15 results on '"Zhenhua Sun"'
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2. Correlation between carbon emissions, fuel consumption of vehicles and speed limit on expressway
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Chao Gao, Jinliang Xu, Miao Jia, and Zhenhua Sun
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Vehicle carbon emission ,Vehicle fuel consumption ,Posted speed limit ,Average speed ,Road longitudinal slope ,Transportation engineering ,TA1001-1280 - Abstract
This paper aimed to investigate the correlation between carbon emissions, fuel consumption, and speed limit. A theoretical model was derived based on the energy conservation law, which expresses the relationship between vehicle's fuel consumption and speed. Subsequently, a total of 40 sets of fuel consumption data were collected through field tests to verify the accuracy of the theoretical model at different speeds and different road longitudinal slope combinations. The fuel consumption was then converted to carbon emissions according to the carbon emission factors specified by Intergovernmental Panel on Climate Change (IPCC). In the field experiment, two types of cars and trucks, which are most common on the expressways in China, were selected. Finally, the travel speed under different posted speed limits was obtained through the previously established model, and the carbon emission changes of different vehicle types at different limited speeds are calculated. The results show that the speed limit has a significant impact on fuel consumption and carbon emissions. When the speed limit increased from 80 to 120 km/h, average vehicle speeds increased about 21%–27%, and fuel consumption and carbon emissions increased from approximately 33%–38%. Another interesting result was that the vehicle's fuel consumption and carbon emissions are only affected by speed. The results of the study explore the effect of speed limits on carbon emissions and provide evidence for road managers to set reasonable speed limits.
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- 2024
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3. Fiber Optic Vacuum Ultraviolet Sensor Based on an AlN-Microwire Probe
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Ying Wang, Jiahui Ye, Dingbang Ma, Peiyao Wang, Baikui Li, Zhenhua Sun, Honglei Wu, Changrui Liao, and Yiping Wang
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Optical fiber sensor ,VUV ,Fabry-Pérot interferometer ,UV sensing ,Applied optics. Photonics ,TA1501-1820 - Abstract
Abstract Vacuum ultraviolet (VUV) light sensing shows great potential applications in the space science, materials, biophysics, and plasma physics. In this work, an all-optical detection method is proposed for VUV sensing by constructing an optical fiber-end Fabry-Pérot interferometer based on a single aluminum nitride (AlN) microwire. Compared with the traditional electrical devices, this all-optical detection method overcomes the difficulties like the fast response and electromagnetic interference immunity in detecting VUV bands at the present stage, and improves the response speed. The proposed device shows the excellent performance of VUV detection, with the static sensitivity of 1.03 nm/(W·cm−2), response rise time of down to 10 µs, and decay time of 0.64 ms. Beneficial from the excellent radiation resistance of AlN microwires and UV resistance of silica fibers, the proposed device is expected to have the good stability and potential applications in the fields of the solar physics and space exploration.
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- 2024
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4. Development of a distributed group control strategy for pumping well groups connected by multisource DC microgrids
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Jixiang Yue, Zhenhua Sun, Haoguang Li, Wenyu Zhu, Fengming Li, and Zhenjie Wang
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Multisource DC microgrid ,Pumping unit group control ,Distributed group control strategy ,Power weighting ,Group weighted moving average ,Medicine ,Science - Abstract
Abstract Due to the alternating loads on pumping units and the integration of new energy sources, multisource DC microgrid pumping unit well groups experience increased fluctuations in voltage and power as well as superimposed peak and valley values. This work presents a distributed control strategy for pumping unit well groups on a multisource DC microgrid based on the weighted moving average algorithm. A centralized control program is implanted in the RTU of the single-well controller of each pumping unit, and communication with each well is realized via SCADA and multicast communication, resulting in a distributed well group system. The real-time power values of the pumping well group are calculated by grouping the power values, and each group is weighted using the total power fluctuation threshold of the well group as the control target. Then, a weighted moving average algorithm is used to predict the next power value and form a table of predicted real-time power spectra. According to the power values in the community power spectrum table, the inverter frequency is proportionally adjusted downwards to reach the power peak before deceleration; after the power peak is crossed, the frequency is increased in the same way to reach the power valley before acceleration. Finally, the peak and valley power values of the bus system level off and further learn to reach the set impulse; ultimately, a stable impulse is formed. In laboratory testing and field application in the Shengli Oilfield XIN-11 block, the group control software module effectively suppressed the active power peak and valley values and voltage fluctuations of the bus system, the active power fluctuation rate range decreased by more than 70%, and the DC bus voltage fluctuation range decreased by more than 80%; moreover, the active power decreased by approximately 6% without additional hardware costs.
