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Production and Characterization of Sterigmatocystin 被引量:2
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作者 LOUJIAN-LONG MENGZHAO-HE 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 1994年第4期293-301,共9页
Fourteen strains of Aspergillus versicolor and 2 strains of A. nidulans were screened for sterigmatocystin (ST) production on a semi-synthetic solid substrate by high performence liquid chromatography (HPLC) analysis.... Fourteen strains of Aspergillus versicolor and 2 strains of A. nidulans were screened for sterigmatocystin (ST) production on a semi-synthetic solid substrate by high performence liquid chromatography (HPLC) analysis. Two strains of A. versicolor producing ST at 550.5 mg.kg-1 substrate and 1160.8 mg·kg-1 substrate were selected to inoculate 4 kg solid ST-producing media. After 30 days stationary incubation at 28 ℃ in the dark, 2271.6 mg of pale-yellow needle-shaped crystals were isolated and purified from the culture with a procedure applying column chromatography and recrystallization method. The crystal was proved to be sterigmatocystin by spectroanalysis and some physico-chemical analysis. The purity of the final material obtained were more than 99.9% as shown by HPLC and TLC detection. With this procedure, ST was obtained at about one tenth of its commercial cost 展开更多
关键词 Co production and characterization of Sterigmatocystin RES
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Variance Analysis of Growth Characteristics and Partial Production and Quality Characters of Different Tobacco Varieties
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作者 母少东 祖庆学 +6 位作者 邓兆权 赵雍平 段琼 朱祖发 谭建 刁朝强 陈兵林 《Agricultural Science & Technology》 CAS 2016年第12期2771-2776,共6页
Objective] This study was conducted to discuss growth characteristics and partial production and quality characters of different varieties, so as to provide can-didates for tobacco production as wel as a theoretical b... Objective] This study was conducted to discuss growth characteristics and partial production and quality characters of different varieties, so as to provide can-didates for tobacco production as wel as a theoretical basis for variety deployment in Guizhou. [Method] ‘K326’ was used as control, the experiment for variance analysis of growth characteristics and partial production and quality characters of dif-ferent tobacco varieties was carried out in Fengsan Town, Kaiyang County, Guizhou Province in 2015. [Result] GY8 grew faster in early stages and slower in late stages, the growth periods of GY2 (130 d) and GY5(129 d) were the longest, while those of Yun85 (121 d) and Yun87 (121 d) were the shortest; and GY2, GY5 and GY8 had larger plant heights, maximum leaf widths and maximum leaf areas, and Yun85, Yun87 and K326 showed larger stem girths and maximum leaf lengths. Yun87 exhibited lower natural incidences of diseases, while Yun85 and GY8 showed higher incidences of diseases. GY2, GY5 and GY8 had higher nicotine, total nitro-gen, K and Cl contents, while Yun85, Yun87 