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煤矿坚硬顶板灾害水力压裂防治技术监测及评估
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作者 石垚 雷瀚 +1 位作者 杨新路 徐世达 《煤炭工程》 北大核心 2024年第2期122-130,共9页
水力压裂技术具备安全性好、施工工艺简单的优点,被广泛应用于煤层坚硬顶板灾害治理。但由于岩体的不均质性,压裂孔周围裂隙网络扩展规律复杂,水力压裂裂纹监测精度低,压裂效果评估难度大。针对上述问题,通过对比分析常见水力压裂监测... 水力压裂技术具备安全性好、施工工艺简单的优点,被广泛应用于煤层坚硬顶板灾害治理。但由于岩体的不均质性,压裂孔周围裂隙网络扩展规律复杂,水力压裂裂纹监测精度低,压裂效果评估难度大。针对上述问题,通过对比分析常见水力压裂监测方法及监测方案的差异,揭示微震监测技术的优越性,并对水力压裂效果评估技术进行了讨论。研究表明,微震监测技术具有监测范围广、灵敏度高、连续性好的优点;地面监测、井下监测、联合监测等微震监测方法适用工况不同,监测精度相差较大,应根据现场工程布置与实际岩层条件选取合适的监测方法。坚硬顶板水力压裂效果评估多采用裂缝发育长度、来压步距等间接指标,基于微震参变量直接指标的效果评估相对较少。在此基础上,提出了水力压裂效果评估精细化的发展建议。研究成果对开展坚硬顶板水力压裂现场监测、优化坚硬顶板水力压裂工程设计具有重要指导意义。 展开更多
关键词 坚硬顶板 水力压裂 裂纹 微震监测
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Megafossils of Betulaceae from the Oligocene of Qaidam Basin and their paleoenvironmental and phytogeographic implications
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作者 Tao Yang Jia-Hao Cai +9 位作者 Yan-Zhi Dai Hong-Yu Chen lei han Li Zhang Wei-Yu Liang Xu-Jun Li Wen-Jia Li Jing-Yu Wu San-Ping Xie De-Fei Yan 《Plant Diversity》 SCIE CAS CSCD 2024年第1期101-115,共15页
Understanding the paleoenvironment and phytogeographical history of the Tibetan Plateau,China relies on discovering new plant fossils.The Qaidam Basin has long been regarded as an ideal‘field laboratory’to investiga... Understanding the paleoenvironment and phytogeographical history of the Tibetan Plateau,China relies on discovering new plant fossils.The Qaidam Basin has long been regarded as an ideal‘field laboratory’to investigate the paleoclimate and paleobiological evolution of the northern Tibetan Plateau.However,fossil angiosperms from the Qaidam Basin are rare,and our knowledge of its paleovegetation is poor.Here,we report fossil leaves and fruits of Betulaceae found from the Oligocene Shangganchaigou Formation of northwestern Qaidam Basin(Huatugou area).Comparative morphological analysis led us to assign the fruits to the Betula subgenus Betula and the leaves to Carpinus grandis.These findings,together with other reported fossil plants from the same locality,reveal a close floristic linkage between the Qaidam Basin and Europe during the Oligocene.The northern pathway of this floristic exchange may have crossed through the Qaidam Basin during the late Paleogene.This floristic linkage may have been facilitated by the continuous narrowing of the Turgai Strait and stronger westerlies,which transported moisture and provided favorable climatic conditions.Indeed,fossil plants collected from the Qaidam Basin suggest that during the Oligocene this region had warm and humid deciduous broad-leaf forest,which differs from the region’s modern vegetation and indicates that the Qaidam Basin may have been a suitable region for these plants to flourish and spread during the Oligocene. 展开更多
关键词 PALEOENVIRONMENT BIOGEOGRAPHY Betulaceous fossil Qaidam basin Tibetan Plateau OLIGOCENE
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Intelligent Recognition Using Ultralight Multifunctional Nano‑Layered Carbon Aerogel Sensors with Human‑Like Tactile Perception
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作者 Huiqi Zhao Yizheng Zhang +8 位作者 lei han Weiqi Qian Jiabin Wang Heting Wu Jingchen Li Yuan Dai Zhengyou Zhang Chris RBowen Ya Yang 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第1期172-186,共15页
