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Soil Organic Matter Composition in Coastal and Continental Date Palm Systems: Insights from Tunisian Oases

Pedosphere 2019年第4期29卷 444-456页

作者： Rawan K. MLIH Martina I. GOCKe Roland bol.Anne e. BeRNS Irabella FUHRMANN Nadhem BRAHIM Institute of Crop Science and resource Conservation University of Bonn Bonn 53115 (Germany) Agrosphere Institute (IBG-3) Forschungszentrum Julich GmbH Julich 52428 (Germany) Department of Geology University of Tunis El Manar Tunis 2092 (Tunisia)

In Tunisia, the coastal Chenini oasis is characterized by a lush vegetation cover, whereas more inland continental oases(e.g., the Guettaya oasis) have a very scarce vegetation cover. For sustaining date palm production in these areas, organic fertilizers are applied,either spread on the soil surface(in Chenini) or buried under a sand layer(in Guettaya). We examined at a molecular level how these management techniques affect soil organic matter composition in oasis systems. A dominance of fresh plant input for Guettaya was indicated by solid-state 13C nuclear magnetic resonance spectroscopy signals, which was most pronounced in the uppermost soil close to palms. evidence for more degraded organic matter was found in deeper soil near the palms, as well as in the soil distant from the palms. Amino sugar contents were low in the uppermost Guettaya soil near the palms. The overall microbial amino sugar residue contents were similar in range as those found in other dryland environments. With increasing distance from trees, the amino sugar contents declined in Guettaya, where the palms grow on bare soil, but this was not the case for Chenini, which has multi-layer vegetation cover under palms. In agreement with the results from previous dryland studies, the soil microbial community in both oasis systems was dominated by fungi in topsoil, and a shift toward bacteria-derived residues in subsurface soil. This might be due to higher variability of temperature and moisture in topsoil and/or lower degradability of fungal remains;however, further research is required to confirm this hypothesis.

关键词： amino sugar dryland microbial community soil organic carbon solid-state NMR subsoil amelioration total nitrogen

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High responsivity and Ultra-Low Detection Limits in Nonlinear a-Si:H p-i-n Photodiodes enabled by Photogating

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Photonic Sensors 2023年第4期13卷 27-38页

作者： Andreas BABLICH Maurice MÜLLeR Rainer BORNeMANN Andreas NACHTIGAL Peter HARING bol.VAR Institute of Graphene-Based Nanotechnology University of SiegenHölderlinstr.357076 SiegenGermany Institute of High Frequency and Quantum electronics University of SiegenHölderlinstr.357076 SiegenGermany

Photodetectors operating at the wavelength in the visible spectrum are key components in high-performance optoelectronic *** this work,massive nonlinearities in amorphous silicon p-i-n photodiodes enabled by the photogating are presented,resulting in responsivities up to 744 mA/W at blue *** detectors exhibit significant responsivity gains at optical modulation frequencies exceeding MHz and a more than 60-fold enhanced spectral response compared to the non-gated *** detection limits down to 10.4 nW/mm^(2) and mean signal-to-noise ratio enhancements of 8.5dB are demonstrated by illuminating the sensor with an additional 6.6μW/mm^(2) red ***-optical simulations verify photocarrier modulation due to defect-induced field screening to be the origin of such high responsivity *** experimental results validate the theory and enable the development of commercially viable and complementary metal oxide semiconductor(CMOS)compatible high responsivity photodetectors operating in the visible range for low-light level imaging and detection.

关键词： Photogating amorphous silicon a-Si:H nonlinearity photodetector responsivity gain

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The Current Status and Future Prospects of Forest Certification in Myanmar

The Current Status and Future Prospects of Forest Certificat...

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作者： ei Thandar bol 北京林业大学

学位级别：硕士

Myanmar had been practicing Sustainable Forest Management since1856. Although Myanmar had a long history in Forest Management, Myanmar does not have internationally recognized certification standard, such as FSC or PeFC. To get Forest Certification is the goal of our Sustainable Forest Management. Nowadays Myanmar faces preparation for potential negotiations with the european Union, ASeAN’s agreement and international organizations in the field of sustainable forest management. The main purpose of this study is that to explore about Forest Certification in Myanmar. In this thesis the researcher tries to analyze the level of Myanmar Forest Certification progress, to identify the key elements for the development and implementation of timber legality in Myanmar by using qualitative research methodology. Myanmar has started Timber Certification process in1988and achieved to some extent. However, it needs to go a long way especially to comply with the standards （C＆I） for the forest management certification. The analysis will also deal with the real situation of forest certification in Myanmar and also try to base on the COCs of timber legality tracking system, market functionality, status of C＆I, policy and remedial measure. It is concluded and argued in this thesis it evident that Myanmar is in a pioneer stage of forest certification and moved the topic on the national level. According to the management systems an adaptation of biodiversity conservation practices, RIL, Code of Forest Harvesting, Community Forest Instructions and Timber Legality Assurance System are some major achievements.

