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Relationships between charcoal property and post fire productivity in the boreal forest
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作者 Lei Gao David Paré +2 位作者 Flavia Lega Braghiroli Mathieu Lamarche Yves Bergeron 《Forest Ecosystems》 2025年第2期201-208,共8页
Fire disturbances are increasing under global climate change and ecological transformations of forests are occurring.Specifically,shifts from productive closed-canopy feather moss forests to low-productivity open-cano... Fire disturbances are increasing under global climate change and ecological transformations of forests are occurring.Specifically,shifts from productive closed-canopy feather moss forests to low-productivity open-canopy lichen(Cladonia spp.)woodlands have been observed in boreal forests of eastern Canada.It has been hypothesized that high severity of fires would be the cause of this change,but this is difficult to validate a posteriori on mature forest stands.Because charcoal properties are affected by fire severity,we have put forward the hypothesis that the amount and physicochemical properties of charcoal(C,N,H,O,ash,surface area)would be different and indicative of a greater fire severity for open-canopy forests compared to closed canopy ones.Our hypothesis was partly validated in that the amount of charcoal found on the ground of closed-canopy forests was greater than that of open-canopy forests.However,the physicochemical properties were not different,albeit a greater variability of charcoal properties for open canopy stands.These results do not allow us to fully validate or reject our hypothesis on the role of fire severity in the shift between open and closed canopy stands.However,they suggest that the variability in fire conditions as well as the amounts of charcoal produced are different between the two ecosystem types.Furthermore,considering the role that biochar may play in improving soil conditions and promoting vegetation restoration,our results suggest that charcoal may play a role in maintaining these two stable alternative ecosystem states. 展开更多
关键词 Charcoal Feather moss LICHEN Fire legacy forest ecosystem Boreal fores
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Diversity of filamentous fungi in organic layers of two forests in Zijin Mountain 被引量:3
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作者 宋福强 田兴军 +4 位作者 李重琦 杨昌林 陈斌 郝杰杰 朱静 《Journal of Forestry Research》 SCIE CAS CSCD 2004年第4期273-279,共7页
A study was conducted to evaluate the cultivable filamentous fungal diversity in organic layers (L, F, and H layers) and A1 layer of two main forest types, Pinus massoniana and Liguidambar formasana mixed forest and Q... A study was conducted to evaluate the cultivable filamentous fungal diversity in organic layers (L, F, and H layers) and A1 layer of two main forest types, Pinus massoniana and Liguidambar formasana mixed forest and Quercus variabilis forest, in Zijin Mountain(325?N, 11848?E), Nanjing, China. A total of 67 taxa comprising 56 Deuteromycetes, 3 Zygomycetes, 5 Asco-mycetes and 3 unidentified fungi were recognized from samples from the forest floor of the two forest types. The most abundant group was Deuteromycetes. The dominant genera in both forests were Alternaria sp., Aspergillus sp., Cladosporium sp., Mucor sp., Penicillium