Humans can perceive our complex world through multi-sensory fusion.Under limited visual conditions,people can sense a variety of tactile signals to identify objects accurately and rapidly.However,replicating this uniq... Humans can perceive our complex world through multi-sensory fusion.Under limited visual conditions,people can sense a variety of tactile signals to identify objects accurately and rapidly.However,replicating this unique capability in robots remains a significant challenge.Here,we present a new form of ultralight multifunctional tactile nano-layered carbon aerogel sensor that provides pressure,temperature,material recognition and 3D location capabilities,which is combined with multimodal supervised learning algorithms for object recognition.The sensor exhibits human-like pressure(0.04–100 kPa)and temperature(21.5–66.2℃)detection,millisecond response times(11 ms),a pressure sensitivity of 92.22 kPa^(−1)and triboelectric durability of over 6000 cycles.The devised algorithm has universality and can accommodate a range of application scenarios.The tactile system can identify common foods in a kitchen scene with 94.63%accuracy and explore the topographic and geomorphic features of a Mars scene with 100%accuracy.This sensing approach empowers robots with versatile tactile perception to advance future society toward heightened sensing,recognition and intelligence. 展开更多
关键词 Multifunctional sensor Tactile perception Multimodal machine learning algorithms Universal tactile system Intelligent object recognition
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Enhancing hydrothermal stability of framework Al in ZSM-5:From the view on the transformation between P and Al species by solid-state NMR spectroscopy 被引量:3
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作者 lei han Ying Ouyang +2 位作者 Enhui Xing Yibin Luo Zhijian Da 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2020年第12期3052-3060,共9页
HZSM-5,with good surface acidity and shape selectivity,was reported as hydrocarbon cracking catalyst for multiple decades,however the hydrothermal stability,especially dealumination of tetrahedrally coordinated framew... HZSM-5,with good surface acidity and shape selectivity,was reported as hydrocarbon cracking catalyst for multiple decades,however the hydrothermal stability,especially dealumination of tetrahedrally coordinated framework aluminum(TFAl),has been proved extensively as one of the major challenges during reactionregeneration process.Phosphorus was proposed to stabilize TFAl and indeed it enhanced the hydrothermal stability.Unfortunately,most of the phosphorus species would remain outside of the zeolite pore,mainly as polyphosphate species,and block the micropore severely,with only a limited portion introduced into the channel being able to interact with TFAl.Enlarging the pore size by alkali treatment(desilication)is one of the most convinced methods,but the details about specific P species during alkali treatment and its transformation upon hydrothermal activation is not acquired,thus the mechanism has not been fully understood.Herein,the P-containing species and its transformation during direct P modification and acid/alkali treatment followed by Pmodification have been studied,and the mechanism on the interaction between P and Al species has been investigated,using several analytical methods,especially Solid-state nuclear magnetic resonance(SSNMR)spectroscopy.It was found that the combination of desilication and subsequent