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Wear behavior of the raw and pre-smashed carbon nanotubes reinforced 6061Al composites fabricated by powder metallurgy

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Science China(Technological Sciences) 2022年第5期65卷 1149-1159页

作者： LI XiaoNan LIU ZhenYu ZAN YuNing XIAO bol. NI DingRui WANG QuanZhao WANG Dong MA ZongYi Shi-changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang110016China School of Materials Science and engineering University of Science and Technology of ChinaShenyang110016China

The raw and pre-smashed(PS)carbon nanotube(CNT)reinforced 6061Al composites(CNT/6061Al)with different CNT contents were respectively fabricated by powder metallurgy *** was found that reducing the CNT cluster size by presmashing processing could sharply reduce the friction coefficient,and significantly improve the density,hardness,and wear resistance of the CNT/6061Al *** the raw-CNT/6061Al composites,the wear rate increased approximately linear trend while the CNT content was over 1 wt.%.The plastic deformation,deep grooves,and serious delamination were presented on the wear *** wear process was gradually transformed from Al-copper base counterpart wear into Al-Al wear for the higher adhesion-binding energy between aluminum and copper base *** for the PS-CNT/6061Al composites,the wear rate gradually decreased as the CNT content increased from 0 to 2 wt.%.This was mainly because the generation of the thinner mechanically mixed layer(MML)and the PS-CNT prevented the direct contact between specimen and copper base counterpart,which effectively inhibited the adhesive *** excessive PS-CNTaddition(~3 wt.%)would weaken the bonding between CNT and 6061Al,and thus the wear resistance of the composite was reduced apparently.

关键词： wear carbon nanotube aluminum matrix composites clustering

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深冷循环对SiC/Al复合材料宏微观残余应力的影响

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金属学报 2024年第8期60卷 1031-1042页

作者：谷黎明冯效铭于朝张峻凡刘振宇何伦华卢怀乐李小虎王晨张晓东肖伯律马宗义中国科学院金属研究所、师昌绪先进材料创新中心沈阳110016 中国科学技术大学、材料科学与工程学院沈阳110016 散裂中子源科学中心东莞523803 中国科学院物理研究所、北京凝聚态物理国家研究中心北京100190 松山湖材料实验室东莞523808 中国科学院高能物理研究所北京100049

铝基碳化硅(SiC/Al)复合材料因其高比模量、高比强度和良好尺寸稳定性等特点广泛应用于精密光学领域。SiC/Al复合材料热处理过程中产生的宏/微观残余应力是影响其尺寸稳定性的关键因素。为了阐明残余应力的降低方法和效果,提高精密光学... 详细信息

铝基碳化硅(SiC/Al)复合材料因其高比模量、高比强度和良好尺寸稳定性等特点广泛应用于精密光学领域。SiC/Al复合材料热处理过程中产生的宏/微观残余应力是影响其尺寸稳定性的关键因素。为了阐明残余应力的降低方法和效果,提高精密光学零件的尺寸稳定性,本工作使用中子衍射和有限元模拟,分析了深冷循环处理对于体积分数为35%的SiC/6092Al复合材料在退火状态下宏微观残余应力的影响,研究了深冷循环次数、样品尺寸、增强相颗粒尺寸和深冷循环温度差等影响因素。结果表明,深冷循环能引起基体塑性应变,从而显著降低退火态SiC/Al复合材料的相应力,并且随着深冷循环次数的增加,单次循环相应力降低效果减弱。深冷循环导致的塑性应变集中在颗粒周围的基体,主要影响颗粒和周围基体的相应力大小,与样品尺寸无明显关联,并且深冷循环不增加退火态样品的宏观残余应力。复合材料多次深冷循环后的相应力降低量与SiC颗粒尺寸无关,并且,多次深冷循环对相应力的降低效果与深冷循环温度差关系较小,100~-196℃和200~-196℃进行多次深冷循环对相应力的改变十分接近。

关键词：深冷循环中子衍射残余应力有限元方法代表性体积单元

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CO_(2)emission and source partitioning from carbonate and non-carbonate soils during incubation