and K326 had higher total sugar and reducing sugar contents and higher total sugar/nicotine ratio. Yun85 and Yun87 showed better economic characters, while GY5 and GY8 showed poorer economic characters. [Conclusion] Yun85 and Yun87 have quality characters better than GY2 and GY8, field natural incidences of diseases lower than GY2 and GY8, and better economic characters, and thus could serve as candidates in future flue-cured tobac-co production in Guizhou. 展开更多
关键词 VARIETIES Growth characteristics production and quality characters Dif-ference Flue-cured tobacco
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Production, Purification and Characterization of Inulinase from a Newly Isolated <i>Streptomyces</i>sp. CP01 被引量:6
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作者 Nirobol Laowklom Rungtrakarn Chantanaphan Pairoh Pinphanichakarn 《Natural Resources》 2012年第3期137-144,共8页
Inulinase is an enzyme catalyzing the hydrolysis of inulin, a plant reserve polysaccharide, into fructoses and fructooligosaccharides which are widely used as food additives. Here we report inulinase from a newly isol... Inulinase is an enzyme catalyzing the hydrolysis of inulin, a plant reserve polysaccharide, into fructoses and fructooligosaccharides which are widely used as food additives. Here we report inulinase from a newly isolated Streptomyces as in the past decade there have been very few reports on inulinases from Streptomyces, especially purification and characterization of these enzymes. Out of 371 Streptomyces isolates, Streptomyces sp. CP01 produced highest inulinase activity of 0.50 U/ml. The enzyme activity was increased to 1.60 U/ml when CP01 was cultivated under the optimal conditions which consisted of using basal medium (Czapek’s Dox) containing 1% (w/v) inulin extract from Jerusalem artichoke’s root tubers and 0.7% (w/v) tryptone at pH8, shaking at 200 rpm and 28℃ for 24 h. The enzyme was purified from culture filtrate to about 67-fold purity by (NH4)2SO4 precipitation followed by four consecutive column chromatography steps. The purified enzyme is a single peptide with approximate molecular mass of 73 kDa as analyzed by gel filtration and 70.8 kDa as assessed by SDS-PAGE. The enzyme is optimally active at 55℃ and pH 6.0, however it still possesses more than 80% of the maximal activity at pH ranging from 5.5 to 9.0. It is stable at temperature up to 50℃ and at broad range of pH from 5.0 to 9.0 for 30 min. Its Km and Vmax values for inulin were 2.34 mM and 440 μmolmin–1mg–1, respectively. This enzyme has potential for industrial application as it is active at moderately high temperature and wide range of pH. 展开更多
关键词 characterization INULINASE productION Purification STREPTOMYCES
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Isolation and characterization of a degradation product in leflunomide and a validated selective stability-indicating HPLC-UV method for their quantification 被引量:1
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作者 Balraj Saini Gulshan Bansal 《Journal of Pharmaceutical Analysis》 SCIE CAS 2015年第3期207-212,共6页
