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Quantification of occlusions influencing the tree stem curve retrieving from single-scan terrestrial laser scanning data

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Forest Ecosystems 2019年第4期6卷 285-297页

作者： peng wan Tiejun wang Wuming Zhang Xinlian Liang Andrew K.Skidmore Guangjian Yan State Key Laboratory of Remote Sensing Science Jointly Sponsored by Beijing Normal University and Institute of Remote Sensing and Digital Earth of Chinese Academy of Sciences Beijing Engineering Research Centre for Global Land Remote Sensing Products Institute of Remote Sensing Science and Engineering Faculty of Geographical Science Beijing Normal University

Background: The stem curve of standing trees is an essential parameter for accurate estimation of stem *** study aims to directly quantify the occlusions within the single-scan terrestrial laser scanning(TLS) data,evaluate its correlation with the accuracy of the retrieved stem curves, and subsequently, to assess the capacity of single-scan TLS to estimate stem ***: We proposed an index, occlusion rate, to quantify the occlusion level in TLS data. We then analyzed three influencing factors for the occlusion rate: the percentage of basal area near the scanning center, the scanning distance and the source of occlusions. Finally, we evaluated the effects of occlusions on stem curve estimates from single-scan TLS ***: The results showed that the correlations between the occlusion rate and the stem curve estimation accuracies were strong(r = 0.60–0.83), so was the correlations between the occlusion rate and its influencing factors(r = 0.84–0.99). It also showed that the occlusions from tree stems were the main factor of the low detection rate of stems, while the non-stem components mainly influenced the completeness of the retrieved stem ***: Our study demonstrates that the occlusions significantly affect the accuracy of stem curve retrieval from the single-scan TLS data in a typical-size(32 m × 32 m) forest plot. However, the single-scan mode has the capacity to accurately estimate the stem curve in a small forest plot(< 10 m × 10 m) or a plot with a lower occlusion rate, such as less than 35% in our tested datasets. The findings from this study are useful for guiding the practice of retrieving forest parameters using single-scan TLS data.

关键词： Stem curve Stem volume Terrestrial laser scanning Scan mode

Efficient Slew-Rate Enhanced Operational Transconductance Amplifier

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Journal of Electronic Science and Technology 2015年第1期13卷 14-19页

作者： Xiao-peng wan Fei-Xiang Zhang Shao-Wei Zhen Ya-Juan He Ping Luo School of Microelectronics and Solid-State Electronics University of Electronic Science and Technology of China

Today, along with the prevalent use of portable equipment, wireless, and other battery powered systems, the demand for amplifiers with a high gain-bandwidth product（GBW）, slew rate（SR）, and at the same time very low static power dissipation is growing. In this work, an operational transconductance amplifier（OTA） with an enhanced SR is proposed. By inserting a sensing resistor in the input port of the current mirror in the OTA, the voltage drop across the resistor is converted into an output current containing a term in proportion to the square of the voltage, and then the SR of the proposed OTA is significantly enhanced and the current dissipation can be reduced. The proposed OTA is designed and simulated with a 0.5μm complementary metal oxide semiconductor（CMOS） process. The simulation results show that the SR is 4.54V/μs, increased by 8.25 times than that of the conventional design, while the current dissipation is only 87.3%.

关键词： Efficient gain-bandwidth product operational transconductance amplifier slew rate

Species-area relationship within and across functional groups at alpine grasslands on the northern Tibetan Plateau,China

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Journal of Mountain Science 2016年第2期13卷 265-275页

作者： ZHOU Nan WU Jian-shuang SHEN Zhen-xi ZHANG Xian-zhou YANG peng-wan Lhasa National Ecological Research Station Key Laboratory of Ecosystem Network Observation and ModellingInstitute of Geographic Sciences and Natural Resources ResearchChinese Academy of sciences University of Chinese Academy of Sciences Functional Biodiversity Dahlem Centre of Plant SciencesFree University of Berlin

