Regions located on the Chinese Loess Plateau are sensitive to changes in the Asian monsoon because they are on the edge of the monsoon region. Based on six 230Th experiments and 109 sets of stable isotope data of LH36 from Lianhua Cave, Yangquan City, Shanxi Province, we obtained a paleoclimate record with an average resolution of 120 years from 54.5 to 41.1 ka BP during the MIS3 on the Chinese Loess Plateau. Both the Hendy test and the replication test indicated an equilibrium fractionation of stable isotopes during the stalagmite deposition. Comparison with four other independently-dated, high-resolution stalagmite δ13C records between 29°N and 41°N in the Asian monsoon region shows that the stalagmite δ13C records from different caves have good reproducibility during the overlapped growth period. We suggest that speleothem δ13C effectively indicates soil CO2 production in the overlying area of the cave, reflecting changes in the cave’s external environment and in the Asian summer monsoon. Five millennial-scale Asian summer monsoon intensification events correspond to the Dansgaard–Oeschger 10–14 cycles recorded in the Greenland ice core within dating errors, and the weak monsoon processes are closely related to stadials in the North Atlantic. The spatial consistency of stalagmite δ13C records in China suggests that the Asian summer monsoon and the related regional ecological environment fluctuations sensitively respond to climate changes at northern high latitudes through sea-air coupling on the millennial timescale.
Micro-continent collision and amalgamation play pivotal roles in continental convergence and contribute significantly to continental crustal growth. However, the understanding of multiple micro-continent amalgamation processes, particularly their influence on the formation of large Li-Be deposits, remains limited. The Altun orogenic system, resulting from the collision and amalgamation of three micro-continents in the Proto-Tethys Ocean, has recently revealed numerous granitic pegmatite-type Li-Be deposits, presenting an ideal opportunity to investigate the mineralization. Our research focused on two granitic pegmatite Li deposits, South Washixia and Tamuqie in the Central Altun Tagh, Northwest China. Our findings suggest: 1) The structural and photomicrograph characteristics observed in both the Tamuqie and South Washixia granitic pegmatite Li deposits, indicate that the pegmatites emplaced in shear zone within a contractional deformation zone. 2) The age of the large granitic pegmatite Li deposit in South Washixia between 447 ∼ 445 Ma, while the Tamuqie Li pegmatites formed at 448 Ma with Li-barren pegmatites formed at around 418 Ma. It is suggested that the large granitic pegmatite Li deposit in the Central Altun Block, encompassing South Washixia and Tamuqie granitic pegmatite Li deposits, originated during the final collision event of three micro-continent blocks (Qaidam, Altun-Qilian, and Dunhuang-Alex). We suggest that during the final collision and amalgamation event of multiple micro-continents triggering intense compression and thickening of the crust, and the thickened lower crust may undergo shear-driven dehydration melting of biotite in granulite facies to produce large-volume granitic magmas. These magmas crystallize and differentiate into lithium-rich pegmatite magmas along shear zones, forming large lithium pegmatite deposits. Our research introduces a novel mechanism for the formation of Li pegmatite deposits, emphasizing the role of shear-driven dehydration melting during the final collision and amalgamation events of three micro-continents.
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Clinical pharmacists play a subjective role in clinical pharmacy. In order to explore an effective training model for clinical pharmacists, this paper provides a reference for clinical pharmacy work. Starting from the standardized training and teaching mode of clinical pharmacists, the paper discusses the training mode, objectives, standards, methods and implementation strategies. Combined with teaching practice, the paper summarizes the relevant advantages of the standardized training and teaching mode of clinical pharmacists, and finally draws the experience and experience of the standardized training and teaching mode of clinical pharmacists, aiming to provide support for the research on the standardized training and teaching mode of clinical pharmacists.
It has been shown that the established nature reserves will affect the surrounding ecological environment, that is, the space neighborhood effect on nature reserves.At present, the ecological environment of the surrounding areas of some nature reserves has changed greatly, especially in the temporal and spatial changes of artificial objects.To study the space neighborhood effect on nature reserves based on temporal and spatial changes of artificial objects will do significant help to maintain the survival and safety of nature reserve and its protected objects.To analyze the variation intervals of the space neighborhood effect and the distance scale, and to identify the driving factors, we chose Ningxia Shapotou National Nature Reserve as a case study.We divided the study area within a range of 20 km around the nature reserve, extracted the artificial objects from the remote image analysis between 1990 and 2015, and used Mann-Kendall trend analysis and driving factor correlation test analysis, to assess the space neighborhood effect of nature reserves based on temporal and spatial changes in artificial objects.Results showed that the areas and patterns of artificial objects were expanding, which meant the impacts of human activities were increasing over time.In addition,
Sharding is a promising technique for increasing a blockchain system’s throughput by enabling parallel transaction processing. The main challenge of state sharding lies in ensuring the atomicity verification of cross-sharding transactions, which results in double communication overhead and increases the transaction’s confirmation time. Previous research has primarily focused on developing cross-shard protocols for the fast and reliable validation of transactions involving multiple shards. These studies typically generate a large number of cross-shard transactions because they primarily use simple address mapping for state sharding, that is, the prefix/suffix of the account address. In this paper, we propose a state sharding scheme via density-based partitioning of the account-transaction graph. In order to reduce cross-shard transactions, the scheme groups correlated accounts into the same shard by generating the densest subgraphs, as the graph density describes the correlation among accounts, i.e., how often transactions have occurred among accounts. We formulate the graph density-based state sharding problem, with the goal of maximizing the average density across all shards under the workload constraint. We prove the NP-completeness of the problem. To reduce the complexity of finding the densest subgraph, we propose the pruning-based algorithm that reduces the search space by pre-pruning some invalid edges based on the concept of core number. We also extend the linear deterministic greedy algorithm and PageRank algorithm to handle new transactions in the dynamic scenario. We conduct extensive experiments using real transaction data from Ethereum. The experimental results demonstrate a strong correlation between the shard density and the number of cross-shard transactions, and the pruning-based algorithm can reduce the running time by an order of magnitude.
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.