Leflunomide (LLM) is subjected to forced degradation under conditions of hydrolysis, oxidation, dry heat, and photolysis as recommended by International Conference on Harmonization guideline Q1A(R2). In total, fou... Leflunomide (LLM) is subjected to forced degradation under conditions of hydrolysis, oxidation, dry heat, and photolysis as recommended by International Conference on Harmonization guideline Q1A(R2). In total, four degradation products (I-IV) were formed under different conditions. Products I, II and IV were formed in alkaline hydrolytic, acidic hydrolytic and alkaline photolytic conditions. LLM and all degradation products were optimally resolved by gradient elution over a C18 column. The major degradation product (IV) formed in hydrolytic alkaline conditions was isolated through column chromatography. Based on its IH NMR, IR and mass spectral data, it was characterized as a British Pharmacopoeial impurity B. The HPLC method was found to be linear, accurate, precise, sensitive, specific, rugged and robust for quantification of LLM as well as product IV. Finally, the method was applied to stability testing of the commercially available LLM tablets. 展开更多
关键词 LEFLUNOMIDE characterization Forced degradation Degradation product HPLC-UV
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Theoretical Study on Quantitative Characterization of Interlayer Interference in Multi-Layer Commingled Production 被引量:1
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作者 Pengfei Mu Shaopeng Wang +2 位作者 Jie Tan Hanqing Zhao Li’an Zhang 《Journal of Power and Energy Engineering》 2021年第4期21-29,共9页
X oilfield is a typical layered reservoir with a large vertical span and many oil-bearing formations. There are significant differences in reservoir types and fluid properties among various formations. The interlayer ... X oilfield is a typical layered reservoir with a large vertical span and many oil-bearing formations. There are significant differences in reservoir types and fluid properties among various formations. The interlayer interference is severe in the development process. At present, the interlayer interference research based on dynamic monitoring data cannot meet development adjustment needs. Combined with the field test results, through the indoor physical simulation experiment method, dynamic inversion method, and reservoir engineering method, this paper analyzes the main control factors and interference mechanism of interlayer interference, studies the variation law of interference coefficient, improves and forms the quantitative characteristic Theory of interlayer interference in multi-layer commingled production, and provides theoretical guidance for the total adjustment of the middle strata division in the oilfield. 展开更多
关键词 Thin Interbedded Reservoir Multi-Layer production Interbedded Interference Quantitative characterization Theoretical Research
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钙源厨余垃圾制备羟基磷灰石的可行性研究
