12%Cr超超临界转子钢锻造裂纹机理分析及损伤模型建立

针对12%Cr超超临界转子钢锻造表面裂纹严重的问题,从变形条件及应力-应变状态的角度出发,基于热拉伸实验获取了相应条件下的应力-应变曲线。通过分析断口形貌,判断了12%Cr超超临界转子钢高温拉伸断裂为典型的韧性断裂,并分析了锻造裂纹的产生与析出相的关系。通过观察试样断口切片,发现了大量相互缠结的位错,这些相互缠结的位错也是导致金属断裂的原因。通过对临界损伤值的比对发现,在应变速率为0.5 s^(-1)、温度为1100~1200℃时锻造最不易产生裂纹;在Normalized Cockcroft&Latham损伤模型的基础上引入温度补偿的应变速率因子Zener-Hollomon参数,建立了临界损伤值与Zener-Hollomon参数的关系式,得到考虑了温度和应变速率综合影响的高温损伤模型。

中国特色社会主义进入新时代的基本依据——中国化马克思主义发展思想研究

党的十九大明确作出"中国特色社会主义进入了新时代"等重大政治论断,清晰定位我国发展新的历史方位和时代坐标,这是我们党从理论和实际相结合、历史和现实相贯通、国际和国内相关联视角思考得出的正确结论。如何认识我国进入新时代?从八个维度加以把握:五年伟大成就是进入新时代的实践基础;重大理论创新是进入新时代的理论标志;快速接近民族复兴是进入新时代的动力源泉;建成社会主义现代化强国是进入新时代的战略指向;全方位改革开放是进入新时代的现实依据;社会主要矛盾变化是进入新时代的时代依据;走近世界舞台中央是进入新时代的国际佐证;坚持和加强党的全面领导是进入新时代的政治保证。新时代,奋力谱写坚持和发展中国特色社会主义新篇章。

3种野生块菌营养成分比较分析

为探究中华夏块菌、假喜马拉雅块菌和攀枝花白块菌的营养价值,采用国家标准方法检测水分、蛋白质、脂肪、粗纤维、灰分、氨基酸、维生素、矿质元素、稀土元素及重金属。结果表明:3种块菌干物质中粗纤维占41.8%~52.8%,蛋白质分别是29.8%、27.8%和31.4%,脂肪在2.16%~2.80%之间,必需氨基酸2.58 g/100 g~3.86 g/100 g,呈味氨基酸3.33 g/100 g~4.78 g/100 g,分别占各自氨基酸总量的33.5%、40.4%和40.2%,远高于必需氨基酸含量。3种块菌都含有丰富的精氨酸、胱氨酸和酪氨酸以及常量元素和微量元素,攀枝花白块菌中钾、钠、钙、镁、锌、铜、锰、锶含量较高,中华夏块菌中硒含量较高,3种块菌稀土元素适量、重金属和农药残留较低。证实3种块菌是富含呈味氨基酸和精氨酸的优质调味食品。

A Study on Anti-oxidative Activity of Soybean Peptideswith Linoleic Acid Peroxidation Systems

Soybean bioactive peptides（SBPs） were prepared from the isolated soybean protein by proteolysis with an alkaline protease, alcalase, at 50℃ and pH = 8.0. The dependence of hydrolysis time on hydrolysis degree and molecular weight distribution were examined. The hydrolysate was fractionated on a Sephadex G-25 column and the anti-oxidative activities of the fractions were detected by the method of pyrogallol auto-oxidation. The average chain length of soybean peptides that have anti-oxidative activity was estimated to be about 7. The anti-oxidative properties of the soy- bean peptide were also studied by using linoleic acid peroxidation systems. The optimal condition of the peroxidation system was set up, Vc/Cu^2 ＋ as the inducer at pH = 7.4 and 25 ℃. In addition, soybean peptides show higher antioxidative activity compared with GSH.

Preparation and Anti-oxidative Effects of Corn Peptides

Corn peptides(CP) were prepared from zein via proteolysis by means of a type of alkaline protease, Alcalase, at 50 ℃ and pH 8.0. The anti oxidative activity of the hydrolysate was examined. It was found that the anti oxidative activity reached the maximum at the fourth hour of the hydrolysis and then decreased. The effect of the enzyme dosage on the solubility of corn protein, the dependence of hydrolysis time on the degree of the hydrolysis(DH) and molecular weight distribution were examined respectively. 30% DH was controlled on the basis of anti oxidative activity. The hydrolysate was fractionated on a Sephadex G 15 column. The anti oxidative activities were examined for all the fractions. The main fraction for anti oxidative activity was collected and characterized by the methods of amino acid analysis, the measurement of average chain length and etc .. The main M W distribution of the main fraction was 300-600 Daltons. The anti oxidative properties of the small peptides in vitro were studied. It was found that they could inhibit the auto oxidation of pyrogallol and the oxidation of hemoglobin. The hemolysis degree of erythrocyte caused by hydroxyl free radicals was decreased greatly, indicating a protective effect of the anti oxidative peptides on the cell membrane damage of erythrocyte.

