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不同炭化条件制备油茶果壳生物质炭的理化性质比较研究

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土壤通报 2024年第2期55卷 383-390页

作者：侯建伟邢存芳杨莉琳杨枣童罗应内蒙古自治区农牧业科学院呼和浩特010031 铜仁学院农林工程与规划学院/贵州省梵净山地区生物多样性保护与利用重点实验室铜仁554300

[目的]比较不同炭化条件制备的油茶果壳生物质炭的理化性质,为生物质炭的制取和应用提供参考依据。[方法]在不同炭化温度(T:400℃、500℃和600℃)、恒温时间(t:2 h、4 h和6 h)和升温速率(v:150℃h^(-1))条件下将油茶果壳制成了9种生物质... 详细信息

[目的]比较不同炭化条件制备的油茶果壳生物质炭的理化性质,为生物质炭的制取和应用提供参考依据。[方法]在不同炭化温度(T:400℃、500℃和600℃)、恒温时间(t:2 h、4 h和6 h)和升温速率(v:150℃h^(-1))条件下将油茶果壳制成了9种生物质炭,借鉴材料科学的方法,研究其热失重特征、形貌结构、表面官能团种类和有机组分含量等内容。[结果]随着炭化温度的升高,纤维素、半纤维素和木质素组分相继分解,600℃以后进入热失重稳定阶段。400℃→600℃升温炭化过程中,油茶果壳生物质炭的氮气吸附-脱附等温线由IV型转为Ⅲ型;400℃时,中孔丰富,总孔容积0.00309~0.00351 cm g^(-1);500℃和600℃时,大孔丰富,平均总孔容积分别为0.00352 cm g^(-1)和0.00390 cm g^(-1)。随着炭化温度的升高和恒温时间的延长,C=O和C-O-C消失,-OH、-CH_(2)、C=C、C=O、O-H和Si-O-Si的伸缩振动峰逐渐缩窄;同时由于C=O、-OH、C-O-C等基团的逐渐分解或重组导致油茶果壳生物质炭中H、O元素减少,C元素富集,H/C、O/C和(N+O)/C也明显降低。[结论]油茶果壳炭化过程是芳香性增强,亲水性和极性减弱的富C脱挥发分过程。炭化温度是影响油茶果壳生物质炭C、H、O、N元素含量、微观特征、氮气吸附-脱附等温线构型的主要因素,而恒温时间是影响油茶果壳生物质炭孔径分布的主要因素。其中,T_(400)t_(4)V_(150)处理的微孔、中孔和大孔结构在体系中大量分布,尤其是中孔结构最为丰富且孔径分布范围更窄。

关键词：油茶果壳生物质炭热重分析微观特征孔隙结构有机组分

生物炭与有机肥等碳量投入土壤肥力与细菌群落结构差异及关系

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环境科学 2024年第7期45卷 4218-4227页

作者：侯建伟邢存芳杨莉琳吴朝都赵辉段玉颜学佳内蒙古自治区农牧业科学院呼和浩特010031 铜仁学院农林工程与规划学院铜仁554300 铜仁市农产品质量安全检验测试中心铜仁554300

为了探究推荐施肥(NPK)、增施生物炭(NPKB)和增施有机肥(NPKO)的土壤肥力和细菌群落结构差异及它们的相互关系,调查了马铃薯根际土壤特性、细菌群落组成和多样性,并分析这些因素对土壤综合肥力指数(IFI)的直接和间接影响.结果表明,NPKB... 详细信息

为了探究推荐施肥(NPK)、增施生物炭(NPKB)和增施有机肥(NPKO)的土壤肥力和细菌群落结构差异及它们的相互关系,调查了马铃薯根际土壤特性、细菌群落组成和多样性,并分析这些因素对土壤综合肥力指数(IFI)的直接和间接影响.结果表明,NPKB和NPKO处理的土壤pH、有效磷(AP)、速效钾(AK)、全氮(TN)、有机碳(SOC)和C/N均显著高于NPK处理(PSOC(49.42%)>pH(27.08%).结构方程表明,土壤pH相关的土壤特性和细菌群落多样性是影响IFI的直接路径,土壤pH相关的土壤特性还可通过影响细菌Shannon多样性间接影响IFI.这些结果表明土壤肥力和细菌群落结构在生物炭和有机肥增施处理间有显著差异且相互关联,土壤pH和细菌群落多样性是影响土壤综合肥力水平的关键因素,其中NPKO处理对土壤综合肥力水平的提升效果最佳.