sp., Rhizopus sp., Gliocladium sp. and Trichoderma spp. The fungal diversity was higher in the mixed forest than that in Q. variabilis forest. For both forest types, the maximum fungal diversity was found in layer F and there existed significantly different in fungal diversity between layer F and layer L. In the mixed forest, richness of fungi isolated from needle litter (P. massoniana) was lower than that from leaf litter (L. formasana). The richness of fungi from needle litter increased with the in-crease of forest floor depth, but for leaf litter, the fungal diversity decreased with the depth of forest floor. The co-species of fungi from the two forest types, as well as from two kinds of litters in mixed forest, increased with the depth of the forest floor. The succession of fungi along with the process of decomposition was discussed here. The results also showed that litter quality was a critical factor affecting fungal diversity. 展开更多
关键词 Zijin Mountain forest type Filamentous fungi DIVERSITY LITTER Quercus variabilis forest Pinus massoniana and Liguidambar formasana mixed fores
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A Study on Strategy and Method of Acquisition of the Second Foreign Language 被引量:1
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作者 刘桂莲 牟薇薇 《海外英语》 2010年第10X期249-251,共3页
With the successful hosting of the Beijing Olympic Games in 2008 and the World Exposition Shanghai China 2010,English,next to our mother tongue,has become the most important language in China.Therefore,learning Englis... With the successful hosting of the Beijing Olympic Games in 2008 and the World Exposition Shanghai China 2010,English,next to our mother tongue,has become the most important language in China.Therefore,learning English well is very important for most Chinese people.However,learning a foreign language well is not easy.We have to master several learning strategies and methods to learn it successfully.This paper will help all the foreign language learners to find the effective way in learning the second foreign languge.The paper mainly talks about two aspects:improving the abilities in listening,speaking and reading in order to communicate well;developing the ability of writing in English and perfecting the function of social communication.It gives out the concrete methods in listening,speaking,reading,writing,and translating.The authors hope that the paper would be helpful in assisting the foreign language learners to learn and master the second foreign language. 展开更多
关键词 STRATEGY metheod ACQUISITION the SECOND foreing LANGUAGE
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Serpentinized Peridotites at the North Part of the Wadi Allaqi District(Egypt): Implications for the Tectono-Magmatic Evolution of Fore-arc Crust 被引量:7
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作者 Ahmed E.S.KHALIL Mohamed A.OBEID Mokhles K.AZER 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2014年第5期1421-1436,共16页
