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Rapid dendrite growth in quaternary Ni-based alloys

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Chinese Science Bulletin 2006年第8期51卷 897-901页

作者： song Xianzheng WANG Haipeng RUAN Ying wei Bingbo Department of Applied Physics Northwestern Polytechnical UniversityXi'an 710072 China

The high undercooling and rapid solidification of Ni-10%Cu-10%Fe-10%Co quaternary alloy were achieved by electromagnetic levitation and glass fluxing techniques. The maximum undercooling of 276 K (0.16TL) was obtained in the experiments. All the solidified samples are determined to be α-Ni single-phase solid solutions by DSC thermal analysis and X-ray diffraction analysis. The microstructure of the α-Ni solid solution phase transfers from dendrite to equiaxed grain with an increase in undercooling, accompanied by the grain refinement effect. When the undercooling is very large, the solute trapping effect becomes quite significant and the microseg-regation is suppressed. The experimental measure-ment of α-Ni dendrite growth velocity indicates that it increases with undercooling according to the relation, V=8×10?2×?T1.2.

关键词：镍基合金四元合金高过冷度枝晶长大快速凝固

SYNERGISTIC EFFECTS OF NOVOLAC-BASED CHAR FORMER WITH A PHOSPHORUS/NITROGEN-CONTAINING FLAME RETARD ANT IN POLYAMIDE 6

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Chinese Journal of Polymer Science 2012年第1期30卷 72-81页

作者： wei-cheng Xiong Li Chen De-yi Wang Fei song Yu-zhong Wang Center for Degradation an-d Flame--Retardant Polymeric Materials College of-Chemistry State Key Laboratory of Polymer Materials Engineering National Engineering Laboratory of Eco-Friendly Polymeric Materials （Sichuan） Sichuan University Chengdu 610064 China

The synergistic effect of phosphorus oxynitride（PON） with a novolac-based char former modified by salification （NA-metal salt） on the flame retardance of polyamide 6（PA6） was *** this purpose,various flame-retardant PA6 systems were melt-compounded with PON,PON/NA,PON/NA-V_2O_5 and PON/NA-Fe_2O_3,and their flame retardance was evaluated by measuring the limiting oxygen index（LOI） values and UL-94 vertical burning *** results showed that,compared with the PA6/PON/NA system,the combination of two char formers（NA-V_2O_5,NA-Fe_2O_3） with PON could obviously improve the char formation and flame retardance of *** flame retardance and cone calorimetric analyses showed the stronger synergism as well as the better flame retardant performance of PON/NA-Fe_2O_3 flame retardant system. The effects of different char formers on the flame retardance and thermal stability of this system were also discussed.

关键词： Polyamide Flame retardance Novolac resin Synergistic effect

Collision detection of virtual plant based on bounding volume hierarchy: A case study on virtual wheat

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Journal of Integrative Agriculture 2018年第2期17卷 306-314页

作者： TANG Liang song wei-guo HOU Tian-cheng LIU Lei-lei CAO wei-xing ZHU Yan National Engineering and Technology Center for Information Agriculture/Key Laboratory for Crop System Analysis and Decision Making Ministry of Agriculture/Jiangsu Key Laboratory for Information Agriculture/Jiangsu Collaborative Innovation Center for Modern Crop Production/Nanjing Agricultural University

Visualization of simulated crop growth and development is of significant interest to crop research and production. This study aims to address the phenomenon of organs cross-drawing by developing a method of collision detection for improving vivid 3D visualizations of virtual wheat crops. First, the triangular data of leaves are generated with the tessellation of non-uniform rational B-splines surfaces. Second, the bounding volumes（BVs） and bounding volume hierarchies（BVHs） of leaves are constructed based on the leaf morphological characteristics and the collision detection of two leaves are performed using the Separating Axis Theorem. Third, the detecting effect of the above method is compared with the methods of traditional BVHs, Axis-Aligned Bounding Box（AABB） tree, and Oriented Bounding Box（OBB） tree. Finally, the BVs of other organs（ear, stem, and leaf sheath） in virtual wheat plant are constructed based on their geometric morphology, and the collision detections are conducted at the organ, individual and population scales. The results indicate that the collision detection method developed in this study can accurately detect collisions between organs, especially at the plant canopy level with high collision frequency. This collision detection-based virtual crop visualization method could reduce the phenomenon of organs cross-drawing effectively and enhance the reality of visualizations.

