期刊文献+
共找到234篇文章
< 1 2 12 >
每页显示 20 50 100
Ecosystem carbon storage and sink/source of temperate forested wetlands in Xiaoxing’anling, northeast China 被引量:8
1
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 xiaoxinganling of China
下载PDF
Anle138b对oAβ_(1-42)诱导大鼠海马神经元线粒体功能损伤的影响
2
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
下载PDF
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
3
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
下载PDF
Anle138b对oAβ_(1-42)诱导海马神经元突触毒性作用影响 被引量:1
4
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
下载PDF
Wild fruit resources and exploitation in Xiaoxing'an Mountains 被引量:4
5
作者 卓丽环 王玲 +1 位作者 陈全涉 刘武生 《Journal of Forestry Research》 SCIE CAS CSCD 1999年第1期31-33,共3页
The ornamental characters, nutritious composition, edible value and medical value of thirteen kinds of major wild fruit resources in Xiaoxing’an Mountains Region were synthetically analyzed such as Rosa spp,, Actinid... The ornamental characters, nutritious composition, edible value and medical value of thirteen kinds of major wild fruit resources in Xiaoxing’an Mountains Region were synthetically analyzed such as Rosa spp,, Actinidia spp. and so on. The results showed that the wild fruit resources in this region had important garden ornamental value, edible value and medical value. A lot of good germplasm resources and honey plant resources hadnt been effectvely protected and enough utilized. The right way of appropriate arrangement and reasonable exploitation of wild fruit resources in this region should be benefit to got rid of economic crisis early in this region. 展开更多
关键词 WILD fruit RESOURCES ORNAMENTAL character NUTRITIOUS composition xiaoxing’an MOUNTAINS
下载PDF
Effect of soil physical–chemical properties on the decay of standing Pinus koraiensis in Xiaoxing'an Mountains,northeast China 被引量:2
6
作者 Tianyong Sun Lihai Wang +1 位作者 Huadong Xu Zhenyu Bao 《Journal of Forestry Research》 SCIE CAS CSCD 2015年第4期859-865,共7页
We selected 18 rotten and nine healthy post- mature live standing Korean pine (Pinus koraiensis) to study the correlation between the degree of tree decay and soil physical-chemical properties in the Dialing Forest ... We selected 18 rotten and nine healthy post- mature live standing Korean pine (Pinus koraiensis) to study the correlation between the degree of tree decay and soil physical-chemical properties in the Dialing Forest District of the Xiaoxing'an Mountains, China. One trans- verse section of each sample tree at 40-50 cm height above the ground was tested by Resistograph to determine the inner decay status. We collected soil samples around the root zones (6-20 cm depth) of each sample tree to test the soil physical-chemical indicators including moisture con- tent, bulk density, total porosity, pH, organic matter con- tent, total and hydrolyzed N contents, total and available P contents, total and available K contents, and C/N ratio. The degree of decay of postmature Korean pine live standing trees was significantly and positively correlated with the C/N ratio (R = 0.838, P 〈 0.05), organic matter (R = 0.615, P = 0.007) and moisture content (R = 0.543, P = 0.020) of soil around the rodt. The contents of total N, hydrolyzed N and available P sample trees were significantly in the soil under healthy greater than those underdecayed sample trees, and larger N and P contents might inhibit the decay fungi breeding in soils of pH 4.4-6.29. The optimum multiple regression equation for degree of tree decay on soil physical-chemical indicators showed that the linear correlations between the degree of decay and soil C/N ratio and pH were significant (P 〈 0.01) and the correlation was high (R2 = 0.778). Enhancement soil C/N ratio and pH could promote the decay of tree trunks. 展开更多
关键词 Pinus koraiensis Soil physical-chemicalproperties Resistograph Trunk decay xiaoxing'anMountains
下载PDF
Study of seasonal snow cover influencing the ground thermal regime on western flank of Da Xing'anling Mountains,northeastern China 被引量:2
7
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
下载PDF
Argillization mechanics of rock from the Xing’anling Group in the Beier depression of the Hailar basin 被引量:1
8
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
下载PDF
Geochemistry and tectonic significance of Early Cretaceous granites in Highland 1248 of Daxing'anling 被引量:1
9
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
下载PDF
Short-term effects of fire disturbance on CH4 emission from forested wetlands in the Xiaoxing’an Mountains, Northeast China
10
作者 Han Gu Wenyu Zheng +1 位作者 Dawei Xu Changcheng Mu 《Journal of Forestry Research》 SCIE CAS CSCD 2019年第3期969-979,共11页
Using static chamber gas chromatography, we determined the seasonal dynamics, controlling factors, and distribution patterns of forest swamp CH4 levels and related environmental factors (temperature, water level) afte... Using static chamber gas chromatography, we determined the seasonal dynamics, controlling factors, and distribution patterns of forest swamp CH4 levels and related environmental factors (temperature, water level) after fire disturbance in the Xiaoxing’an Mountains. The results showed the following: during the growing season, the annual CH4 emission distribution ranged from - 0.001 ± 0.012 to 22.373 ± 3.650 mg m^-2 h^-1;mild fire caused the swamp CH4 emission flux of tussock, shrub, Alnus sibirica and birch swamp to increase by 56.0–524.7%;at low water levels, temperature had a significant influence on the swamp type, and the correlation between the methane emission flux and temperature was significantly strengthened;after a fire disturbance, methane emissions from all types of marsh were highest in summer and second highest in autumn, with a weak absorption in spring;and along the water environment gradient of the transition zone, the CH4 emission flux presented a decreasing trend in its spatial distribution pattern. 展开更多
关键词 xiaoxing’an MOUNTAINS FOREST SWAMP CH4 emission Fire DISTURBANCE
下载PDF
Classification,metallogenesis and exploration of silver deposits in Daxing’anling of Inner Mongolia and its adjacent areas
