Influence of Hydrogen on the Microstructures and Superplasticity of a Ti3Al-Nb Alloy

The effect of hydrogen on the microstructures and superplasticity of a Ti3Al-Nb alloy was studied. The results showed that hydrogenation made the volume fraction of B2 phase increase and facilitated the dynamic recrystallization of the lath-like phase. The addition of hydrogen. reduced the flow stresses and made the maximum m value move to a lower temperature during the superplastic deformation. The superplastic deformation temperature of the alloy can be lowered by about 60 ℃.     

三辊连轧管(PQF)的计算机仿真

针对影响连轧管产品质量的几大关键因素进行了三维弹塑性大变形有限元分析，建立了相应的各种分析模型，以动态图形形式的模拟了变形过程与壁厚变化规律，为产品工艺设计提供科学依据。     

Phantoms with 10BF3 detectors for boron neutron capture therapy applications

Two acrylic cube phantoms have been constructed for BNCT applications that allow the depth distribution of neutrons to be measured with miniature 10BF3 detectors in 0.5-cm steps beginning at 1-cm depth. Sizes and weights of the cubes are 14 cm, 3.230 kg, and 11 cm, 1.567 kg. Tests were made with the epithermal neutron beam from the patient treatment port of the Brookhaven Medical Research Reactor. Thermal neutron depth profiles were measured with a bare 10BF3 detector at a reactor power of 50 W, and Cd-covered detector profiles were measured at a reactor power of 1 kW. The resulting plots of counting rate versus depth illustrate the dependence of neutron moderation on the size of the phantom. But more importantly the data can serve as benchmarks for testing the thermal and epithermal neutron profiles obtained with accelerator-based BNCT facilities. Such tests could be made with these phantoms at power levels about five orders of magnitude lower than that required for the treatment of patients with brain tumors.     

The distribution of radio-activity in rats given [3H]bishydroxymethyl-1-methylpyrrole and its relationship to that from [3H]synthanecine A bis-N-ethylcarbamate

Electron microscopic visualization of molecular hybrids formed in situ is feasible at the present time. It can be accomplished by two alternative approaches. In one, the in situ hybridization is carried out on ultrathin sections of target embedded in glycol methacrylate. In the other, whole cells are used for hybridization and they are subsequently prepared for electron microscopy. The choice of the method to be adopted depends on the type of target tissue. When there is a choice, the second approach seems preferable. Some of the important technical steps in the hybridization procedure, such as DNA denaturation in ultrathin sections, have been discussed and attention has been drawn to practical problems that may arise during the preparatory steps. Our light microscope experiments demonstrate that preparations made after glutaraldehyde fixation have a lower hybridization efficiency than those fixed with 3 : 1 methanol-acetic acid. Attempts are therefore being made to explore the possibility of using methanol-acetic acid for electron microscope in situ hybridization. First results of straight-forward fixation show that the preservation of nuclear structure may be fairly satisfactory for the purpose. However, the cumultative effects of subsequent treatments in the procedure still remain to be examined. For electron microscope autoradiograph (EM ARG) of hybridized preparations, the most suitable emulsion at present appears to be Ilford L4. Various factors conductive to optimum resolution consistent with maximum efficiency in this emulsion have been pointed out. Practical problems that may arise in autoradiographs of hybridized preparations such as background and variation of grain density in adjacent sections have also been considered.     

Combustion synthesis of Ni3Al and Ni3Al-matrix composites

The self-propagating mode of combustion synthesis (SHS) of Ni₃Al starting from compacts of stoichiometrically mixed Ni and Al powders readily forms fully reacted structures with about 3 to 5 pct porosity, if green density of the compacts is greater than about 75 pct of theoretical. SHS-produced Ni₃Al matrix composites with up to 2 wt pct A1₂O₃ whiskers also have relatively low porosity levels. Porosity increases rapidly with lower green densities, higher Al₂O₃, or SiC whisker contents, and the degree of reaction completeness diminishes. The SiC whiskers undergo reaction with the matrix, while Al₂O₃ whiskers are nonreactive. All of these observations correlate well with temperature measurements made during the course of the reaction. The SHS mode can be achieved with agglomerated particle size ratioD _Al/D _Ni ≥ 1, larger than the limit established from studies of the thermal explosion mode of combustion synthesisD _Al/D _Ni ≃ 0.3. This paper is based on a presentation made in the symposium “Reaction Synthesis of Materials” presented during the TMS Annual Meeting, New Orleans, LA, February 17–21, 1991, under the auspices of the TMS Powder Metallurgy Committee.     

Familial type V hyperlipoproteinemia with hyper-remnant-like particle-cholesterol accompanied with apolipoprotein E3/E4 phenotype

From November 1993 to December 1994, a prospective multi-centre phase II clinical trial was done in 137 patients with advanced cancer on China-made pepleomycin (PEP). PEP was effective in patients with cancer of the head and neck, malignant lymphmo and lung cancer, with response rate of 66.7%, 50% and 30%, respectively. The major adverse reactions were fever and mild gastrointestinal reaction. In the controlled study of combination chemotherapy with China-made and Japan-made PEP, the response rates and side effects were similar. The results indicate that China made PEP can be used in lieu of that made in Japan.     

