Safety assessment of high density polyethylene pipe with thermal damages

High density polyethylene pipes exposed in fire spot need to be assessed properly to assure safety operation. In this essay, thermal aging experiments were conducted to gain specimen containing thermal damage. Changes in mechanical properties and microstructure have been investigated by means of various characterisation analyses. The effect of exposure temperature, heat duration time, and cooling method on the mechanical properties were studied, respectively. Analysis results revealed that the effect on the mechanical properties is the consequence of interaction between annealing and heat damage. The results of oxidative induction time experiments, in accordance with attenuated total reflectance Fourier transform infrared spectroscopy analysis, indicated the consumption and migration of antioxidants. On the basis of practice and research, safety assessment procedure and method of high density polyethylene pipe after fire was proposed.     

Dangote水泥项目燃油燃气管网施工调试要点

简要介绍了水泥厂燃油燃气管网工程安装、试验的的主要施工步骤和方法,结合现场经验提出了一些施工过程中的注意事项。重点介绍了重油、热油、天燃气管道进行管道试验的内容、方法及应采取的安全保证措施;对管网调试过程中因焊接缺陷导致的管道泄漏问题进行分析并提出一些处理方法。     

Synthesis and photocatalysis of hierarchical heteroassemblies of ZnO branched nanorod arrays on Ag core nanowires

In this paper, hierarchical heteroassemblies made of interwoven Ag core nanowires (NWs) covered by ZnO branched nanorods (ZnO BNRs) are successfully prepared on a large scale via a solution bottom-up strategy coupling with a templating method. Briefly, heteroepitaxial growth of ZnO nanorods (ZnO NRs) on ZnO seed-coated Ag NWs is first conducted to form fluffy worm-like heteroassemblies. Then, by templating these, ZnO BNRs with exposed high-energy (001) planes on Ag NWs are fabricated with preserved morphology through the second nucleation and growth processes. When evaluated with UV-induced photo-degradation of rhodamine B (RhB), the heteroassemblies of Ag NWs-ZnO BNRs exhibit high photocatalytic properties, due to the decisive roles of the synergistic effect of the unique metal-semiconductor heterojunction and the hierarchical fluffy worm-like morphologies as well as the (001) plane-dominant surface of ZnO BNRs which are attractive for highly efficient photocatalysis.     

Synthesis, characterization, and optical properties of new metal complexes with the multi-sulfur 1,2-dithiolene ligand

Metal complexes containing a new multi-sulfur atom containing 1,2-dithiolene ligand, [4′,5′:5,6] [1,4] dithiino[2,3-b] quinoxaline-1′,3′-dithiolate, have been synthesized and characterized by electrochemical measurements, IR, UV-NIR and ESR spectroscopies. X-ray structure analysis reveals that the anions of the Ni-complex derived from the new ligand form a zig-zag chain along the b axis, and the anions of Au complex of the ligand stack along the a axis while the cations occupy the holes. The Ni-complex exhibits remarkable absorption at 1082 nm (? = 15?000 dm³ mol⁻¹ cm⁻¹) and good solubility that render this complex as a promising near-IR dye for Q-switching neodymium lasers. The third-order non-linear optical properties of the complexes are measured by the Z-scan technique with a 6.5 ns pulsed laser at 532 nm. The Au complexes exhibit non-linear optical absorptive abilities, while the non-linear absorption of the nickel complex is negligible. All of the complexes show effective self-defocusing performance. The third-order non-linear optical susceptibilities for the Au complexes have been determined to be of the order of 10⁻¹³ esu.     

Generation and characterization of a novel recombinant antibody against 15-ketocholestane isolated by phage-display

The employment of monoclonal antibodies (Mabs) to identify disease-associated biomarkers in clinical samples represents the underlying principle for many diagnostic tests. To date, these have been principally developed for protein targets with few reported applications for lipids due to their hydrophobicity and poor immunogenicity. Oxysterols represent a family of lipids implicated in diverse human diseases where Mab-based detection assays could have a profound effect on their utility as clinical biomarkers. These are usually identified in patients' samples by mass- spectrometry based approaches. Here, we describe an antibody phage-library based screening methodology for generating a recombinant monoclonal antibody (RAb) targeting the oxysterol-15-ketocholestane (15-KA), a lipid implicated in multiple sclerosis and Autoimmune Encephalomyelitis (EAE). The antibody is highly specific for 15-KA and shows little or no binding activity for other closely related oxysterols. We employ RAb2E9 to address the controversy over whether 15-KA is a true biomarker for MS/EAE and show that 15-KA is undetectable in serum taken from mice with EAE using antibody based detection methodologies; a finding confirmed by mass-spectrometry analysis. This study demonstrates the technical feasibility of using phage display to isolate highly specific antibodies against poorly immunogenic, small molecule lipids.     

Evaluation of Antioxidant and Antiproliferative Properties of Three Actinidia (Actinidia kolomikta, Actinidia arguta, Actinidia chinensis) Extracts in Vitro

The total phenolic content, total flavonoid content, vitamin C content, and antioxidant activities of ethanol extracts from different kiwifruit varieties (Actinidia kolomikta, Actinidia arguta, Actinidia chinensis) were determined in this study. Multiple scavenging activity assays including the hydroxyl radical, O(2) (-)·radical, DPPH, and the ABTS(+) radical scavenging activity assays were used to identify the antioxidant activities of Actinidia extracts. The cell viability of HepG2 and HT-29 cells was also examined in this study. The results demonstrated that the Actinidia kolomikta extract had a higher antioxidant activity than the other two Actinidia extracts. There is a positive correlation between antioxidant activity and the polyphenols and vitamin C content in all three extracts (R(2) ≥ 0.712, p < 0.05). The Actinidia arguta extract had the highest inhibitory effect on HepG2 and HT-29 cell growth. These results provide new insight into the health functions of fruit and demonstrate that Actinidia extracts can potentially have health benefits.     

VERSA滑阀的应用与维护

控制阀在工业生产中具有很大的应用空间。结合现场的实际应用情况,对VERSA滑阀的原理、应用和维护做了分析和论述。     

物理化学实验教学模式改革与探索

以培养学生实践能力和创新能力为目标,通过对教学内容、教学方法及考核方式等方面的探索与改革,构建了本校物理化学实验教学的新模式。实践证明,物理化学实验的教学改革,调动了学生的实验兴趣和主观积极性,取得了良好的教学效果。     

核电二回路吗啉与乙醇胺加药工况的水化学影响研究

文章立足于国外技术研究和试验结果,结合国内部分投加有机胺机组的设计、试验和现场运行资料,旨在评估与归纳吗啉与乙醇胺对核电二回路运行与腐蚀控制的影响等,核电设计、建设与运行人员普遍关注的问题。