动态充氢电流密度对BG110S油井管力学性能的影响

利用 MTS-810材料试验机测量了BG110S油井管在动态拉伸(边充氢边拉伸)实验中的力学性能,并利用扫描电镜观察分析了拉伸断口形貌,研究了动态充氢电流密度对油井管力学性能的作用,讨论了氢原子浓度对油井管氢脆敏感性的影响。实验结果表明：随着充氢电流密度的增加,BG110S试样的屈服强度和抗拉强度先增大后减小;试样的伸长率、断面收缩率及拉伸韧性连续降低;试样的拉伸断口形貌由韧性断裂特征向脆性断裂特征转变;试样的氢脆敏感性连续增加。当动态充氢电流密度i＜30 mA/cm2时,氢原子在 BG110S试样中呈现固溶强化作用,而当i≥30 mA/cm2后,氢原子在BG110S试样中则呈现氢致脆化作用。     

基于PCI总线的数据采集和输出系统

介绍了PCI总线的特点以及基于PCI总线的快速数据采集和输出系统的结构、组成，研究了PCI总线接口技术在数据传输系统中的应用和软件编程具体设计方法。实验测试证明，采用PCI总线接口技术进行数据采集和输出，与采用ISA总线相比，数据传输速度得到明显提高。     

包钢BG型布料器替代常规齿轮箱布料器

文章以一次检修施工为切入点,介绍了包钢BG型高炉布料器替代常规齿轮箱布料器的过程,从布料器的设计原理、结构及现场使用介绍了具有自主知识产权的包钢BG型高炉布料器的特点,对2种类型的设备进行对比,阐述了更换的理论依据和替代大高炉常规齿轮箱布料器的可能性。     

Numerical investigation on the effect of CO2 and steam for the H2 intermediate formation and NOX emission in laminar premixed methane/air flames

One-dimensional premixed freely-propagating flames for (CH₄+CO₂/H₂O)/air(79%N₂+21%O₂) mixtures were modeled using ChemkinⅡ/Premix Code with the detailed mechanism GRI-Mech 3.0. The investigation of the effects of CO₂ and steam addition on the H₂ intermediate formation and NO emission was conducted at the initial conditions of 1 atm and 398 K. Both physical and chemical effects of CO₂, H₂O on laminar burning velocities and adiabatic flame temperatures were also analyzed. The calculations show that with the increase of α_CO2 and α_H2O, both physical and chemical effects of CO₂ and H₂O result in the reduction of laminar burning velocities (LBVs) and adiabatic flame temperatures (AFTs) in which the chemical effects of CO₂ addition are more significantly than H₂O. Especially, the chemical effects of steam promote the increase of AFTs and the influence in rich BG65 flames are larger than in methane. With a proper amount of H₂O addition, the chemical effects of H₂O on the peak concentration of H₂ are more significantly than physical at Φ = 1.2. Moreover, CO₂, steam and their mixture addition have significant reduction on the NO emission. The most sensitive reaction for the formation of H₂ and NO emission were determined. The responsible reactions for H₂ formation and NO emission are R84 OH + H₂ <=> H + H₂O and R240 CH + N₂ <=> HCN + N (a prompt routine), respectively.     

安徽某难选硫化铜矿石浮选试验研究

安徽某热液蚀变的接触变质原生硫化铜矿矿石因性质复杂而难选,以常用浮选药剂按常规铜硫混浮铜硫分离流程进行选矿试生产不能达到设计指标,致使选厂不能正常投产。为此,对该矿石进行了合理浮选工艺流程和新药剂制度的试验研究。试验采用自行研制的新型酯类捕收剂QL先脱除易浮脉石,然后用复合捕收剂MC进行铜硫混浮、以石灰为抑制剂进行铜硫分离,获得了铜品位22．78％、回收率86．80％的铜精矿,超过铜精矿铜品位21．30％、回收率85．50％的设计指标。新的工艺流程适应矿石性质,药剂制度简单、用量少,易于工业化。     