phosphorus modification can enhance the activity of the ZSM-5 for the cracking of ethylcyclohexane,due to the better hydrothermal stabilization of acid sites by the enhanced interaction between phosphorus and TFAl,resulting from the improved accessibility of TFAl because of the successful generation of mesoporosity.Whereas the acid treatment followed by phosphorus modification,with declined retention of crystallinity and P/Al ratio,monoclinic/orthorhombic transition during steam activation,and the failed generation of mesopores,would cause obvious aggregation of the phosphorus species and could not improve the hydrothermal stability of the ZSM-5 effectively,and the direct phosphatation turned out much worse.Finally,a specific index that the intensity of the signal at 39 in 27Al MAS NMR spectra before steam activation was proposed as the indicator for determining the efficiency of phosphorus modification.And the proposed mechanism on the interaction between phosphorus and TFAl during the phosphorus modification could also be applicable in other zeolites. 展开更多
关键词 Phosphorus modification TFAl NaOH/alkali treatment Interaction ZSM-5
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A dynamic evaluation technique for assessing gas output from coal seams during commingling production within a coalbed methane well: a case study from the Qinshui Basin 被引量:3
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作者 Chuan Wu Chengxiang Yuan +2 位作者 Guojun Wen lei han Haojie Liu 《International Journal of Coal Science & Technology》 EI 2020年第1期122-132,共11页
Gas drainage is carried out based on output from each coal bed throughout commingling production of coalbed methane(CBM).A reasonable drainage process should therefore initially guarantee main coal bed production and ... Gas drainage is carried out based on output from each coal bed throughout commingling production of coalbed methane(CBM).A reasonable drainage process should therefore initially guarantee main coal bed production and then enhance gas output from other beds.Permanent damage can result if this is not the case,especially with regard to fracture development in the main gas-producing coal bed and can greatly reduce single well output.Current theoretical models and measuring devices are inapplicable to commingled CBM drainage,however,and so large errors in predictive models cannot always be avoided.The most effective currently available method involves directly measuring gas output from each coal bed as well as determining the dominant gas-producing unit.A dynamic evaluation technique for gas output from each coal bed during commingling CBM production is therefore proposed in this study.This technique comprises a downhole measurement system combined with a theoretical calculation model.Gas output parameters(i.e.,gas-phase flow rate,temperature,pressure)are measured in this approach via a downhole measurement system;substituting these parameters into a deduced theoretical calculation model then means that gas output from each seam can be calculated to determine the main gas-producing unit.Trends in gas output from a single well or each seam can therefore be predicted.The laboratory and field test results presented here demonstrate that calculation errors in CBM outputs can be controlled within a margin of 15%and therefore conform with field use requirements. 展开更多
关键词 Commingling production Gas output Dynamic evaluation Coalbed methane Qinshui Basin
