基于E81T8-Ni2填充盖面的L415M管线钢的焊接工艺评定

L415M管线钢环向焊接接头焊接工艺填充盖面焊丝采用E81T8-Ni2代替E71T8-Ni1,替代原则不符合GB/T 31032—2014《钢质管道焊接及验收》的覆盖原则,需要重新进行焊接工艺评定。基于施工单位焊接工艺需求,为了验证E81T8-Ni2能否用于L415M对接焊缝的填充盖面焊接,采用焊条电弧焊打底,自保护药芯焊丝半自动焊填充盖面组合焊接方法,根焊焊接材料为E6010,填充盖面为E81T8-Ni2,依据GB/T31032—2014进行焊接工艺评定。对评定试样进行外观检查、无损检测、拉伸试验、弯曲试验、刻槽锤断试验以及冲击试验。试验结果表明,L415M管线钢环向焊接接头各项指标合格,拉伸试样断在母材上,焊接接头满足高强匹配要求。焊接工艺评定试验研究成果可为长输管道用L415M管线钢焊接工艺以及焊材选择提供参考。

阻尼改进抗差L-M匹配下全景图像拼接平滑优化

为了解决大面积视觉全景图像受拼接缝影响,拼接平滑面积较小的问题,提出阻尼改进抗差L-M匹配下全景图像拼接平滑优化方法。阻尼因子改进抗差L-M算法,计算抗差L-M迭代向量;利用改进抗差L-M算法,融合球面投影理论,对特征匹配误差目标函数进行优化。融合拉普拉斯算法和高斯滤波金字塔对图像进行分解重构,确定图像拼接缝重叠区域后完成全景图像拼接平滑优化。实验结果表明,所提方法的拼接缝平滑面积能够达到95.8%,解决了拼接平滑面积较小的问题。

基于L-M算法的铝合金铸造过程界面换热系数的反问题模型

铝合金铸造过程铸件-铸模之间的界面换热系数的变化非常复杂,且预测非常困难。本文基于L-M(Levenberg-Marquardt)算法建立了铝合金铸造过程传热反问题模型,通过反问题分析获得铝合金铸造过程中铸件-铸模界面换热系数。通过将铸件-铸模界面换热系数反演值与标准值进行比较,验证传热反问题模型的准确性。在此基础上,分析了铸模上测点位置(与铸件-铸模界面距离、相邻测点间距)和温度测量误差对铸件-铸模界面换热系数反演值的影响规律,并给出了最优的测点布置方案和温度测量误差要求。通过铝合金铸造实验,用该反问题模型能求解出铝合金凝固过程中的铸件-铸模界面换热系数。

L555M管线钢自动焊工艺焊接裂纹原因分析

全自动焊技术因其可靠的焊接质量、高效的焊接效率在油气长输管道建设中被广泛使用。针对国内某在建天然气管道工程L555M钢在焊接过程中出现的裂纹,采用化学成分分析、无损检测、宏观分析、微观分析、扫描电镜联合能谱等分析方法,分析了该裂纹产生原因。研究结果表明:该裂纹缺陷为铜元素富集所致。铜元素富集的原因为:全自动焊接设备的铜质导电嘴在焊接过程中与焊缝坡口碰壁产生短路,短路电流产生的高温导致铜质导电嘴部分熔化,随着焊接完成,被熔化的铜元素聚集在母材和焊缝的晶界处,晶界铜富集区域在焊缝残余拉应力作用下发生脆化进而导致产生裂纹。

苦瓜(Momordica CharantiaL.)MADS-box基因BAG启动子的克隆分析及表达载体的构建

作者提取苦瓜基因组总DNA,构建了DNA步移文库,并根据已克隆并公布的苦瓜MADS box基因BAG的基因序列设计引物,通过染色体步移技术克隆出BAG基因起始密码子上游调控序列BAGP.对BAGP的鉴定和分析表明其具备大多数高等植物启动子的保守元件,预测它对BAG基因的表达具有一定的作用.为鉴定BAG基因的基本启动子元件,将基因5′侧翼序列做缺失片段分析,利用PCR方法从BAGP中得到3个大小不等两端带有HindⅢ,BamHⅠ酶切位点的片段BAGP1,BAGP2和BAGP3,定向插入载体pMGFP4(pBI221改建,报告基因为GFP)中,取代原有的CaMV35S启动子,构建了由驱动报告基因GFP的植物表达载体BAGPV1,BAGPV2和BAGPV3.

