastated more than 1.33?06 hm2 of natural forests, which leaded to the formation of some mosaic areas with different burn intensities. Two forest farms of Tuqiang Forest Bureau (124?5-122?8E, 53?4-52?5N) were chosen as a typical area to analyze the post-fire landscape change by drawing and comparing the two digital forest stand maps of 1987 and 2000. The landscape lands of forest were classi-fied into 12 types: coniferous forest, broadleaf forest, needle-broadleaf mixed forest, shrub, nursery, harvested area, burned blanks, agricultural land, swamp, water, built-up, grass. The results showed that: 1) The burned blanks was almost restored, some of them mainly converted into broadleaf forest land during the process of natural restoration, and coniferous forest land by the artificial re-forestation, and the others almost changed into swamp or grass land; 2) The proportion of forest area increased from 47.6% in 1987 to 81.3% in 2002. Therefore, a few management countermeasures, such as the enhancing peoples consciousness of fire-proofing and constructing species diversity, were put forward for forest sustainable development. 展开更多
关键词 Landscape change Burned blanks daxing抋n Mountains
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Anle138b对oAβ_(1-42)诱导海马神经元突触毒性作用影响 被引量:1
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作者 孙琳 王炳超 朱天立 《青岛大学学报(医学版)》 CAS 2023年第4期518-521,共4页
目的探究Anle138b对慢性β淀粉样蛋白寡聚体1-42(oAβ_(1-42))诱导的海马神经元突触毒性作用影响。方法培养原代海马神经元细胞,细胞发育成熟后分为对照组(不进行任何处理)、oAβ_(1-42)组(100 nmol/L oAβ_(1-42)处理7 d)、Anle138b组(... 目的探究Anle138b对慢性β淀粉样蛋白寡聚体1-42(oAβ_(1-42))诱导的海马神经元突触毒性作用影响。方法培养原代海马神经元细胞,细胞发育成熟后分为对照组(不进行任何处理)、oAβ_(1-42)组(100 nmol/L oAβ_(1-42)处理7 d)、Anle138b组(50 nmol/L Anle138b处理2 d)、oAβ_(1-42)+Anle138b组(100 nmol/L oAβ_(1-42)+50 nmol/L Anle138b共处理7 d)、oAβ_(1-42)+Anle138b 2 d组(100 nmol/L oAβ_(1-42)处理7 d,在oAβ_(1-42)处理的最后2 d加用50 nmol/L Anle138b)。各组处理结束后,应用单细胞膜片钳技术检测自发性兴奋性突触后电流(sEPSCs)的幅值、频率、半衰减时间。结果各组海马神经元细胞sEPSCs幅值、半衰减时间比较差异无统计学意义(F=2.215、1.043,P>0.05)。各组sEPSCs频率比较差异有统计学意义(F=15.490,P<0.001),两两比较显示,oAβ_(1-42)组的sEPSCs频率较对照组明显增加(q=6.507,P<0.001),oAβ_(1-42)+Anle138b组和oAβ_(1-42)+Anle138b 2 d组的sEPSCs频率较oAβ_(1-42)组明显降低(q=9.517、9.471,P<0.001),其他组间比较差异均无统计学意义(P>0.05)。结论Anle138b不仅可以预防慢性oAβ_(1-42)诱导的海马神经元细胞突触毒性作用,还可以消除慢性oAβ_(1-42)诱导的海马神经元细胞突触毒性作用。 展开更多
关键词 阿尔茨海默病 β淀粉样蛋白寡聚体 anle138b 海马 神经元 电生理
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A new pathotype characterization of Daxing and Huangyuan populations of cereal cyst nematode(Heterodera avenae) in China 被引量:8
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作者 CUI Jiang-kuan HUANG Wen-kun +4 位作者 PENG Huan LIU Shi-ming WANG Gao-feng KONG Lin-an PENG De-liang 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2015年第4期724-731,共8页
The cereal cyst nematode(CCN, Heteroder aavenae) causes serious yield loss on cereal crops, especially wheat, worldwide. Daxing population in Beijing City and Huangyuan population in Qinghai Province, China, are two... The cereal cyst nematode(CCN, Heteroder aavenae) causes serious yield loss on cereal crops, especially wheat, worldwide. Daxing population in Beijing City and Huangyuan population in Qinghai Province, China, are two CCN populations. In this study, the CCN pathotypes of Daxing and Huangyuan populations were characterized by tests on 23 standard "International Test Assortment" with the local species Wenmai 19 as the susceptible control. Tested materials were grouped by three nematode populations' virulence on resistant genes(Rha1, Rha2, Rha3, Cre1) and nonresistant genes, varieties and lines. Both Daxing and Huangyuan populations were avirulent to Ortolan(Ha1). Barley cvs. Ortolan, Siri, Morocco, Bajo Aragon 1-1, and Martin 403-2 were all resistant to both populations. Cultivars Herta, Harlan 43 and wheat Iskamish-K-2-light were all susceptible to Huangyuan population, all of them, however, were resistant to Daxing population. The other five oats were all resistant to the two tested CCN populations. Except Iskamisch K-2-light, all the other wheat cultivars(Capa, Loros×Koga, AUS 10894, and Psathias) were susceptible to Daxing population. Because the pathotypes of the two tested CCN populations in Beijing and Qinghai were not identical to any of the 13 pathotypes previously characterized by the test assortment, we classified Daxing and Huangyuan populations as the new pathotypes, named Ha91. 展开更多
关键词 cereal cyst nematode Heterodera avenae daxing population Huangyuan population PATHOTYPE