关键词： wheat collision detection bounding volume hierarchy virtual plant morphology

Enhanced oil recovery by low-salinity water spontaneous imbibition (LSW-SI) in a typical tight sandstone formation of mahu sag from core scale to field scale

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Petroleum 2021年第3期7卷 272-281页

作者： Bing wei Lele Wang Tao song Mengying Zhong Mikhail A.Varfolomeev State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Southwest Petroleum UniversityChengdu610500China Department of Petroleum Engineering Kazan Federal UniversityKremlevskaya Str.18Kazan420008Russia

Accelerating mass exchange between matrix and fractures is the essence of enhanced oil recovery(EOR)in tight formations after natural *** salinity water(LSW)injection has been commerciallyproven in conventional reservoirs EOR,with scale projects in progress *** is,however,a lack of understanding of the EOR effect in tight ***,in this work,we introduced LSWEOR to a target tight formation using huff-puff *** imbibition(SI)tests were firstly performed on homogenous Berea sandstone cores with decreasing salinity brine to observe the production *** results indicated that the oil recovery of the tight rock was boosted by tuning brine *** all the used brines with salinity ranging from 0.021%to 2.1%TDS(total dissolved salinity),the 0.21%TDS brine showed a rapid increase in oil production over imbibing time,which finally led to an incremental oil recovery of 4.5%OOIP(original oil in place).Core-scale modeling was conducted by history-matching the oil recovery dynamics of the SI results through modifying capillary pressure and relative permeability.A full-scale reservoir model was constructed using micro-seismic data to model fracture geometry combing fracturing results and scaling parameters obtained from core scale *** is proven that LSW huff-n-puff stimulated the oil production after natural depletion and improved MEE(mass exchange efficiency)of the target formation,but the EOR benefit was not comparable to CO2 and surfactant-assisted water huff-puff methods.

关键词： Fractured tight formation Enhanced oil recovery Low-salinity effect Spontaneous imbibition Huff-n-puff

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种植年限对头花蓼土壤微生物群落的影响

西南农业学报 2024年第1期37卷 66-74页

作者：杨玲魏升华杜富强严福林朱勋翠安江勇贵州中医药大学药学院贵阳550025 兴黔科技发展有限公司贵阳550025

【目的】探明不同种植年限头花蓼土壤微生物(细菌和真菌)群落组成及物种多样性的变化趋势,从土壤微生物的角度探究其连作障碍机制,为贵州头花蓼产业的可持续发展提供理论依据。【方法】采用Illumina测序技术,以头花蓼与玉米轮作地块土... 详细信息