The Neoproterozoic Allaqi-Heiani suture (800-700 Ma) in the south Eastern Desert of Egypt is the northernmost linear ophiolitic belt that defines an arc-arc suture in the Arabian- Nubian shield (ANS). The Neoprote... The Neoproterozoic Allaqi-Heiani suture (800-700 Ma) in the south Eastern Desert of Egypt is the northernmost linear ophiolitic belt that defines an arc-arc suture in the Arabian- Nubian shield (ANS). The Neoproterozoic serpentinized peridotites represent a distinct lithology of dismembered ophiolites along the Allaqi-Heiani suture zone. The alteration of peridotites varies, some contain relicts of primary minerals (Cr-spinel and olivine) and others are extremely altered, especially along thrusts and shear zones, with development of talc, talc-carbonate and quartz-carbonate. The fresh cores of the chromian spinels are rimmed by ferritchromite and Cr- magnetite. The fresh chromian spinels have high Cr# (0.62 to 0.79), while Mg# shows wider variation (0.35-0.59). High Cr# in the relict chromian spinels and Fo content in the primary olivines indicate that they are residual peridotites after extensive partial melting. The studied ophiolitic upper mantle peridotites are highly depleted and most probably underwent high degrees of partial melting at a supra-subduction zone setting. They can be produced by up to -20%-22% dynamic melting of a primitive mantle source. The mineralogical and geochemical features of the studied rocks reflect that the mantle peridotites of the north part of the Wadi Allaqi district are similar to the fore-arc peridotites of a supra-subduction zone. 展开更多
关键词 NEOPROTEROZOIC SERPENTINITE Arabian-Nubian Shield EGYPT Chromian spinel olivine fore-ARC
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Screening and Identification Differentially Displayed Genes in Fore Stomach Carcinoma of Mice 被引量:1
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作者 Hong-xu Zhang Dan-dan Liu Lin Li Ru-bing Duan Li Wang Jing Cao Li-juan Zhi 《Chinese Journal of Cancer Research》 SCIE CAS CSCD 2009年第1期37-43,共7页
Objective: To screen and identify key genes differentially displayed in mouse fore stomach carcinoma, in order to elucidate the molecular mechanism underlying carcinogenesis. Methods: The animal models complied wit... Objective: To screen and identify key genes differentially displayed in mouse fore stomach carcinoma, in order to elucidate the molecular mechanism underlying carcinogenesis. Methods: The animal models complied with each period of NIH mouse fore stomach carcinoma induced by N-Nitrososarcosineethylester (NSEE) were used in this study. The mice were euthanized on days 14, 28, 56, 77 and 84, respectively, after NSEE-piped treatment, and classified according to their pathologies. The differentially expressed genes were isolated from both normal and morbid tissues by mRNA differential display technique and screened by using Reverse Northern blot. Bioinformatics were employed to analyze the results observed. After identification, ten fragments were cloned and matched with GENEBANK database through homologous analysis. Results: One gene was found identical to splicing factor 3b subunit 1 (Sf3bl), while seven fragments hold the homology of known cDNA clones. In contrast, other two fragments had extremely low identity to any genes registered in GENBANK databases. Conclusion: It is the first time to demonstrate in this study that splicing factor3b, subunitl (Sf3bl) is related to mouse fore stomach carcinoma. Furthermore, ESC-3 and ESC-4 are suggested to contribute to the development of mouse fore stomach carcinoma, thus may be candidates of new targets of oncogenes. 展开更多
关键词 NIH mouse fore stomach carcinoma DDRT-PCR Sf3b1