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Pedosphere 2022年第3期32卷 452-462页

作者： Yi ZHAO Roland bol.Zhaoan SUN Yuping ZHUGe Xiaoxia SHI Wenliang WU Fanqiao MeNG Beijing Key Laboratory of Biodiversity and Organic Farming College of Resources and Environmental SciencesChina Agricultural UniversityBeijing 100193(China) Institute of Bio-and Geosciences Agrosphere(IBG-3)Forschungszentrum Jülich GmbHJülich 52425(Germany) Key Laboratory of Biology and Molecular Biology in University of Shandong College of Biological and Agricultural EngineeringWeifang UniversityWeifang 261061(China) National engineering Laboratory for efficient Utilization of Soil and Fertilizer resources College of Resources and EnvironmentShandong Agricultural UniversityTai'an 271018(China) Sinocarbon Innovation&Investment Jiangsu Co. Ltd.(SCII)Nanjing 210046(China)

The accurate quantification and source partitioning of CO_(2)emitted from carbonate(i.e.,Haplustalf)and non-carbonate(i.e.,Hapludult)soils are critically important for understanding terrestrial carbon(C)*** two main methods to capture CO_(2)released from soils are the alkali trap method and the direct gas sampling method.A 25-d laboratory incubation experiment was conducted to compare the efficacies of these two methods to analyze CO_(2)emissions from the non-carbonate and carbonate-rich *** isotopic fraction was introduced into the calculations to determine the impacts on partitioning of the sources of CO_(2)into soil organic carbon(SOC)and soil inorganic carbon(SIC)and into C3 and/or C4 plant-derived *** results indicated that CO_(2)emissions from the non-carbonate soil measured using the alkali trap and gas sampling methods were not significantly *** the carbonate-rich soil,the CO_(2)emission measured using the alkali trap method was significantly higher than that measured using the gas sampling method from the 14 th day of incubation *** SOC and SIC each accounted for about 50%of total soil C in the carbonate-rich soil,SOC decomposition contributed 57%–72%of the total CO_(2)*** both non-carbonate and carbonate-rich soils,the SOC derived from C4 plants decomposed faster than that originated from C3 *** propose that for carbonate soil,CO_(2)emission may be overestimated using the alkali trap method because of decreasing CO_(2)pressure within the incubation jar,but underestimated using the direct gas sampling *** gas sampling interval and ambient air may be important sources of error,and steps should be taken to mitigate errors related to these factors in soil incubation and CO_(2)quantification studies.

关键词： alkali trap C3/C4 plant inorganic carbon stock isotope fractionation organic carbon stock

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Spatial-temporal variations and driving factors of soil organic carbon in forest ecosystems of Northeast China

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Forest ecosystems 2023年第2期10卷 141-152页

作者： Shuai Wang bol.Roland Kabindra Adhikari Qianlai Zhuang Xinxin Jin Chunlan Han Fengkui Qian College of Land and environment Shenyang Agricultural UniversityShenyang110866China Key Laboratory of ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources ResearchCASBeijing100101China Institute of Bio-and Geosciences Agrosphere(IBG-3)Forschungszentrum Jülich GmbHWilhelm-Johnen-Straße52428JülichGermany School of Natural Sciences Environment Centre WalesBangor UniversityBangorLL572UWUK USDA-ARS GrasslandSoil and Water Research LaboratoryTempleTX76502USA Department of earth Atmosphericand Planetary SciencesPurdue UniversityWest LafayetteIN47907USA

Forest soil carbon is a major carbon pool of terrestrial ecosystems,and accurate estimation of soil organic carbon(SOC)stocks in forest ecosystems is rather *** study compared the prediction performance of three empirical model approaches namely,regression kriging(RK),multiple stepwise regression(MSR),random forest(RF),and boosted regression trees(BRT)to predict SOC stocks in Northeast China for 1990 and ***,the spatial variation of SOC stocks and the main controlling environmental factors during the past 25 years were identified.A total of 82(in 1990)and 157(in 2015)topsoil(0–20 cm)samples with 12 environmental factors(soil property,climate,topography and biology)were selected for model *** selected80%of the soil sample data were used to train the models and the other 20%data for model verification using mean absolute error,root mean square error,coefficient of determination and Lin's consistency correlation coefficient *** found BRT model as the best prediction model and it could explain 67%and 60%spatial variation of SOC stocks,in 1990,and 2015,*** maps of all models in both periods showed similar spatial distribution characteristics,with the lower SOC in northeast and higher SOC in *** annual temperature and elevation were the key environmental factors influencing the spatial variation of SOC stock in both *** stocks were mainly stored under cambosols,Gleyosols and Isohumosols,accounting for 95.6%(1990)and 95.9%(2015).Overall,SOC stocks increased by 471 Tg C during the past 25 *** study found that the BRT model employing common environmental factors was the most robust method for forest topsoil SOC stocks *** spatial resolution of BRT model enabled us to pinpoint in which areas of Northeast China that new forest tree planting would be most effective for enhancing forest C ***,our approach is likely to be useful in forestry management and ecologic