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作者 郑永红 周新伟 +4 位作者 张治国 欧祥鹏 马庆斌 孔自豪 吴月 《安徽理工大学学报(自然科学版)》 CAS 2024年第4期68-76,共9页
目的为了提高钙源厨余垃圾利用率,改善水热合成法制备羟基磷灰石的工艺条件,更好的满足在水体和土壤污染中的修复应用。方法以典型的钙源厨余垃圾鸡蛋壳作为制备材料,采用水热合成法制备羟基磷灰石。通过正交实验筛选羟基磷灰石制备最... 目的为了提高钙源厨余垃圾利用率,改善水热合成法制备羟基磷灰石的工艺条件,更好的满足在水体和土壤污染中的修复应用。方法以典型的钙源厨余垃圾鸡蛋壳作为制备材料,采用水热合成法制备羟基磷灰石。通过正交实验筛选羟基磷灰石制备最佳工艺,并利用X-射线衍射(XRD)、傅里叶变换红外光谱(FTIR)、扫描电镜(SEM)、及比表面积检测(BET)对其结构和合成产率进行表征分析,并探讨了羟基磷灰石制备主要影响因素钙磷摩尔比和陈化时间对合成产率的影响。结果鸡蛋壳制备羟基磷灰石的最佳工艺条件为pH值9.5,振荡时间3h,振荡温度70℃,煅烧时间1h;XRD与FTIR分析明确了制备得到的产物为羟基磷灰石,SEM表明羟基磷灰石微观形貌主要为棒状和片状,BET表明羟基磷灰石的比表面积、孔容和孔径分别为12.4m^(2)/g、0.18cm^(3)/g和58.12nm;通过调整钙磷摩尔比可以提升羟基磷灰石的合成产率至70.4%,延长陈化时间可以改善羟基磷灰石表面的晶体形貌和团聚现象。结论鸡蛋壳作为典型的钙源厨余垃圾,可以实现低成本地制备羟基磷灰石,应用到环境污染修复中。 展开更多
关键词 钙源厨余垃圾 鸡蛋壳 羟基磷灰石 合成产率 材料表征
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知识生产模式转型视角下交叉学科建设的问题表征及应对策略
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作者 王宝玺 杜蕾 《黑龙江高教研究》 北大核心 2024年第3期69-75,共7页
交叉学科是学科,学科建设遵循知识逻辑,而知识生产模式转型意味着大学知识生产的逻辑取向发生变化进而影响交叉学科建设。从知识生产模式转型的视角分析我国交叉学科建设中存在的学术逻辑与社会需求逻辑的失衡、箱格化与交叉性学科知识... 交叉学科是学科,学科建设遵循知识逻辑,而知识生产模式转型意味着大学知识生产的逻辑取向发生变化进而影响交叉学科建设。从知识生产模式转型的视角分析我国交叉学科建设中存在的学术逻辑与社会需求逻辑的失衡、箱格化与交叉性学科知识的割裂、排他性与融合性学科文化的对立、国家外部干预与知识被动的无序、传统评价方式与交叉学科的错位等问题,在一定程度上是由于知识生产从个人兴趣转向问题解决、学科边界从单一学科转向跨学科、组织形式从等级森严转向灵活多元、问责制度从学术自治转向社会问责、质量控制从同行评议转向多维控制导致的。为有效应对上述问题,可以从树立“问题解决”导向的行动原则、构建“协同共生”的知识生产团队、形成“开放共享”的学科组织文化、执行“权力分化”的学科管理制度、秉持“和而不同”的学科评价标准等方面着手制定相应策略。 展开更多
关键词 交叉学科建设 知识生产模式1 知识生产模式2 问题表征
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丙硫菌唑合成工艺中副产物形成分析
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作者 闫景铭 王夏菲 +4 位作者 程绎南 张蒙萌 马艺超 王利民 李洪连 《农药学学报》 CAS CSCD 北大核心 2024年第1期61-68,共8页
在丙硫菌唑不同合成路线及纯化过程中会发生一些副反应,导致副产物的产生,严重影响工艺收率及产品质量。通过研究工艺、分离副产物和1H NMR、13C NMR、ESI-MS或X-射线衍射等结构表征,明确了丙硫菌唑3种主要合成路线中所生成的2-(1-氯环... 在丙硫菌唑不同合成路线及纯化过程中会发生一些副反应,导致副产物的产生,严重影响工艺收率及产品质量。通过研究工艺、分离副产物和1H NMR、13C NMR、ESI-MS或X-射线衍射等结构表征,明确了丙硫菌唑3种主要合成路线中所生成的2-(1-氯环丙基)-1-(2-氯苯基)-3-(4H-1,2,4-三唑-4-基)-2-丙醇(7)、6-(2-氯苄基)-6-(1-氯环丙基)-5,6-二氢-4H-1,3,4-噁二嗪-4-硫代甲酰胺(8)、丙硫菌唑缩合物(9)和2-(2-氯苄基)-2-((5-硫酮-4,5-二氢-1,2,4-三唑-1-基)甲基)环丁酮(10) 4种主要副产物及其结构。其中,副产物8首次在取代肼-丙酮合成路线中被发现。通过工艺分析和验证进一步阐明了4种副产物的形成机制,为丙硫菌唑产品的合成路线选择、工艺控制及产品质量的提高提供了有益参考。 展开更多
关键词 丙硫菌唑 合成工艺 副产物 结构表征
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古代青铜器锡腐蚀产物研究回顾——特点、表征方法、腐蚀模型
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作者 邹非池 刘建宇 +1 位作者 刘瀚文 曲亮 《文物保护与考古科学》 北大核心 2024年第4期128-142,共15页
对青铜器腐蚀机理的研究是对其进行保护修复的重要前提,在过去的数十年间,与铜和铅的腐蚀产物相比,文物保护领域对于锡腐蚀产物的认识和研究是相对缺乏且零散的。本文回顾了不同领域在锡腐蚀产物发展过程、特点以及表征方法等方面的研... 对青铜器腐蚀机理的研究是对其进行保护修复的重要前提,在过去的数十年间,与铜和铅的腐蚀产物相比,文物保护领域对于锡腐蚀产物的认识和研究是相对缺乏且零散的。本文回顾了不同领域在锡腐蚀产物发展过程、特点以及表征方法等方面的研究成果。青铜器中锡腐蚀后一般首先形成复杂的水合氧化物(SnO_(x)·nH_(2)O),随后在氧化性条件下进一步氧化脱水,向锡石(SnO_(2))转变,但由于此转变过程漫长而复杂,导致了锡腐蚀产物具有低结晶度、高电阻率、离子交换等特殊性质。通过梳理X射线衍射分析技术、拉曼光谱以及X射线光电子能谱以及其他分析方法在青铜器锡腐蚀产物表征中的应用进一步探讨了锡腐蚀产物的性质。最后,本文在回顾不同环境下的锡腐蚀产物的研究成果的基础上,介绍并比较了不同环境下青铜器的腐蚀模型。 展开更多
关键词 锡腐蚀产物 非晶 表征方法 腐蚀模型
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吸入制剂微细粒子空气动力学粒径分布评价方法研究
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作者 贾茵茵 张财树 +6 位作者 周颖 刘丽 耿颖 魏宁漪 钮思静 陈华 许卉 《中国药物警戒》 2024年第2期141-146,共6页
