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用气相色谱-质谱法测定纺织柔软剂中的环硅氧烷

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纺织学报 2020年第8期41卷 69-73,80页

作者：于岩章若红钟毅杜英英毛志平徐红东华大学生态纺织教育部重点实验室上海201620 上海市质量监督检验技术研究院上海201114

为开发纺织柔软剂中环硅氧烷高效定量分析方法,建立了气相色谱-质谱(GC-MS)联用测定纺织柔软剂中环硅氧烷的分析方法。利用乙酸乙酯作为提取溶剂对样品进行振荡提取,并将提取的溶液经过滤后与六甲基二硅氮烷进行衍生化反应,反应后的溶... 详细信息

为开发纺织柔软剂中环硅氧烷高效定量分析方法,建立了气相色谱-质谱(GC-MS)联用测定纺织柔软剂中环硅氧烷的分析方法。利用乙酸乙酯作为提取溶剂对样品进行振荡提取,并将提取的溶液经过滤后与六甲基二硅氮烷进行衍生化反应,反应后的溶液采用GC-MS进行检测。结果表明:在混合标准溶液质量浓度为1~100 mg/L范围内,GC-MS法测定八甲基环四硅氧烷(D4)、十甲基环五硅氧烷(D5)和十二甲基环六硅氧烷(D6)的峰面积与混合标准溶液质量浓度具有良好的线性关系,相关系数R^2≥0.9953;GC-MS法的检出限为0.1170~0.2010 mg/L,定量限为0.3900~0.6700 mg/L,重复性和稳定性相对标准偏差分别小于1.0%和7.4%,样品加标回收率为89.8%~114.3%,相对标准偏差为1.3%~6.4%,满足检测的要求;GC-MS法的操作简单,可精准地检测出纺织柔软剂中D4、D5、D6的微量残留。

关键词：气相色谱-质谱联用法纺织柔软剂环硅氧烷测定八甲基环四硅氧烷十甲基环五硅氧烷十二甲基环六硅氧烷

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平幅轧染中针织物形变对染色的影响

纺织学报 2019年第11期40卷 94-99页

作者：王秋平毛志平钟毅徐红张琳萍东华大学化学化工与生物工程学院上海201620 东华大学生态纺织教育部重点实验室上海201620 东华大学纺织科技创新中心上海201620

针对平幅轧染中针织物易形变、张力不均带来皱褶和染色不匀等问题,通过选用多种化学结构活性染料对棉针织物进行浸轧染色,借助方差分析的手段,考察针织物在不同拉伸形变条件下固色后染料结构对染色性能的影响。结果表明:针织物采用不同... 详细信息

针对平幅轧染中针织物易形变、张力不均带来皱褶和染色不匀等问题,通过选用多种化学结构活性染料对棉针织物进行浸轧染色,借助方差分析的手段,考察针织物在不同拉伸形变条件下固色后染料结构对染色性能的影响。结果表明:针织物采用不同活性基活性红实施平幅轧染,无论在横向还是纵向张力拉伸条件下预烘及汽蒸固色,拉伸对针织物的染色与匀染影响较小;由于染料结构的差异导致棉针织物对染料的吸附固色不同,不同的染料对同一种针织物的浸轧染色提升力有所区别;染中浅色时轧染可节省更多染料,尤其对于活性红WBRH(KN型),轧染色深明显高于浸染,更推荐轧染方式;染色后针织物皂洗牢度大于或等于4级。

关键词：针织物平幅形变轧染活性染料

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纺织品中喹啉含量的快速测定

纺织学报 2022年第12期43卷 125-130页

作者：尹喆赵海浪徐红毛志平谭玉静东华大学生态纺织品教育部重点实验室上海201620 上海市质量监督检验技术研究院上海200040

为解决现有纺织品中喹啉化学提取法样品提取时间长、有机试剂用量大的问题,建立了热裂解/热脱附-气相色谱-质谱(Py/TD-GC-MS)法快速测定纺织品中喹啉的分析方法。该方法所测样品无需处理,直接在热裂解/热脱附装置中热脱附出喹啉,再进入... 详细信息

为解决现有纺织品中喹啉化学提取法样品提取时间长、有机试剂用量大的问题,建立了热裂解/热脱附-气相色谱-质谱(Py/TD-GC-MS)法快速测定纺织品中喹啉的分析方法。该方法所测样品无需处理,直接在热裂解/热脱附装置中热脱附出喹啉,再进入气相色谱-质谱联用仪进行定性和定量测定。针对喹啉标准溶液中喹啉在等待分析过程中挥发的问题,加入了聚氯乙烯(PVC)作为喹啉的吸附剂,提高喹啉标准溶液分析的准确性;确定了热脱附条件:温度为240℃,时间为6 s,升温速率为50℃/min,接口温度为300℃。结果表明,该方法在线性范围10~1000 mg/kg内,相关系数为0.994,方法检出限为3.520 mg/kg,定量限为11.760 mg/kg,加标回收率为90.02%~102.07%,相对标准偏差为1.27%~4.53%,适用于纺织品中喹啉的快速测定。