高饱和磁化强度ε Fe3N磁性液体的研制

 采用自行研制的氮化铁磁性液体热解装置，制备出最高饱和磁化强度Ms=0163 3 T的氮化铁磁性液体。X射线分析表明，磁性颗粒为单一的ε Fe3N物相成分。经透射电镜观测，其颗粒尺寸在15~20 nm范围内，而且分布均匀。在反应基载液中添加浓缩油NS，经热解，在较短时间内能获得Ms＞01 T的氮化铁磁性液体，并大大缩短了反应时间。     

ART restorations and glass ionomer sealants in Zimbabwe: survival after 3 years

Preliminary investigations have been made in normally hearing alert adults to establish whether the 40 Hz modulation-following response (MFR) can be used to predict 400 Hz uncomfortable loudness levels (ULLs). The MFR stimulus was a 400 Hz carrier, amplitude- and frequency-modulated by a 40 Hz sine function. Subjective ULLs were obtained using standard procedures. Objective ULLs were obtained from MFR parameter intensity functions using rms amplitude, phase angle and magnitude-squared coherence (40 Hz components). The best predictions of the subjective ULL were made using objective ULLs calculated from the gradients of linear best-fit lines for individual phase-intensity functions (80 per cent predicted within 10 dB of the subjective ULL; maximum deviation=16 dB). Poorest predictions were based on inter-subject average rms amplitude-intensity functions, where as few as 14 per cent were within 10 dB of the subjective value. The best predictions were considered sufficiently accurate to warrant further investigation using a variety of modulation and carrier frequencies in different age groups and with varying degrees of hearing loss.     

Corrosion of Zinc Ferrite Based Inert Anodes in AlF3-NaF-Al2O3 Melts Under Conditions of Anodic Polarization

ZnFe2O4-based inert anodes were made to conduct the aluminum electrolysis tests. The corrosion behaviors of the inert anodes were examined and discussed. Experiment results prove that: (1) ZnFe2O4-based inert anodes are good corrosion resistant to AlF3-NaF-Al2O3 melts under the conditions of anodic polarization; (2) High anodic current density(＞1.5 A·cm-2), high alumina concentration and low ratio of NaF/AlF3 in the molten salts will be the most important conditions for using inert anode.     

Cerebral complications of murine monoclonal CD3 antibody (OKT3): CT and MR findings

Treatment of acute renal allograft rejection with mouse monoclonal antibody (OKT3) is associated with systemic and neurologic side effects. We describe cerebral abnormalities in a 13-year-old boy with steroid-resistant renal allograft rejection. After treatment with OKT3, an acute neurologic syndrome developed, including seizures, lethargy, and decreased mental function. CT and MR imaging revealed confluent cerebral lesions at the corticomedullary junction. Contrast-enhanced MR images showed patchy enhancement, indicating blood-brain barrier dysfunction. The diagnosis of OKT3-induced encephalopathy with cerebral edema and capillary leak syndrome was made. Although CT and MR findings are nonspecific, neuroradiologists should be aware of this condition in transplant patients treated with OKT3.     

Exceptional hardness and corrosion resistance of Mo5Ru3and W3Ru2films

Films of MO₅Ru₃ and WgRu₂ prepared by sputtering on hot sapphire substrates exhibit interesting properties. The films are among the hardest known electrical conductors and show Khoop hardness values comparable to sapphire. They exhibit high resistance to most common etchants (particularly acid etchants), have high scratch resistance, and have excellent adhesion to the (sapphire) substrates. The temperature coefficient of electrical resistivity can be made either negative, positive, or zero by varying the substrate deposition temperature. Reflectivity measurements from ultraviolet to infrared are also reported to assess their possible use as reflecting surfaces.     

Imported hepatozoonosis in the dog: 3 cases

Canine hepatozoonosis is presented with 3 cases. The most common signs are: fever, anorexia, weight loss, diarrhea and vomiting, muscle weakness, lymphadenopathy, anemia and purulent discharge from the nose and the eyes. Because an infection with H. canis in the dog is often associated with other infectious diseases such as leishmaniasis, ehrlichiosis and babesiosis, the clinical picture may be dominated by these diseases. The diagnosis is made with the typical inclusions in neutrophilic granulocytes and monocytes. Only short remissions may be obtained with the presently available medications.     

Histamine H3 receptor desensitization in the guinea-pig ileum

Histamine H3 receptor ligands are usually tested in guinea-pig intestine preparations. A possible desensitization of agonist-induced twitch inhibition was studied in longitudinal muscle-myenteric plexus from ileal segments. A cumulative concentration-response curve for R-alpha-methylhistamine was made; when a second curve was made 30 min afterwards, a marked decrease of pD2 and a more modest decrease of Emax were observed without changes in tissue sensitivity to electrical stimulation or morphine inhibition. At 120 min, pD2 and Emax were not different from those for the first curve. Receptor desensitization seems homologous and reversible and could interfere with repetitive testing of histamine H3 receptor ligands.     