在役L245M输油管道腐蚀穿孔的原因

为研究L245M输油管道在服役期内出现腐蚀穿孔失效的原因,采用金相显微镜、扫描电镜、能谱仪及X射线衍射仪等分析了失效管道的显微组织、蚀坑形貌和腐蚀产物成分。结果表明:腐蚀产物主要为Fe、O、S、Cl的化合物,结合现场环境发现管道运输的凝析油中含有Cl^(-)、H_(2)O、H_(2)S以及CO_(2)等物质,这些物质对管道金属具有腐蚀作用,并且形成的腐蚀产物会加快管道腐蚀,在这些侵蚀性物质与腐蚀产物的共同作用下,管道发生点蚀,最终穿孔。

(M^(3+)Y)L配合物对醇胺氧化抑制作用的实验研究

以最具有代表性的有机胺单乙醇胺(MEA)水溶液为研究对象,研究了抗氧剂(M^(3+)Y)L对MEA溶液氧化降解的抑制作用。主要考察了CO_(2)酸气含量、氧气压力、抗氧剂量、MEA溶液浓度、反应温度等因素对氧化抑制作用的影响。结果表明,在反应温度为120℃、氧气压力为1.0 MPa、搅拌速度为400 r/min时,添加0.2%抗氧剂可使3 mol/L的MEA水溶液的抗氧化降解能力提高近16倍。此外,还对(M^(3+)Y)L氧化抑制作用失效的原因进行分析并提出了相应对策。

基于Levenberg Marquardt算法的列车最优黏着控制研究

电空制动是轨道车辆应用最广泛的黏着制动方式,其制动性能主要受制于轮轨间的黏着状态。在复杂低黏着条件下,传统制动控制系统面临的最大问题是无法使黏着时刻保持最优。因此,基于轮轨黏滑特性和车辆动力学理论,本文首先建立以黏着观测器为核心的蠕滑寻优模型;其次提出以Levenberg Marquardt(L-M)算法为核心的神经网络控制器,完成最优黏着控制系统;最后使用Matlab/Simulink平台分别对基于多交替轨面和实验低黏着轨面的列车黏着控制进行仿真模拟,并与传统比例积分微分控制器(PID)作用下的黏着情况做对比。结果表明,即使面对具有不同特性的低黏着轨面,轮轨黏着在控制系统作用下都能迅速维持在当前轨面下的最优值,有效缩短了制动距离和时间。相比传统PID控制,本文提出的控制系统在制动时间和制动距离上同比减小4.9%与4.1%,调控能力更强,适用于低黏着和大蠕滑下的列车制动工况。

灵孢多糖对M146L细胞APP mRNA表达的影响研究

目的:探讨灵孢多糖(GLPS)对M146L细胞APP mRNA表达的影响,寻找潜在的能够抑制Aβ分泌的中药单体,以达到治疗阿尔茨海默病(AD)的目的。方法:以可过表达β淀粉样蛋白42(Aβ_(42))的β淀粉样蛋白前体蛋白(APP)/突变型早老素1(PS1)双转基因的CHO细胞(M146L细胞)为体外AD治疗药物筛选模型。经不同浓度的GLPS(100,200,300μg/mL)处理后,采用MTT比色法检测细胞活性;应用逆转录聚合酶链式反应(RT-PCR)检测灵孢多糖对M146L细胞APP mRNA表达的影响;蛋白质免疫印迹法(Western blot)检测M146L细胞中APP,Aβ_(42),Bax,Bcl-2等蛋白表达情况;酶联免疫吸附法(ELISA)检测M146L细胞外Aβ_(42)的表达情况。结果:低、中剂量GLPS组细胞活性与对照组比较差异无统计学意义(P>0.05);高剂量GLPS组相比于对照组,细胞活性明显下降(P<0.05)。相比于对照组,低、中、高剂量GLPS组APP mRNA,APP,Aβ_(42),Bax表达水平及细胞外Aβ_(42)浓度均降低(P<0.05),Bcl-2表达水平均升高(P<0.05),且呈一定浓度依赖性(P<0.05)。结论:GLPS可抑制M146L细胞表达APP mRNA,具有成为治疗AD药物的潜质。

基于L-M算法的移动载荷识别数值分析与研究

近几年,国内运输行业呈现出了极为迅猛的发展趋势,作为连接各地区的主体,桥梁在促进经济发展等方面起到重大作用,如何在保证桥梁性能的前提下,对其寿命进行延长已成为社会各界热议的话题。文章以移动载荷识别为切入点,首先对识别所用L-M算法进行了介绍,其次以斜拉桥、简支梁为例,围绕载荷识别、结构分析相关内容展开了讨论,最后以研究所得出结论为依据,针对不确定参数建立了相应的分析模型,创造性地引入了模糊隶属度等指标,希望能够为日后计算响应区间等工作的开展提供帮助。

Identification and Evaluation of Cold Tolerance in Bitter Gourd (Momordica charantia L.) at Bud and Seedling Stages under Different Temperature Conditions