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- 2024
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5. Species assemblages and their drivers differ between trees and lianas in a seasonal evergreen forest in Thailand
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Wirong Chanthorn, Thorsten Wiegand, Anuttara Nathalang, Rajapandian Kanagaraj, Stuart Davies, Zhenhua Sun, Nitin K. Tripathi, Maxime Réjou‐Méchain, and Warren Y. Brockelman
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disturbance ,habitat association ,indicator species ,multivariate regression tree ,seedlings ,soil nutrients ,Ecology ,QH540-549.5 - Abstract
Abstract Despite a long tradition in ecology of studying tree species assembly and its potential drivers in tropical forest communities, little information exists with respect to lianas (woody climbers), the second most abundant life form of woody plants in tropical forests. Lianas influence forest diversity and stability and provide critical resources for forest fauna. Using a unique dataset of a 30‐ha plot in Thailand, where tree and liana individuals were fully mapped, we investigated the degree to which local species assemblages of trees and lianas of different size classes (i.e., seedlings, established individuals, and large individuals) are related to local environmental conditions. We asked (1) What are the spatial patterns and environmental drivers of local tree and liana species assemblages? (2) How do such patterns and drivers differ among size classes? (3) Which species associate with these assemblages? Local assemblages of established trees showed substantial structuring by environmental variables, whereas we found only weakly structured assemblages of tree seedlings, large trees, and lianas of all size classes. Our results indicated that the biotic and abiotic drivers of local species assemblages differed strongly between tree and liana communities and across size classes. Species assemblages of trees were mainly driven by soil nutrients, leading to patchy assemblages associated with high base saturation (Alfisols) and assemblages associated with lower levels of base saturation and higher aluminum (Ultisols), whereas tree seedling assemblages were only weakly structured by riparian zones. In contrast, species assemblages of established and large lianas were primarily associated with forest canopy structure, separating low‐canopy forests from high‐canopy forests, whereas soil nutrients were the only factors associated with liana seedling assemblages. The weak environmental structuring of tree seedlings and large trees suggests that other mechanisms, such as stochastic disturbances, competition for space, or animal seed dispersal, may play an important role in structuring tree communities in this seasonal tropical forest. The weak patterns observed in liana communities across all life stages raise questions about the underlying mechanisms of liana community assembly, and further research should focus on liana niches, their dispersal mechanisms, and host tree relations.
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- 2024
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6. Case report: A case of giant breast skin warts caused by HPV infection
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Chaohui Wang, Yuyang Zhao, Zhenhua Sun, and Mingjun Li
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human papillomavirus (HPV) ,condyloma acuminatum (CA) ,Buschke-Lowenstein tumor ,squamous cell carcinoma (SCC) ,skin tumor ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
GCA, also known as Buschke-Lowenstein tumor, is a rare sexually transmitted disease associated with HPV types 6 and 111. These warts are considered histologically benign, but there is a risk of localized invasion and development of malignancy. This malignant transformation occurs most often in the perianal and vulvar areas, and involvement of other sites is relatively rare2. In this case, we report a rare case of a giant wart originating from breast skin infected with HPV and progressing to cutaneous squamous cell carcinoma.
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- 2024
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7. Towards high performance polyimide cathode materials for lithium–organic batteries by regulating active-site density, accessibility, and reactivity
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Jun Wang, Haichao Liu, Chunya Du, Bing Liu, Haoran Guan, Yu Liu, Shaowei Guan, Zhenhua Sun, and Hongyan Yao
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Organic cathode materials ,Polymer electrode ,Lithium-ion batteries ,Carbonyl ,Polyimides ,Mechanical engineering and machinery ,TJ1-1570 ,Electronics ,TK7800-8360 - Abstract
Organic carbonyl electrode materials offer promising prospects for future energy storage systems due to their high theoretical capacity, resource sustainability, and structural diversity. Although much progress has been made in the research of high-performance carbonyl electrode materials, systematic and in-depth studies on the underlying factors affecting their electrochemical properties are rather limited. Herein, five polyimides containing different types of diamine linkers are designed and synthesized as cathode materials for Li-ion batteries. First, the incorporation of carbonyl groups increases the active-site density in both conjugated and non-conjugated systems. Second, increased molecular rigidity can improve the accessibility of the active sites. Third, the introduction of the conjugated structure between two carbonyl groups can increase the reactivity of the active sites. Consequently, the incorporation of carbonyl structures and conjugated structures increases the capacity of polyimides. PTN, PAN, PMN, PSN, and PBN exhibit 212, 198, 199, 151, and 115 mAh g−1 at 50 mA g−1, respectively. In addition, the introduction of a carbonyl structure and a conjugated structure is also beneficial for improving cycling stability and rate performance. This work can deepen the understanding of the structure–function relationship for the rational design of polyimide electrode materials and can be extended to the molecular design of other organic cathode materials.