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Ecosystem carbon storage and sink/source of temperate forested wetlands in Xiaoxing’anling, northeast China 被引量:8
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作者 Biao Wang Changcheng Mu +3 位作者 Huicui Lu Na Li Yan Zhang Li Ma 《Journal of Forestry Research》 SCIE CAS CSCD 2022年第3期839-849,共11页
Wetlands play an important role in the global carbon cycle, but there are still considerable uncertainties in the estimation of wetland carbon storage and a dispute on whether wetlands are carbon sources or carbon sin... Wetlands play an important role in the global carbon cycle, but there are still considerable uncertainties in the estimation of wetland carbon storage and a dispute on whether wetlands are carbon sources or carbon sinks. Xiaoxing’anling are one of several concentrated distribution areas of forested wetland in China, but the carbon storage and carbon sink/source of forested wetlands in this area is unclear. We measured the ecosystem carbon storage (vegetation and soil), annual net carbon sequestration of vegetation and annual carbon emissions of soil heterotrophic respiration of five typical forested wetland types (alder swamp, white birch swamp, larch swamp, larch fen, and larch bog) distributed along a moisture gradient in this area in order to reveal the spatial variations of their carbon storage and quantitatively evaluate their position as carbon sink or source according to the net carbon balance of the ecosystems. The results show that the larch fen had high carbon storage (448.8 t ha^(−1)) (6.8% higher than the larch bog and 10.5–30.1% significantly higher than other three wetlands (P < 0.05), the white birch swamp and larch bog were medium carbon storage ecosystems (406.3 and 420.1 t ha^(−1)) (12.4–21.8% significantly higher than the other two types (P < 0.0 5), while the alder swamp and larch swamp were low in carbon storage (345.0 and 361.5 t ha^(−1), respectively). The carbon pools of the five wetlands were dominated by their soil carbon pools (88.5–94.5%), and the vegetation carbon pool was secondary (5.5–11.5%). At the same time, their ecosystem net carbon balances were positive (0.1–0.6 t ha^(−1) a^(−1)) because the annual net carbon sequestration of vegetation (4.0–4.5 t ha^(−1) a^(−1)) were higher than the annual carbon emissions of soil heterotrophic respiration (CO_(2) and CH_(4)) (3.8–4.4 t ha^(−1) a^(−1)) in four wetlands, (the alder swamp being the exception), so all four were carbon sinks while only the alder swamp was a source of carbon emissions (− 2.1 t ha^(−1) a^(−1)) due to a degraded tree layer. Our results demonstrate that these forested wetlands were generally carbon sinks in the Xiaoxing’anling, and there was obvious spatial variation in carbon storage of ecosystems along the moisture gradient. 展开更多
关键词 Temperate forested wetlands Ecosystem carbon storage Carbon sink or source Xiaoxing’anling of China
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Site classification of the eastern forest region of Daxing'an Mountains 被引量:1
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作者 扬凯 马英 +1 位作者 谷会岩 刘鹏 《Journal of Forestry Research》 SCIE CAS CSCD 1999年第2期129-130,共2页
Based on the plot data from the investigation and the theory of forest ecology and ecological system,the site classification of the eastern forest region of Daxing’an Mountains was made by mean of mathematical method... Based on the plot data from the investigation and the theory of forest ecology and ecological system,the site classification of the eastern forest region of Daxing’an Mountains was made by mean of mathematical method. The main factors were slope, thickness of soil layer, slope position and slope aspect. Grades of slope were used as the division standard for site type group. The slope aspect, slope position and thickness of soil layer were used as the division standards for site type. Altogether 7 site type groups and 15 main site types were determined the region. It provided reliable fundamental basis for the reasonable management and planting design in the area. 展开更多
关键词 daxing’an MOUNTAINS FOREST SITE classification SITE TYPE GROUP SITE TYPE
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Spring habitat selection of sables in Daxing'an Mountains 被引量:1
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作者 张洪海 《Journal of Forestry Research》 SCIE CAS CSCD 1999年第2期111-114,共4页