[ Objectives] This study was conducted to screen the temperature index most suitable for identification of cold tolerance in bitter gourd （Momordica charantia L. ） at bud and seedling stages. [ Methods] With six different bitter gourd germplasms as experimental materials, the cold tolerance at bud and seedling stages were identified and evaluated. [ Results] At 18℃ , the largest change range of germination potential among different gernlplasms was 11.3% -96.0%, and the largest change range of germination rate was 13.3% - 100.0% ; and the six germplasms could be divided into three grades of cold tolerance. Therefore, 18 9C is an ideal temperature for the identification of cold tolerance in bitter gourd germplasms at bud stage. At 20℃, the cold tolerance in bitter gourd germplasms at bud stage could also be divided into three grades, and the change ranges of germination potential and germination rate were larger than 50.0%, so 20℃ could serve as the candidate temperature for the identification of cold tolerance in bitter gourd germplasms at bud stage. After 1 d of treatment at 6℃, the six bitter gourd germplasms could be divided into three grades, and the cold injury index had the largest range of 20.31 - 84.38 and could serve as the temperature index for the identification of cold tolerance in bitter gourd at seedling stage. [ Conclusions] This study will provide reference for the identification of cold tolerance in bitter gourd at bud stage and seedling stage.

Fusarium Wilt Resistance Identification and Genetic Analysis of Momordica charantia L. Germplasm

Fusarium wilt seriously affects the yield and quality of Momordica charantia L.Breeding resistant varieties is the most economical and effective measure to control Fusarium wilt in M.charantia L.This study had comprehensively conducted pathogen identification of Fusarium wilt,resistance evaluation of M.charantia L.germplasm to Fusarium wilt,and genetic analysis of Fusarium wilt resistance in M.charantia L.,so as to provide reference for breeding resistant varieties and accelerating the breeding process.

m6A修饰促进宫颈癌的增殖和迁移并调控PD⁃L1表达

目的:探索N6‑甲基腺嘌呤(m6A)修饰相关基因甲基转移酶14(METTL14)和YTH结构域家族蛋白1(YTHDF1)对宫颈癌细胞增殖、迁移和凋亡能力的影响,并探讨其与细胞程序性死亡‑配体1(PD‑L1)表达的相关性。方法:通过免疫组织化学技术分析METTL14、YTHDF1和PD‑L1在宫颈癌组织和正常宫颈组织中的表达水平。采用小干扰RNA(si‑RNA)敲低宫颈癌细胞中METTL14、YTHDF1基因的表达,实时荧光定量PCR(qPCR)验证敲低效果。敲低METTL14、YTHDF1后,CCK‑8实验检测细胞增殖能力,Transwell实验检测细胞迁移能力,流式细胞术检测细胞凋亡情况,qPCR和蛋白质印迹法(Western blot)检测PD‑L1 mRNA和蛋白表达。结果:免疫组化结果显示,METTL14、YTHDF1和PD‑L1在宫颈癌组织中高表达。敲低METTL14和YTHDF1基因表达后,宫颈癌细胞的增殖和迁移能力明显抑制,凋亡增加,PD‑L1 mRNA和蛋白表达水平也随之下调。结论:m6A甲基化修饰可通过调控宫颈癌细胞中PD‑L1的表达来影响宫颈癌细胞的增殖、迁移和凋亡。

关联代数上的Jordan三重中心化子和(m,n,l)-Jordan三重中心化子的刻画

应用代数组合方法,设(X,≤)是一个有限预序集,R是含单位元的2-扭自由的交换环。设I(X,R)是定义在R上的关于X的关联代数,且φ:I(X,R)→I(X,R)是一个线性映射。得到了对任意a∈I(X,R),满足φ(a^(3))=aφ(a)a或3φ(a^(3))=φ(a)a^(2)+aφ(a)a+a^(2)φ(a),那么存在常数λ∈Z(I(X,R)),有φ(a)=λa的结果及若R是含单位元的|(n+l)(m+l)(m+n+l)|-扭自由的交换环,对任意a∈I(X,R),满足(m+n+l)φ(a^(3))=mφ(a)a^(2)+na^(2)φ(a)+laφ(a)a,那么存在常数λ∈Z(I(X,R)),有φ(a)=λa的结果,丰富和拓展了关联代数上的中心化子相关映射。

Impact of Four Fiber Sources and the Strategy of Feeding on the Nutritional Quality of Rabbit Meat (Oryctogalagus cuniculis)