关键词：生物炭有机肥根际微生物土壤肥力培肥机制

The First Total Synthesis of Saurufuran B

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Chinese Chemical Letters 2006年第10期17卷 1287-1289页

作者： Yi Hua yang Yu lin li State Key Laboratory of Applied Organic Chemistry and Institute of Organic Chemistry Lanzhou University Lanzhou 730000

First total synthesis of saurufuran B 1, a furanoditerpene, from （E, E）-farnesol 2 and citraconic anhydride 3 through thirteen steps is described. Our work involves two key steps：（1） High regioselective alkylation of 2-（tert-butyldimethylsiloxy）-4-methylfuran 6 with aUylic iodides 5 in the presence of silver wifluoroacetate and （2） Conversion of substituted 7-1actone 7 into furan derivative 8.

关键词： Saurufuran B first total synthesis furanoditerpene regioselective alkylation.

大学英语四、六级考试三十七年历程之思考:质量、特色及挑战

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教育与考试 2024年第3期 28-35,58页

作者：夏伟蓉唐俊杨林李巍西南交通大学外国语学院成都610031 四川省教育考试院非学历教育考试处成都610093

文章概述了大学英语四、六级考试的中国本土特色、其质量背后等值技术的科学运用,分析了CET引发应试教学及考试结果被误用的社会及教育层面的原因,提出维护中国自主品牌考试、建设外语测试质量国家标准等建设性意见,以期为推动和建立符... 详细信息

文章概述了大学英语四、六级考试的中国本土特色、其质量背后等值技术的科学运用,分析了CET引发应试教学及考试结果被误用的社会及教育层面的原因,提出维护中国自主品牌考试、建设外语测试质量国家标准等建设性意见,以期为推动和建立符合中国国情的外语测试体系提供借鉴。。

关键词：大学英语四、六级考试中国特色外语测试体系等值技术

ANALYSIS OF FIRST TRANSIENT PRESSURE OSCILLATION FOR LEAKDETECTION IN A SINGLE PIPElinE

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Journal of Hydrodynamics 2012年第3期24卷 363-370页

作者： yang Kai-lin li Fu-tian WANG Tao FU hui State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin China Institute of WaterResources and Hydropower Research Beijing 100038 China

The leak detection is of great importance in the reliable operation and management of a pipeline system. Recently, attention is shifted to the use of the time domain or frequency domain methods based on the transient analysis. These methods sometimes require accurate pressure signals obtained during the transient period or by creating ideal conditions in testing. This paper proposes a method that does not require transient simulations over the whole or an extended period of time, but uses the first transient pressure oscillation to detect leaks. The method considers the propagation of the pressure oscillation wave created from a fast valve closure and the reflected damp wave from the leak. A leak in the pipe gives rise to reflected waves which in turn create discontinuities in the observed signal at the measurement section. The timing of the reflected damp wave and the magnitude represent the location and the size of the leak, respectively. An analytical expression is derived based on the Method Of Characteristic （MOC） for the relationship between the leakage and the reflected magnitude. The leak detection procedure based on the method is also given. Then the reliability of the method is tested on numerically simulated pressure signals and experimental pressure signals with calibrated leak parameters, and the results indicate a successful application and the promising features of the method.

关键词： leak detection hydraulic transient pressure oscillation pipeline

耦合新安江模型与LSTM模型的赣江流域径流模拟研究

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水电能源科学 2024年第7期42卷 12-15页

作者：邹佳成黄监初杨丽琳顾雯叶赣江下游水文水资源监测中心江西宜春336028 山东省水利勘测设计院有限公司山东济南250013 中交第三航务工程勘察设计院有限公司上海200032

准确的径流模拟对流域水资源优化配置、防汛抗旱具有重要作用。为此,以赣江流域为例,构建了新安江模型与LSTM的耦合模型(XAJ-LSTM),对比分析了XAJ-LSTM、新安江模型和LSTM模型的径流模拟差异,并评估了汛期划分对径流模拟精度的影响。结... 详细信息

准确的径流模拟对流域水资源优化配置、防汛抗旱具有重要作用。为此,以赣江流域为例,构建了新安江模型与LSTM的耦合模型(XAJ-LSTM),对比分析了XAJ-LSTM、新安江模型和LSTM模型的径流模拟差异,并评估了汛期划分对径流模拟精度的影响。结果表明,在赣江流域,LSTM模型的最佳神经元参数为第一层18个,第二层36个;LSTM模型的径流模拟效果要优于新安江模型,且利用新安江模型对LSTM模型进行物理约束后,R RMSE的降幅达11%;考虑汛期划分能够提升XAJ-LSTM模型对汛期与非汛期径流的模拟精度,且在汛期的改善效果更明显,R RMSE减幅达18%。研究成果可为赣江流域径流模拟与预报提供参考。

关键词：径流模拟长短期记忆神经网络新安江模型汛期划分

Prokaryotic Expression and Purification of HIV-1 Vif and hAPOBEC3G, Preparation of Polyclonal Antibodies