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Evaluation of the Land Production Potential in the Context of Returning Farmland to Forest in Karst Region:A Case Study of Guizhou Province 被引量:2
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作者 Shuang YU Guang LI Ruiping RAN 《Asian Agricultural Research》 2013年第1期21-26,共6页
In this paper, we take Guizhou Province (the heart of southwestern Karst region in China) as the research object. By establishing gray forecasting model and time series forecasting model, we conduct the accuracy test ... In this paper, we take Guizhou Province (the heart of southwestern Karst region in China) as the research object. By establishing gray forecasting model and time series forecasting model, we conduct the accuracy test on the actual production capacity of land and the forecasted production capacity of land in 2007 and 2008, and then conduct comprehensive forecast of the land production potential in Guizhou Province in 2020. On this basis, considering the nutritional standards needed by three kinds of life type (dressing warmly and eating one's fill, well-off life, relatively affluent life), we evaluate the land production potential in Guizhou Province under the project of returning farmland to forest. Based on the evaluation results, we put forth the relevant recommendations for achieving sustainable land use in the context of returning farmland to forest in Guizhou Province. 展开更多
关键词 KARST region Project of RETURNING FARMLAND to fore
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Tectono-magmatic evolution of Tethyan oceanic lithosphere in supra subduction zone fore arc regime:Geochemical fingerprints from crust-mantle sections of Naga Hills Ophiolite 被引量:1
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作者 Anisha Verencar Abhishek Saha +1 位作者 Sohini Ganguly Manikyamba C. 《Geoscience Frontiers》 SCIE CAS CSCD 2021年第3期19-41,共23页
The Naga Hills Ophiolite(NHO)belt in the Indo-Myanmar range(IMR)represents a segment of Tethyan oceanic crust and upper mantle that was involved in an eastward convergence and collision of the Indian Plate with the Bu... The Naga Hills Ophiolite(NHO)belt in the Indo-Myanmar range(IMR)represents a segment of Tethyan oceanic crust and upper mantle that was involved in an eastward convergence and collision of the Indian Plate with the Burmese Plate during the Late Cretaceous-Eocene.Here,we present a detailed petrological and geochemical account for the mantle and crustal sections of NHO,northeastern India to address(i)the mantle processes and tectonic regimes involved in their genesis and(ii)their coherence in terms of the thermo-tectonic evolution of Tethyan oceanic crust and upper mantle.The NHO suite comprises well preserved crustal and mantle sections discretely exposed at Moki,Ziphu,Molen,Washelo and Lacham areas.The ultramafic-mafic lithologies of NHO are mineralogically composed of variable proportions of olivine,orthopyroxene,clinopyroxene and plagioclase.The primary igneous textures for the mantle peridotites have been overprinted by extensive serpentinisation whereas the crustal section rocks reflect crystal cumulation in a magma chamber.Chondrite normalised REE profiles for the cumulate peridotite-olivine gabbro-gabbro assemblage constituting the crustal section of NHO show flat to depleted LREE patterns consistent