Epigenomic Features and Potential Functions of K+ and Na+ Favorable DNA G-Quadruplexes in Rice

DNA G-quadruplexes (G4s) are non-canonical four-stranded DNA structures involved in various biological processes in eukaryotes. Molecularly crowded solutions and monovalent cations have been reported to stabilize in vitro and in vivo G4 formation. However, how K⁺ and Na⁺ affect G4 formation genome-wide is still unclear in plants. Here, we conducted BG4-DNA-IP-seq, DNA immunoprecipitation with anti-BG4 antibody coupled with sequencing, under K⁺ and Na⁺ + PEG conditions in vitro. We found that K⁺-specific IP-G4s had a longer peak size, more GC and PQS content, and distinct AT and GC skews compared to Na⁺-specific IP-G4s. Moreover, K⁺- and Na⁺-specific IP-G4s exhibited differential subgenomic enrichment and distinct putative functional motifs for the binding of certain trans-factors. More importantly, we found that K⁺-specific IP-G4s were more associated with active marks, such as active histone marks, and low DNA methylation levels, as compared to Na⁺-specific IP-G4s; thus, K⁺-specific IP-G4s in combination with active chromatin features facilitate the expression of overlapping genes. In addition, K⁺- and Na⁺-specific IP-G4 overlapping genes exhibited differential GO (gene ontology) terms, suggesting they may have distinct biological relevance in rice. Thus, our study, for the first time, explores the effects of K⁺ and Na⁺ on global G4 formation in vitro, thereby providing valuable resources for functional G4 studies in rice. It will provide certain G4 loci for the biotechnological engineering of rice in the future.     

MT890高功率密度柴油机润滑油规范及油品性能剖析研究

文章介绍了德国MTU公司的MT890高功率密度柴油机系列以及配套用油规范,并对符合该规范的油品进行了性能剖析研究,结果表明：MT890高功率密度柴油机润滑油质量级别相当于API CF-4,油品性能剖析结果验证了这一结论。     

探索晶圆级芯片贴装薄膜和芯片制备集成工艺的新挑战

分析了在多芯片叠装封装产品中采用晶圆级芯片贴装薄膜对传统芯片制备以及后续封装工艺所产生的巨大影响。阐述了在晶圆级芯片贴装薄膜贴覆工艺,芯片制备以及后序工艺中所遇到的巨大挑战。     

Evaluation of Region-of-Interest coders using perceptual image quality assessments

A perceptual measure emulates the human vision for image quality assessment. This paper illustrates the evaluation of Region-of-Interest (ROI) coders using perceptual image quality assessments. The goal of this evaluation is to characterize the coder performance by controlling the ROI quality. Perceptual measures are taken into account for evaluation since they behave as a human-made evaluation. Moreover, a perceptual assessment named Wavelet Quality Index (WQI), is introduced as another image coder evaluator. Proposed assessment aims at emulating the human vision by a weighted linear combination of three wavelet-based perceptual measures. We evaluate the following types of ROI-coders: those preserving the quality of ROI by coarse compression of background (Max-Shift coder), and those balancing the quality between ROI and background (SCM-Shift, and BbB-Shift coders). Using considered assessments for the performance evaluation of coders, results show a variation of evaluation by nature of measurement.     

热输入对Q890高强钢焊缝组织及性能的影响

针对国内某钢厂最新研制的Q890高强钢,采用三种不同的热输入对其进行气体保护焊接,研究了不同热输入对焊缝金属组织、硬度及冲击韧性的影响.结果表明,3种热输入下,焊缝组织主要以板条贝氏体为主,并含有粒状贝氏体、少量的板条马氏体和残余奥氏体.随着热输入的增大,焊缝组织中贝氏体铁素体板条粗化,板条马氏体逐渐减少,而粒状贝氏体逐渐增多,部分残余奥氏体由薄膜状向块状转变;焊缝金属硬度随着热输入的增大而下降;焊缝金属的冲击韧性亦呈逐渐下降的趋势.