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- 2024
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8. CAR-T cell therapy in advanced thyroid cancer: from basic to clinical
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Zhenhua Sun, Chaohui Wang, Yuyang Zhao, and Qingyi Ling
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CAR-T cell therapy ,thyroid cancer ,biological basis ,clinical application ,immunotherapy ,Immunologic diseases. Allergy ,RC581-607 - Abstract
The majority of patients with thyroid cancer can attain a favorable prognosis with a comprehensive treatment program based on surgical treatment. However, the current treatment options for advanced thyroid cancer are still limited. In recent years, chimeric antigen receptor-modified T-cell (CAR-T) therapy has received widespread attention in the field of oncology treatment. It has achieved remarkable results in the treatment of hematologic tumors. However, due to the constraints of multiple factors, the therapeutic efficacy of CAR-T therapy for solid tumors, including thyroid cancer, has not yet met expectations. This review outlines the fundamental structure and treatment strategies of CAR-T cells, provides an overview of the advancements in both preclinical investigations and clinical trials focusing on targets associated with CAR-T cell therapy in treating thyroid cancer, and discusses the challenges and solutions to CAR-T cell therapy for thyroid cancer. In conclusion, CAR-T cell therapy is a promising therapeutic approach for thyroid cancer, and we hope that our review will provide a timely and updated study of CAR-T cell therapy for thyroid cancer to advance the field.
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- 2024
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9. Effects of combined ecological restoration measures on water quality and underwater light environment of Qingshan Lake, an urban eutrophic lake in China
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Xiaowen Lin, Xiaodong Wu, Jianying Chao, Xuguang Ge, Lingxiao Tan, Wenting Liu, Zhenhua Sun, and Jianjun Hou
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Qingshan Lake ,Ecological restoration ,Water quality ,Light intensity ,Light quality ,Ecology ,QH540-549.5 - Abstract
Ecological restoration is vital in the management of eutrophic lakes. However, the effect of combined ecological restoration measures on the improvement of water quality and the light environment of urban eutrophic lakes requires further exploration. This study considered Qingshan Lake, a typical urban eutrophic lake in the middle reaches of the Yangtze River in China and explored the changes in the water quality and light environment before and after the implementation of combined ecological restoration measures from 2021 to 2022. The results showed that: (1) Ecological restoration significantly improved the transparency of Qingshan Lake (P
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- 2024
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10. Ambient Electrochemical Ammonia Synthesis: From Theoretical Guidance to Catalyst Design
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Jianjia Mu, Xuan‐Wen Gao, Tong Yu, Lu‐Kang Zhao, Wen‐Bin Luo, Huicong Yang, Zhao‐Meng Liu, Zhenhua Sun, Qin‐Fen Gu, and Feng Li
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electrocatalyst design ,electrochemical ammonia synthesis ,nitrate reduction reaction ,nitrogen reduction reaction ,Science - Abstract
Abstract Ammonia, a vital component in the synthesis of fertilizers, plastics, and explosives, is traditionally produced via the energy‐intensive and environmentally detrimental Haber–Bosch process. Given its considerable energy consumption and significant greenhouse gas emissions, there is a growing shift toward electrocatalytic ammonia synthesis as an eco‐friendly alternative. However, developing efficient electrocatalysts capable of achieving high selectivity, Faraday efficiency, and yield under ambient conditions remains a significant challenge. This review delves into the decades‐long research into electrocatalytic ammonia synthesis, highlighting the evolution of fundamental principles, theoretical descriptors, and reaction mechanisms. An in‐depth analysis of the nitrogen reduction reaction (NRR) and nitrate reduction reaction (NitRR) is provided, with a focus on their electrocatalysts. Additionally, the theories behind electrocatalyst design for ammonia synthesis are examined, including the Gibbs free energy approach, Sabatier principle, d‐band center theory, and orbital spin states. The review culminates in a comprehensive overview of the current challenges and prospective future directions in electrocatalyst development for NRR and NitRR, paving the way for more sustainable methods of ammonia production.