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Distribution of wetlands and salt lakes in the Yadong region of Tibet based on remote sensing, and their geo-climatic environmental changes 被引量:1
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作者 Ang Sun Qing-hua Yang +6 位作者 Zhi Liu Hua Chen lei han Shou-min Jiang Yue-yue Meng Yu Bian Yong-peng Yang 《China Geology》 CAS 2022年第4期637-648,共12页
Based on the 16 scenes GF-1 satellite multi-spectral remote sensing images,through the adoption of data processing methods including orthorectification,geometric rectification,data fusion and image mosaic,integrated w... Based on the 16 scenes GF-1 satellite multi-spectral remote sensing images,through the adoption of data processing methods including orthorectification,geometric rectification,data fusion and image mosaic,integrated with field surveys,the remote sensing interpretation signs for the inland wetland types have been built,and the remote sensing survey of inland wetlands in Yadong region has been initiated,with six types of inland wetlands recognized in Yadong region,namely permanent rivers,seasonal rivers,lakes,salt lakes,alpine meadows,and inundated land.The spatial distribution characteristics and the spreading rules of these wetlands have also been revealed.Based on full understanding of the overall characteristics of the inland wetlands in the Yadong region,using the three phases of TM images acquired in 1989,2003 and 2008 as well as the PMS2 data gathered by GF-1 in 2014,and the wide-range data(WFV3)gathered by GF-1 in 2020.As to the typical salt lakes,a long-time salt lakes transition study was carried out.The results show that the typical salt lakes in Yadong have been shrinking in the past three decades.The average annual shrinkage of Duoqing Co(Co means lake in Tibetan)was stronger than that of Gala Co,which are respective 87.30 hectares(usually short as ha;1 ha equals to 0.01 km^(2))/a and 24.20 ha/a;the shrinkage degree of Gala Co was higher than that of Duoqing Co,shrank by 59.27% and 35.73% respectively.Based on the remote sensing survey results and an integrated analysis of the predecessors’researchers,the reason for the shrinkage of the salt lakes is more inclined to geological factors.Geological process is manifested by a series of extensional faults at the bottom of the lake basin generated from tectonic activities,providing fluid infiltration channels,and inducing the eventual leakage of lake water to the lower strata.The result provides an important instance for understanding the evolution characteristics of wetlands and salt lakes in specific environment of the Tibetan Plateau. 展开更多
关键词 Yadong WETLANDS Salt lakes Duoqing Co Gala Co Geological survey engineering Tibet Plateau
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市场化改革与共同富裕——基于企业间工资差距视角 被引量:2
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作者 韩雷 冯彤 张诗涵 《产业经济评论》 2023年第2期116-133,共18页
中国式现代化要求着力促进全体人民共同富裕。我国收入差距问题仍然存在且形式复杂,长此以往可能阻碍经济高质量发展,不利于实现全体人民共同富裕目标。与此同时,我国市场化改革有力提高了经济发展效率,但其对公平的影响还有待验证。为... 中国式现代化要求着力促进全体人民共同富裕。我国收入差距问题仍然存在且形式复杂,长此以往可能阻碍经济高质量发展,不利于实现全体人民共同富裕目标。与此同时,我国市场化改革有力提高了经济发展效率,但其对公平的影响还有待验证。为此,本文基于企业间工资差距视角,分析了市场化改革是否有利于促进共同富裕。研究结果显示,市场化改革显著缩小了企业间工资差距。具体来说,市场化指数每增加一个单位,企业工资基尼系数将下降3.37%。该结果在更换收入差距衡量指标、更换研究样本后仍然稳健。机制分析显示,生产率差距缩小和劳动者企业间流转是市场化改革影响企业间工资差距的两个主要机制。此外,本文发现进入企业、中小企业和非国有企业间工资差距更小,且市场化改革缩小企业间工资差距的作用在这些企业组中更显著。本文研究结果显示,市场化改革可以促进收入分配结果公平,有助于推进全体人民共同富裕。 展开更多