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Virologica Sinica 2008年第3期23卷 173-182页

作者： Lan li Yi-shu yang Ze-lin li Yi ZENG College of life Science ＆ Bio-engineering Beijing University of Technology Beijing 100124 China

To prepare HIV-1 Vif and hAPOBEC3G and to produce their antibodies, the full length gene fragment of HIV-1 vif was amplified by PCR from a plasmid of HIV-1 NL4.3 cDNA, and the APOBEC3G gene was obtained by RT-PCR from the total RNA of H9 cells. The resulting DNA construct was cloned into a prokaryotic expression vector (pET-32a). Recombinant pET-vif and pET-APOBEC3G were expressed respectively in Eserichia coli BL21 (DE3) as an insoluble protein. The vector also contained a six-histidine tag at the C-terminus for convenient purification and detection. To express and purify the HIV-1 Vif and hAPOBEC3G in *** cells, the accuracy of inserted gene and specificity of proteins were detected by the two enzyme digestion method, SDS-PAGE, and Western blotting. Rabbits were then immunized by Vif or APOBEC3G protein and serum samples were tested by indirect EliSA to determine the level of antibodies. Immunoenzyme and immunofluorescence assays were performed to identify the specificity of polyclonal antibodies. The titer of the anti-Vif antibodies was 1:204800, and that of the anti-APOBEC3G antibodies was 1:102400. Thus the antibodies could detect the antigen expression in the cells, demonstrating that fusion proteins with high purity and their corresponding polyclonal antibodies with high titer and specificity were achieved.

关键词： Human immunodeficiency virus type 1 (HIV-1) Viral infectivity factor hAPOBEC3G Protein purification Polyclonal antibody

Zinc Absorption from Representative Diet in a Chinese Elderly Population Using Stable Isotope Technique

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Biomedical and Environmental Sciences 2017年第6期30卷 391-397页

作者： li Ya Jie li Min liU Xiao Bing REN Tong Xiang li Wei Dong yang Chun WU Meng yang lin li MA Yu Xia WANG Jun PIAO Jian Hua yang li Chen yang Xiao Guang Key Laboratory of Trace Element Nutrition National Health and Family Planning Commission of China Department of Trace Element Nutrition National Institute for Nutrition and Health Chinese Center for Disease Control and Prevention Beijing 100050 China National Institute of Metrology Beijing 100029 China Department of Nutrition and Food Hygiene Capital University of Medical Sciences Beijing 100069 China HeBei Medical University Shijiazhuang 050017 Hebei China

Objective To determine the dietary zinc absorption in a Chinese elderly population and provide the basic data for the setting of zinc （Zn） recommended nutrient intakes （RNI） for Chinese elderly people. Methods A total of 24 elderly people were recruited for this study and were administered oral doses of 3 mg 67Zn and 1.2 mg dysprosium on the fourth day. The primary macronutrients, energy, and phytic acid in the representative diet were examined based on the Chinese National Standard Methods. Fecal samples were collected during the experimenta and dysprosium content. period and analyzed for zinc content, 67Zn isotope ratio, Results The mean （± SD） zinc intake from the representative Chinese diet was 10.6 ± 1.5 mg/d. The phytic acid-to-zinc molar ratio in the diet was 6.4. The absorption rate of 67Zn was 27.9% ±9.2%. The RNI of zinc, which were calculated by the absorption rate in elderly men and women, were 10.4 and 9.2 mg/d, respectively. Conclusion This study got the dietary Zn absorption in a Chinese elderly population. We found that Zn absorption was higher in elderly men than in elderly women. The current RNI in elderly female is lower than our finding, which indicates that more attention is needed regarding elderly females＇ zinc status and health.

关键词： Zinc absorption Chinese elderly people Stable isotope technique

High-performance flexible semiconductor fibres for multi-scenario communication applications

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Science China Materials 2024年第7期67卷 2363-2364页

作者： Qinghui lin yang li Guozhen Shen School of Information Science and Engineering University of JinanJinan 250022China School of Microelectronics Shandong UniversityJinan 250101China School of Integrated Circuits and Electronics Beijing Institute of Technology Beijing 100081China

With the advances in the field of flexible fibre technology in recent years,a variety of flexible fibres with different preparation processes have emerged[1,2].However,most of the flexible fibres in the past have structural breaks,making them unsuitable for long-term use as wearable fabrics[3,4].Glass semiconductors are widely used in thermally stretched fibres due to their advantages such as controllable fluidity,but they suffer from electronic defects compared with crystalline semi conductors in electronic semiconductors such as silicon(Si)and germanium(Ge)[5].Obviously,the semiconductor component in flexible optic fibres is a key component in regulating their mechanical and electrical properties[6].

关键词： wear fibres fibre