气相色谱-串联质谱法测定三七中五氯硝基苯残留量的不确定度评定

目的评定气相色谱-串联质谱法(gas chromatography-tandem mass spectrometry,GC-MS/MS)测定三七中的五氯硝基苯残留量的不确定度。方法根据JJF1059-1999《测量不确定度评定与表示》中有关规定,建立了不确定度评定的数学模型,对各分量在构成合成不确定度时的影响率进行分析。结果本方法不确定度控制的关键在于控制好样品的标准曲线和检测过程中的随机效应。当三七中五氯硝基苯残留量为0.034 mg/kg,扩展不确定度为0.0039 mg/kg,五氯硝基苯残留量表示为(0.034±0.0039)mg/kg(k=2)。结论该评定方法清晰合理,可用于三七中五氯硝基苯残留的不确定度评定。

Inhibition of Growth of Human Ileocecal Adenocarcinoma Cells HCT-8 and Inducing Apoptosis by Different RGD-containing Peptides

Human ileocecal adenocarcinoma cells HCT-8 were treated with RGD-containing cellular adhesion peptides including RGD, RGD（NH2）2（i.e., RGE-NH2）, RGDS, and RGDS-NH2. MTT assay was prepared to examine their inhibiting effects on HCT-8 cells after treatment. The methods including Haematoxylin and Eosin（HE） staining, transmission electron microscopy（TEM）, immunohistochemistry, flow cytometry, and Reverse TranscriptionPolymerase Chain Reaction（RT-PCR） were used to observe the morphology of the apoptotic cells and analyze the mechanism of apoptosis. The experimental results indicate that RGD-containing cellular adhesion peptides can inhibit the growth and proliferation of tumor HCT-8 cells in a dose-dependent manner and induce the apoptosis of HCT-8 cells. At the same time, the high conservative property of RGD was confirmed again.

Synthesis of Cell Adhesive Motif RGD Tripeptide by a Novel Chemical Method and Its Purification

The cell adhesive motif RGD tripeptide was synthesized by using a novel chemical method. First, Gly-Asp（GD） was synthesized in two steps including the chloroacetylation of free L-aspartic acid and the ammonolysis of the chloroacetylated L-aspartic acid. The yield of chloroacetylated L-aspartic acid was 83.0%. For the ammonolysis of chloroacetylated L-aspartic acid, the yield of the ammonolyzed product was 92. 3%. Second, the coupling between Arg and Gly-Asp was carried out by using the NCA method. The maximum yield of RGD was about 50% at 0℃ and pH = 9. 5. The prepared RGD tripeptide was confirmed by using amino acid component analysis and mass spectrographic analysis.

豆腐皮中乌洛托品残留量的测定不确定度评估

目的评定液相色谱-质谱法测定豆腐皮中乌洛托品留量的不确定度。方法运用JJF 1059.1-2012《测量不确定度评定与表示》分析豆腐皮中的乌洛托品残留量测量过程中的不确定度来源,通过建立数学模型量化不确定度分量,计算合成不确定度和扩展不确定度。结果本方法的不确定度主要来源于液相色谱质谱仪设备。当豆腐皮中乌洛托品残留量为0.523 mg/kg,扩展不确定度为0.018 mg/kg,乌洛托品残留量表示为(0.523±0.018)mg/kg(k=2)。结论该评定方法可为液相色谱-质谱法测定豆腐皮中乌洛托品残留量的结果和方法的可靠性提供科学依据。

“双循环”新发展格局下后扶贫时代的“双线逻辑”

