稀土纳米荧光粉显现潜指纹研究进展

稀土纳米荧光粉用于潜指纹可视化,利用了稀土荧光粉发光强度高和纳米粉体与潜指纹具有适宜的附着力特性,显示的潜指纹具有高对比度、高质量和高强度的荧光,特别是上转换纳米荧光粉和长余辉纳米荧光粉显示潜指纹能消除背景干扰,然而用紫外光激发的稀土荧光粉受到基底背景颜色和强背景自发荧光的干扰,在潜指纹显现方面应用具有局限性。本文综述了荧光粉合成方法、形貌、粒度和结构以及各种荧光粉对显示潜指纹特征脊细节级别的影响,特别是继续开发发光强度高、背景干扰小、适应各种基底表面显示潜指纹的稀土纳米荧光粉仍然是一个挑战。     

The rediscovery of a neglected part of care. Palliative care is one of the main tasks in nursing

The dimensional accuracy, surface hardness and reproduction of surface detail of stone casts produced from alginate impressions treated with 4.65% sodium hypochlorite, were investigated. To test dimensional accuracy, a Reflex Microscope was used to compare casts from 10 untreated impressions with casts from 10 impressions immersed in the solution for 30 mins. Surface detail and hardness were investigated on casts produced from impressions of a master stainless steel plate with 10 micro-indentations of increasing size. Surface detail of the casts were assessed by observation and surface hardness by a Vickers Hardness Machine. The dimensional accuracy test showed no significant differences between the experimental and control groups. Surface detail was unaffected after immersion of up to 10 mins. Surface hardness decreased linearly with respect to immersion time, when this was greater than 5 mins.     

Accuracy, detail reproduction, and hardness of gypsum casts produced from silicone impressions treated with glow discharge

Plasma treatment has been reported to improve the wettability of silicone impression materials. This study investigated whether plasma treatment of silicone impressions influenced the linear dimensional accuracy, detail reproducibility, and surface hardness of models produced from a type IV dental die stone. Five silicone impressions materials were used in this study. Linear dimensional accuracy and detail reproduction were tested according to ISO standards. Surface hardness was evaluated with a Vickers hardness test. The results indicated that plasma-treated impressions from Xantopren and Provil silicone impression materials had significantly smaller dimensional change than their respective controls, and the other materials were not influenced. The detail reproduction was superior in casts produced from plasma-treated impressions from President silicone. Surface hardness was not influenced by the treatment. Plasma treatment of silicone impressions has no negative influence on the tested physical properties of die stone models.     

Collaborative study of accelerated development of latent fingerprint images on paper by application of steam

Nine latent fingerprint examiners participated in a collaborative study in the use of a steam iron to accelerate chemical development of latent images on bond and newsprint papers treated with a 0.5% solution of ninhydrin in acetone. Four latent images were placed on each paper by the Associate Referee during an 8 hr period. The papers were paired and numbered 1, 2, and 3. Three pairs were mailed to each collaborator who treated Pair 1 by dipping, Pair 2 by brushing or swabbing, and Pair 3 by spraying. After air-drying, the papers were subjected to heat and steam from a household steam iron until the images developed. The average time for developing all images was 5.8 min/paper. Of the total images available, 92.1% were developed to some degree; 47.9% of these images or 43.5% of all images were identified by the collaborators. The method has been adopted as offical first action.     

Detection of latent fingerprints using luminescent Gd0.95Eu0.05PO4 nanorods

Lanthanide ions doped luminescent materials are widely studied for latent fingerprint detection. However, most of these materials are synthesized at very high temperatures and use UV C light for visualization, which is harmful to eye, skin, etc. Herein, the Gd_0.95Eu_0.05PO₄ nanorods synthesized by a simple co-precipitation method at 185 °C were reported for latent fingerprint visualization under 395 nm light. The Gd_0.95Eu_0.05PO₄ nanomaterial has monoclinic crystal structure and shows rod-shaped morphology. Further, these Gd_0.95Eu_0.05PO₄ nanorods exhibit excellent photoluminescence properties and strong fuchsia emission under UV light. These nanorods have been employed for developing latent fingerprints on various porous and non-porous substrates by the powder dusting technique, which exhibits clear and well defined details with high contrast, selectivity and sensitivity under 395 nm UV light. Latent fingerprints developed after 72 h of their deposition also show clear contrast with these nanorods. Therefore, the Gd_0.95Eu_0.05PO₄ nanorods can be used for latent fingerprint visualization applications.     