The species-area relationship （SAR） is one of the most fundamental concepts in community ecology and is helpful for biodiversity conservation. However, few studies have systematically addressed this topic for different alpine grassland types on the Tibetan Plateau, China. We explored whether the plant composition of different functional groups affects the manner in which species richness inereases with increasing area at scales ≤ 1.0 m^2. We also compared species richness （S） within and across forbs, legumes, sedges and grasses, with sampling subplot area （A） increasing from 0.0625 m^2 to 1.0 m^2 between alpine meadow and steppe communities. We applied a logarithmic function （S = b0 ＋ b1 ln A） to determine the slope and intercept of SAR curves within and across functional groups. The results showed that the logarithmic relationship holds true between species richness and sampling area at these small scales. Both the intercept and slope of the logarithmic forbs-area curves are significantly higher than those for the three other functional groups （P 〈 0.05）. Forb accounts for about 91.9 % of the variation in the intercept and 75.0% of the variation in the slope of the SAR curve when all functional groups＇ data were pooled together. Our results indicated that the different SAR patterns should be linked with species dispersal capabilities, environmental filtering, and life form composition within alpine grassland communities. Further studies on the relationship between species diversity and ecosystem functions should specify the differential responses of different functional groups to variations in climate and anthropogenic disturbances.

关键词： Changtang Nature Reserve Complementary response Plant functional groups Plant life forms Species coexistence

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矿山主井提升机电气传动系统改造

世界有色金属 2024年第9期 19-21页

作者：张文鹏金万鹏吴文权张晓龙金川集团股份有限公司甘肃金昌737100 上海华菱电站成套设备股份有限公司上海200083

金川集团股份有限公司三矿区50行主井提升机传动系统采用中压交直交变频驱动控制方式。主传动变频器使用ABB公司的ACS6000中压交直交变频器,配套4500KW低速直联交流同步电机。原传动系统只有一套变频器,通过改造,实现了主井提升机主传... 详细信息

金川集团股份有限公司三矿区50行主井提升机传动系统采用中压交直交变频驱动控制方式。主传动变频器使用ABB公司的ACS6000中压交直交变频器,配套4500KW低速直联交流同步电机。原传动系统只有一套变频器,通过改造,实现了主井提升机主传动装置及配套设备的冗余控制,提高了系统的保障能力。

关键词：提升机电气传动变频器设备冗余

维普期刊数据库博看期刊

新型抗凝剂甲磺酸萘莫司他在急诊连续性肾脏替代治疗中的临床应用研究

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临床和实验医学杂志 2024年第9期23卷 934-937页

作者：施晨熊万鹏谭莹莹张鹏攀钢集团总医院肾病内科四川攀枝花617000

目的研究新型抗凝剂甲磺酸萘莫司他在急诊连续性肾脏替代治疗(CRRT)中的应用价值。方法采用回顾性分析,选取2021年6月至2023年1月入攀钢集团总医院的72例脓毒症伴发AKI患者为研究对象。所有患者均行连续性肾脏替代治疗(CRRT),参考是否... 详细信息