目的评估吸入制剂的空气动力学粒径分布(APSD),提高药品质量和安全有效性。方法通过对不同国家药典收载的检测APSD的方法以及相关标准进行比较与总结,用多种计量学参数来表征APSD,通过微细粒子剂量的大小和在总收集剂量中所占的比例作... 目的评估吸入制剂的空气动力学粒径分布(APSD),提高药品质量和安全有效性。方法通过对不同国家药典收载的检测APSD的方法以及相关标准进行比较与总结,用多种计量学参数来表征APSD,通过微细粒子剂量的大小和在总收集剂量中所占的比例作为评估吸入产品的关键指标。结果安德森撞击器(ACI)和新一代撞击器(NGI)是目前应用最广泛也是《美国药典》中所收载的方法,《中华人民共和国药典》又额外收载了玻璃二级撞击器,《欧洲药典》除以上3种装置外还收载了多级液体撞击器。空气动力学质量中值经(MMAD)是控制颗粒在肺部沉积位置的重要变量,几何标准偏差(GSD)表征的是药物颗粒粒度分布曲线形状,越接近于1说明粒度分布越窄。有效数据分析(EDA)中大粒子质量(LPM)与小粒子质量(SPM)的比值以及撞击粒子总质量(ISM)可检测APSD的变化。药物微粒的大小及分布很大程度上决定了粒子在呼吸系统中的沉积部位和沉积量,进而影响药物的疗效。所以若使吸入制剂中的活性药物成分(API)能够经由呼吸系统递送至肺,其气溶胶的空气动力学粒径应在1~5μm。结论合适的测试方法能够保证吸入产品的质量、安全性和有效性,合理的给药剂量和药物颗粒大小是决定吸入制剂性能的关键指标。不断改进细颗粒的测试方法,深入研究体内外的相关性,能够为吸入产品的进一步研究与开发创造有利条件。 展开更多
关键词 吸入制剂 空气动力学直径 级联撞击法 表征方法 数据分析 安全性 一致性评价 标准
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普通煤油燃烧及排放产物特性研究
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作者 陈夏琳 耿瑞 徐靖 《广东化工》 CAS 2024年第16期19-21,33,共4页
普通煤油作为日常及工业中常用的液体燃料,其燃烧过程及排放特性的研究显得尤为重要。本文采用实验和表征的方法,搭建煤油燃烧实验平台,利用热泳技术进行碳烟颗粒采集,利用透射电镜、XPS等技术进行碳烟颗粒表征。结果表明:(1)普通煤油... 普通煤油作为日常及工业中常用的液体燃料,其燃烧过程及排放特性的研究显得尤为重要。本文采用实验和表征的方法,搭建煤油燃烧实验平台,利用热泳技术进行碳烟颗粒采集,利用透射电镜、XPS等技术进行碳烟颗粒表征。结果表明:(1)普通煤油在燃烧过程中,其火焰中碳烟生成符合颗粒成核、表面生成、团簇凝聚、颗粒氧化等碳烟颗粒物的演变规律;(2)火焰外生成碳烟中,官能团最多的为C=C,达到60.71%,而碳烟颗粒中的氮化物含量都较小,但吡啶含量远高于其他氮化物;(3)在火焰外碳烟颗粒粒径分布在91.28nm~341.99nm之间,相比于火焰内利用TEM图像统计的碳烟颗粒粒径明显增大;(4)在热重实验中,氮气气氛下,碳烟颗粒在567℃时,发生质量转折式下降。 展开更多
关键词 普通煤油 燃烧产物 实验表征 机理研究
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超声改性甲壳素吸附水产品加工副产物中脂溶性维生素的作用效果研究
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作者 赵宝鼎 杨约萍 +1 位作者 邹小雨 宋茹 《食品安全质量检测学报》 CAS 2024年第4期114-121,共8页
目的探讨超声改性甲壳素(ultrasonic modified chitin,UM-C-chitin)对水产品加工副产物中脂溶性维生素的吸附效果。方法商品甲壳素(commercial chitin,C-chitin)经超声法改性,采用扫描电镜观察甲壳素改性前后微观形貌,傅里叶变换红外光... 目的探讨超声改性甲壳素(ultrasonic modified chitin,UM-C-chitin)对水产品加工副产物中脂溶性维生素的吸附效果。方法商品甲壳素(commercial chitin,C-chitin)经超声法改性,采用扫描电镜观察甲壳素改性前后微观形貌,傅里叶变换红外光谱和X射线衍射分析甲壳素改性前后的官能团和衍射峰变化,检测UM-C-chitin对水产品加工副产物中脂溶性维生素(维生素A、维生素D和维生素E)静态吸附效果。结果C-chitin经超声处理后微观结构由致密向疏松转变,并伴有无规则孔道及小孔形成,UM-C-chitin的酰胺I基团含有与α-型甲壳素相关的1665cm^(-1)特征峰,但是1624cm^(-1)处特征峰强度减弱接近消失,X射线衍射分析中UM-C-chitin在9.18°、12.68°、19.12°、23.04°和26.16°处有α-型甲壳素特征衍射峰,但各衍射峰强度较C-chitin的出现不同程度降低。与C-chitin相比较,UM-C-chitin对水产品加工副产物中维生素E的吸附效果较好(P<0.05),吸附量达到6.10μg/mg,较C-chitin的提高了84.8%。结论超声改性会降低C-chitin的结晶度,形成的无规则孔道及小孔结构有助于提高维生素E的负载量。本研究为快速富集水产品加工副产物中脂溶性维生素,特别是维生素E提供了技术依据。 展开更多
关键词 甲壳素 超声改性 结构表征 水产品加工副产物 脂溶性维生素 吸附
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Cu/AC臭氧催化氧化深度处理复糟酱香型白酒废水
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作者 李博文 梁家伟 +4 位作者 代吉华 万东锦 李圣斐 买文宁 张坡 《中国酿造》 CAS 北大核心 2024年第9期140-146,共7页
该实验考察了活性炭负载铜氧化物(Cu/AC)为催化剂的微气泡臭氧催化氧化工艺对复糟酱香型白酒废水生化出水的深度处理效果。结果表明,序批式反应中催化剂投加量为15 g/L,臭氧投加量为12.5 mg/min,初始pH为7.5时,在此条件下,化学需氧量(C... 该实验考察了活性炭负载铜氧化物(Cu/AC)为催化剂的微气泡臭氧催化氧化工艺对复糟酱香型白酒废水生化出水的深度处理效果。结果表明,序批式反应中催化剂投加量为15 g/L,臭氧投加量为12.5 mg/min,初始pH为7.5时,在此条件下,化学需氧量(COD)和波长254nm处紫外吸光值(UV_(254))去除率分别为79.0%和94.7%。催化剂多次使用后COD和UV_(254)去除率下降幅度均<5%。表征结果显示,催化剂表面形态平整,铜元素主要以CuO的形式存在并分散在AC上,有利于提升催化性能。经过长时间连续运行,COD和UV_(254)去除率仍能达到76%和92%,有较强稳定性和抗冲击能力。研究结果为微气泡臭氧催化氧化体系在复糟酱香白酒废水处理领域应用提供参考。 展开更多
关键词 复糟酱香白酒废水 微气泡臭氧 非均相催化剂 催化剂表征