关键词 市场化改革 生产率差距缩小 劳动者企业间流转 企业间工资差距 共同富裕
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The Climate Change in Qingdao during 1899-2015 and Its Response to Global Warming 被引量:1
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作者 Feiyan Guo Yan Ma +2 位作者 Kaijing Zhang lei han Lina Guo 《Journal of Geoscience and Environment Protection》 2018年第9期58-70,共13页
In this work, the average mean (TAvg), maximum (TMax), and minimum temperature (TMin) and precipitation records of Qingdao from 1899 to 2015 are analyzed. The TAvg, TMax and TMin all go through several warm and cold p... In this work, the average mean (TAvg), maximum (TMax), and minimum temperature (TMin) and precipitation records of Qingdao from 1899 to 2015 are analyzed. The TAvg, TMax and TMin all go through several warm and cold periods, and exhibit statistically significant linear warming trend especially in spring and winter, as a response to global warming. Besides, the TAvg reflects more the TMin evolution for the most part, either as a trend or an abrupt change, and the contribution of TMin to Tavg is far greater than that of TMax. The abrupt change year of climate is also around 1979 in Qingdao, and it is 2 or 3-years later than the TAvg for the TMin, while there is no abrupt change of TMax. In terms of the precipitation in Qingdao, it varies periodically and dramatically with a slow increasing trend. As for the seasonal precipitation, the precipitation varies widely year by year for the four seasons but with no obvious variation trend except for spring. 展开更多
关键词 CLIMATE TREND Global WARMING Temperature PRECIPITATION
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定子无铁心轴向磁通永磁电机的绕组损耗与效率研究
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作者 魏国 王率军 +2 位作者 雷晗 李绍民 周欣沂 《微特电机》 2023年第2期1-7,共7页
定子无铁心轴向磁通永磁电机没有定子铁心,具有输出转矩平稳、质量轻、装配简单等优势,但同时也存在绕组涡流损耗大的问题。基于利兹线绕组,对定子无铁心轴向磁通电机的绕组涡流损耗进行了分析,给出了绕组涡流损耗计算的解析公式与有限... 定子无铁心轴向磁通永磁电机没有定子铁心,具有输出转矩平稳、质量轻、装配简单等优势,但同时也存在绕组涡流损耗大的问题。基于利兹线绕组,对定子无铁心轴向磁通电机的绕组涡流损耗进行了分析,给出了绕组涡流损耗计算的解析公式与有限元结合的非均匀分层混合计算模型,并通过简化的全绕组三维有限元模型,验证了混合计算模型的正确性和有效性。研究了以电机效率最大化为目标的利兹线规格选型方法。由于利兹线的实际制造工艺的问题,对电机效率进行了计算和分析,并给出了利兹线选型相关的定性结论。 展开更多
关键词 轴向磁通电机 定子无铁心 绕组涡流损耗 利兹线
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开放式动态法金属热导率测量设备研发
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作者 张开骁 苑晓丽 +3 位作者 向圆圆 姚红兵 雷撼 钱仰德 《大学物理》 2023年第8期21-26,共6页
本文基于傅里叶热传导的实验原理,自主设计并开发了一种开放式动态法金属热导率实验测量设备.通过对实验测量结果与误差进行系统分析,给出了进一步提高实验测量精度的理论改进模型和对应的实验测量方法.相关实验设备、内容与原理对于大... 本文基于傅里叶热传导的实验原理,自主设计并开发了一种开放式动态法金属热导率实验测量设备.通过对实验测量结果与误差进行系统分析,给出了进一步提高实验测量精度的理论改进模型和对应的实验测量方法.相关实验设备、内容与原理对于大学物理实验教学具有一定借鉴意义,设备不仅可用于物理实验教学与科研实验,还可用于开放条件下的工业测量实践等. 展开更多
关键词 开放式 动态法 热导率 测量设备
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滇杨性别连锁的SSR标记
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作者 李启少 雷瀚 +6 位作者 沈伟祥 赵文植 王飞 徐剑 瞿绍宏 董章宏 辛培尧 《福建农业学报》 CAS CSCD 北大核心 2023年第8期953-959,共7页
【目的】在滇杨幼苗时期和开花前利用形态差异对雌雄株进行性别鉴定极为困难,因此亟需探明对其性别进行快速鉴定的分子标记方法。【方法】以滇杨雌雄各30株为材料,利用简单重复序列(SSR)筛选与滇杨性别相关的分子标记,并利用所获得的SS... 【目的】在滇杨幼苗时期和开花前利用形态差异对雌雄株进行性别鉴定极为困难,因此亟需探明对其性别进行快速鉴定的分子标记方法。【方法】以滇杨雌雄各30株为材料,利用简单重复序列(SSR)筛选与滇杨性别相关的分子标记,并利用所获得的SSR标记对未知性别滇杨幼苗进行鉴定,分析滇杨苗期的性别分化情况。【结果】从已报道的相关文献中选出15对与植物性别连锁的SSR引物,经试验筛选出1对(BPCA90)在琼脂糖凝胶检测中显现清晰条带且反应稳定的SSR引物,并将这对引物经聚丙烯酰胺凝胶电泳进行复筛,经PCR扩增后在滇杨雄株中出现1条特异性条带,大小在680 bp左右。利用这对SSR引物对30株滇杨幼苗进行性别鉴定,结果表明雄株明显多于雌株,且比例为13∶2。【结论】试验筛选所得到的SSR引物可以用于滇杨早期进行性别鉴定。研究结果可作为滇杨早期性别鉴定的遗传标记,为今后滇杨在生产中的分性别利用提供技术支持。 展开更多
关键词 滇杨 SSR 引物筛选 性别鉴定