Preparation of void-free casts from vinyl polysiloxane impressions

PURPOSE: To investigate two techniques to produce void-free casts from vinyl polysiloxane impressions. MATERIALS AND METHODS: Thirty casts prepared using a conventional technique were compared with 30 casts prepared using a technique involving syringing of stone in terms of numbers of surface voids. RESULTS: Significantly fewer surface voids were observed in the casts prepared using syringing technique. CONCLUSION: The syringing technique investigated is considered to have advantages over the conventional technique for the production of casts from vinyl polysiloxane impressions.     

中小孔径控制爆破技术在南芬露天矿的应用

介绍了南芬露天矿在开挖两个积水坑连接部分岩体的控制爆破方法，针对爆破工程的特点，首次采用瑞典阿特拉斯127mm孔径边坡钻机进行钻孔作业，使用性能稳定的岩石乳化炸药药卷与澳瑞凯高精度非电导爆管雷管，结合逐孔起爆技术和覆盖方法，取得了较好的控制爆破效果。     

Bootstraps taxometrics: Solving the classification problem in psychopathology.

Classification in psychopathology is a problem in applied mathematics; it answers the empirical question "Is the latent structure of these phenotypic indicator correlations taxonic (categories) or nontaxonic (dimensions, factors)?" It is not a matter of convention or preference. The taxometric procedures, MAMBAC and MAXCOV-HITMAX, provide independent tests of the taxonic conjecture and satisfactorily accurate estimates of the taxon base rate, the latent means, and the valid and false-positive rates achievable by various Cuts. The method requires no gold standard criterion, applying crude fallible diagnostic "criteria" only in the phase of discovery to identify plausible candidate indicators. Confidence in the inference to taxonic structure and numerical accuracy of latent values is provided by multiple consistency tests, hence the term coherent cut kinetics for the general approach. Further revision of diagnostic systems should be based on taxometric analysis rather than on committee decisions based on clinical impressions and nontaxometric research. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

An in vivo study of a clinical surfactant used with poly(vinyl siloxane) impression materials

The aim of this study was to determine whether the use of a topical surfactant (Hydrosystem), designed for clinical use, improved the quality of the impression surface of two poly(vinyl siloxane) materials used in vivo. Before impressions were taken, Hydrosystem was applied to the maxillary left or right premolar teeth, allocated at random, in 50 subjects. The untreated side acted as a control for each subject. The impressions were examined for quality of reproduction and number of surface defects. Hydrosystem was found to significantly improve the quality of reproduction.     

Low-frequency vibrations in the treatment of patients with acute maxillary sinusitis and ethmoiditis. Non-specific resistance and immunity

Effect of sodium hypochlorite disinfection of impressions on the size and quality of plaster models is studied. Twenty-minute submerging of silicone impressions in 0.5% sodium hypochlorite solution did not change their size and did not deteriorate the quality of surface and hardness of plaster models. Stomalgin impressions cannot be disinfected by sodium hypochlorite solution because of expressed destructive effect of this disinfectant on the impressions.     

抗挤毁油井套管用钢管裂纹分析

通过对衡钢生产的抗挤毁油井套管表面裂纹进行分析,得出裂纹是钢中的残余有害元素造成,并经轧制,调质,回火后使裂纹扩大暴露的结论。据此,结合生产现场现有设备技术条件,提出了减少裂纹的工艺改进措施。     

Development of latent fingerprints using a corona discharge

A novel technique for the development of latent fingerprints is presented. It is based on placing a fingerprint-bearing object inside a corona discharge induced plasma. The development of various real and artificial fingerprints on metallic substrates under a wide range of conditions is studied. Using the results of the development experiments and the results of X-ray photoelectron spectroscopy, it is shown that the development is based on oxidation of the fingerprint background. This is achieved by strong oxidizers generated by the discharge process, while saturated fatty-acids found in sebaceous fingerprints protect the area beneath them, resulting in a visible fingerprint. The process is optimized by minimizing the electrode gap distance and maximizing the peak discharge voltage and the pulse repetition frequency.     