11
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 Daxing’anling Inner Mongolia
下载PDF
Daxing'anling Prefecture:unspoiled Land and a Green Source
12
《China Today》 2001年第4期72-77,共6页
关键词 Daxing’anling Prefecture:unspoiled Land and a Green Source
下载PDF
《诗经·豳风·东山》虫名考释
13
作者 嵇保中 《农业考古》 北大核心 2024年第3期172-178,共7页
《诗经·豳风·东山》中的虫名解释存在不同的观点。结合已有的研究成果和昆虫学知识,本文提出了新解释。“蜎蜎者蠋”中的“蠋”应为“人工放养的家蚕”,“伊威在室”中的“伊威”属于鼠妇,如光滑鼠妇、多霜腊鼠妇以及卷甲虫... 《诗经·豳风·东山》中的虫名解释存在不同的观点。结合已有的研究成果和昆虫学知识,本文提出了新解释。“蜎蜎者蠋”中的“蠋”应为“人工放养的家蚕”,“伊威在室”中的“伊威”属于鼠妇,如光滑鼠妇、多霜腊鼠妇以及卷甲虫科的普通卷甲虫,而“熠耀宵行”中的“宵行”属于萤火虫。“鹳鸣于垤”,应为“鹤鸣于垤”,其中的“垤”应为白蚁冢。 展开更多
关键词 《诗经·豳风·东山》 伊威 宵行 鹳鸣于垤
下载PDF
大兴安岭沿麓黑土区翻耕农田微立垡覆盖阻风减蚀技术创新与应用
14
作者 张向前 师晶晶 +6 位作者 戎美仁 路战远 任永峰 程玉臣 张德健 孟天天 郝楠森 《北方农业学报》 2024年第2期107-114,共8页
大兴安岭沿麓是我国重要的农畜产品生产基地,由于长期过度耕作和单一翻耕等不合理的耕作方式,加速了该地区农田风蚀退化、质量下降和产能降低,因此,减少土壤风蚀、提升农田地力和作物产量是农业可持续发展亟待解决的问题。文章综述了不... 大兴安岭沿麓是我国重要的农畜产品生产基地,由于长期过度耕作和单一翻耕等不合理的耕作方式,加速了该地区农田风蚀退化、质量下降和产能降低,因此,减少土壤风蚀、提升农田地力和作物产量是农业可持续发展亟待解决的问题。文章综述了不同类型生态区传统翻耕、长期免耕、合理轮耕技术及其应用效果,论述了翻耕地微立垡覆盖阻风减蚀核心技术的内容及其对土壤风蚀、蓄水保墒、作物生长与产量等方面的影响,明确了微立垡覆盖是大兴安岭沿麓黑土区翻耕地冬春季风蚀防控的关键技术和途径。翻耕地微立垡覆盖阻风减蚀技术大面积应用效果显著,破解了长期以来翻耕农田裸露风蚀重、水土流失损失大导致农田逐步退化的科技难题,为大兴安岭沿麓及其生态类型相似区翻耕农田风蚀防控研究提供了重要支撑。 展开更多
关键词 大兴安岭沿麓 黑土区 翻耕农田 微立垡覆盖 阻风减蚀技术
下载PDF
贵州望谟安乐萤石矿成矿规律及找矿标志分析
15
作者 钱富武 刘添益 《四川地质学报》 2024年第1期58-62,共5页
贵州望谟安乐萤石矿呈脉状、似层状赋存于二叠系上统吴家坪组张性断裂构造和三叠系罗楼组底部“硅化蚀变体”中。本文在总结该区萤石矿床地质特征的基础上,分析了矿床形成时期、空间分布规律、成矿物质来源、界面与构造控矿成矿规律。... 贵州望谟安乐萤石矿呈脉状、似层状赋存于二叠系上统吴家坪组张性断裂构造和三叠系罗楼组底部“硅化蚀变体”中。本文在总结该区萤石矿床地质特征的基础上,分析了矿床形成时期、空间分布规律、成矿物质来源、界面与构造控矿成矿规律。根据成矿规律分析结果,认为该区萤石矿与地层岩性(界面)、构造、围岩蚀变等地质条件相关,为浅成低温热液矿床,同时总结4个找矿标志,旨在为新一轮找矿突破战略行动萤石矿找矿工作提供参考。 展开更多
关键词 成矿规律 找矿标志 萤石矿 望谟安乐
下载PDF
呼中林业局乔木林碳储量及碳密度研究
16
作者 刘会锋 兰岚 +4 位作者 王恩久 邓长贺 李海臣 齐亮亮 王立中 《林业勘查设计》 2024年第4期65-70,共6页
依据呼中林业局2017年森林资源二类调查数据,在分树种、起源、龄组的基础上,采用生物量扩展因子法,对呼中林业局乔木林碳储量、碳密度进行估算和分析。结果显示,呼中林业局乔木林资源总碳储量为29371948.3 t,平均碳密度为39.98 t/hm^(2)... 依据呼中林业局2017年森林资源二类调查数据,在分树种、起源、龄组的基础上,采用生物量扩展因子法,对呼中林业局乔木林碳储量、碳密度进行估算和分析。结果显示,呼中林业局乔木林资源总碳储量为29371948.3 t,平均碳密度为39.98 t/hm^(2);天然林碳储量占乔木林碳储量的99.4%,处于绝对优势;兴安落叶松和白桦碳储量占乔木林总碳储量的96.6%,中龄组碳储量最大,占比接近乔木林碳储量的1/2;樟子松林平均碳密度远高于其他树种。 展开更多
关键词 乔木林碳储量 碳密度 大兴安岭呼中林业局
下载PDF
高频陡降型听损患者助听前后ANL的研究 被引量:3
17
作者 林莹 陈韩超 张国军 《中华耳科学杂志》 CSCD 北大核心 2017年第5期523-526,共4页
目的探讨可接受噪声级(acceptable noise level,ANL)测试是否适用于评估高频陡降型听力损失人群的助听器选配效果。方法选取佩戴助听器半年以上的20位高频陡降型的听障患者,对其进行裸耳和助听后的ANL测试、助听情况下的Speechmap测试,... 目的探讨可接受噪声级(acceptable noise level,ANL)测试是否适用于评估高频陡降型听力损失人群的助听器选配效果。方法选取佩戴助听器半年以上的20位高频陡降型的听障患者,对其进行裸耳和助听后的ANL测试、助听情况下的Speechmap测试,通过软件SPSS19.0分析对比助听前后的ANL值和真耳分析的测试结果,比较其差异性,评估助听器效果,得出结果。结果 (1)20位听障者在裸耳状态时最舒适响度级(most comfortable level,MCL)为80.70±8.05d B HL,助听情况下MCL为65.80±9.03d B HL,具有统计学意义;裸耳状态下背景噪声级(back-ground noise level,BNL)值为73.75±7.16d B HL,助听后BNL值为59.25±6.93d B HL,该结果具有统计学意义(P<0.001),而助听前后ANL值分别为6.95±4.20 d B HL和6.55±4.21 d B HL,该结果无统计学意义(P<0.05),表明患者ANL值与配戴助听器与否无相关性;(2)助听后Speechmap得分验证了裸耳ANL值小于7d B HL时,助听效果很好;但裸耳ANL值大于7d B HL时患者Speechmap得分偏低,助听效果不好。结论通过测试裸耳的可接受噪声级(ANL值)可以较为准确地预测高频陡降型听力损失患者选配助听器的效果,并对此类患者是否选配助听器进行指导。 展开更多
关键词 可接受噪声级 真耳分析 助听效果评估
下载PDF