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不同稻草还田技术对烟-稻轮作系统土壤养分、有机碳及微生物多样性的影响 被引量:2
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作者 黄锦文 李日坤 +6 位作者 陈志诚 张汴泓 雷涵 潘睿欣 杨铭榆 潘美清 唐莉娜 《中国水稻科学》 CAS CSCD 北大核心 2023年第4期415-426,共12页
【目的】探讨不同稻草还田技术措施对土壤特性的影响及根际微生物修复和改良土壤的内在机制,探索适合福建烟-稻轮作区的稻草高效还田技术,以期为烟-稻轮作区作物优质高效栽培提供依据。【方法】以烤烟“云烟87”和晚稻“甬优1540”为材... 【目的】探讨不同稻草还田技术措施对土壤特性的影响及根际微生物修复和改良土壤的内在机制,探索适合福建烟-稻轮作区的稻草高效还田技术,以期为烟-稻轮作区作物优质高效栽培提供依据。【方法】以烤烟“云烟87”和晚稻“甬优1540”为材料,通过不同的稻草还田配施技术处理,进行了2年的田间定位试验,分析比较了烟-稻轮作系统耕层土壤养分、根际微生物和作物产量的变化规律以及根际微生物与土壤环境因子间的内在关系。【结果】产量分析表明,连续2年稻草还田后,各处理产量均比对照显著增加,其中配施石灰和尿素的T_(2)处理最显著,其烟草和水稻产量分别比对照提高25.67%、11.49%;其次是配施腐秆灵和尿素的T_(3)处理,纯稻草T_(1)还田处理效果最差;T_(1)处理第1年稻草还田后烟草产量与对照差异不显著,第2年烟草和水稻产量分别比对照提高3.77%和5.90%。耕层土壤养分特性分析表明,经连续2年的稻草还田处理后,耕层土壤养分与有机碳含量均显著增加,其中T_(2)处理效果最好,其次是T_(3)处理。T_(2)处理碱解氮、有效磷、速效钾、有机碳和可溶性有机碳含量分别比对照提高了7.09%、5.97%、3.01%、11.32%和5.47%。根际微生物群落分析表明,与对照相比,T_(2)、T_(3)处理下碳源代谢相关的HSB_OF53-F07、自毒物质降解有关的节杆菌属(Arthrobacter)和纤维素分解有关的假散囊菌属(Pseudeurotium)丰度均显著上升,而与发病相关的腐质霉属(Humicola)和青霉菌属(Penicillium)相对丰度则显著下降。相关分析表明,根际有益菌丰度与土壤养分因子多为正相关,而致病菌的丰度则与土壤养分因子负相关。【结论】稻草还田配施石灰或腐秆灵和适量速效氮肥,有利于提高耕层养分含量,促进固氮等有益微生物生长,抑制病原菌,为烟-稻轮作提供良好的土壤环境,进而提高作物产量。 展开更多
关键词 稻草还田 烟-稻轮作 土壤养分 根际微生物 群落多样性
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深耕对烤烟产量产值及根际土壤微环境的影响
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作者 张汴泓 雷涵 +6 位作者 李日坤 杨铭榆 潘睿欣 潘美清 王成己 唐莉娜 黄锦文 《南方农业学报》 CAS CSCD 北大核心 2023年第8期2195-2206,共12页
【目的】探讨深耕栽培对烤烟产量产值及根际土壤特性和微生态系统的影响,以期为福建烟区构建合理耕层及建立烤烟优质高效栽培体系提供科学依据。【方法】以福建烟区自然耕深15 cm+中耕培土为对照(CK),设耕深20 cm+中耕培土(D1)、耕深25 ... 【目的】探讨深耕栽培对烤烟产量产值及根际土壤特性和微生态系统的影响,以期为福建烟区构建合理耕层及建立烤烟优质高效栽培体系提供科学依据。【方法】以福建烟区自然耕深15 cm+中耕培土为对照(CK),设耕深20 cm+中耕培土(D1)、耕深25 cm+中耕培土(D2)和耕深25 cm+免中耕培土(D3)3个深耕处理,对比分析各处理的烤烟产量产值及土壤理化性质差异,并采用Illumina MiSeq高通量测序技术,系统分析深耕处理下根际细菌结构差异与功能多样性变化,运用Spearman相关系数与随机森林模型评估根际细菌群落与土壤养分及烤烟产量的相关性。【结果】深耕可显著提高烤烟产量产值(P<0.05,下同),以D2处理增产增效效果最好,但与D3处理间差异不显著(P>0.05,下同)。土壤性质方面,各深耕处理均可较CK显著改善土壤总孔隙度和毛管孔隙度;土壤碱解氮含量及脲酶、蔗糖酶和过氧化氢酶活性随着耕深的加深而提高。适当深耕可显著提高细菌α多样性;深耕处理下绿弯菌门(Chloroflexi)与伯克氏菌属(Burkholderia)相对丰度显著上升,而罗河杆菌属(Rhodanobacter)相对丰度显著下降。Bugbase表型预测结果表明,深耕处理可显著提高根际土壤好氧菌与革兰氏阴性菌丰度,D2和D3处理较CK和D1处理显著提高氧化胁迫耐受菌相对丰度。FAPROTAX功能预测结果显示,各深耕处理均可较CK显著提升固氮作用(Nitrogen fixation)、纤维素分解(Cellulolsis)等养分循环方面功能相对丰度。随机森林模型预测结果显示,固氮作用是影响烤烟产量形成的最主要因素。【结论】在福建烟区耕层普遍变浅现状下,适度深耕(25 cm)对改善烤烟根际微生态环境有积极作用,但适度深耕下烤烟旺长前是否进行中耕培土对烤烟产量产值无显著影响。 展开更多
关键词 深耕 烤烟 根际土壤 高通量测序 随机森林模型
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从阳衰土湿论肠道菌群紊乱
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作者 唐永富 高颖 +3 位作者 孙杰培 雷晗 刘静 李霞(指导) 《光明中医》 2023年第19期3709-3712,共4页
肠道菌群紊乱致病学说是当今病因研究的一大热点,胃肠功能紊乱、内分泌系统疾病、自身免疫性疾病乃至癌症的发生都与其息息相关,粪菌移植治疗疾病疗效不一,究其根本乃是治标不治本的治疗手段,其生存的内环境没有改变,移植的益生菌很难... 肠道菌群紊乱致病学说是当今病因研究的一大热点,胃肠功能紊乱、内分泌系统疾病、自身免疫性疾病乃至癌症的发生都与其息息相关,粪菌移植治疗疾病疗效不一,究其根本乃是治标不治本的治疗手段,其生存的内环境没有改变,移植的益生菌很难生存下来,导致其疗效大打折扣。黄元御先生提出“阳衰土湿”的概念,认为“阳衰土湿”是大多数疾病的基本病机。“阳衰土湿”证候与肠道菌群紊乱病症在病因、症状上有共同的特点,因此研究“阳衰土湿”与肠道菌群紊乱之间的关系,辨证论治,实现异病同治,标本兼顾,提高临床疗效。 展开更多
关键词 肠道菌群紊乱 阳衰土湿 异病同治
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钢顶管纵向失稳特性及加固措施数值分析研究 被引量:1
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作者 孙任运 许大鹏 +2 位作者 宣锋 雷晗 何剑平 《特种结构》 2023年第4期12-17,共6页
由于钢顶管在施工过程中容易发生失稳破坏,对其稳定性以及加固措施进行研究对于保证钢顶管工程的安全具有重要意义。基于ABAQUS有限元软件建立了钢顶管模型,分析了不同长度钢顶管的失稳特性,并对环向加筋和纵向加筋两种加固措施的提升... 由于钢顶管在施工过程中容易发生失稳破坏,对其稳定性以及加固措施进行研究对于保证钢顶管工程的安全具有重要意义。基于ABAQUS有限元软件建立了钢顶管模型,分析了不同长度钢顶管的失稳特性,并对环向加筋和纵向加筋两种加固措施的提升作用进行了研究。研究发现:土弹簧刚度会影响钢顶管的变形特性和极限顶力;随长度的增大,钢顶管的极限顶力和纵向稳定性会下降;采用环向加筋和纵向加筋两种加固方式会改变长距离钢顶管的失稳形态并且有效提升钢顶管的极限顶力和纵向稳定性。研究可为钢顶管工程的设计与施工提供理论参考。 展开更多