目的研究新型抗凝剂甲磺酸萘莫司他在急诊连续性肾脏替代治疗(CRRT)中的应用价值。方法采用回顾性分析,选取2021年6月至2023年1月入攀钢集团总医院的72例脓毒症伴发AKI患者为研究对象。所有患者均行连续性肾脏替代治疗(CRRT),参考是否接受甲磺酸萘莫司他体外抗凝分为研究组(n=36)与对照组(n=36)。研究组接受甲磺酸萘莫司他体外抗凝,对照组未接受甲磺酸萘莫司他体外抗凝。比较两组患者治疗前、治疗72 h后的实验室指标[国际标准化比值(INR)、活化部分凝血活酶时间(APTT)、血清钠、血清钙、血清钾、尿酸、半胱氨酸蛋白酶抑制剂C(CysC)、尿素氮、血清肌酐、血小板计数、血红蛋白]水平与治疗后滤器使用量、不良反应(过敏反应、高血钾、消化道症状、血小板下降、出血)发生率。结果治疗72 h后,两组患者尿酸、CysC、尿素氮、血清肌酐、血小板计数、血红蛋白水平均明显低于治疗前,研究组患者治疗72 h后尿酸、CysC、尿素氮、血清肌酐水平分别为(86.41±15.24)μmol/L、(0.98±0.19)mg/L、(4.43±2.01)mmol/L、(99.32±15.61)μmol/L,均明显低于对照组[(105.29±20.43)μmol/L、(1.19±0.23)mg/L、(6.92±2.23)mmol/L、(127.54±20.47)μmol/L],差异均有统计学意义(P0.05)。结论新型抗凝剂甲磺酸萘莫司他在急诊连续性肾脏替代治疗中的效果显著,可有效降低脓毒症伴发AKI患者的滤器更换频率,还可进一步改善其尿酸、CysC、尿素氮、血清肌酐水平,且未增大不良反应发生风险,安全性高。

关键词：急诊连续性肾脏替代治疗甲磺酸萘莫司他脓毒症急性肾损伤抗凝

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深度学习视角下电磁感应现象中的单杆问题

物理教学探讨 2024年第2期42卷 12-13,17页

作者：吴晓明万鹏鲍习中合肥市第一中学合肥230601 安徽省滁州中学安徽文滁州239000 池州市贵池区教育体育局安徽池州247099

以电磁感应现象中的金属单杆模型为例,带领学生从物质、运动、相互作用及能量等角度,运用模型建构思维方式解决问题,同时也为教师命制试题提供思路。

关键词：电磁感应单杆模型深度学习

Emergence,Mating and Oviposition Behavior of the Chinese Population in Pink Bollworm,Pectinophora gossypiella (Lepidoptera:Gelechiidae)

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Journal of Integrative Agriculture 2013年第4期12卷 653-662页

作者： WU Huai-heng HUANG Min-song wan peng Kris A G Wyckhuys WU Kong-ming State Key Laboratory for Biology of Plant Diseases and Insect Pests/Institute of Plant Protection Chinese Academy of Agricultural Sciences Institute of Plant Protection and Soil Fertilizer Hubei Academy of Agricultural Sciences International Center for Tropical Agriculture CIAT-Asia

The pink bollworm, Pectinophora gossypiella （Lepidoptera： Gelechiidae） is one of the most serious lepidopteran pests of cotton in the world. This pest invaded China at the onset of the 20th century, possibly through repeated introductions from several different locations worldwide. In this paper, we describe different behavioral parameters of this Hubei P. gossypiella strain under laboratory and field conditions. Using an infra-red video recorder, we observed （nocturnal） emergence, flight and mating activities, and oviposition patterns. Moth emergence started from 13：00 and continued up till 23：00. Under laboratory and field conditions, 2-7-d-old moths initiated flight around sunset, peaked 50 rain later and gradually declined until 04：00. Although mating started immediately after darkness （i.e., 20：00）, mating behavior was most intense from 23：00 to 03：40. Oviposition also showed distinct time-related patterns, with approx. 70% eggs laid between 20：00 and 22：00. In the studies of the relationship between flight and oviposition, the duration of flight had an effect on oviposition. The 1-d-old moths flown for 6 and 12 h began oviposition earlier than the unflown ones, and the 6-h flight had no effect on the egg production. However, the longevity of the flown moths was shortened after flight. In addition, the peaks of oviposition for the flown moths were advanced 2-3 d. The age when the moths flied affected the oviposition of adult moths. The earlier the moths started to fly after emergence, the greater the fecundity they had. The average egg production of moths flown for 24 h was less than that of non-flown moths which were of the same age. Both flight and delay in mating could advance the oviposition peak. Our study provides detailed insights in nocturnal activities and the reproductive biology of local P. gossypiella populations, which could be employed to fine-tune current pest management programs in China.