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Comparative study on production,purification of penicillin by Penicillium chrysogenum isolated from soil and citrus samples 被引量:1
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作者 S Anto Jeya Dayalan Pramod Darwin Prakash S 《Asian Pacific Journal of Tropical Biomedicine》 SCIE CAS 2011年第1期15-19,共5页
Objective:To explore various unexplored locations where Penicillium spp.would be available and study the production of penicillin from the isolated Penicillium spp.in different media with altered carbohydrate source.M... Objective:To explore various unexplored locations where Penicillium spp.would be available and study the production of penicillin from the isolated Penicillium spp.in different media with altered carbohydrate source.Methods:The collected soil samples were screened for the isolation of Penicillium chrysogenum(P.chrysogenum) by soil dilution plate.The isolated Penicillium species were further grown in different production media with changes in the carbohydrate source.The extracted penicillin from various isolates was analyzed by HPLC for the efficacy of the product.Further the products were screened with various bacterial species including methicillin resistant Staphylococcus aureus(MRSA).And the work was extended to find the possible action on MRSA,along with characterization using other pathogens.Results:From the various soil and citrus samples used for analysis,only the soil sample from Government General Hospital of Bangalore,India,and Sanjay Gandhi Hospital,Bangalore,India,showed some potential growth of the desired fungi P.chrysogenum.Different production media showed varied range of growth of PenicilUum.Optimum production of penicillin was obtained in maltose which proved maximum zone of inhibition during assay.Characterization of penicillin on pathogens,like wild Escherichia coli strain,Klebsiella spp.,and MRSA,gave quite interesting results such as no activity on the later strain as it is resistant.HPLC data provided the analytical and confirmation details of the penicillin produced.Accordingly,the penicillin produced from the soil sample of Government General Hospital had the high milli absorbance unit of 441.5 mAu compared with that of the penicillin produced from Sanjay Gandhi Hospital sample,8S.S2 mAu.Therefore,there was a considerable change in quantity of the penicillin produced from both the samples.Conclusions: The Penicillium spp.could be possibly rich in hospital contaminants and its environments.This research focuses on various unexplored sources of medical ailments,and also shows that the growth of penicillin is high in maltose rich media that could possibly enhance the growth. 展开更多
关键词 PENICILLIUM chrysogenum SOIL CITRUS PENICILLIN Bioefficacy Antibiotic activity PENICILLIUM spp. productION SOIL dilution plate Staphy lococcus AUREUS characterization productION media Zone of inhibition Carbohydrate source Isolation Efficacy Pathogen
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Review of Agro Waste Plastic Composites Production