This paper studies the habitat selection of sables (Martes. zibellina) in spring adopting radio-tracking and GPS (Global Positioning System) in Daxing’an Mountains of China. Sables liked mature and elder forest, but ... This paper studies the habitat selection of sables (Martes. zibellina) in spring adopting radio-tracking and GPS (Global Positioning System) in Daxing’an Mountains of China. Sables liked mature and elder forest, but it avoided uncovered and young growth land. In spring sables had strong selection to medium cover-degree forest, but it avoided widen ground and especial high cover-degree forest. On the contrary sables didn’t have the strong selection to shrubs cover-degree, but strong selection to dominant tree species, slope degree and slope direction, especially sable liked medium and lower slope. At the same time, sables had the strong selection to the log’s density and the crown’s cover-degree. Generally it avoided high elevation and lower slope land. 展开更多
关键词 SABLE RADIO-TRACKING GPS Habitat Selection daxing’an Mountains
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Study of seasonal snow cover influencing the ground thermal regime on western flank of Da Xing'anling Mountains,northeastern China 被引量:2
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作者 XiaoLi Chang HuiJun Jin +1 位作者 YanLin Zhang HaiBin Sun 《Research in Cold and Arid Regions》 CSCD 2015年第6期666-674,共9页
Although many studies relevant to snow cover and permafrost have focused on alpine, arctic, and subarctic areas, there is still a lack of understanding of the influences of seasonal snow cover on the thermal regime of... Although many studies relevant to snow cover and permafrost have focused on alpine, arctic, and subarctic areas, there is still a lack of understanding of the influences of seasonal snow cover on the thermal regime of the soils in permafrost regions in the mid-latitudes and boreal regions, such as that on the westem flank of the Da Xing'anling (Hinggan) Mountains, northeastern China. This paper gives a detailed analysis on meteorological data series from 2001 to 2010 provided by the Gen'he Weather Station, which is located in a talik of discontinuous permafrost zone and with sparse meadow on the observation field. It is inferred that snow cover is important for the ground thermal regime in the middle Da Xing'anling Mountains. Snow cover of 10-cm in thickness and five to six months in duration (generally November to next March) can reduce the heat loss from the ground to the atmosphere by 28%, and by 71% if the snow depth increases to 36 cm. Moreover, the occurrence of snow cover resulted in mean annual ground surface temperatures 4.7-8.2℃ higher than the mean annual air temperatures recorded at the Gen'he Weather Station, The beginning date for stable snow cover establishment (SE date) and the initial snow depth (SDi) also had a great influences on the ground freezing process. Heavy snowfall before ground surface freeze-up could postpone and retard the freezing process in Gen'he. As a result, the duration of ground freezing was shortened by at least 20 days and the maximum depth of frost penetration was as much as 90 cm shallower. 展开更多
关键词 snow cover thermal regime ground freezing Da Xing'anling Mountains northeastern China
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Argillization mechanics of rock from the Xing’anling Group in the Beier depression of the Hailar basin 被引量:1
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作者 LIU Qin-fu FU Zheng YANG Bao-quan 《Journal of China University of Mining and Technology》 EI 2008年第2期237-240,共4页
The reservoir of the Xing'anling Group in the Beier depression of the Hailar basin is loosely cemented with many tuffaceous grains.This causes argillization and collapse of the grain framework of the reservoir san... The reservoir of the Xing'anling Group in the Beier depression of the Hailar basin is loosely cemented with many tuffaceous grains.This causes argillization and collapse of the grain framework of the reservoir sandstones.A detailed study on the characteristics of rocks and minerals was carried out through polarized microscope,X-ray diffraction,X-ray fluorescence,SEM and energy spectrum analysis.The results indicate that the reason for argillization is the abundant pyroclastic,and especially tuffaceous,grains in the reservoir.The alkaline component is relatively high in some strata.These are easily altered to montmorillonite in diagenesis.Na+montmorillonite swells strongly when exposed to water.This is the fundamental reason for the reservoir's argillization and plugging. 展开更多