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- 2024
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11. Case report: A case of hyperthyroidism secondary to bone metastasis of differentiated thyroid cancer
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Tingyu Gu, Zhihong Zhao, Yuanyuan Shi, Zhenhua Sun, Yao Wang, Zhiyuan He, and Kun Wang
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bone metastasis ,secondary hyperthyroidism ,differentiated thyroid cancer ,diagnosis ,pathology ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
It is usually believed that differentiated thyroid cancer is less likely to have distant metastases and rarely occurs secondary to hyperthyroidism. In our case report, we describe a patient diagnosed with thyroid fetal adenoma in 2002 who subsequently presented with a painful lump in her right rib. Through puncture biopsy, the mass was considered as metastatic follicular thyroid carcinoma, and then she appeared to have hyperthyroidism. The results of SPECT examination and other tests suggested that the hyperthyroidism was secondary to the thyroid cancer. The patient further underwent total thyroidectomy, and the pathology did not find any follicular thyroid foci. In this article, we analyze and discuss this case and review the relevant literature.
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- 2024
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12. Investigation of Car following and Lane Changing Behavior in Diverging Areas of Tunnel–Interchange Connecting Sections Based on Driving Simulation
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Zhenhua Sun, Jinliang Xu, Chenwei Gu, Tian Xin, and Wei Zhang
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tunnel–interchange sections ,signage information volume ,car following ,lane changing ,driving stability ,road safety ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
Tunnel–interchange connecting sections pose significant safety challenges on mountainous expressways due to their high incidence of accidents. Improving road safety necessitates a comprehensive understanding of driver behavior in such areas. This study explores the influences of road characteristics, signage information volume, and traffic conditions on drivers’ car-following and lane-changing behavior in tunnel–interchange diverging areas. Utilizing driving data from 25 subjects of 72 simulated road models, driving performance is assessed using the Friedman rank test and multivariate variance analysis. The results highlight the significant influence of both connection distance and signage information load on driving behavior. In tunnel–interchange scenarios, the reduction in velocity increased by 62.61%, and speed variability surged by 61.11%, indicating potential adverse effects on driving stability due to the environmental transitions. Decreased connection distances are associated with reduced lane-changing durations, larger steering angles, and increased failure rates. Furthermore, every two units of increase in signage information leads to a 13.16% rise in maximum deceleration and a 5% increase in time headway. Notably, the signage information volume shows a significant interaction with connection distance (F > 1.60, p < 0.045) for most car-following indicators. Hence, the study recommends a maximum connection distance of 700 m and signage information not exceeding nine units for optimal safety and stability.
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- 2024
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13. Research on the Stability of Different Polar Surfaces in Aluminum Nitride Single Crystals
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Zhao Liu, Wenliang Li, Zuoyan Qin, Lei Jin, Zhenhua Sun, and Honglei Wu
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aluminum nitride (AlN) ,spontaneous polarization ,polar surface ,surface energy ,lattice structure ,Crystallography ,QD901-999 - Abstract
Wurtzite aluminum nitride (AlN) crystal has a non-centrosymmetric crystal structure with only a single axis of symmetry. In an AlN crystal, the electronegativity difference between the Al atom and N atom leads to a distortion of electron cloud distribution outside the nucleus and a spontaneous polarization (SP) along the c-axis direction. The N-polar surface along the directions of [000-1] has higher surface energy than the Al-polar surface along the directions of [0001]. Due to the different atomic arrangement, Al atoms on the Al-polar surface bond with O and OH− in the environment to generate Al2O3·xH2O, which prevents the reaction from occurring inside the crystal. After the Al2O3·xH2O dissolve in an alkaline environment, N atoms have three dangling bonds exposed on the surface, which can also protect OH− from destroying the internal Al-N bonds, so the Al-polar surface is more stable than the N-polar surface.