关键词： Pectinophora gossypiella nocturnal activities emergence mating oviposition

A chain-like compound of Si@CNT nanostructures and MOF-derived porous carbon as an anode for Li-ion batteries

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International Journal of Minerals,Metallurgy and Materials 2021年第10期28卷 1611-1620页

作者： Ying-jun Qiao Huan Zhang Yu-xin Hu wan-peng Li Wen-jing Liu Hui-ming Shang Mei-zhen Qu Gong-chang peng Zheng-wei Xie Chengdu Institute of Organic Chemistry Chinese Academy of SciencesChengdu 610041China University of Chinese Academy of Sciences Beijing 100039China

Silicon anodes are considered to have great prospects for use in batteries;however,many of their defects still need to be *** preparation of hybrid materials based on porous carbon is one of the effective ways to alleviate the adverse impact resulting from the volume change and the inferior electronic conductivity of a silicon ***,a chain-like carbon cluster structure is prepared,in which MOF-derived porous carbon acts as a shell structure to integrally encapsulate Si nanoparticles,and CNTs play a role in connecting carbon *** on the exclusive structure,the carbon shell can accommodate the volume expansion more effectively,and CNTs can improve the overall stability and *** resulting composite reveals excellent rate capacity and enhanced cycling stability;in particular,a capacity of 732 mA·h·g^(-1) at 2 A·g^(-1) is achieved with a reservation rate of 72.3% after cycling 100 times at 1 A·g^(-1).

关键词： silicon carbon nanotubes metal-organic framework Li-ion batteries

优良紫花苜蓿品种骑士t在庆阳市的适应性研究

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饲料研究 2024年第5期47卷 117-121页

作者：张金霞窦晓利耿智广梁万鹏韩庆辉庆阳市农业科学研究院甘肃庆阳745000 甘肃省农业科学院畜草与绿色农业研究所甘肃兰州730070 北京佰青源畜牧业科技发展有限公司北京101500

试验旨在探讨紫花苜蓿骑士t在庆阳市的综合生产能力及适应性。试验采用随机区组试验方法,分析引进品种骑士t、当地主栽品种甘农5号和陇东紫花苜蓿的田间生产性状、生长势、鲜草产量、营养成分和饲用价值。结果表明,苜蓿不同品种生长曲... 详细信息

试验旨在探讨紫花苜蓿骑士t在庆阳市的综合生产能力及适应性。试验采用随机区组试验方法,分析引进品种骑士t、当地主栽品种甘农5号和陇东紫花苜蓿的田间生产性状、生长势、鲜草产量、营养成分和饲用价值。结果表明,苜蓿不同品种生长曲线一致,但同一品种不同时期生长速度不同;3个苜蓿品种种植当年(春播)产量低,但品质优、营养价值高,初花期粗蛋白(CP)含量20%以上,酸性洗涤纤维(ADF)含量在28%~30%之间,中性洗涤纤维(NDF)含量在35.0%~38.5%之间,相对饲用价值(RFV)在161~172之间。骑士t播种当年越冬率为100%,抗寒性好,翌年第一茬株高达105.24 cm,显著高于甘农5号和陇东紫花苜蓿(P<0.05);茎粗为3.46 mm,显著低于甘农5号(P<0.05);鲜草产量达1 235.06 kg/667 m2。甘农5号抗旱性好,越夏成活率为73.38%,分枝较多,鲜草产量明显高于陇东紫花苜蓿(P<0.05)。骑士t粗脂肪含量低,但RFV高,鲜干比为2.96,粗蛋白和磷含量可达22.6%和0.3%,ADF和NDF含量为28.8%和35.97%,RFV为172,相对饲草品质(RFQ)为170,总可消化养分(TDN)含量为60%。研究表明,骑士t适宜在庆阳市及气候相似的区域种植。

关键词：紫花苜蓿骑士t 生长特性庆阳市