关键词 Xing'anling Group clay mineral TUFF Na^+-montmorillonite argillization
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Population Characteristics of Dendrolims Superans in Daxing'an Mountains
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作者 孟庆繁 杨晓光 +3 位作者 闫绿光 洪国奇 林同 刘宽余 《Journal of Forestry Research》 SCIE CAS CSCD 1997年第4期227-230,共4页
Dendrolims superans produced one generation every two years Large larvae and small larvae exist at the sametime. lt broke out in Daxiang an Mountains in 1990. and seriously destroyed growth of Larix gmelum Rupr In ord... Dendrolims superans produced one generation every two years Large larvae and small larvae exist at the sametime. lt broke out in Daxiang an Mountains in 1990. and seriously destroyed growth of Larix gmelum Rupr In order to control D Superans.the population properties of D.superans were stedied from 1991 to 1992 including sex ratio.age distribution. pattern etc.. The sex ratio of D. superans population is The larvae age distrihution indicates that larvaeover 5 instar is less than younger larvae under 4 instar in Yongqing forest farm- but the younger larvae under 4 instar is morethan larvae over 5 instar in Hanjiayuanzi Forest Farm. The population of D. superans in Yongqing Farm has heen declining.and incrcasing in Hanjiayuanzi. Pupae and eggs are mainly distributed in middle and lower crowns layer of trees. respec-tively account for 66% and 59.5%, of total individuals. The pupae in higher cown layer is lightly regular distrihution. andclumping distribution middle and lower crowns layer of trees. The eggs in higher crown is light clumpin1g distribution. andrandom in middle and low crown of tree. 展开更多
关键词 Dendrolims superans daxing AN MOUNTAINS POPULATION Characteristics SPECIAL PATTERN METHODS
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Quantitative dynamics on stimulating regeneration and sowing seedlings of Larix gmelinii in Daxing'an Mountains
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作者 徐振邦 代力民 +4 位作者 陈高 潘禄 陈涛 初得志 杨善勋 《Journal of Forestry Research》 SCIE CAS CSCD 2000年第4期231-236,共6页
To understand the quantitative dynamics and death reason of stimulating regeneration seedlings is significant for stimulating the natural regeneration ofLarix gmelinii and implement of conservation project of natural ... To understand the quantitative dynamics and death reason of stimulating regeneration seedlings is significant for stimulating the natural regeneration ofLarix gmelinii and implement of conservation project of natural forest. This paper summarized location observations and directly-seeding simulation experiments of six permanent sample plots that were set up after the seed bumper harvest year ofLarix gmelinii in 1989. The study showed that stimulating natural regeneration seedlings had a large mortality in the first three years, especially in the first year of seedling emergence. After three years seedlings died less and stepped into the stable regeneration stage. A large number of seedlings died of sunscald as the primary death reason. For those areas of good site conditions and rich soil, damping-off would cause seedlings to death in large quantities. The task of stimulating regeneration is mainly to get rid of the litter (forest floor) on burned areas. By means of promoting measures, emergence rate of sown seeds would be several times and dozens of times higher than that of seed shedding on the condition of retention of forest floor. Promoting the regeneration need to select the suitable site against great slope and low-lying lands; at the same time, be careful of the avoidance of frost heaving by depression water. 展开更多
关键词 Larix gmelinii LARCH Stimulating natural regeneration SEEDLINGS Burn area daxing’an Mountains
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Research on Grade Renewing of Cultivated Land at County Level:A Case Study of Daxing District,Beijing
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作者 MA Jian-hui JIN Jing +2 位作者 WU Ke-ning KOU Zong-miao FU Bo 《Asian Agricultural Research》 2012年第12期55-60,65,共7页
