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Response of warm season secondary pollutants to emissions and meteorology in the North China Plain region during 2018-2022
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作者 Yueqi Gao Siyu Wang +7 位作者 zhaolei zhang Wenxuan Yu Shuai Wang Shengqiang Zhu Peng Wang Yan Li Yele Sun Hongliang zhang 《Atmospheric and Oceanic Science Letters》 CSCD 2024年第4期58-64,共7页
自2013年起中国空气质量虽改善,但华北平原(NCP)重污染仍存在且二次污染加剧,而人们对其成因和变化了解有限.本研究利用2018-2022年数据,惜助CMAQ模型探讨此污染响应.结果显示,在2018-2022年间,PM_(2.5)浓度显著下降31%-37%,O_(3)和NO_... 自2013年起中国空气质量虽改善,但华北平原(NCP)重污染仍存在且二次污染加剧,而人们对其成因和变化了解有限.本研究利用2018-2022年数据,惜助CMAQ模型探讨此污染响应.结果显示,在2018-2022年间,PM_(2.5)浓度显著下降31%-37%,O_(3)和NO_(2)的年下降速率分别为1%和0.5%SIA和SOA也显著减少,每年分别减少9%和6%PM_(2.5)主要因排放减少而下降,而O_(3)则受气象影响而波动.硫酸盐和铵下降的主因是减排,而硝酸盐对气象变化敏感排放和气象变化对SOA的总体臧少同样重要,但人为SOA对排放控制敏感生物SOA易受气象变化影响.研究强调了控制人为排放对缓解NCP地区夏季二次污染的重要性. 展开更多
关键词 PM_(2.5) 二次污染物 人为排放 气象 华北平原
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Design and Test of the Semi-Automatic Test-Bed with Inclined Belt of Garlic Transplanting Machine 被引量:2
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作者 zhaolei zhang Aijun Geng +2 位作者 Jianning Yang Ruxin Li Jialin Hou 《American Journal of Plant Sciences》 2015年第19期3298-3305,共8页
In order to verify the feasibility of semi-automatic garlic planter with inclined belt program and determine its reasonable operating parameters, the semi-automatic test-bed with inclined belt of garlic transplanting ... In order to verify the feasibility of semi-automatic garlic planter with inclined belt program and determine its reasonable operating parameters, the semi-automatic test-bed with inclined belt of garlic transplanting machine was designed, and the garlic box experiments were conducted. The angle of inclined belt on the test-bed and its running speed were adjustable. Single factor test results showed that the program of the semi-automatic garlic planter with inclined belt was feasible, and the angle of inclined belt and the test bed running speed affected the indicators. Orthogonal experiment results showed that the angle of inclined belt was the main factor affecting the test indicators. It is also found that the best angle was 30 degrees, while the most reasonable running speed was 0.75 Km/h. 展开更多
关键词 GARLIC PLANTER Inclined BELT TEST-BED
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Enrichment analysis of Alu elements with different spatial chromatin proximity in the human genome 被引量:4
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作者 Zhuoya Gu Ke Jin +7 位作者 M. James C. Crabbe Yang zhang Xiaolin Liu Yanyan Huang Mengyi Hua Peng Nan zhaolei zhang Yang Zhong 《Protein & Cell》 SCIE CAS CSCD 2016年第4期250-266,共17页
Transposable elements (TEs) have no longer been totally considered as "junk DNA" for quite a time since the continual discoveries of their multifunctional roles in eukaryote genomes. As one of the most important a... Transposable elements (TEs) have no longer been totally considered as "junk DNA" for quite a time since the continual discoveries of their multifunctional roles in eukaryote genomes. As one of the most important and abundant TEs that still active in human genome, Alu, a SINE family, has demonstrated its indispensable regulatory functions at sequence level, but its spatial roles are still unclear. Tech- nologies based on 3C (chromosome conformation capture) have revealed the mysterious three-dimensional structure of chromatin, and make it possible to study the distal chromatin interaction in the genome. To find the role TE playing in distal regulation in human genome, we compiled the new released Hi-C data, TE annotation, histone marker annotations, and the genome-wide methylation data to operate correlation analysis, and found that the density of Alu elements showed a strong positive correlation with the level of chromatin interactions (hESC: r= 0.9, P〈 2.2 × 10^16; IMRg0 fibroblasts: r= 0.94, P 〈 2.2 ×10^16) and also have asignificant positive correlation with some remote functional DNA elements like enhancers and promoters (Enhancer: hESC: r= 0.997, P= 2.3× 10^-4; IMR90: r- 0.934, P= 2 × 10^-2; Promoter: hESC: r= 0.995, P= 3.8 × 10^-4; IMR90: r= 0.996, P = 3.2 × 10^-4). Further investigation involving GC content and methylation status showed the GC content of Alu covered sequences shared a similar pattern with that of the overall sequence, suggesting that Alu elements also function as the GC nucleotide and CpG site provider. In all, our results suggest that the Alu elements may act as an alternative parameter to evaluate the Hi-C data, which is confirmed by the correlation analysis of Alu elements and histone markers. Moreover, the GC-rich Alu sequence can bring high GC content and methylation flexibility to the regions with more distal chromatin contact, regulating the transcription of tissue-specific genes. 展开更多
关键词 chromatin interaction alternativeparameter of Hi-C data open chromatin methylationpotential
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