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Numerical Simulation of Moisture Movement in Unsaturated Expansive Soil Slope Suffering Permeation

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Journal of China University of Geosciences 2005年第4期16卷 359-362页

作者： Chen Shanxiong Yu song Liu zhiguo Xu Haibin School of Civil Engineering and Mechanics Huazhong University of Science and Technology Wuhan 430074 China Institute of Rock and Soil Mechanics Chinese Academy of Sciences Wuhan 430071 China Institute of Rock and Soil Mechanics Chinese Academy of Sciences Wuhan 430071 China

This study develops a way of analyzing moisture movement in unsaturated expansive soil slope. The basic equations and the integrated finite difference method for moisture movement in unsaturated soils are briefly described, and the calculation code MFUS2 has been developed. The moisture movements in unsaturated expansive soil slopes suffering precipitation were simulated numerically. The simulation results show that expansion or contraction must be taken into account in an analysis model. A simplified equivalent model for calculating rainwater infiltration into expansive soil slopes has been developed. The simplified equivalent model divides the soil slope into two layers according to the extent of weathering of the soil mass at depth. Layer Ⅰ is intensively weathered and moisture can be fully evaporated or rapidly absorbed. The moisture movement parameters take into account the greater soil permeability caused by fissures. Layer Ⅱ is unweathered and the soil is basically undisturbed. The moisture movement parameters of homogeneous soils are applicable. The moisture movements in unsaturated ex- pansive soil slopes suffering precipitation were simulated numerically using the simplified equivalent model. The simulation results show that the moisture movement in the expansive soil slope under rainfall permeation mainly takes place in the extensively weathered layer Ⅰ which closely simulates the real situation.

关键词： expansive soils unsaturated soil slope infiltration transient distribution of water content.

制动装置耐低温橡胶密封材料的研制及其与润滑脂适配性的研究

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橡胶工业 2024年第3期71卷 211-215页

作者：刘金朋刘志国曹江勇张晓林丁琦宋传云青岛博锐智远减振科技有限公司山东青岛266114 中车青岛四方车辆研究所有限公司山东青岛266031

分析轨道车辆制动装置橡胶密封件在低温下的失效形式及原理,通过优化配方研制耐低温橡胶密封材料,研究耐低温橡胶密封材料与润滑脂的适配性,通过橡胶密封件的低温密封试验以及疲劳试验对耐低温橡胶密封材料进行验证。结果表明:Molykote... 详细信息

分析轨道车辆制动装置橡胶密封件在低温下的失效形式及原理,通过优化配方研制耐低温橡胶密封材料,研究耐低温橡胶密封材料与润滑脂的适配性,通过橡胶密封件的低温密封试验以及疲劳试验对耐低温橡胶密封材料进行验证。结果表明:Molykote 55润滑脂对耐低温橡胶密封材料的体积变化率、物理性能及耐低温性能影响较小,适合作为制动装置的润滑脂;所制橡胶密封件可满足-55℃低温气密性以及疲劳寿命要求。

关键词：耐低温密封材料橡胶密封件丁腈橡胶润滑脂制动装置

Effect of aerial spray adjuvant applying on the efficiency of small unmanned aerial vehicle for wheat aphids control

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International Journal of Agricultural and Biological Engineering 2018年第5期11卷 46-53页

作者： Yanhua Meng Yubin Lan Guiying Mei Yongwang Guo Jianli song zhiguo Wang College of Engineering South China Agricultural UniversityGuangzhou 510642China National Center for International Collaboration Research on Precision Agricultural Aviation Pesticide Spraying Technology Guangzhou 510642China School of Environmental Sciences University of GuelphGuelphONN1G 2W1Canada The National Agro-Tech Extension and Service Center Beijing 100125China College of Science China Agricultural UniversityBeijing 100193China Key Laboratory of Aviation Plant Protection Ministry of Agriculture and Rural AffairsBeijing 100193China Anyang Quanfeng Biological Technology Co. LtdAnyang 455000China

Small unmanned aerial vehicles(UAVs)have been widely used in different aspects of modern farming management,including pest and disease control in China in recent *** this study,the spray performance of a small plant protection UAV at low volume spray was evaluated by adjusting the pesticide dosage and adding aerial spraying *** deposition,droplet density,coverage,control effect and pesticide residue from field trials were *** addition,the residue and control effect of UAV spray were compared to manual knapsack at high volume *** results showed that,the adjuvant applying improved the efficiency of UAV ***,the adjuvant applying reduced the dosage of imidacloprid by 20%.However,there was no significant difference on initial residue between UAV spray and knapsack ***,plant protection UAV spraying pesticide by adding appropriate adjuvant showed the ability of improving the pesticide effectiveness by improving the control efficiency,reducing the pesticide dosage and residue.