with their generation from depleted MORB-type precursor melt in an extensional tectonic setting,while the mantle peridotites depict U-shaped REE patterns marked by relative enrichment of LREE and HREE over MREE.These features collectively imply a dual role of depleted MORB-type and enriched arc-type mantle components for their genesis with imprints of melt-rock and fluid-rock interactions.Tectonically,studied lithologies from NHO correspond to a boninitic to slab-proximal Island Arc Tholeiite affinity thereby conforming to an intraoceanic supra subduction zone(SSZ)fore-arc regime coherent with the subduction initiation process.The geochemical attributes for the crustal and mantle sections of NHO as mirrored by Zr/Hf,Zr/Sm,Nb/Ta,Zr/Nb,Nb/U,Ba/Nb,Ba/Th,Ba/La and Nd/Hf ratios propound a two-stage petrogenetic process:(i)a depleted fore arc basalt(FAB)type tholeiitic melt parental to the crustal lithologies was extracted from the upwelling asthenospheric mantle at SSZ fore-arc extensional regime thereby rendering a refractory residual upper mantle;(ii)the crust and upper mantle of the SSZ fore arc were progressively refertilised by boninitic melts generated in response to subduction initiation and slab-dehydration.The vestiges of Tethyan oceanic lithosphere preserved in NHO represent an accreted intra-oceanic fore arc crust and upper mantle section which records a transitional geodynamic evolution in a SSZ regime marked by subduction initiation,fore arc extension and arc-continent accretion. 展开更多
关键词 Tethyan Ocean Naga Hills Ophiolite Suprasubduction Zone Subduction initiation fore arc extension Mantle refertilisation
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Curriculum Discourse and Foreign Language Teachers'Professional Development 被引量:1
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作者 张冬梅 《海外英语》 2012年第13期282-283,共2页
The significance and status of the teachers'professional development make the education system and the society pay more and more attentions.The article elaborates the internal contact of curriculum discourse and t... The significance and status of the teachers'professional development make the education system and the society pay more and more attentions.The article elaborates the internal contact of curriculum discourse and teachers'professional development from a few respects such as the rationality of curriculum discourse,the long-term nature of the teachers'professional development and many factors affecting the teachers'professional development.The article also analyzes the external and internal factors influencing Tibet foreign language teachers'professional development,and puts forward the corresponding countermeasures in the light of these problems. 展开更多
关键词 CURRICULUM DISCOURSE PROFESSIONAL DEVELOPMENT fore
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EXPRESSION OF PCNA,AKP AND ACP DURING DEVELOPMENT OF MOUSE FORE STOMACH CARCINOMA
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作者 张红绪 孔祥会 +4 位作者 李春梅 刘丹丹 邢文会 胡萍 徐存拴 《Chinese Journal of Cancer Research》 SCIE CAS CSCD 2006年第3期209-213,共5页