关键词： Soil organic carbon stocks Forest ecosystem Spatial-temporal variation carbon sink Digital soil mapping

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Mechanical properties of(B_(4)C+Al_(2)O_(3))/Al neutron absorbing materials with various microstructures constructed by hot forging,rolling and extrusion

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Science China(Technological Sciences) 2022年第5期65卷 1206-1209页

作者： ZAN YuNing LI XinNan ZHOU Cong LIU ZhenYu WANG QuanZhao XIAO bol. MA ZongYi Key Laboratory of Nuclear Materials and Safety Assessment Institute of Metal ResearchChinese Academy of SciencesShenyang110016China Shi-changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang110016China Nuclear equipment Division Beijing Institute of Nuclear EngineeringChina Nuclear Power Engineering Co.Ltd.Beijing100840China

Neutron absorbing materials(NAMs)are necessary in the nuclear industry for the storage and transportation of spent *** all the NAMs,B_(4)C/Al composites are widely used because of the specific neutron absorption capacity[1–4].Compared with traditional low-strength functional NAMs such as B_(4)C/1100Al and B_(4)C/6061Al,NAMs with enough high-temperature(350℃)strength are competent for further structural usage and exhibit huge advantages in the dry storage of spent fuel because of heat transfer ability and weight reduction[5].

关键词： absorbing strength enough

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Stem cell therapy for faecal incontinence: Current state and future perspectives

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World Journal of Stem Cells 2018年第7期10卷 82-105页

作者： Jacobo Trébol.Ana carabias-Orgaz Mariano García-Arranz Damián García-Olmo General and Digestive Tract Surgery Department Salamanca University Healthcare Centre Anaesthesiology Department Complejo Asistencial de ávila New Therapies Laboratory Instituto de Investigación Sanitaria-Fundación Jiménez Díaz General and Digestive Tract Surgery Department Quiron-Salud Hospitals Surgery Department Universidad AutónomaMadrid

Faecal continence is a complex function involving different organs and systems. Faecal incontinence is a common disorder with different pathogeneses, disabling consequences and high repercussions for quality of life. Current management modalities are not ideal, and the development of new treatments is needed. Since 2008, stem cell therapies have been validated, 36 publications have appeared(29 in preclinical models and seven in clinical settings), and six registered clinical trials are currently ongoing. Some publications have combined stem cells with bioengineering technologies. The aim of this review is to identify and summarise the existing published knowledge of stem cell utilization as a treatment for faecal incontinence. A narrative or descriptive review is presented. Preclinical studies have demonstrated that cellular therapy, mainly in the form of local injections of muscle-derived(muscle derived stem cells or myoblasts derived from them) or mesenchymal(bone-marrow-or adipose-derived) stem cells, is safe. Cellular therapy has also been shown to stimulate the repair of both acute and subacute anal sphincter injuries, and some encouraging functional results have been obtained. Stem cells combined with normal cells on bioengineered scaffolds have achieved the successful creation and implantation of intrinsically-innervated anal sphincter constructs. The clinical evidence, based on adipose-derived stem cells and myoblasts, is extremely limited yet has yielded some promising results, and appears to be safe. Further investigation in both animal models and clinical settings is necessary to drawing conclusions. Nevertheless, if the preliminary results are confirmed, stem cell therapy for faecal incontinence may well become a clinical reality in the near future.

关键词： Faecal incontinence Anal sphincter Cell implantation Tissue engineering Cell therapy Stem cells

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与bol.话:Mousetrap

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英语沙龙（高中） 2006年第12期 4-5页

作者： bol

本期 Bob 给我们讲了一个有趣的故事:一只小老鼠发现房子里多了一个捕鼠器,就去和母鸡、小猪等其他动物商量,然而大家都觉得捕鼠器不会对自己造成威胁,所以对小老鼠态度冷淡。但是最后的结局却出乎意料,想必能对您有所启发。

关键词：捕鼠器故事动物母鸡小猪结局本期捕鼠夹威胁态度

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