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作者 Hammajam Alhaji Abba Ismarrubie Zahari Nur Sapuan Mohd Salit 《Journal of Minerals and Materials Characterization and Engineering》 2013年第5期271-279,共9页
This article reviews the literature reports base on agro waste plastic composites using different fiber as fillers and reinforcements. Various processing methods and conditions;compression molding process, injection m... This article reviews the literature reports base on agro waste plastic composites using different fiber as fillers and reinforcements. Various processing methods and conditions;compression molding process, injection molding, and extrusion method are used in the composites productions. Characterization challenges associated with the agro waste plastic composites productions were also examined. Thus, the findings of this research review can be use as a data base for further inquiring into the agro waste plastic composites in a view to enhance the development of the sector. 展开更多
关键词 Agro WASTE PLASTIC COMPOSITE characterIZATION productION
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四川盆地普光高含硫气田长周期高产稳产关键技术 被引量:15
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作者 曾大乾 张庆生 +4 位作者 李童 宿亚仙 张睿 张诚 彭松 《天然气工业》 EI CAS CSCD 北大核心 2023年第1期65-75,共11页
普光气田是我国探明储量最大的高含硫气田,储层以礁滩相为主,具有非均质性强、边水能量强、高含硫等特点,面临礁滩储层地震预测精度低、气藏边水推进快、产能快速递减、硫沉积逐步析出、气井产能和气藏储量动用效果差等一系列技术难点... 普光气田是我国探明储量最大的高含硫气田,储层以礁滩相为主,具有非均质性强、边水能量强、高含硫等特点,面临礁滩储层地震预测精度低、气藏边水推进快、产能快速递减、硫沉积逐步析出、气井产能和气藏储量动用效果差等一系列技术难点和挑战。为此,针对普光气田开发面临的难点和挑战,全面、系统总结了自“十三五”以来,为实现气田长周期高产稳产而开展的技术攻关与矿场实践。研究结果表明:①建立了台内滩储层预测岩石物理量版,提出了有效动用对策,研发了“自转向清洁酸+降阻滑溜水+缝内暂堵”造复杂缝酸压工艺,实现了超深礁滩相低品位台内滩储层有效动用;②建立了礁滩相储层气水前缘运动方程,研发了新型抗硫三元复合泡排剂、高抗硫超高膨胀率比桥塞,设计了过油管注塞堵水工艺,实现了高含硫气井全生命周期控水稳气;③揭示了高含硫天然气单质硫析出机理,建立了高含硫气藏硫沉积分布模型,研发了快速分散型溶硫剂,配套射流冲洗工艺,形成了井筒硫沉积治理技术。结论认为,普光气田目前边水突进导致剩余气分布复杂、硫沉积逐渐从井筒扩展到地层、井口压力接近外输压力,下一步需要开展剩余气精细描述与挖潜、精准堵水、储层硫沉积治理、集输系统增压开采等技术攻关,以期进一步改善气田开发效果进而提高采收率。 展开更多
关键词 普光高含硫气田 低品位储层 有效动用 全生命周期 控水稳气 硫沉积 精细描述与挖潜 增压开采
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基于改进多目标粒子群算法的机器人轨迹规划研究 被引量:1
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作者 黄婷婷 《机械设计与制造工程》 2023年第11期37-42,共6页
针对传统机器人轨迹规划算法无法实现全局寻优的问题,提出一种基于改进多目标粒子群的机器人轨迹规划算法。首先对机器人的当前位置进行定位并确定偏转角度,在粒子寻优过程中引入一种外部机制形成非劣解容器,引入SA算法对种群内部的粒... 针对传统机器人轨迹规划算法无法实现全局寻优的问题,提出一种基于改进多目标粒子群的机器人轨迹规划算法。首先对机器人的当前位置进行定位并确定偏转角度,在粒子寻优过程中引入一种外部机制形成非劣解容器,引入SA算法对种群内部的粒子位置进行重新排布,避免解集陷入局部最优;再根据多机器人拥塞概率进行分解和乘积表征,消解冲突,避免发生碰撞。实验结果显示:所提算法能够规划出一条最短的路径,并可以有效地避免机器人发生碰撞,且移动时间少于传统算法。 展开更多
关键词 改进多目标粒子群 物流机器人 轨迹规划 乘积表征 冲突消解
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面向关键核心技术领域的科技情报感知服务体系构建研究 被引量:5
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作者 储节旺 李佳轩 《情报杂志》 CSSCI 北大核心 2023年第5期145-153,共9页
[研究目的]面对关键核心技术受制于人的局面,研究将情报感知的全过程融入科技情报服务体系中,提出面向关键核心技术的科技情报感知服务体系,以期有效引导我国关键核心技术的攻关,实现高水平科技自立自强。[研究方法]研究对我国关键核心... [研究目的]面对关键核心技术受制于人的局面,研究将情报感知的全过程融入科技情报服务体系中,提出面向关键核心技术的科技情报感知服务体系,以期有效引导我国关键核心技术的攻关,实现高水平科技自立自强。[研究方法]研究对我国关键核心技术领域的情报感知研究现状予以分析并指出问题,提出情报主体间的协同模式,并对情报感知的各个阶段,包括情报采集、扫描、识别、刻画、评估等进行详细描述,分别提出针对关键核心技术的扫描指标、识别模式、监测体系、技术导航,最终通过实证分析论证科技情报体系的有效性。[研究结论]关键核心技术领域情报感知服务体系能够有效促进情报主体间的协同合作,为关键核心技术的攻关提供指导。研究所提出的情报采集模式有助于识别科技弱信号,通过情报刻画与评估能够准确分析技术演化路线与技术关联,最终形成情报产品,为国家科技管理与相关决策部门提供情报支持。 展开更多