Objective: To find out the relationship of the expressions of proliferating cell nuclear antigen (proliferating cell nuclear antigen, PCNA), alkaline phosphotase (alkaline phosphotase, AKP) and acid phosphotase ... Objective: To find out the relationship of the expressions of proliferating cell nuclear antigen (proliferating cell nuclear antigen, PCNA), alkaline phosphotase (alkaline phosphotase, AKP) and acid phosphotase (acid phosphotase, ACP) with the development of mouse fore stomach cancerization. Methods: The animal models, including the various stages during the development of NIH mouse fore stomach carcinoma, were made by N-Nitrososarcosineethylester (N-Nitrososarcosineethylester, NSEE). The mice were sacrificed on the 14th, 28th, 42nd, 56th, 70th and 84th days respectively after mice were irrigated with NSEE. The fore stomach was taken out and dissected. The methods of histopathology, immunohistochemistry and isoenzyme electrophoresis were adopted to study the dynamic changes of cell shape and expression of PCNA, AKP and ACP. Results: On the 42nd and 56th days after NSEE treatment, the expression of PCNA increased gradually along with the cancerization. Comparing with the control, there were significant differences (P〈0.05). On the 70th and 84th days, the expression of PCNA increased further (compared with the control P〈0.01). The activity of AKP increased gradually along with the cancerization. On the 14th, 28th, 42nd and 56th days, there were significant differences (P〈0.05); on the 70th and 84th days, the activity of AKP increased further (P〈0.01). The activity of ACP also increased on the 14th, 28th, 42nd and 56th days, and there were significant differences on the 70th days (P〈0.05) and on the 84th days (P〈0.01) compared with the control. Conclusion: During the carcinogenesis of NIH mouse fore stomach, the expressions of PCNA, AKP and ACP increased gradually and were consisted with the changes of cell shapes. 展开更多
关键词 fore stomach carcinoma NIH mouse Proliferating cell nuclear antigen Alkaline phosphotase Acid phosphotase
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FORES系统存在的问题及解决办法
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作者 宋世德 《陕西林业科技》 北大核心 1990年第2期45-46,共2页
林业部科技情报中心和南京中医药大学森计中心联合开发的《全国林业中文科技文献检索系统(FORES)》,不失为一个系统功能强、标准化程度高、值得推广的系统。但它同其他任何系统一样,会不可避免地出现一些错误。今就其中存在的一点问题进行剖... 林业部科技情报中心和南京中医药大学森计中心联合开发的《全国林业中文科技文献检索系统(FORES)》,不失为一个系统功能强、标准化程度高、值得推广的系统。但它同其他任何系统一样,会不可避免地出现一些错误。今就其中存在的一点问题进行剖析,并提出相应的解决办法。1 问题的发现在进行资料输入时。 展开更多
关键词 数据库 检索 林业 文献 foreS系统
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前置旋流器的超音速分离管内流动特性
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作者 袁淑霞 裴龙瑶 +1 位作者 冯森森 吴松 《西安石油大学学报(自然科学版)》 北大核心 2025年第5期95-103,共9页
超音速分离管结构简单,但其流动以及气液相变过程较为复杂,为掌握其成核和相变机理,对超音速分离管内流动特性进行研究。以甲烷-水蒸气双组分为介质,采用数值模拟与理论分析相结合的方式,对超音速分离管内流动特性及凝结过程进行研究,... 超音速分离管结构简单,但其流动以及气液相变过程较为复杂,为掌握其成核和相变机理,对超音速分离管内流动特性进行研究。以甲烷-水蒸气双组分为介质,采用数值模拟与理论分析相结合的方式,对超音速分离管内流动特性及凝结过程进行研究,得到流场压力、温度、速度以及过冷度变化规律,并研究了流场最值位置。结果表明:受几何结构的影响,混合气体流经超音速分离管会在扩张段产生低温低压区域,此时速度为超音速状态。入口压力、入口温度与出口背压是超音速分离管流动特性研究的关键参数。提高入口压力,降低出口背压,超音速分离管内压降和温降逐渐增大,其过冷度也随之增大;降低入口温度使流场内温度最小值减小,形成的低温低压区域增大,有利于可凝组分自发凝结。超音速分离管流动特性分析结果可为后续管内可凝组分凝结研究提供依据。 展开更多
关键词 超音速分离管 前置旋流器 天然气脱水 流动特性
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FORE模型:乡村小学校本教研的危机与重构 被引量:1
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作者 朱海龙 《中小学班主任》 2022年第18期26-29,共4页
校本教研是一线教师立足于解决工作中的实际问题,改进教育教学行为的重要途径。但在目前的实施中还不尽如人意,存在改进的必要性。通过对校本教研现状危机的调查和分析,提出基于FORE模型的校本教研形式,以教师的问题为指向,以灵活的扁... 校本教研是一线教师立足于解决工作中的实际问题,改进教育教学行为的重要途径。但在目前的实施中还不尽如人意,存在改进的必要性。通过对校本教研现状危机的调查和分析,提出基于FORE模型的校本教研形式,以教师的问题为指向,以灵活的扁平结构组织实施,激活教师的研修动力,在实践中实现校本教研的真实价值。 展开更多