NdFeB废料回收Nd2O3工艺试验及实践

较系统地研究了ＮｄＦｅＢ废料回收Ｎｄ２Ｏ３的工艺试验,并进行了工业生产,产品纯度高（Ｎｄ２Ｏ３≥９９％,Ｄｙ２Ｏ３≥９９％）,非稀土杂质低（ＳｉＯ２、ＣａＯ、Ｆｅ２Ｏ３均≤００５％）。产品可作为生产金属钕的原料,满足ＮｄＦｅＢ生产的要求,该工艺流程短,操作简便,且回收率高（ＮｄＯ３实收率＞８２％）,工业生产投资少,见效快,环境污染小等优点     

国际粉碎工程领域的新进展(续三)

评述了国际粉碎工程领域尤其是设备方面的最新进展、主要发展动向和特点,内容涉及粉碎理论研究、破碎、粉磨、筛分、分级、耐磨材料、超细磨、超细分级、特殊粉碎方法及设备等。介绍和评述了目前国际上最先进、最著名和最大规格的粉碎工程设备的最新发展,包括瑞典Sandvik集团的液压圆锥破碎机和芬兰Metso集团的Symons体系圆锥破碎机、我国与俄罗斯合作制造的惯性圆锥破碎机、德国Krupp Polysius公司和KHD公司的辊压机、芬兰Metso集团的Nordberg Barmac B系列立式冲击破碎机、瑞典Mogensen公司的振动筛、世界最大规格的自磨机、球磨机和搅拌球磨机、美国Krebs公司的水力旋流器和美国Derrick公司的高频振动细筛。评述了我国粉碎工程的发展现状以及与先进国家的差距,介绍了新近出现的、有发展前途的粉碎方法和设备。     

Activities in the liquid system NaF-MgF2-AIF3

Measurements were made at 1020 ‡C of the contents of Mg and Na in Al in equilibrium with NaF-MgF₂-AlF₃ melts in the range of NaF/AlF₃ molar ratios of 2.5 to 4 and MgF₃ molar frac-tions up to 0.13 (15 wt pct). The theory necessary to derive activities of the three constituents is given. In terms of NaF being a base and A1F₃ an acid, MgF₂ is an acid. The activity coef-ficients of MgF₂ can be accounted for quantitatively on the basis of the existence of Na₂MgF₄ and Na₂Mg₂F₆ species in the melt. A few similar measurements were made at 970 ‡C, permitting estimation of the amount of Mg to be expected in the metal of a reduction cell. Discrepancies suggest that the CaF₂ and A1₂O₃ present in the electrolyte of the latter influence the activity coefficients of MgF₂ and/or A1F₃. The experimental work was carried out when both authors were at what was then the Arvida, Quebec, Laboratory of The Aluminum Company of Canada Ltd.     

Determination of total estrogen in urine with 3-methyl-2-benzothiazolinone hydrazone

The determination of total estrogens in urine with 3-methyl-2-benzothiazolinone hydrazone (MBTH) is reported. The method utilizes a colorimetric reaction consisting of the oxidative coupling of MBTH to the phenol portion of the steroid molecule. Colorimetric measurements were made at 530 nm manually or with an AutoAnalyzer at an analysis rate of 50 samples/hour. Comparison with a fluorometric method gave a correlation coefficient of .96 and with a gas chromatographic method, a coefficient of .94. Therefore this proposed method may be suitable as an alternative method for the determination of total estrogens in pregnancy urine samples.     

3D Scan Information Management System for Construction Management

This paper presents an internet-based three-dimensional (3D) scan information management system (3DSIMS) that can be used as an interface to input, display, and inspect design as-built construction information. This system is mainly developed using 3D scan data. The function of the 3DSIMS is to integrate the scan data collected before, during, and after a scan scheme that is designed to capture as-built 3D records. The information included in this system consists of a scan scheme, scanned point clouds, construction records, and postscan processed clouds for the display, search, and comparison of scans made each week during the construction of a campus building. This study represents a long-term effort that has rarely been done before. A web page is used to deliver and share scan information. The feasibility of this approach is explained by the examples of dimension-related checks through as-built data.     

Nd2O3-NdF3-LiF熔盐体系中电导率及钕溶解度的测定

研究了Nd2O3-NdF3-LiF熔盐体系中电导率及钕的溶解度，并根据实验数据拟合了回归方程，分析TN度、LiF浓度、Nd2O3浓度对两种物理性质的影响。结果表明，升高温度，提高LiF浓度以及降低Nd2O3浓度可以提高熔盐体系的电导率；而降低温度，降低LiF浓度以及提高Nd2O3浓度可以减少钕在熔盐中的溶解度。所得研究结果可为电解氟盐法生产钕选择合理的电解质成分提供依据。