关键词 关键核心技术 情报感知 科技情报 情报服务体系 情报刻画 情报产品
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A soluble FcγR homolog inhibits Ig M antibody production in ayu spleen cells 被引量:3
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作者 Kai Chen Yu-Hong Shi +1 位作者 Jiong Chen Ming-Yun Li 《Zoological Research》 SCIE CAS CSCD 2019年第5期404-415,共12页
Classical Fc receptors (FcRs) mediate the binding to and recognition of the Fc portion of antibodies and play an important role during immune responses in mammals. Although proteins similar to soluble FcRs have been i... Classical Fc receptors (FcRs) mediate the binding to and recognition of the Fc portion of antibodies and play an important role during immune responses in mammals. Although proteins similar to soluble FcRs have been identified in fish, little is known about the role of such proteins in fish immunity. Here, we cloned a cDNA sequence encoding a soluble Fc receptor for an immunoglobulin G (FcγR) homolog from ayu (Plecoglossus altivelis)(PaFcγRl). The predicted protein was composed of two immunoglobulin C2-like domains but lacked a transmembrane segment and a cytoplasmic tail. The PaFcγRl transcripts were distributed at low levels in all tested tissues, but significantly increased after Vibrio anguillarum infection. The PaFcγRl protein was expressed in the head kidney, trunk kidney, and neutrophils. Recombinant PaFcγRl (rPaFcγRl) was secreted when transfected into mammalian cells and the native protein was also detected in serum upon infection. rPaFcγRl was also demonstrated to bind to ayu IgM, as assessed by cell transfection. Suppressive activity of the recombinant mature protein of PaFcγRl (rPaFcγRlm) on in vitro anti-sheep red blood cell (SRBC) responses was detected by a modified hemolytic plaque forming cell assay. In conclusion, our study revealed that PaFcγRl is closely involved in the negative regulation of IgM production in the ayu spleen. 展开更多
关键词 SOLUBLE FCΓR HOMOLOG Sequence characterization IgM-binding protein Inhibition of IGM production Plecoglossus altivelis
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硫酸盐溶液对掺石灰石粉砂浆抗硫酸盐侵蚀性能的影响
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作者 唐志 杜镔 +1 位作者 王圳 王德辉 《公路交通科技》 CSCD 北大核心 2023年第8期51-56,62,共7页
掺石灰石粉可以减少环境污染,降低混凝土的生产成本,并改善其相关性能,但也会带来硫酸盐侵蚀问题。在不同浓度的硫酸钠和硫酸镁溶液侵蚀下,掺石灰石粉水泥基材料的抗硫酸盐侵蚀性能相差较大,限制了石灰石粉在硫酸盐侵蚀环境中的工程应... 掺石灰石粉可以减少环境污染,降低混凝土的生产成本,并改善其相关性能,但也会带来硫酸盐侵蚀问题。在不同浓度的硫酸钠和硫酸镁溶液侵蚀下,掺石灰石粉水泥基材料的抗硫酸盐侵蚀性能相差较大,限制了石灰石粉在硫酸盐侵蚀环境中的工程应用。为了研究不同硫酸盐对掺石灰石粉水泥基材料性能的影响,通过差热分析和X射线衍射仪分析了侵蚀产物,借助扫描电镜观测了侵蚀产物的微观形貌,研究了5%和10%硫酸钠和硫酸镁溶液对掺石灰石粉砂浆外观质量、强度、侵蚀产物和微观结构的影响。结果表明:不同硫酸盐溶液浸泡下,钙矾石含量相差不大,钙矾石不是砂浆硫酸盐腐蚀的主要原因;当硫酸镁溶液的浓度从5%增大到10%时,水镁石的含量增大了92.8%,而石膏的含量降低了20.5%;在5%和10%的硫酸镁溶液中浸泡1 a后,砂浆仍保持完整性,抗压强度变化系数分别为82.3%和86.5%,硫酸镁溶液浸泡后的样品主要为石膏型化学侵蚀;当硫酸钠溶液的浓度从5%增大到10%时,芒硝含量从10.0%增大到14.1%,浸泡1 a后,砂浆未能保持完整性并失去了强度,硫酸钠溶液浸泡后的样品主要为芒硝型物理侵蚀。研究结果可为提高掺石灰石粉水泥基材料的抗硫酸盐侵蚀性能,并为石灰石粉在水泥基材料中的应用提供理论基础。 展开更多
关键词 道路工程 抗硫酸盐侵蚀 微观结构表征 侵蚀产物 砂浆 石灰石粉
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