关键词 fore模型 校本教研 行动路径
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An enlightening view of the antigravity between antimatter
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作者 MA Ru-yun 《西北师范大学学报(自然科学版)》 2025年第1期10-11,I0002,共3页
We put forward an enlightening view on repulsive force between antimatter:Antimatter repels each other,and the repulsive force is proportional to the product of their masses and inversely proportional to the square of... We put forward an enlightening view on repulsive force between antimatter:Antimatter repels each other,and the repulsive force is proportional to the product of their masses and inversely proportional to the square of the distance between them;There is no gravitational or anti-gravitational interaction between antimatter and positive matter.As their applications,we explain the Big Bang process in a new light. 展开更多
关键词 UNIVERSE Big Bang ANTIMATTER gravitational force repulsive fore
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藏南日喀则弧前盆地中新世流纹岩成因研究:对后碰撞地壳生长及再造的启示
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作者 张宇 孟元库 +3 位作者 裴军令 熊发挥 王庆玲 周京浩 《岩石学报》 北大核心 2025年第11期3707-3734,共28页
日喀则弧前盆地是藏南地区最为重要的构造-沉积单元,记录了冈底斯弧和新特提斯洋演化的关键信息。本文在日喀则弧前盆地中厘定了一套中新世流纹岩脉,为探讨藏南地区后碰撞期地壳演化与再造以及大地构造背景提供了难得的地质素材。本文... 日喀则弧前盆地是藏南地区最为重要的构造-沉积单元,记录了冈底斯弧和新特提斯洋演化的关键信息。本文在日喀则弧前盆地中厘定了一套中新世流纹岩脉,为探讨藏南地区后碰撞期地壳演化与再造以及大地构造背景提供了难得的地质素材。本文围绕该岩脉开展了系统的锆石U-Pb年代学、全岩地球化学及Hf-Nd-O多同位素体系综合研究,以阐明其成因机制与深部动力学背景。锆石U-Pb定年结果显示,该套流纹岩脉形成于中新世中期(~13.15Ma),岩石学属性为典型的高分异I型流纹岩。地球化学组成上,其具有高硅、富碱,稀土元素总量(2.19×10^(-6)~5.57×10^(-6))极低,并表现出显著的铕正异常(Eu/Eu^(*)平均值为3.11)等特征。在同位素方面,Hf-Nd同位素与全岩O同位素呈明显解耦,即锆石ε_(Hf)(t)均为正值(+3.16~+6.23),磷灰石ε_(Nd)(t)介于-1.42~+1.56(平均值为+0.06),共同指示其主要物源来自于亏损的新生下地壳。全岩异常偏高的δ^(18)O值并非壳源沉积物混染所致,而是岩浆侵位后与围岩发生低温水-岩作用的结果。综合分析认为,该套流纹岩并非源区部分熔融的直接产物,而是长期演化的地壳晶粥式岩浆储库中被抽离出的高硅质残余熔体。研究区中新世中期(塞拉瓦莱期)的岩浆活动,反映了藏南后碰撞伸展构造在弧前盆地的直接响应,其深部动力学机制与岩石圈拆沉/减薄引发的软流圈上涌和热底侵紧密相关。本研究为大陆碰撞带壳幔相互作用和大陆地壳再造过程提供了关键实例,并表明后碰撞伸展体制的影响范围可能远超传统认识。 展开更多
关键词 日喀则弧前盆地 流纹岩 中新世 岩石成因 后碰撞伸展
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维持性血液透析患者认知功能障碍预测模型构建的研究进展
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作者 王冰莹 王楠 《临床肾脏病杂志》 2025年第9期798-802,共5页
认知功能障碍是影响维持性血液透析患者生活质量和病死率的重要影响因素。建立预测模型可以帮助医务人员提前发现认知功能障碍和识别风险,为患者早期干预提供时间窗。相关预测模型的构建主要依靠传统统计学,而近年来,随着人工智能技术... 认知功能障碍是影响维持性血液透析患者生活质量和病死率的重要影响因素。建立预测模型可以帮助医务人员提前发现认知功能障碍和识别风险,为患者早期干预提供时间窗。相关预测模型的构建主要依靠传统统计学,而近年来,随着人工智能技术的迅速发展,极大地推进了其在相关领域的应用。本文总结比较了传统统计学与机器学习的特点以及其在研究血液透析患者认知功能障碍方面的临床应用,为建立预测维持性血液透析患者认知功能障碍模型提供参考和借鉴。 展开更多
关键词 人工智能 机器学习 认知障碍 血液透析 预测模型
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粤西北杉木与桉树萌芽林混交培育技术
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作者 蔡维就 陈伟军 +5 位作者 梁榕侣 何应创 梁树江 钱猛初 杨晓慧 伍观娣 《林业科技情报》 2025年第1期1-3,共3页
当前,广东省正在加速推进绿美广东生态建设,实施森林质量精准提升行动,着眼于开展林分优化提升、营造多树种针阔混交林等工作。该文通过在粤西北地区探索利用桉树萌芽林,补植套种杉木良种,营造杉木与桉萌混交林,并总结其混交林培育技术... 当前,广东省正在加速推进绿美广东生态建设,实施森林质量精准提升行动,着眼于开展林分优化提升、营造多树种针阔混交林等工作。该文通过在粤西北地区探索利用桉树萌芽林,补植套种杉木良种,营造杉木与桉萌混交林,并总结其混交林培育技术,以期为杉木优化林分结构、提高林分质量提供应用参考。 展开更多
关键词 杉木 桉树萌芽林 混交林 培育技术
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内蒙古西乌旗扎很花蛇绿岩的识别与古亚洲洋东段初始俯冲
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作者 李英杰 董培培 +3 位作者 李红阳 郭菁华 张夏炜 王帅 《岩石学报》 北大核心 2025年第11期3802-3817,共16页