关键词 钢顶管 稳定性 加固措施 ABAQUS
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MMP14 is a diagnostic gene of intrahepatic cholangiocarcinoma associated with immune cell infiltration
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作者 Jun Wu Yang Guo +2 位作者 Zhi-Fan Zuo Zi-Wei Zhu lei han 《World Journal of Gastroenterology》 SCIE CAS 2023年第19期2961-2978,共18页
BACKGROUND Intrahepatic cholangiocarcinoma(ICC)is a malignant tumor of the hepatobiliary system with concealed onset,strong invasiveness and poor prognosis.AIM To explore the disease characteristic genes that may be h... BACKGROUND Intrahepatic cholangiocarcinoma(ICC)is a malignant tumor of the hepatobiliary system with concealed onset,strong invasiveness and poor prognosis.AIM To explore the disease characteristic genes that may be helpful in the diagnosis of ICC and affect immune cell infiltration.METHODS We downloaded two ICC-related human gene expression profiles from GEO database as the training group(GSE26566 and GSE32958 datasets)for difference analysis,and performed enrichment analysis on differential genes.The least absolute shrinkage and selection operator(LASSO),support vector machinerecursive feature elimination(SVM-RFE)and random forest(RF),three machine learning algorithms,were used to screen the characteristic genes.Double verification was carried out on GSE107943 and The Cancer Genome Atlas,two verification groups.Receiver operating characteristic curve and area under the curve(AUC)were used to evaluate the diagnostic efficacy of genes for ICC.CIBERSORT and ssGSEA algorithms were used to evaluate the effect of characteristic genes on immune infiltration pattern.Human Protein Atlas(HPA)was used to analyze the protein expression level of the target gene.RESULTS A total of 1091 differential genes were obtained in the training group.Enrichment analysis showed that the above genes were mainly enriched in small molecular catabolism,complement and coagulation cascade,bile secretion and other functions and pathways.Twentyfive characteristic genes were screened by LASSO regression,19 by SVM-RFE algorithm,and 30 by RF algorithm.Three algorithms were used in combination to determine the characteristic gene of ICC:MMP14.The verification group confirmed that the genes had a high diagnostic accuracy(AUC values of the training group and the verification group were 0.960,0.999,and 0.977,respectively).Comprehensive analysis of immune infiltration showed that MMP14 could affect the infiltration of monocytes,activated memory CD4 T cells,resting memory CD4 T cells,and other immune cells,and was closely related to the expression of CD200,cytotoxic T-lymphocyteassociated antigen 4,CD14,CD44,and other immune checkpoints.The results of immunohistochemistry in HPA database showed was indeed overexpressed in ICC.CONCLUSION MMP14 can be used as a disease characteristic gene of ICC,and may regulate the distribution of immune-infiltrating cells in the ICC tumor microenvironment,which provides a new method for the determination of ICC diagnostic markers and screening of therapeutic targets. 展开更多
关键词 Intrahepatic cholangiocarcinoma MMP14 Machine learning Immune infiltration Characteristic gene Diagnostic markers
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30kW车载取力发电设备设计
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作者 周欣沂 贺廿六 +4 位作者 赵益 雷晗 王率军 李绍民 邹加壮 《移动电源与车辆》 2023年第1期9-13,17,共6页