关键词： unmanned aerial vehicle(UAV) aerial spraying adjuvant deposition control efficiency pesticide residue wheat aphid

结直肠锯齿状息肉相关研究热点及趋势的可视化分析

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实用临床医药杂志 2024年第12期28卷 92-95,117页

作者：宋姝李志国郭在强苏丽双北京市丰台中西医结合医院消化内分泌科北京100853

目的采用CiteSpace软件对结直肠锯齿状息肉相关研究的现状、热点及难点进行分析。方法在中国知网(CNKI)数据库检索中文文献,检索时间为建库至2023年3月6日。在Medline数据库检索英文文献,检索时间为建库至2023年3月21日。采用CiteSpace... 详细信息

目的采用CiteSpace软件对结直肠锯齿状息肉相关研究的现状、热点及难点进行分析。方法在中国知网(CNKI)数据库检索中文文献,检索时间为建库至2023年3月6日。在Medline数据库检索英文文献,检索时间为建库至2023年3月21日。采用CiteSpace软件绘制可视化图谱,并对发文量、机构、关键词进行可视化分析。结果本研究共纳入中文文献198篇,北京军区总医院发表文献最多。“病理学”关键词出现频次最高,临床、内镜特征学为近年来研究热点。本研究共纳入英文献1257篇。关键词“colorectal cancer”(结直肠癌)出现频次最高,腺瘤检测、结肠癌筛查、计算机辅助检测、腺瘤漏诊率、人工智能为近年来研究热点。结论国内外有关结直肠锯齿状息肉的研究热度逐渐增高,研究热点集中于腺瘤检测、结肠癌筛查、计算机辅助检测、腺瘤漏诊率、人工智能。

关键词：结直肠锯齿状息肉 CiteSpace软件可视化分析结直肠癌

黄芪建中汤合暖胃汤治疗患儿脾胃虚寒型急性肠胃炎

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吉林中医药 2024年第4期44卷 440-443页

作者：李海华宋金岭张志国王芳河北省沧州中西医结合医院河北沧州061000

目的观察黄芪建中汤合暖胃汤治疗脾胃虚寒型急性肠胃炎患儿的疗效。方法选取2021年2月-2023年5月医院收治的74例脾胃虚寒型急性肠胃炎患儿,以随机数字表法分为研究组与对照组,各37例。2组均接受对症治疗,对照组在此基础上采用奥美拉唑... 详细信息

目的观察黄芪建中汤合暖胃汤治疗脾胃虚寒型急性肠胃炎患儿的疗效。方法选取2021年2月-2023年5月医院收治的74例脾胃虚寒型急性肠胃炎患儿,以随机数字表法分为研究组与对照组,各37例。2组均接受对症治疗,对照组在此基础上采用奥美拉唑肠溶胶囊治疗,研究组在对照组的基础上接受黄芪建中汤合暖胃汤治疗。2组均治疗14 d。对比2组中医证候评分、病症恢复时间、临床疗效、炎症反应、胃肠激素及不良反应。结果治疗后,2组主症评分、次症评分、总评分明显降低(P0.05)。结论黄芪建中汤合暖胃汤治疗脾胃虚寒型急性肠胃炎患儿疗效确切,可改善患儿临床症状与胃肠功能,促进患儿康复,减轻炎症反应,且安全可靠。

关键词：黄芪建中汤暖胃汤脾胃虚寒型急性胃肠炎小儿临床疗效安全性

Effect of N fertilization rate on soil alkalihydrolyzable N, subtending leaf N concentration,fiber yield, and quality of cotton