爆轰波三波点擦除烟迹表面积碳机制

为理解三波点在壁面及端面积碳留下记录的确切机制,推动对螺旋爆轰内部结构的研究,采用端面烟熏玻璃与内壁烟膜结合的实验方法记录胞格结构,并得到不稳定、较稳定及稳定预混气的侧壁及端面爆轰记录.2H₂+O₂+3Ar给出了清晰精细的端面结果,其单头螺旋结果表明相对于结果近似的侧壁结果,内部螺旋结构并非固定.进而从附着碳粒的粒度尺寸分析出碳迹附着原理并结合五种预混气的反应特性,确定键能足以克服碳迹吸附在表面的力时才能擦除烟迹.另外预混气中的碳分子也会导致烟迹堆积而影响端面结果,反射激波的强度也影响记录的清晰度.最终确定烟迹擦除机制受预混气影响,应针对预混气选用表面粗糙度载体和积碳颗粒尺寸,并给出了记录爆轰结构的方法.      

Competitive flow injection enzyme immunoassay for steroids using a post-column reaction technique

An automated immunoassay, with one affinity component immobilized on a solid surface, has been developed to monitor the production of different immunoglobulins during mammalian cell cultivation processes. The whole analysis device is based on the principle of flow injection analysis (FIA) and a cartridge with the immobilized affinity component is implemented into the FIA system. This cartridge is filled with a carrier material to which protein G is covalently bound. After sample injection, binding of the IgG on the protein G within the cartridge takes place while after a washing step, the IgGs are eluted by a pH shift, and the IgG concentration is monitored via fluorescence. In the automated immunoassay, undiluted cell free samples from the reactor or from down-stream processing can be analyzed directly. Due to the separation the IgG can be detected without interference from other sample components by protein fluorescence. The results are obtained with analysis times below 6 min. Sample volumes of less than 100 microliters may be used. The assay is sensitive to concentrations from 5 up to 500 micrograms ml-1. Using this FIA-System, immunoglobulins G, produced in different media, were successfully monitored. The results of the assay were validated by ELISA.     

Clinical significance of surface activation of silicone impression materials

OBJECTIVES: Surface activation of silicone impression materials enhances impression accuracy as well as the quality of stone casts. This study examined the relation between impression quality and the hydrophilicity of silicone impression materials used in a two-stage putty and wash technique. METHODS: The study included 14 silicone impression materials with and without surface activation. The contact angles of the light body materials were measured using deionised water. Free surface energies were calculated. A total of 140 impressions of wet intact permanent molar teeth were examined for definition of the gingival sulcus reproduction and then classified in a quality ranking. The percentage of the sulcus reproduction ability of each material was calculated from the sulcus depths of cross-sectioned resin casts from the impressions and clinically measured sulcus depths. RESULTS: Free surface energies (mJ/m2) of hydrophobic materials (contact angle > 90 degrees) ranged from 16.8 to 26.8 mJ/m2. Surface activated materials (contact angle < 90 degrees) exhibited free surface energies from 38.1 to 55.7 mJ/m2. Not all materials described as surface activated showed hydrophilic properties. Medians of impression quality ranking ranged from 1.75 (best) to 13.25 (worst), mean sulcus reproduction ranged from 30 to 52%. Significant differences (P < 0.05) in quality ranking and sulcus reproduction were found between certain materials but correlations were found neither between sulcus reproduction and free surface energy nor between quality ranking and free surface energy. CONCLUSIONS: For clinical impression recording, surface activation seems to be of minor relevance, at least in the two-stage putty and wash technique investigated and is superimposed by other material properties.     