关键词：纺织品喹啉吸附剂热脱附-气相色谱-质谱分析快速测定聚氯乙烯

新型氮杂杯[4]吡啶[4]嘧啶的合成与晶体结构研究

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有机化学 2013年第12期33卷 2607-2611页

作者：杨梓君尹冲张琳萍钟毅徐红毛志平东华大学化学化工与生物工程学院生态纺织教育部重点实验室上海201620

从简单易得的2,6-二溴吡啶、4,6-二氯嘧啶两种原料出发,通过钯催化的"2+2"片段偶联法,简捷有效地合成了一种新型氮杂杯[4]吡啶[4]嘧啶,产物结构通过IR,1H NMR,13C NMR和HRMS进行了表征;并培养得到了氮杂杯[4]吡啶[4]嘧啶的晶体,对其晶... 详细信息

从简单易得的2,6-二溴吡啶、4,6-二氯嘧啶两种原料出发,通过钯催化的"2+2"片段偶联法,简捷有效地合成了一种新型氮杂杯[4]吡啶[4]嘧啶,产物结构通过IR,1H NMR,13C NMR和HRMS进行了表征;并培养得到了氮杂杯[4]吡啶[4]嘧啶的晶体,对其晶体结构进行了X射线单晶衍射分析.

关键词：氮杂杯吡啶嘧啶合成表征晶体结构

Three-dimensional reconstruction of precession warhead based on multi-view micro-Doppler analysis

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Journal of Systems Engineering and Electronics 2024年第3期35卷 541-548页

作者： ZHANG Rongzheng WANG Yong mao Jian School of Electronics and Information Engineering Harbin Institute of TechnologyHarbin 150001China Laboratory of Pinghu Pinghu 314200China

The warhead of a ballistic missile may precess due to lateral moments during release. The resulting micro-Doppler effect is determined by parameters such as the target's motion state and size. A three-dimensional reconstruction method for the precession warhead via the micro-Doppler analysis and inverse Radon transform(IRT) is proposed in this paper. The precession parameters are extracted by the micro-Doppler analysis from three radars, and the IRT is used to estimate the size of targe. The scatterers of the target can be reconstructed based on the above parameters. Simulation experimental results illustrate the effectiveness of the proposed method in this paper.

关键词： time-frequency analysis inverse Radon transform(IRT) precession warhead

Modulation of phase boundary and domain structures to engineer strain properties in BNT-based ferroelectrics

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Journal of Advanced Ceramics 2024年第7期13卷 967-975页

作者： Yule Yang Zhiyong Liu Pengrong Ren Yuqing mao Haijun Sun Bingliang Liang Pu mao Kun Guo Bing Xie Longlong Shu School of Materials Science and Engineering Nanchang Hangkong UniversityNanchang 330063China School of Materials Science and Engineering Xi'an University of TechnologyXi’an 710048China School of Aircraft Engineering Nanchang Hangkong UniversityNanchang 330063China School of Physics and Materials Science Nanchang UniversityNanchang 330031China

Bismuth sodium titanate(BNT)ceramics exhibit outstanding strain responses but are unfavorable for application in high-sensitivity displacement actuators due to the large negative strain resulting from irreversible changes in their phase transition and domain ***,(1−x)Bi_(0.50)Na_(0.41)K_(0.09)TiO_(3)-xNaNbO_(3)(BNKT−xNN)solid solutions were prepared to improve the strain properties through the strategy of modulating the phase boundary and domain *** introduction of sodium niobate could effectively regulate the relative content of the tetragonal(P4bm)and rhombohedral(R3c)phases in the phase boundary *** ferroelectric-to-relaxor phase transition(T_(F−R))was reduced,and the ergodic relaxor(ER)state was nurtured at room *** zero-negative strain properties of S=0.41%and d_(33)^(*)=742 pm/V were achieved from the reversible transition between the ER and ferroelectric states under an applied electric field(x=0.04).Additionally,understanding the domain states via piezoelectric force microscopy(PFM)and firstorder reversal curve(FORC)revealed that the superior strain responses originated from the reversible inter-transformation of substable macrodomains and polar nanoregions(PNRs)in the phase *** study provides new insight into the interplay between the evolution of phase boundaries and domain structures and the strain properties of BNT-based ceramics.