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- 2024
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14. A Hydrothermal Synthesis Process of ZSM-5 Zeolite for VOCs Adsorption Using Desilication Solution
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Zhenhua Sun, Qingxiang Shu, Qikun Zhang, Shaopeng Li, Ganyu Zhu, Chenye Wang, Jianbo Zhang, Huiquan Li, and Zhaohui Huang
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ZSM-5 zeolite ,hydrothermal synthesis ,adsorption ,volatile organic compounds ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
ZSM-5 zeolite is a kind of high-value-added porous aluminosilicate zeolite. The use of the coal gasification slag utilization process by-product desilication liquid as a silicon raw material to replace the current raw materials such as water glass will help reduce production costs and achieve high-value utilization of solid waste. ZSM-5 zeolites for volatile organic compounds (VOCs) adsorption were prepared by a one-step hydrothermal method using the desilication solution prepared from coal gasification slag as the main silicon source and sodium source. The effects of crystallization reaction time, the crystallization temperature, the Na2O/SiO2 molar ratio, and the SiO2/Al2O3 molar ratio on the relative crystallinity and the specific surface area of the ZSM-5 zeolite were investigated and optimized. The optical reaction conditions were as follows: a crystallization time of 12 h, a crystallization temperature of 170 °C, a Na2O/SiO2 molar ratio of 0.2, and a SiO2/Al2O3 molar ratio of 200. The optimal ZSM-5 zeolite synthesized is hexagonal, with regular grains, a relative crystallinity of 101.48%, a specific surface area of 337.48 m2·g−1, and a pore volume of 0.190 cm3·g−1. And the optimal ZSM-5 zeolite was composed of SiO2 content of 97.52 wt%, Al2O3 content of 1.58 wt%, Na2O content of 0.33 wt%, and SiO2/Al2O3 molar ratio of 104.93. Na2O/SiO2 molar ratio is 0.0033. The results of static adsorption experiments show that the static adsorption capacities of ZSM-5 zeolite for p-xylene, benzene, toluene, and butyl acetate were 118.85, 69.98, 68.74, and 95.85 mg·g−1, respectively, which can effectively adsorb VOCs. The synthetic process of the ZSM-5 zeolite is a simple preparation process and short in synthesis time. The results of this study not only help to realize the high-value utilization of silicon components in solid waste, but also provide an economical and effective way to synthesize VOCs adsorption materials.
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- 2024
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15. The coordinated impact of forest internal structural complexity and tree species diversity on forest productivity across forest biomes.
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Qin Ma, Yanjun Su, Tianyu Hu, Lin Jiang, Xiangcheng Mi, Luxiang Lin, Min Cao, Xugao Wang, Zhenhua Sun, Jin Wu, Keping Ma, and Qinghua Guo
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CARBON sequestration in forests ,OPTICAL radar ,LIDAR ,STRUCTURAL frame models ,FOREST biodiversity ,FOREST productivity - Abstract
Forest structural complexity can mediate the light and water distribution within forest canopies, and has a direct impact on forest biodiversity and carbon storage capability. It is believed that increases in forest structural complexity can enhance tree species diversity and forest productivity, but inconsistent relationships among them have been reported. Here, we quantified forest structural complexity in three aspects (i.e., horizontal, vertical, and internal structural complexity) from unmanned aerial vehicle light detection and ranging data, and investigated their correlations with tree species diversity and forest productivity by incorporating field measurements in three forest biomes with large latitude gradients in China. Our results show that internal structural complexity had a stronger correlation (correlation coefficient = 0.85) with tree species richness than horizontal structural complexity (correlation coefficient = -0.16) and vertical structural complexity (correlation coefficient = 0.61), and it was the only forest structural complexity attribute having significant correlations with both tree species richness and tree species evenness. A strong scale effect was observed in the correlations among forest structural complexity, tree species diversity, and forest productivity. Moreover, forest internal structural complexity had a tight positive coordinated contribution with tree species diversity to forest productivity through structure equation model analysis, while horizontal and vertical structural complexity attributes have insignificant or weaker coordinated effects than internal structural complexity, which indicated that the neglect of forest internal structural complexity might partially lead to the current inconsistent observations among forest structural complexity, tree species diversity, and forest productivity. The results of this study can provide a new angle to understand the observed inconsistent correlations among forest structural complexity, tree species diversity, and forest productivity. [ABSTRACT FROM AUTHOR]
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- 2024
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