【目的】探明不同种植年限头花蓼土壤微生物(细菌和真菌)群落组成及物种多样性的变化趋势,从土壤微生物的角度探究其连作障碍机制,为贵州头花蓼产业的可持续发展提供理论依据。【方法】采用Illumina测序技术,以头花蓼与玉米轮作地块土壤为对照(CK),通过对头花蓼连续种植2年(T2)、3年(T3)和4年(T4)地块土壤微生物进行测序分析,研究种植年限对头花蓼土壤微生物群落的影响。【结果】随连作年限增加,细菌群落丰度呈上升趋势,丰度从1620.30升至1787.22,物种多样性逐渐趋于平稳;真菌群落丰度呈下降趋势,丰度从635.00降至612.89,物种多样性变化不大。细菌群落:门水平下,变形菌门与酸杆菌门为优势菌群,相对丰度总占比>64%;变形菌门相对丰度显著降低(从40.80%降至34.80%),酸杆菌门显著增加(从24.20%升至29.10%);变形菌门(40.80%、40.20%、37.60%和34.80%)、浮霉菌门(1.50%、1.50%、2.60%和2.50%)在不同连作年限间相对丰度存在显著差异;属水平下,uncultured_bacterium_c_Subgroup_6所占比例最大,为10.66%~20.50%。真菌群落:门水平下,子囊菌门和担子菌门为优势菌群,其相对丰度总占比>61%,较CK逐年下降;被孢霉门和壶菌门在连作第4年(T_(4))几乎完全消失。属水平下,被孢霉属占比最大,为2.66%~14.30%,在连作第3年(T3)出现多孢囊霉属真菌。【结论】连作加大了头花蓼土壤中微生物群落差异。随着连续种植年限增加,变形菌门细菌、被孢霉门被孢霉属真菌等相对丰度逐渐降低,酸杆菌门细菌、子囊菌门镰刀菌属真菌等相对丰度逐渐增加,可能是头花蓼连作障碍发生的原因之一。

关键词：头花蓼连作连作障碍土壤微生物

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A Regularized LSTM Method for Predicting Remaining Useful Life of Rolling Bearings

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International Journal of Automation and computing 2021年第4期18卷 581-593页

作者： Zhao-hua Liu Xu-Dong Meng hua-Liang wei Liang Chen Bi-Liang Lu Zhen-Heng Wang Lei Chen School of Information and Electrical Engineering Hunan University of Science and TechnologyXiangtan 411201China Department of Automatic Control and Systems Engineering University of SheffieldSheffield SI 3JDUK

Rotating machinery is important to industrial production. Any failure of rotating machinery, especially the failure of rolling bearings, can lead to equipment shutdown and even more serious incidents. Therefore, accurate residual life prediction plays a crucial role in guaranteeing machine operation safety and reliability and reducing maintenance cost. In order to increase the forecasting precision of the remaining useful life(RUL) of the rolling bearing, an advanced approach combining elastic net with long short-time memory network(LSTM) is proposed, and the new approach is referred to as E-LSTM. The E-LSTM algorithm consists of an elastic mesh and LSTM, taking temporal-spatial correlation into consideration to forecast the RUL through the LSTM. To solve the over-fitting problem of the LSTM neural network during the training process, the elastic net based regularization term is introduced to the LSTM *** this way, the change of the output can be well characterized to express the bearing degradation mode. Experimental results from the real-world data demonstrate that the proposed E-LSTM method can obtain higher stability and relevant values that are useful for the RUL forecasting of bearing. Furthermore, these results also indicate that E-LSTM can achieve better performance.

关键词： Deep learning fault diagnosis fault prognosis long and short time memory network(LSTM) rolling bearing rotating machinery regularization remaining useful life prediction(RUL) recurrent neural network(RNN)

Screening microsatellite markers from EST sequences of bay scallop Argopecten irradians

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High Technology Letters 2006年第1期12卷 97-102页

作者：王玲玲 song Linsheng Xu wei Zhang huan Institute of Oceanology Chinese Academy of Sciences Qingdao 266071 P.R. China Graduate School Chinese Academy of Sciences Beijing 100039 P.R. China

Seventy-five simple sequence repeats （SSRs） were identified by the bioinformatic analysis from 5008 expressed sequence tags （ESTs） of Argopecten irradians. Among the SSRs, the number of repeat nucleotide varied from 2 to 6. Dinucleotide and trinueleotide repeat motifs were dominant in EST-SSRs of bay scallop, with a proportion of 80% over the total screened SSRs. Twenty-nine pairs of primer were designed based on the flank sequences of the selected ESTs using the software of Primet 5, and verified under the given PCR reaction condition. Eighteen of the 29 primer pairs resulted in the expected products, while the remaining either failed to produce any fragments or yielded products over expected size. Thirteen of the 18 SSRs, accounting for 72%, were detected to show polymorphism in the examined scallop samples. A preliminary test in this study indicated that the majority of the identified SSRs were informative in the cultured bay scallops, making them suitable for the population and other genetic analysis. EST-SSR markers have more advantages than the traditional genomic-derived SSRs and there is a wide range of application in comparative mapping, functional gene cloning and marker assisted selection. This research provides a reference to the identification of EST-SSRs with relative bioinformatic analysis from aquaculture species, as well as to those with a large number of ESTs.