Effect of thinning intensity on the carbon sequestration of natural mixed coniferous and broadleaf forests in Xiaoxing'an Mountains, China
18
作者 Hangfeng Qu Xibin Dong +5 位作者 Hui Liu Baoshan Zhang Tong Gao Yuan Meng Yunze Ren Ying Zhang 《Journal of Forestry Research》 SCIE EI CAS 2024年第6期198-209,共12页
To study the effect of thinning intensity on the carbon sequestration by natural mixed coniferous and broad-leaf forests in Xiaoxing’an Mountains,China,we established six 100 m×100 m experimental plots in Dongfa... To study the effect of thinning intensity on the carbon sequestration by natural mixed coniferous and broad-leaf forests in Xiaoxing’an Mountains,China,we established six 100 m×100 m experimental plots in Dongfanghong For-est that varied in thinning intensity:plot A(10%),B(15%),C(20%),D(25%),E(30%),F(35%),and the control sample area(0%).A principal component analysis was performed using 50 different variables,including species diversity,soil fertility,litter characteristics,canopy structure param-eters,and seedling regeneration parameters.The effects of thinning intensity on carbon sequestration were strongest in plot E(0.75),followed by D(0.63),F(0.50),C(0.48),B(0.22),A(0.11),and the control(0.06).The composite score of plot E was the highest,indicating that the carbon sequestration effect was strongest at a thinning intensity of 30%.These findings provide useful insights that could aid the management of natural mixed coniferous and broadleaf forests in Xiaoxing’an Mountains,China.This information has implications for future studies of these forests,and the methods used could aid future ecological assessments of the natural forests in Xiaoxing’an Mountains,China. 展开更多
关键词 Thinning intensity xiaoxing’an Mountains China Natural mixed coniferous and broadleaf forest Carbon sequestration
下载PDF
Anle138b对慢性AβOs诱导海马神经元毒性作用影响 被引量:1
19
作者 刘伟 《青岛大学学报(医学版)》 2021年第5期662-665,共4页
目的观察二苯基吡唑化合物Anle138b对β淀粉样蛋白寡聚体(AβOs)诱导的海马神经元毒性作用的影响。方法原代培养的海马神经元细胞成熟后,将其分为空白对照组、AβOs处理组(用0.1μmol/L AβOs处理7 d)和Anle138b处理组(用0.1μmol/L A... 目的观察二苯基吡唑化合物Anle138b对β淀粉样蛋白寡聚体(AβOs)诱导的海马神经元毒性作用的影响。方法原代培养的海马神经元细胞成熟后,将其分为空白对照组、AβOs处理组(用0.1μmol/L AβOs处理7 d)和Anle138b处理组(用0.1μmol/L AβOs处理7 d,在AβOs处理的后2 d加用0.1μmol/L Anle138b)。使用乳酸脱氢酶(LDH)试剂盒检测细胞损伤情况,采用蛋白质免疫印迹(Western blot)法检测凋亡蛋白cleaved caspase-3的表达。结果与空白对照组相比较,AβOs处理组海马神经元细胞LDH释放量增加(F=14.810,q=7.481,P<0.01),凋亡蛋白cleaved caspase-3的表达升高(F=6.677,q=4.816,P<0.05)。与AβOs处理组相比,Anle138b处理组海马神经元细胞LDH释放量降低(q=5.310,P<0.05),凋亡蛋白cleaved caspase-3的表达有下降趋势,但差异无统计学意义(P>0.05)。结论 Anle138b在慢性AβOs诱导的海马神经元凋亡模型中具有一定的保护作用。 展开更多
关键词 阿尔茨海默病 蛋白质聚集体 淀粉样β肽类 anle138b 海马 神经元 毒性作用
下载PDF
基于碳储量分布状态分析黑龙江省典型林型碳汇结构 被引量:1
20
作者 李丹 王文帆 +2 位作者 刘强 李靖彤 张亚楠 《林业科技》 2023年第2期42-44,49,共4页
基于碳储量分布状态分析黑龙江省典型林型,对黑龙江省小兴安岭地区典型树种进行碳汇测定分析。结果表明,不同树种间不同组分(根、干、冠)碳比例存在显著的差异,但同一树种不同组分的碳密度比例不存在显著差异。不同林型不同样地针阔混... 基于碳储量分布状态分析黑龙江省典型林型,对黑龙江省小兴安岭地区典型树种进行碳汇测定分析。结果表明,不同树种间不同组分(根、干、冠)碳比例存在显著的差异,但同一树种不同组分的碳密度比例不存在显著差异。不同林型不同样地针阔混交林垂直空间上不同组分(根、干、冠)的碳密度比例存在一定的差异,垂直空间碳比例平均值差异不明显,树根、树冠、树干的平均垂直碳密度比例平均值分别为:25.05±1.14%、16.35±0.96%、58.59±1.62%。 展开更多
关键词 碳储量 小兴安岭 碳汇树种
下载PDF
上一页 1 2 12 下一页 到第
使用帮助 返回顶部