2019年底爆发的全球性新型冠状病毒感染肺炎/全球新冠肺炎疫情(COVID-19)使得供应链运输受到严峻挑战,成为逆全球化浪潮的导火索。2020年4月习近平总书记在中央财经委员会第七次会议上首次提出“双循环”新发展格局,将国内循环畅通提到了前所未有的高度。乡村经济受限于地理因素,市场占有率较低,通过扶贫攻坚和乡村振兴的接续发力,将在“双循环”新发展格局中发挥“蓝海战略”优势。文章运用Nvivo12.0质性分析软件,收录政府官方网站公布的政策文本,分析关键词词频、绘制词云图,并通过编码找到扶贫攻坚与乡村振兴之间的内在联系。研究发现,扶贫攻坚与乡村振兴之间在历史逻辑上是接续发力;在需求层次上是社会需求的阶梯式提升;在产业发展上,更加注重第一产业保质增量和第三产业的绿色发展。根据后扶贫时代的“双线逻辑”,2020年后乡村将通过持续深化农业供给侧结构性改革、引进优质人才、加强绿色基础设施建设、推动城乡一体化进程和常态化贫困治理等措施,进一步扩大社会保障的覆盖范围,积极融入国内大循环市场,构建新时代新农村发展的“中国智慧”。

Optimization of Detection Methods for Avermectin Residue

[ Objective] To develop an efficient and practical method for detecting avermectin residue in animal-derived food. [ Method ] Acetonitrile was used as the extraction fluid. After the removal of moisture, trifluoroacetic anhydride and N-methyl imidazole were used for derivatization and mixed well. After complete derivatization, high-performance liquid chromatography （HPLC） with C18 column was used for accurate qualitative and quantitative analysis of the detected substance using methanol aqueous solution （92： 8, V/ V）. [ Result] The detection limit of HPLC connected with a fluorescence detector was up to 0.1 ug/L. When the standard was added to the substrate at a final concentration in the range of 0.1 -20.0 lag/L, the recoveries were in the range of 80% -108% and the relative deviation was in the range of 4.1% -11.4%. [ Conclusion] The developed HPLC con- nected with a fluorescence detector is simple, practical, highly sensitive and resistant to interference, and it thus can meet the needs for determina- tion of biological toxin residues of avermectins in animal-derived food in laboratory.

核电机架系统边界条件对抗震性能的影响

机架系统是核电领域内使用较多的承载平台,主要功能是确保机架系统内安装设备正常运行,避免与危险因素接触,保护设备操作人员的安全。在地震作用下,机架系统易发生结构变形、倾倒、开裂等多种破坏。根据机架系统边界条件对其抗震性能的影响,通过选型测试,在机架系统底部增加减隔震装置,结合计算分析和实验对比,分析机架系统不同边界条件在地震载荷作用下的地震响应。结果表明,减隔震装置对高频振动隔振效果明显,垂直方向隔振率高于水平方向,减震器减小地震中机架加速度响应的同时,增加机架顶部的位移,提高机架的偏移角度。

腹部恶性肿瘤患者围手术期谵妄危险因素分析

目的总结腹部恶性肿瘤患者围手术期谵妄的危险因素。方法选取2016年5月～2018年5月本院住院部收治的120例腹部恶性肿瘤患者作为观察组,选择同期入院腹部恶性肿瘤患者,围手术期未出现谵妄症状的40例患者作为对照组,以自制调查问卷详细记录患者围手术期相关因素。结果观察组高血压发生率(66.67% VS 40.00%,P <0.05)、糖尿病发生率(60.00% VS 30.00%,P <0.05)、冠心病发生率(54.17% VS 22.50%,P <0.05)、手术时间3小时以上比例(58.33% VS 30.00%,P <0.05)、术后低氧血症发生率(60.00% VS 32.50%,P <0.05)、电解质紊乱发生率显著高于对照组(56.67% VS 45.00%,P <0.05)。高血压、糖尿病、手术时间3小时以上、术后低氧血症、电解质紊乱、术后VRS评分≥4分为围手术期谵妄发生的危险因素。手术时间3小时以上(OR=6.174,P <0.05)、术后低氧血症(OR=6.857,P <0.05)、电解质紊乱(OR=5.836,P <0.05)、术后VRS评分≥4分(OR=6.027,P<0.05)。结论腹部恶性肿瘤患者围手术期谵妄与手术时间过长、术后低氧血症、电解质紊乱、术后疼痛等密切相关。

Chemo-enzymatic Synthesis of Z-Asp-Val-Tyr-NH_2——A Precursor Tripeptide of Thymopentin

Z-Asp-Val-Tyr-NH2,a precursor tripeptide of thymopentin（TP-5）,was successfully synthesized by a combination of chemical and enzyme methods.Firstly,the precursor dipeptide Val-Tyr-NH2 was synthesized by a novel chemical method in four steps including the preparation of NCA-Val,the esterification of L-tyrosine and the ammonolysis of L-tyrosine ethyl ester,and the formation of Val-Tyr-NH2 from NCA-Val and L-Tyr-NH2.Secondly,a thermolysin,thermoase PC 10F was used to catalyze the formation of Z-Asp-Val-Tyr-NH2 in an aqueous/organic solvent diphase system with Z-Asp-OH and Val-Ty-NH2 as the substrates under thermodynamic control.The optimum conditions were pH=6.5,40 ℃,thermoase 100 mg,in 2-（N-morpholino） ethanesulfonic acid MES/NaOH（containing 5 mmol/L CaCl2） of n-butanol system（15/85,volume ratio） for 20 h in a maximum yield of 27.02%.