关键词： Argopecten irradians microsatellite markers expressed sequence tags

Double-layer microwave absorber of nanocrystalline strontium ferrite and iron microfibers

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Chinese Physics B 2012年第2期21卷 541-547页

作者： wei Chun-Yu Shen Xiang-Qian song Fu-Zhan School of Materials Science and Engineering Jiangsu UniversityZhenjiang 212013China

Microwave absorption properties of the nanocrystalline strontium ferrite （SrFe12O19） and iron （α-Fe） microfibers for single-layer and double-layer structures are investigated in a frequency range of 2 GHz 18 GHz. For the singlelayer absorbers, the nanocrystalline SrFe12O19 microfibers show some microwave absorptions at 6 GHz 18 GHz, with a minimum reflection loss （RL） value of -11.9 dB at 14.1 GHz for a specimen thickness of 3.0 mm, while for the nanocrystalline α-Fe microfibers, their absorptions largely take place at 15 GHz-18 GHz with the RL value exceeding -10 dB, with a minimum .RL value of about -24 dB at 17.5 GHz for a specimen thickness of 0.7 mm. For the doublelayer absorber with an absorbing layer of α-Fe microfibers with a thickness of 0.7 mm and matching layer of SrFe12O19 microfibers with a thickness of 1.3 ram, the minimum RL value is about -63 dB at 16.4 GHz and the absorption band width is about 6.7 GHz ranging from 11.3 GHz to 18 GHz with the RL value exceeding -10 dB which covers the whole Ku-band （12.4 GHz 18 GHz） and 27% of X-band （8.2 GHz 12.4 GHz）.

关键词： nanocrystalline microfibers microwave absorber double-layer structure

短凯伦藻高效溶藻菌Pseudoalteromonas shioyasakiensis SE3的分离、鉴定及溶藻作用研究

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海洋与湖沼 2024年第4期55卷 896-904页

作者：姚玉芳吴在兴袁涌铨贺立燕曹西华宋秀贤俞志明中国科学院海洋研究所、海洋生态与环境科学重点实验室山东青岛266071 青岛海洋科技中心、海洋生态与环境科学功能实验室山东青岛266237 中国科学院大学北京100049

微生物防控法以其生态调控功能和环境友好特征成为赤潮治理领域备受关注的一种方法。从短凯伦藻(Karenia brevis)藻际微生物中筛选出一株高效溶藻菌,研究了其对短凯伦藻的溶藻特性、溶藻作用方式及机制。经16S rDNA鉴定,该溶藻菌属于假... 详细信息

微生物防控法以其生态调控功能和环境友好特征成为赤潮治理领域备受关注的一种方法。从短凯伦藻(Karenia brevis)藻际微生物中筛选出一株高效溶藻菌,研究了其对短凯伦藻的溶藻特性、溶藻作用方式及机制。经16S rDNA鉴定,该溶藻菌属于假交替单胞菌属细菌Pseudoalteromonas shioyasakiensis SE3。结果表明,菌株SE3的溶藻效果不受细菌生长阶段的影响,主要受细菌数量的影响,当细菌密度为1.2×107 cells/mL时,在6 h即能达到100%的溶藻率。基于扫描与透射电镜等研究发现,菌株SE3主要以与藻细胞直接接触的作用方式溶藻,菌株SE3首先破坏短凯伦藻膜结构,侵入藻细胞内部,导致藻细胞的死亡。上述研究结果为利用藻际细菌防控赤潮提供了重要参考。

关键词：赤潮治理微生物方法溶藻细菌假交替单胞菌溶藻机制