Optimal metric for condition rating of existing buildings: is five the right number?

In the context of the built environment in the recent years, the concept of maintenance has changed from corrective to preventive maintenance. There is evidence that preventive maintenance is much more efficient than corrective maintenance, since severe deteriorations that may represent danger to people are avoided, and also money is saved. To make periodic inspections of the buildings is useful to quantify, the extent to which deteriorations are severe or not, in order to facilitate decision making and prioritise interventions. To this purpose, many scales have been used and are used to assess the severity of damage and degradation of the building components. But it appears evident that there is not consensus among users and these scales are different between them, with different number of degrees and metrics for the measurement of the condition state. The main goal of this paper is to calculate which is the optimal metric (which is the optimal number of degrees) of a severity scale of damages in buildings, so the corresponding scale could be of widespread and of common use among professionals, avoiding the problems of comparison between different evaluators. The proposed methodology to calculate the optimal metric of a scale can be also extended to other scopes.     

W波段光控Gunn管谐波振荡器的实验研究

本文提出了Ｗ波段Ｇｕｎｎ管谐波型光控振荡器的设计方案，该方案在振荡器的基波腔内填充本征半导体Ｓｉ片，并通过光纤将半导体激光器产生的光束耦合到Ｓｉ片，以达到光对振荡器工作频率的控制，在实验中采用波长为０．８６３μｍ的激光照射Ｓｉ片，取得了光控频率达７ＭＨｚ的结果。     

复合材料微波快速抢修技术在某重型战机抢修中的应用

我国空军多架现役重型战斗机的结构损伤(裂纹)经用复合材料微波快速抢修技术修复.本文以此为例,详细推介了这一我国独创的快速抢修技术.     

反垄断法损害赔偿研究

反垄断法损害赔偿与一般民事侵权损害赔偿不同。由于反垄断法特殊的立法目的和公法属性决定了反垄断损害赔偿具有不同于一般民事损害赔偿的惩罚性。《中华人民共和国反垄断法》第50条的规定太过简略,需要进行更多的探讨。     

Synthesis and characterization of novel negative-working aqueous base developable photosensitive polyimide precursors

Through molecular designing, three poly(amic esters) (PAEs) have been synthesized from pyromellitic dianhydride (PMDA), 2,2′-bis-(3-amino-4-hydroxyphenyl) hexafluoropropane (BisAPAF), 4,4′-diaminodiphenyl ether (4,4′-ODA) and 2-hydroxyethyl methacrylate (HEMA). Due to the introduction of photosensitive acrylate groups and aqueous base soluble phenolic hydroxyl groups in the backbone, these poly(amic esters) can be used as the precursors of negative-working, aqueous base developable photosensitive polyimides (PSPIs). These poly(amic esters) were prepared by direct polymerization by using phenyl phosphonic dichloride (PPD) as an activator. The inherent viscosities of these polymers were 0.20 (dL/g). Their structures were characterized by Fourier transform infrared spectroscopy (FTIR) and ¹H NMR. In order to improve the photolithographic performance of these PSPIs, different photosensitizers, photoinitiators and a crosslinker have been added in the PSPI formulations. Among them, the Michler's ketone (MK)/tribromomethyl phenyl sulfone (TBPS) system gave the best results. Using a 2.38 wt% aqueous TMAH solution as a developer, patterns with a resolution of 10 μm were obtained from these PSPI formulations. In addition, the effects of the molecular structure of the precursors and the concentration of developer on the photosensitivity of the PSPI formulations were also discussed.     

Effects of reactive end-capper on mechanical properties of chemical amplified photosensitive polyimide

Photosensitive polyimide (PSPI) was synthesized and characterized to replace the conventional polyimide buffer layer because direct patterning with PSPI could reduce the processing procedure to the half. Since PSPI should be dissolved in alkaline aqueous solution and have good mechanical properties after imidization, low molecular weight of PSPI was synthesized with reactive end-capper, which could extend the chain length of PSPI during imidization. Therefore norbornene end-capped PSPI precursor was synthesized with various 5-norbornene-2,3-dicarboxylic anhydride (NDA) content.Although molecular weight of PSPI decrease with increasing NDA content, the elongation at break and the glass transition temperature (T_g) of PSPI films imidized at 300 °C increased with increasing NDA content. On the other hand, elongation at break of PSPI films imidized at 350 °C decreased but T_g of those increased with increasing NDA content. Above T_g, thermal expansion coefficient decreased dramatically by introducing NDA end-capper. From mechanical and thermal properties of PSPI, it appears that low molecular weight of PSPI can be chain-extended and crosslinked during imidization.     

低收缩感光性高分子材料的研究

报道了非收缩单体SOC_7的光引发正离子共聚合,证明少量SOC_7加到ERL—4221体系中,可抑制固化收缩,而材料性能没有明显降低。并证明是共聚物结构。     

Suitable laser irradiation position from perspective of TIG arc behaviour. Study of high‐speed surface treatment by TIG arc combination with laser (Report 5)

The results of evaluation of the possibility of removing surface long corrosion damage by repair surfacing in a caisson on pipes after long-term service are described.     

沥青路面的病害分析与维护建议

路面在行车荷载和外界环境等因素的影响下，性能衰减甚至破坏是在所难免的。根据沥青路面病害的不同类型和诱发机理，选择恰当的维护和维修手段，不仅能够大大降低维修费用，而且能够保证路面的长期使用性能，延长其使用寿命。沥青路面的再生利用技术在我国具有广阔的应用前景。     

Alteration of ADP-ribosylation in aging rat brain astrocytes

DNA damage and the enzyme poly (ADP-ribose) polymerase (PARP) associated with the pathogenesis of numerous age-related neurodegenerative disorders. Astrocytes play crucial roles in both support metabolic functions and cell viability of the brain. PARP regulates DNA damage and repair in the brain cells. In this study PARP activity and DNA strand break were investigated in the astrocytes isolated from young and aged rat brain. Three and 30-month-old rats were killed by decapitation and brains were removed onto an ice cooled glass plate. Astrocytes were isolated by sucrose density gradient centrifugation and glutamine synthetase (GS) served as a marker of the astrocytes lineage. The specific activity of PARP was assayed in permeabilized cells by measuring the incorporation of the ADPribose moiety of [3H]NAD into the nuclear acceptor proteins. The rate of DNA strand breaks was determined using a fluorescent dye and monitored spectrofluorimetry. An increase (about 75%) in the PARP activity was observed in the whole homogenates of aged rats, whereas this rise was more pronounced (about 360%) when the reaction was measured in the purified astrocyte preparations. The amount of DNA strand breaks was also higher in the astrocytes isolated from the aged brain as compared to that of young levels. The close relationship between the level of DNA strand breaks and PARP activity in the astrocytes suggest that these cells are susceptible to the metabolic alterations in aging. It is concluded that the astrocytes PARP might be considered as a therapeutic target for combating age related neurodegenerative disorders.