To create a scientific way to renew the grades of cultivated land at county level, monitoring points were set up according to the monitoring control regions and grade types of cultivated land in Daxing District, Beiji... To create a scientific way to renew the grades of cultivated land at county level, monitoring points were set up according to the monitoring control regions and grade types of cultivated land in Daxing District, Beijing, and soil samples were collected to carry out chemical analysis. Afterwards, the input and output data of cultivated land in each village were surveyed to renew the grades of cultivated land. The results indicate that the average natural grade of cultivated land was 8.4, which was equal to that of 2004; the average utilization grade was 8.1, which was slightly higher than that of 2004; the average economic grade was 9.9, which was lower than that of 2004. It is concluded that it is scientific to renew cultivated land grades through scientifically setting monitoring points according to the monitoring control regions and grade types of cultivated land. 展开更多
关键词 LAND management GRADE renewing of CULTIVATED LAND
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Beijing Daxing Airport is Finally Open
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作者 高洁 《疯狂英语(初中天地)》 2020年第1期16-17,共2页
关键词 Beijing daxing Airport is Finally Open
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面向一统的都城规划——再论隋大兴的空间形制建构及其历史意义
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作者 栾滨 孙晖 《城市规划》 CSSCI CSCD 北大核心 2024年第9期99-110,共12页
隋大兴是在一统全国过程中规划建设的新都城。其营建不仅在于都城空间本身,也包括以都城为核心面向整个疆域的一系列空间建构。本文分析了中国古代“大一统”思想的发展演变以及隋大兴的建设背景,认为隋初围绕大兴城在疆域范围、近畿区... 隋大兴是在一统全国过程中规划建设的新都城。其营建不仅在于都城空间本身,也包括以都城为核心面向整个疆域的一系列空间建构。本文分析了中国古代“大一统”思想的发展演变以及隋大兴的建设背景,认为隋初围绕大兴城在疆域范围、近畿区域、都城形态三个层面的一系列空间建构是中国古代“大一统”思想与全国一统进程实际需要相结合的空间政治实践,呼应了当时的军事、政治、经济、文化等需求,丰富和发展了“大一统”理念在都城规划中的表达,提高了都城在国家秩序建构和国家认同形成方面的作用,推动了隋唐“大一统”时代的形成和巩固。 展开更多
关键词 隋大兴 大一统 都城形制 疆域建构 国家秩序
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Zircon SHRIMP U-Pb Dating and Geochemical Characteristics of Late Variscan Granites of the Daitongshan Copper Deposit and Lamahanshan Polymetallic-Silver Deposit, Southern Daxing'anling, China 被引量:9
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作者 周振华 李泊洋 +3 位作者 王挨顺 武新丽 欧阳荷根 冯佳睿 《Journal of Earth Science》 SCIE CAS CSCD 2013年第5期772-795,共24页
Daxing'anling (大兴安岭) area is one of the regions that Phanerozoic granites are extremely developed in NW China. At present, the Hercynian granitoid research lags behind the Mesozoic granitoid research. In this a... Daxing'anling (大兴安岭) area is one of the regions that Phanerozoic granites are extremely developed in NW China. At present, the Hercynian granitoid research lags behind the Mesozoic granitoid research. In this article, we have taken systematic petrochemistry and geochronology researches on the Hercynian granitoids in Daitongshan (代铜山) copper deposit and Lamahanshan (喇嘛罕山) silver poly- metallic deposit, which were located at southern section of Daxing'anling metallogenic belt. Zircon SHRIMP U-Pb dating results show that, the granite aplites in Daitongshan and the gneissic granites inLamahanshan were formed at (265±5)-(268±9) Ma and (252±2)-(252.6±3.4) Ma, respectively, which were both the products of late Herynian tectonic-magmatic events. Samples from Lama- hanshan are characterized by high SiO2 (69.72 wt.%-74.65 wt.%), high potassium (3.53 wt.%-4.55 wt.%) and low P205 (0.03 wt.%0.12 wt.%), aluminum saturation index (A/CNK) range from 0.95 to 0.98, Rb, Nd and K are en- riched, whereas the elements such as Nb, Ta, P and Ti are depleted, which belong to I-type grani- toids. Characteristics of samples from Daitong- shan are similar to H-type granitoids. The magmasource may be mostly originated from the lithospheric mantle component which were transformated or affected by the subduction components, and its formation may be closely related with the subduction and orogenesis of the Paleo-Asian Ocean. 展开更多
关键词 SHRIMP U-Pb dating geochemistry VARISCAN Daitongshan copper deposit Lamahan-shan silver polymetallic deposit daxing'anling.
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基于MIDAS的DAX网络发布技术在油田WebGIS中的应用研究 被引量:2
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作者 刘显德 李欣 +2 位作者 曹闻渊 孙宁 许少华 《微型电脑应用》 2002年第10期11-12,8,共3页
提出了基于 MIDAS的 DAX网络发布技术在Web GIS中的设计方法。该方法在一个共享的中间层上封装了商业规则 ,集中的实现了应用服务器所要实现的功能 ,使客户程序将重点放在显示数据和与用户交互上。将这项技术应用于油田中的地质图绘制方... 提出了基于 MIDAS的 DAX网络发布技术在Web GIS中的设计方法。该方法在一个共享的中间层上封装了商业规则 ,集中的实现了应用服务器所要实现的功能 ,使客户程序将重点放在显示数据和与用户交互上。将这项技术应用于油田中的地质图绘制方面 ,解决了油田中多层分布式异构数据库的访问、管理和地质图件的动态生成问题。研制开发的“基于 Web GIS地质图绘制软件包”在大庆油田推广使用 ,取得了良好的效果。 展开更多
关键词 MIDAS dax 网络发布 WEBGIS 网络地理信息系统 油田勘探
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