在兴蒙造山带北部的贺根山蛇绿岩东侧新识别出扎很花前弧蛇绿岩。野外填图结果显示,扎很花蛇绿岩呈NE向展布,出露宽约3km,长约10km,蛇绿岩各单元出露较齐全,岩性主要为蛇纹石化方辉橄榄岩、层状辉长岩、暗色均质辉长岩、浅色均质辉长岩... 在兴蒙造山带北部的贺根山蛇绿岩东侧新识别出扎很花前弧蛇绿岩。野外填图结果显示,扎很花蛇绿岩呈NE向展布,出露宽约3km,长约10km,蛇绿岩各单元出露较齐全,岩性主要为蛇纹石化方辉橄榄岩、层状辉长岩、暗色均质辉长岩、浅色均质辉长岩、块状前弧玄武岩、枕状前弧玄武岩(fore-arc basalt,FAB)和泥质硅质岩,其岩性组合和岩石序列可与代表洋内初始俯冲的迪彦庙前弧蛇绿岩相对比。扎很花蛇绿岩岩石序列中玄武岩锆石U-Pb年龄约326Ma,与东部迪彦庙蛇绿岩的辉长岩同期。扎很花前弧玄武岩主要发育无斑结构,基质呈球颗结构、间粒结构,枕状构造。岩石SiO_(2)含量为45.67%~58.70%,较低的TiO_(2)(0.82%~0.98%),富Na_(2)O(0.01%~5.09%)而贫K_(2)O(0.04%~1.31%),Na_(2)O/K_(2)O为0.01~93.25;岩石具有亏损型稀土元素配分模式,类似N-MORB,但高场强元素(HFSE)Nb、Ta和Ti等比N-MORB稍低,相容元素Cr、Ni和大离子亲石元素(LILE)K、Rb、Ba、U比N-MORB稍高,与弧拉斑玄武岩相似。地球化学特征指示扎很花玄武岩兼有洋中脊(MORB)与岛弧双重特性,而更像MORB,与马里亚纳前弧玄武岩(FAB)和迪彦庙前弧玄武岩相一致。扎很花前弧蛇绿岩和贺根山玄武岩的微量元素和Nd同位素揭示,它们都起源于亏损的MORB型地幔,源区未受俯冲组分影响。但是随着俯冲作用的进行,扎很花玄武岩的源区由于熔体的抽提作用源区逐渐更加亏损,同时也逐渐有来自俯冲板片的熔体或流体的加入,并由此也导致了源区的氧逸度的不断升高,揭示扎很花蛇绿岩具有前弧环境岩浆源区演化的特征,类似于IBM前弧和迪彦庙前弧蛇绿岩的演化。这一发现为明确贺根山蛇绿岩带早石炭世存在前弧玄武岩提供了岩石学和地球化学佐证,表明贺根山洋早石炭世发生了洋内初始俯冲岩浆作用,记录了早石炭世古亚洲洋东段洋内初始俯冲事件。 展开更多
关键词 前弧玄武岩 初始俯冲 早石炭世 贺根山蛇绿岩 古亚洲洋 内蒙古
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Fore-aft asymmetry of the ~2H(n,γ)~3H at very low energies
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作者 H.Khalili H.Sadeghi 《Chinese Physics C》 SCIE CAS CSCD 2013年第9期13-18,共6页
We have used the recent effective field theory (EFT) which is constructed from two- and three-nucleon interactions, using minimal substitution in the momentum dependence of these interactions. We present the calcula... We have used the recent effective field theory (EFT) which is constructed from two- and three-nucleon interactions, using minimal substitution in the momentum dependence of these interactions. We present the calcula- tions of the fore-aft asymmetry of γ-rays in the reaction 2H(n,γ)3H which are based on EFT up to next-to-next-to leading order (N2LO). The results are compared with the recently reported calculations and measurements of the fore-aft asymmetry of T-rays from neutron-deuteron radiative capture. The calculated fore-aft asymmetry of the nd radiative capture process above deuteron breakup threshold is in good agreement with the available experimental data up to 20 MeV. 展开更多
关键词 effective field theory neutron-deuteron radiative capture photonuclear observables fore-aft asymmetry
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全自动化学需氧量水质分析仪性能实验测试
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作者 张迪 赵倩 +1 位作者 潘双叶 薛令楠 《上海计量测试》 2025年第4期54-57,61,共5页
根据HJ 168—2020,对四台不同型号的全自动化学需氧量水质分析仪测定水样的方式进行实验数据测试,并与常规方法即重铬酸盐方法进行了比对。在标准样品和实际水样的监测分析中,仪器法具有较好的准确度、精密度和灵敏度。全自动化学需氧... 根据HJ 168—2020,对四台不同型号的全自动化学需氧量水质分析仪测定水样的方式进行实验数据测试,并与常规方法即重铬酸盐方法进行了比对。在标准样品和实际水样的监测分析中,仪器法具有较好的准确度、精密度和灵敏度。全自动化学需氧量水质分析仪通过控制消解和滴定分析过程中的各环节,完善了质量控制措施,在环境监测领域具备广阔的应用前景。 展开更多
关键词 化学需氧量 全自动 水环境监测 前景
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基于注意力机制的TCN_GRU的光伏功率预测应用
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作者 夏鹏 黄磊 +1 位作者 徐浩 王雷 《无线互联科技》 2025年第11期79-84,共6页
目前全世界都在大力开发和利用太阳能,但是,太阳能的实际使用量还远远没有达到人们所能承受的水平。随着科技领域的发展、社会的进步以及人们对于环境保护意识的不断增长,人们对新能源的需求逐日增加。如何更好地获取新能源,已经成了亟... 目前全世界都在大力开发和利用太阳能,但是,太阳能的实际使用量还远远没有达到人们所能承受的水平。随着科技领域的发展、社会的进步以及人们对于环境保护意识的不断增长,人们对新能源的需求逐日增加。如何更好地获取新能源,已经成了亟待解决的问题。文章主要对光伏功率预测进行研究,深入开展光伏功率数据特征分析与预处理工作,充分利用深度学习在特征学习方面的优势,挖掘时间序列数据的时间相关性联系并构建多种不同类型的预测模型。文章设计了3种光伏发电功率预测模型,分别是基于注意力机制的TCN_GRU预测模型、LSTM_CNN模型以及TSMixer预测模型,对比验证了所建立的模型在同一时间内进行预测时,在时间序列误差评价指标和预测可视化方面的优良表现。实验结果表明,基于注意力机制的TCN_GRU预测模型对预测光伏发电量的效果更好。 展开更多
关键词 光伏发电 深度学习 神经网络 短期预测
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