为了解决大功率车载取力设备的设计需求,本文仔细阐述了30kW车载取力发电设备的组成与设计,从结构以及电气两方面描述了该取力发电设备的组成及工作原理,并将该取力发电设备分为四个部分进行详细设计,系统地展示了30kW车载取力发电设备... 为了解决大功率车载取力设备的设计需求,本文仔细阐述了30kW车载取力发电设备的组成与设计,从结构以及电气两方面描述了该取力发电设备的组成及工作原理,并将该取力发电设备分为四个部分进行详细设计,系统地展示了30kW车载取力发电设备的原理与设计思路,并进行了试验验证。 展开更多
关键词 取力发电设备 设计 车载
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基于三维非等温多相模型的质子交换膜燃料电池局部传质机理
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作者 雷涵 李小龙 +1 位作者 邓呈维 杨声 《华东理工大学学报(自然科学版)》 CAS CSCD 北大核心 2023年第6期828-835,共8页
为使质子交换膜燃料电池(PEMFC)内部的电极反应物和电极产物有一个更加稳定与均衡的分布,在燃料电池传统阴极蛇形流道的基础上,对其U形转弯入口及出口处进行渐缩渐扩处理,使流道U形转弯处侧壁形成一定角度的坡面,并建立了缩放坡面流道... 为使质子交换膜燃料电池(PEMFC)内部的电极反应物和电极产物有一个更加稳定与均衡的分布,在燃料电池传统阴极蛇形流道的基础上,对其U形转弯入口及出口处进行渐缩渐扩处理,使流道U形转弯处侧壁形成一定角度的坡面,并建立了缩放坡面流道的单电池三维数值模型。对比研究了不同几何参数对流道内液态水动力学行为、排水效率、反应气体质量分数、电池最大功率密度的影响,结果表明坡面结构在一定程度上引导了液滴的流动路径,使流道底面的气体扩散层(GDL)附近气流扰动增强,氧质量分数和电流密度分布更加均匀,最大功率密度得到了明显提高,整体上提高了PEMFC内部的传质能力。 展开更多
关键词 质子交换膜燃料电池(PEMFC) 流道设计 多相传热传质 过程强化 计算流体力学
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Recent progress in microbial cell surface display systems and their application on biosensors
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作者 HAIYING CHEN YUQING WU +1 位作者 BAOJIAN HUANG lei han 《BIOCELL》 SCIE 2023年第6期1213-1223,共11页
Microbial cell surface display technology is a recombinant technology to express target proteins on the cell membrane,which can be used to redesign the cell surface with functional proteins and peptides.Bacterial and ... Microbial cell surface display technology is a recombinant technology to express target proteins on the cell membrane,which can be used to redesign the cell surface with functional proteins and peptides.Bacterial and yeast surface display systems are the most common cell surface display systems of prokaryotic and eukaryotic proteins,that are widely applied as the core elements in the field of biosensors due to their advantages,including enhanced stability,high yield,good safety,expression of larger and more complex proteins.To further promote the performance of biosensors,the biomineralized microbial surface display technology was proposed.This review summarized the different microbial surface display systems and the biomineralized surface display systems,where the mechanisms of surface display and biomineralization were introduced.Then we described the recent progress of their applications on biosensors for different types of detection targets.Finally,the outlooks and tendencies were discussed and forecasted with the expectation to provide some general functions and enlightenments to this aspect of research. 展开更多
关键词 BIOSENSOR Microbial surface display technology Bacterial surface display Yeast surface display BIOMINERALIZATION Analytical chemistry
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神经母细胞瘤基因组结构性变异特征的研究进展
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作者 韩雷 杨嘉兴 +1 位作者 龚宝成 赵强 《中国肿瘤临床》 CAS CSCD 北大核心 2023年第9期458-462,共5页
神经母细胞瘤(neuroblastoma,NB)是起源于神经嵴细胞的儿童胚胎恶性肿瘤,表现为较强的生物学和临床异质性。基因组测序研究显示,NB具有较低的突变负荷和频发突变。NB表现为携带较多的基因组结构性变异,是其发生、发展的重要驱动因素。... 神经母细胞瘤(neuroblastoma,NB)是起源于神经嵴细胞的儿童胚胎恶性肿瘤,表现为较强的生物学和临床异质性。基因组测序研究显示,NB具有较低的突变负荷和频发突变。NB表现为携带较多的基因组结构性变异,是其发生、发展的重要驱动因素。临床上已将MYCN扩增和11q缺失等基因组结构性变异纳入风险分组中,但目前对于NB基因组结构性变异的了解与NB的生物学、临床复杂性仍存在差距。高通量基因组学技术的发展推动了研究者对NB基因组特征尤其是结构性变异特征有了更加全面的认识,为探索NB发生、发展机制以及更加精细的风险分层提供了数据基础。本文就近年来NB的基因组结构性变异特征研究进展进行综述。 展开更多
关键词 神经母细胞瘤 基因组特征 结构变异 预后价值
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