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The Crop Journal 2016年第4期4卷 323-330页

作者： Binglin Chen Hongkun Yang Weichao song Chunyu Liu Jiao Xu Wenqing Zhao zhiguo Zhou Key Laboratory of Crop Physiology Ecology and Production Management Nanjing Agricultural UniversityJiangsu Collaborative Innovation Center for Modern Crop Production

Soil alkali-hydrolyzable nitrogen, which is sensitive to N fertilization rate, is one of the indicators of soil nitrogen supplying capacity. Two field experiments were conducted in Dongtai(120°19″ E, 32°52″ N), Jiangsu, China in 2009 and Dafeng(120°28″ E, 33°12″ N), Jiangsu province, China in 2010. Six nitrogen rates(0, 150, 300, 375, 450, and 600 kg ha^(-1)) were used to study the effect of N fertilization rate on soil alkali-hydrolyzable nitrogen content(SAHNC), subtending leaf nitrogen concentration(SLNC), yield, and fiber quality. In both Dongtai and Dafeng experiment station, the highest yield(1709 kg ha^(-1)), best quality(fiber length 30.6 mm, fiber strength 31.6 c N tex^(-1), micronaire 4.82), and highest N agronomic efficiency(2.03 kg kg^(-1)) were achieved at the nitrogen fertilization rate of 375 kg ha^(-1). The dynamics of SAHNC and SLNC could be simulated with a cubic and an exponential function,respectively. The changes in SAHNC were consistent with the changes in SLNC. Optimal average rate(0.276 mg day^(-1)) and duration(51.8 days) of SAHNC rapid decline were similar to the values obtained at the nitrogen rate of 375 kg ha^(-1)at which cotton showed highest fiber yield, quality, and N agronomic efficiency. Thus, the levels and strategies of nitrogen fertilization can affect SAHNC dynamics. The N fertilization rate that optimizes soil alkali-hydrolyzable nitrogen content would optimize the subtending leaf nitrogen concentration and thereby increase the yield and quality of the cotton fiber.

关键词： Cotton(Gossypium hirsutum L) Soil alkali-hydrolyzable nitrogen Subtending leaf nitrogen concentration Fiber yield Fiber properties Nitrogen use efficiency

Enhancement of solar-driven photocatalytic activity of oxygen vacancy-rich Bi/BiOBr/Sr_(2)LaF_(7)∶Yb^(3+),Er^(3+)composites through synergetic strategy of upconversion function and plasmonic effect

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Journal of Environmental Sciences 2022年第5期34卷 76-87页

作者： Yongjin Li Yingying Zhang Jiajing Wang Youzhun Fan Taizhong Xiao Zhaoyi Yin Tianhui Wang Jianbei Qiu zhiguo song School of Materials Science and Engineering Kunming University of Science and TechnologyKunming 650093China

For better use of solar energy,the development of efficient broadband photocatalyst has attracted extraordinary *** this study,a ternary composite consisting of Sr_(2)LaF_(7)∶Yb^(3+),Er^(3+)upconversion(UC)nanocrystals and Bi nanoparticles loaded BiOBr nanosheets with oxygen vacancies(OVs,SLFBB)was designed and synthesized by multi-step solvent-thermal *** of in-situ formation of Bi nanoparticles and OVs in BiOBr/Sr_(2)LaF_(7)∶Yb^(3+),Er^(3+)composites(SFLB)are *** Bi metal and OVs enhanced the light-harvesting capacity in the region of visible-near-infrared(Vis-NIR),and promoted the separation of electron-hole(e-/h+)***,the surface plasmon resonance(SPR)effect of Bi metal can improve the energy transfer from Sr_(2)LaF_(7)∶Yb^(3+),Er^(3+)to BiOBr via nonradiative energy transfer process,resulting in enhancing the light utilization from up-converting NIR into Vis *** to the synergistic effects of UC function,SPR and OVs,the SFLBB exhibited obviously enhanced photocatalytic ability for the degradation of BPA with a rate of 8.9×10^(-3) min^(-1),which is about 2.78 times higher than 3.2×10^(-3) min^(-1) of BiOBr(BOB)under UV-Vis-NIR light *** work provides a novel strategy for the project of high-efficiency Bismuth-based broadband photocatalysts,which is helpful to fur-ther understand the mechanism of enhanced photocatalysis by UC function and plasmonic effect.