This study was conducted to valorize four sources of fiber (Gliricidia sepium, Leucaena leucocephala, Moringa oleifera and palm nut fibers) in animal production. The experiments were carried out on 128 rabbits divided into 4 batches of 32 animals, reared for 8 weeks under the same conditions. Each batch was subdivided into two subgroups, one fed with a complete diet (a diet containing one of the fiber sources and served all day) and the other with the same diet separated from the fiber source (served at 9 a.m. and supplemented with the fiber source at 4 p.m.). Eight (8) experimental rations were, respectively, tested on the subgroups: complete feed Gliricidia sepium (CFG);supplemented feed Gliricidia sepium (SFG);complete feed Leucaena leucocephala (CFL);supplemented feed Leucaena leucocephala (SFL);complete feed Moringa oleifera (CFM);supplemented feed Moringa oleifera (SFM);complete feed palm nut fiber (CFF);supplemented feed palm nut fiber (SFF). In each subgroup, 4 rabbits were slaughtered at 15 weeks of age for a total of 32 rabbits. Physico-chemical parameters were evaluated on the feed and the meat. Data were analyzed using SAS 2013 software. Fiber content was similar (p > 0.05) for complete feeds. Fat content was high (p < 0.001) for the palm nuts fiber (27.34%) and the CFF feed (11.36%). Feeding rabbits with G. sepium leaves or palm nut fiber continuously increased the fat content of the meat in contrast to sequential feeding. Meat quality was also better when the fiber source was used in the feed of the rabbits in the evening.

Effects of Light-Emitting Diode (LED) Red and Blue Light on the Growth and Photosynthetic Characteristics of <i>Momordica charantia</i>L.

With andromonoecious Momordica charantia L. (bitter gourd) as material, three light qualities (50 μmol·m-2·s-1) including white LED light (WL), blue monochromatic light (B, 465 nm), and red monochromatic light (R, 650 nm) were carried out to investigate their effects on seed germination, physiological and biochemical parameters, sex differentiation and photosynthetic characteristics of bitter gourd. The results showed that compared to the WL treatment, the R treatment significantly promoted seed germination, seedling height elongation and soluble sugar content, the B treatment significantly increased seedling stem diameter, reducing sugar content and soluble protein content, the R and B treatments both significantly reduced sucrose content, but their POD activity showed no significant difference. Compared with the R treatment, the B treatment significantly increased the total female flower number and female flower nod ratio in 30 nods of main stems. The study of photosynthetic characteristics found that the R and B treatments could effectively increase the stomatal conductance (GS) of leaves, significantly improved the net photosynthetic rate (Pn) compared to the WL treatment, and the effect of the B treatment was better. Compared to the R and WL treatments, the B treatment increased the maximum photosynthetic rate (Pmax), apparent quantum efficiency (AQE) and light saturation point (LSP), and reduced the dark respiration rate (Rd) and light compensation point (LCP) of the leaves. Fit light response curves showed that the adaptability and utilization of weak light in bitter gourd were middle or below, but it showed higher adaptability and utilization of strong light. Thus, it suggests that Momordica charantia is a typical sun plan with lower Rd. In summary, it is concluded that blue light has a positive effect on the seed germination, seedling growth, sex differentiation and improving the photosynthetic performance, and this will lay the foundation for artificially regulating optimum photosynthesis using specific LEDs wavelength, and help to elucidate the relationship how light quality influences the sex differentiation of plant.

Field Evaluation on Agronomic Characteristics of Newly Introduced Bitter Gourd(Momordica charantia L.)Accessions in Thua Thien Hue Province,Vietnam

The main objective of this study was to evaluate ability of growth and yield of introduced bitter gourd accessions in winter-spring 2016-2017 in Thua Thien Hue province.A total of seven accessions were used in this study.Of these,six accessions were provided by the World Vegetable Center(AVRDC),namely,AVRDC 1329,AVRDC 1330,AVRDC 1331,AVRDC 1333,AVRDC 1334,AVRDC 1335 and one Vietnam local accession(control)from Dien Hai commune,Phong Dien district,Thua Thien Hue province.The results showed that experiment accessions can grow under Thua Thien Hue conditions.AVRDC 1329,AVRDC 1330,and AVRDC 1335 were considered as displaying good growth and development ability.Of those,AVRDC 1330 was the most suitable to consumer as regards to appearance and bitter taste.AVRDC 1330,the control check and AVRDC 1331 had the high actual yield with 16.57,10.65 and 7.88 tons/ha,respectively,and these two introduced accessions can be used for breeding and cultivation under local condition.

基于L-M算法的家用空调主动节能技术的研究

提出一种基于L-M算法的家用空调主动节能技术,通过获取空调的运行数据实时预测室内环境温度达到用户设定温度所需时长,并结合降温速率控制压缩机运行频率,绘制并不断优化运行曲线,从而寻找到最节能的运行路径,减少对潜热做功,同时降低阻尼,结合PID控制使得室内温度控制更加平稳,更顺滑地达到设定温度以减少温度震荡带来的无用能耗的增加,达到越用越节能、越用越舒适的目的。测试结果表明,该算法在某些环境下节能率近25%,节能效果良好,具有很大的推广价值。