脉冲等离子爆炸工艺表面改性H13钢

 为研究脉冲等离子爆炸工艺制备H13钢(4Cr5MoSiV1)表面改性层的组织和性能,通过对显微组织形貌、相结构、残余应力、硬度和耐磨性的分析,对脉冲等离子爆炸工艺的改性机制和影响进行了讨论。结果表明,脉冲等离子爆炸工艺使H13钢表面发生快速熔凝和快速淬火过程,在材料表面形成厚度均匀、组织致密、高硬度的改性层;改性层中马氏体细化,同时由于不同物理变化过程分别形成残余奥氏体和逆变奥氏体;随着脉冲次数的增加,材料表面的残余应力经历了由压应力先增大后减小然后转变成拉应力的过程;改性层的厚度和硬度随脉冲次数的增加而提高,但同时表面熔化程度加剧,表层低硬度熔凝区厚度增加。当脉冲次数为8次时,H13钢具有最优的耐磨损性能。     

Detonation sprayed WC-Co coatings: unique aspects of their structure and mechanical behaviour

Tungsten Carbide-Cobalt (WC-Co) Cermets are known for their excellent wear resistance. Conventionally, WC-Co cermets are produced by liquid phase sintering and such a process results in optimum combination and distribution of WC and Co phases and thus a good combination of hardness and toughness. In contrast to using bulk WC-Co, there are many applications wherein a thick coating of WC-Co over the surface of the engineering component (usually made from steel) represents a cost-effective option. Numerous thermal spray coating techniques have been extensively used to deposit thick WC-Co coatings on a variety of components and detonation spray coating represents one such coating technique capable of depositing hard and dense WC-Co coatings. However, as compared to bulk WC-Co, detonation sprayed WC-Co exhibit inferior properties and performance primarily because of the nature of the detonation spray coating process. In addition, depositing a WC-Co coating on a component automatically introduces an interface between the coating and the substrate and the properties of this interface also become important in determining the overall performance of the WC-Co coating. The purpose of this article is to describe in detail the unique aspects of the structure and mechanical behaviour of detonation sprayed WC-Co coatings and contrast the same with the behaviour of bulk, liquid-phase sintered WC-Co cermet.     

油套管使用技术研究进展及展望

随着石油工业的发展,石油管材的服役条件越来越苛刻,油套管的损坏已成为目前国内外石油开采中一个急需解决的重要问题。因此油田及石油管制造商有必要充分了解油井管的服役环境,开展油套管的使用技术研究。针对目前油套管的服役工况,阐述了油套管的主要失效形式。从管柱设计的可靠性和螺纹连接及密封的可靠性两方面介绍了油套管使用技术的进展及使用过程中应该注意的问题,并对国内企业在油套管使用技术方面需要展开的工作进行了展望。     

Respirator cartridge service lives for exposure to vinyl chloride

Respirator cartridge service lives (1 ppm breakthrough) were determined for low level (approximately 10 ppm) exposures to vinyl chloride using simple apparatus and an infrared spectrophotometer. Two classes of organic vapor cartridges were tested; six brands which received approval from MESA-NIOSH before July 15, 1975 ahd two brands which were not approved but were available through local safety supply outlets on that date. Cartidges were tested both as they came from the supplier and after being preconditioned for 6 hours. Effects of insult concentration, preconditioning, and absorbent weight were investigated. No cartridge service life exceeded 1 hour; many did not provide protection for even 30 minutes. As a result, the use of cartridge containing half mask respirators for vinyl chloride exposure should be questioned.     

Interviewer predictions of applicant qualifications and interviewer validity: Aggregate and individual analyses.

The relative effects of varied interviewee cues on line managers' hiring decisions were examined, as was the relative predictability of various criteria by line managers' interview impressions. Aggregate and individual regression analyses revealed that 3 nursing directors' impressions of 186 nursing applicants shaped their hiring recommendations more than did the applicants' resume credentials. Moreover, managers' interview impressions significantly predicted employees' job attitudes, though predictions of attitudes did not exceed predictions of performance. Finally, individual managers based hiring decisions on different interview impressions, and these impressions forecast employees' job attitudes with differential validity. Implications for future interviewing research are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)