关键词： BiOBr/Sr_(2)LaF_(7)∶Yb^(3+),Er^(3+)composites In-situ generation Bi metal Oxygen vacancies Broadband photocatalysis

A robust ethane-trapping metal-organic framework for efficient purification of ethylene

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Science China Chemistry 2021年第4期64卷 666-672页

作者： Sisi Jiang Liangying Li Lidong Guo Changhua song Qiwei Yang zhiguo Zhang Yiwen Yang Qilong Ren Zongbi Bao Key Laboratory of Biomass Chemical Engineering of the Ministry of Education College of Chemical and Biological EngineeringZhejiang UniversityHangzhou 310027China Institute of Zhejiang University-Quzhou Quzhou 324000China

Owing to the similar physicochemical properties between ethane(C_(2)H_(6))and ethylene(C_(2)H_(4)),obtaining polymerization-grade C_(2)H_(4)(≥99.95%pure)is still a tricky problem in the petrochemical ***,we report a robust scandium-based metalorganic framework(Sc BPDC),which is connected by oxygen-rich phenyl ligand with exceptionally high thermal stability(up to873 K)and capacity of C_(2)H_(6)(4.94 mmol/g at 100 k Pa and 283 K),exhibiting superior separation performance of C_(2)H_(6)/C_(2)H_(4) mixture(the IAST selectivity is up to 1.7 at 283 K).Importantly,Sc BPDC can produce 8.96 L/kg C_(2)H_(4) with≥99.99%purity while the C_(2)H_(4)/C_(2)H_(6)(50:50,v/v)as the mixture injection and the low isosteric heat of Sc BPDC(16.4 k J/mol for C_(2)H_(6))validates the facility of adsorbent ***,theoretical calculations demonstrate the C_(2)H_(6) molecules are trapped in the nonpolar pore surface via C–H···πand C–H···O interactions between multiple hydrogen atoms of C_(2)H_(6) and the host framework.

关键词： metal-organic frameworks adsorption separation ethane ethylene

On the timing of the East Asian summer monsoon maximum during the Holocene—Does the speleothem oxygen isotope record reflect monsoon rainfall variability?

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Science China Earth Sciences 2016年第12期59卷 2328-2338页

作者： CHEN JianHui RAO zhiguo LIU JianBao HUANG Wei FENG song DONG GuangHui HU Yu XU QingHai CHEN FaHu Key Laboratory of West China s Environmental System(Ministry of Education) College of Earth and Environmental SciencesLanzhou University Department of Geosciences University of Arkansas Institute of Nihewan Archaeology Research Hebei Normal University

The evolution of the East Asian summer monsoon(EASM) during the Holocene has long been of significant *** of past EASM variability not only increases our understanding of monsoon dynamics on a long timescale,but it also provides an environmental and climatic background for research into Chinese cultural ***,the timing of the EASM maximum remains *** popular concept of an "early Holocene maximum" is mainly based on speleothemδ18O(δ18Oc) records from caves in southern China;however,the interpretation of δ18OCas a reliable proxy for EASM intensity is being increasingly *** present paper is a critical review of the climatic significance of the δ18OCrecord from ***,we suggest that precipitation in northern China is an appropriate index of EASM intensity,the variation of which clearly indicates a mid-Holocene monsoon ***,an interregional comparison demonstrates that the precipitation record in northern China is quite different from that in southern China on a range of timescales,and is inconsistent with the spatial similarity exhibited by speleothem oxygen isotope ***,both modeling and observational data show that the δ18OCrecords from southern China indeed reflect changes in precipitation δ18O(δ18OP) rather than precipitation amount,and therefore that their use as an EASM proxy is ***,we address several significant monsoon-related issues-including the driving mechanism of the EASM on an orbital timescale,the climatic significance of speleothem oxygen isotopes,and the relationship between atmospheric circulation and precipitation in monsoonal regions.

关键词： East Asian summer monsoon Holocene Speleothem oxygen isotopes