5B05防锈铝预绞丝断裂失效分析

采用光学显微镜、扫描电镜等测试手段 ,对断裂的 5B0 5 (LF1 0 )防锈铝预绞丝进行了分析。结果表明 ,由于退火处理不规范及金属夹杂物的存在 ,引起零件的强度增高、韧性降低 ,在外力的作用下 ,导致预绞丝断裂失效     

N-Functionalization of 5-Aminotetrazoles: Balancing Energetic Performance and Molecular Stability by Introducing ADNP

5-aminotetrazole is one of the most marked high-nitrogen tetrazole compounds. However, the structural modification of 5-aminotetrazole with nitro groups often leads to dramatically decreased molecular stability, while the N-bridging functionalization does not efficiently improve the density and performance. In this paper, we report on a straightforward approach for improving the density of 5-aminotetrazole by introducing 4-amino-3,5-dinitropyrazole. The following experimental and calculated properties show that nitropyrazole functionalization competes well with energetic performance and mechanic sensitivity. All compounds were thoroughly characterized using IR and NMR spectroscopy, elemental analysis, and differential scanning calorimetry (DSC). Two energetic compounds (DMPT-1 and DMPT-2) were further confirmed by implementing single-crystal X-ray diffraction studies. Compound DMPT-1 featured a high crystal density of 1.806 g cm⁻³, excellent detonation velocity (v_D = 8610 m s⁻¹), detonation pressure (P = 30.2 GPa), and impact sensitivity of 30 J.     

预应力混凝土空心板梁锚端裂缝成因分析与防治措施

针对某空心板梁桥在施工中出现锚端裂缝的问题,对照试验结果和现行规范,结合施工经验,分析裂缝产生原因是垫板尺寸小、梁预拱度设置不合理、锚端混凝土局部受压及斜交板钝角支承处反力大等.指出裂缝对梁承载力和正常使用的影响,提出防治措施.最后指出在实际设计施工过程中要注意新老规范的区别,以保证安全.     

战略后方仓库军用集装箱装运机械优化配置模拟仿真研究

以某战略后方仓库为例,通过构建1个包括龙门吊、集卡和跨运车的动态多级排队网络,运用仿真技术描述战略后方仓库集装箱装卸系统,对系统输出指标进行分析,给出了某战略后方仓库的最优机械配置比和最优的：龙门吊台数。     

Single-event effects induced by medium-energy protons in 28 nm system-on-chip

Single-event effects(SEEs) induced by medium-energy protons in a 28 nm system-on-chip(So C) were investigated at the China Institute of Atomic Energy. An on-chip memory block was irradiated with 90 MeV and70 MeV protons, respectively. Single-bit upset and multicell upset events were observed, and an uppermost number of nine upset cells were discovered in the 90 MeV proton irradiation test. The results indicate that the SEE sensitivities of the 28 nm SoC to the 90 MeV and 70 MeV protons were similar. Cosmic Ray Effects on Micro-Electronics Monte Carlo simulations were analyzed, and it demonstrates that protons can induce effects in a 28 nm SoC if their energies are greater than 1.4 MeV and that the lowest corresponding linear energy transfer was 0.142 MeV cm~2 mg~(-1). The similarities and discrepancies of the SEEs induced by the 90 MeV and 70 MeV protons were analyzed.     

MicroRNAs as Potential Biomarkers in the Differential Diagnosis of Lipomatous Tumors and Their Mimics

Adipocytic tumors are the most common subtype of soft tissue tumors. In current clinical practice, distinguishing benign lipomas from well-differentiated liposarcomas (WDLPS), as well as dedifferentiated liposarcomas (DDLPS) from their morphologic mimics, remains a significant diagnostic challenge. This is especially so when examining small biopsy samples and without the aid of additional ancillary tests. Recognizing the important role that microRNAs (miRNAs) play in tumorigenesis and their potential utility in tumor classification, we analyzed routine clinical tissue samples of benign and malignant lipomatous tumors, as well as other sarcoma mimics, to identify distinguishing miRNA-based signatures that can aid in the differential diagnosis of these entities. We discovered a 6-miRNA signature that separated lipomas from WDLPS with high confidence (AUC of 0.963), as well as a separate 6-miRNA signature that distinguished DDLPS from their more aggressive histologic mimics (AUC of 0.740). Functional enrichment analysis unveiled possible mechanistic involvement of these predictive miRNAs in adipocytic cancer-related biological processes and pathways such as PI3K/AKT/mTOR and MAPK signaling, further supporting the relevance of these miRNAs as biomarkers for adipocytic tumors. Our results demonstrate that miRNA expression profiling may potentially be used as an adjunctive tool for the diagnosis of benign and malignant adipocytic tumors. Further validation studies are warranted.     

The E3 Ligase GmPUB21 Negatively Regulates Drought and Salinity Stress Response in Soybean

E3-ubiquitin ligases are known to confer abiotic stress responses in plants. In the present study, GmPUB21, a novel U-box E3-ubiquitin ligase-encoding gene, was isolated from soybean and functionally characterized. The expression of GmPUB21, which possesses E3-ubiquitin ligase activity, was found to be significantly up-regulated by drought, salinity, and ABA treatments. The fusion protein GmPUB21-GFP was localized in the cytoplasm, nucleus, and plasma membrane. Transgenic lines of the Nicotiana benthamiana over-expressing GmPUB21 showed more sensitive to osmotic, salinity stress and ABA in seed germination and inhibited mannitol/NaCl-mediated stomatal closure. Moreover, higher reactive oxygen species accumulation was observed in GmPUB21 overexpressing plants after drought and salinity treatment than in wild-type (WT) plants. Contrarily, silencing of GmPUB21 in soybean plants significantly enhanced the tolerance to drought and salinity stresses. Collectively, our results revealed that GmPUB21 negatively regulates the drought and salinity tolerance by increasing the stomatal density and aperture via the ABA signaling pathway. These findings improved our understanding of the role of GmPUB21 under drought and salinity stresses in soybean.     

PLC应用中的问题及解决办法

就教学及实践工作中遇到的一些典型问题做一探讨,以期对正在学习和应用PLC的人员有所帮助.     

汽车主动悬架免疫模糊控制策略研究

针对汽车四分之一主动悬架模型,提出免疫模糊控制策略.该策略兼有模糊控制的快速简单和免疫控制的全局搜索最优解的优点,并可同时考虑车身垂直加速度、悬架动行程和轮胎动载等多种因素.结果表明,与独立的免疫控制和模糊控制比较,该免疫模糊控制策略的综合性能最优.