Protease-catalyzed Synthesis of Bz-Arg-Gly-Asp-OMe in Full Aqueous Medium

Synthesis of N-benzoyl-argininylglycylasparagine methyl ester（ Bz-Arg-Gly-Asp-OMe）, a precursor tripeptide of Arg-Gly-Asp） was catalyzed by papain under kinetic control, at alkaline pH, in a full aqueous medium. The substrates were N-benzoyl-argininylglycine ethyl ester and asparagine dimethyl ester. An aqueous solution of 0. 1 mol/L KCl/NaOH containing 8 mmol/L EDTA and 2 mmol/L DTT was selected as the reaction medium. The synthesized hydrophilic tripeptide was soluble in the reaction medium during the reaction process, however, the secondary hydro- lysis of the tripeptide product was not considerable. The effects of different factors, including water content, temperature, reaction time, and molar ratio of the substrates, on the yield of Bz-Arg-Gly-Asp-OMe were examined. The optimal reaction conditions were 0. 05 mol/L Bz-Arg-Gly-OEt and 0. 15 mol/L Asp（ -OMe）2·HCl in 0. 1 mol/L KCl/ NaOH solution（pH 8.5）, at 40 ℃, and a reaction time of 60 min, with a maximum conversion yield of 62.4%.

Chemoenzymatic Synthesis of Cellular Adhesion Tripeptide RGD Precursor in Organic Media

Chemoenzymatic synthesis of tripeptide Bz-RGD-（OEt）2 was conducted in this study. First, the free dipeptide Gly-Asp was synthesized via a novel chemical method, wherein only L-aspaxtic acid was used and was followed by the esterification of Gly-Asp. The formation of the linkage between the third amino acid Bz-Arg-OEt and Gly-Asp-（OEt）2 was completed by using the enzymatic method in organic media. The effects of several factors such as pH, the water content, triethylamine （TEA）, the molar ratio of the substrates, and the reaction time on the yield of Bz-RGD- （OEt）2 were examined. It was obtained that the optimum conditions for Bz-RGD-（OEt）2 synthesis in an ethanol/ Tris-HC1 buffer system （ volume ratio 93： 7 ） were as follows ： pH = 8.0 ; temperature, 30 ℃ ; reaction time, 7 h. The tripeptide yield was 75.2%.

Studies on the Conformation of Poly (1-naphthol) Assembled by Horseradish Peroxidase in Aqueous Micelle

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RGDC Peptide Modified Quantum Dots Labelling and Imaging of Tumor Cells

The labelling and imaging of tumor cells were investigated via arginine-glycine-aspartic acidcysteine（RGDC） peptide-labelled quantum dots（QDs）. The results show that RGDC modified QDs can label SMMC-7721 tumor cells and adhere to cellular membrane. In constrast, the unmodified QDs are mainly dispersed around the cell. We also found that the RGDC-QDs can penetrate into the cell at 2 h of incubation. After 6 h of incubation, RGDC-QDs can accumulate in a unique intracellular region.

A Study of Bioactivity of Corn Peptides with Low Molecular Weight Ⅱ: Effect on Plasma Free Amino Acid Concentrations in Rats

The effects of the ingestion of corn peptides with a low molecular weight(LMCP) prepared from zein on some plasma free amino acid concentrations in rats that had taken ethanol were investigated. LMCP(1 0 g/kg body weight) in 15% ethanol(10 mL/kg body weight) was given to Wister rats by intragastrical administration. The amino acid analysis showed that the concentrations of alanine, leucine, and proline in the plasma reached their maximum levels at 30 min for the LMCP-intake group. They are 582.39, 99.60 and 272.51 μg/L , respectively. But in the control group, the plasma free amino acid levels were not changed obviously. Therefore, LMCP could cause an increase in concentration of some free amino acids such as alanine, leucine and proline etc . in plasma of the rats that have taken ethanol.