关键词： bismuth sodium titanate(BNT) domain structure phase boundary strain response relaxor state

Precise Asymptotics in Limit Theorems for a Supercritical Branching Process with Immigration in a Random Environment

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Acta Mathematica Sinica,English Series 2024年第8期40卷 1850-1874页

作者： Chun mao HUANG Rui ZHANG Zhi Qiang GAO Department of Mathematics Harbin Institute of Technology(Weihai)Weihai 264209P.R.China School of Mathematical Sciences Beijing Normal UniversityBeijing 100875P.R.China

Let(Zn)be a supercritical branching process with immigration in an independent and identically distributed random *** necessary moment conditions,we show the exact convergence rate in the central limit theorem on log Zn and establish the corresponding local limit theorem by using the moments of the natural submartingale and the convergence rates of its *** similar approach and with the help of a change of measure,we also present the so-called integrolocal theorem and integral large deviation theorem to characterize the precise asymptotics of the upper large deviations.

关键词： Branching process with immigration random environment central limit theorem large deviation

Can whole steps of grain production be outsourced? Empirical analysis based on the three provinces of Jiangsu,Jilin,and Sichuan in China

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Journal of Integrative Agriculture 2024年第1期23卷 336-347页

作者： Jiacheng Liu Shengzhi mao Qiufen Zheng Zhigang Xu School of Finance and Taxation Nanjing University of Finance and EconomicsJiangsu 210023China School of Economics Southwestern University of Finance and EconomicsSichuan 611130China School of Economics and Management Nanjing Agricultural UniversityJiangsu 210095China

Certain outsourcing services for agricultural management in China,such as pest control in grain production,have experienced prolonged sluggishness,contrasting with the relatively high level of outsourcing services observed in harvesting,land preparation,and *** study examines the feasibility of implementing whole-step outsourcing in grain production by conducting a case study of rice and maize production in Jiangsu,Jilin,and Sichuan provinces in *** provision of outsourcing services hinges on two essential conditions:technological advancements fostering specialized production and economies of scale,coupled with a market size sufficient to realize the aforementioned potential economies of *** results showed that outsourcing pest control or harvesting services had varying economies of *** outsourcing services in pest control were less common than in harvesting services,and their marginal growth space of the economies of scale with technological change was also *** by the operational characteristics of pest control itself,the market scale of its professional services is ***,achieving the whole-step outsourcing of grain production necessitates not only technological innovation but also effective policy interventions to overcome the constraints of market *** interventions include(1)optimizing crop layouts between planning regions and reducing land fragmentation and(2)supplying timely and effective inter-regional agricultural information for service providers aided by information technology.

关键词： outsourcing services economy of scale technical conditions market scale

Improved Segmented Belief Propagation List Decoding for Polar Codes with Bit-Flipping

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China Communications 2024年第3期21卷 19-36页

作者： mao Yinyou Yang Dong Liu Xingcheng Zou En School of Electronics and Information Technology(SEIT) Sun Yat-sen University(SYSU)Guangzhou 510006China School of Information Science Guangzhou Xinhua UniversityGuangzhou 510520China Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai) Zhuhai 519080China

Belief propagation list(BPL) decoding for polar codes has attracted more attention due to its inherent parallel nature. However, a large gap still exists with CRC-aided SCL(CA-SCL) *** this work, an improved segmented belief propagation list decoding based on bit flipping(SBPL-BF) is proposed. On the one hand, the proposed algorithm makes use of the cooperative characteristic in BPL decoding such that the codeword is decoded in different BP decoders. Based on this characteristic, the unreliable bits for flipping could be split into multiple subblocks and could be flipped in different decoders simultaneously. On the other hand, a more flexible and effective processing strategy for the priori information of the unfrozen bits that do not need to be flipped is designed to improve the decoding convergence. In addition, this is the first proposal in BPL decoding which jointly optimizes the bit flipping of the information bits and the code bits. In particular, for bit flipping of the code bits, a H-matrix aided bit-flipping algorithm is designed to enhance the accuracy in identifying erroneous code bits. The simulation results show that the proposed algorithm significantly improves the errorcorrection performance of BPL decoding for medium and long codes. It is more than 0.25 d B better than the state-of-the-art BPL decoding at a block error rate(BLER) of 10^(-5), and outperforms CA-SCL decoding in the low signal-to-noise(SNR) region for(1024, 0.5)polar codes.

关键词： belief propagation list(BPL)decoding bit-flipping polar codes segmented CRC