CTO-1脱氧催化剂的开发及工业应用

开发了一种用于一氧化碳气源的CTO-1脱氧催化剂,该催化剂采用浸渍法以γ-Al2O3负载过渡金属盐和助剂,经高温焙烧制得。催化剂使用前需活化,使用空速可达4000h-1左右,反应温度可低至40℃,可将φ(O2)为0.002%～2.0%的原料气中的氧脱除至φ(O2)在1×10-6～10×10-6以下。工业应用表明CTO-1脱氧催化剂性能优良。     

Modelling of growth rate uniformity of CdTe epilayer by MOCVD

A 2-dimensional mathematical model was established to simulate the growth rate uniformity of CdTe epilayers which were grown in a horizontal MOCVD reactor. Both transport phenomena and the surface decomposition kinetics of diethyl telluride were considered. The calculated effects of reactor pressure and substrate temperature on growth rates along the flow axis were compared with experimental results. They agreed well with each other. These effects were then explained by the relative importance of mass transfer to reaction kinetics. In general, higher growth temperature and higher reactor pressure both favor a mass transfer controlled CVD growth situation. However, to obtain uniformly grown epilayers, one would wish to operate under reaction kinetics controlled region,i.e. low substrate temperature and low reactor pressure.     

Prognostic factors in surgically treated small cell cervical carcinoma followed by adjuvant chemotherapy

BACKGROUND: Small cell carcinoma of the uterine cervix is an uncommon tumor associated with high mortality even among patients with early stage disease. The role of adjuvant chemotherapy after surgery has been suggested by regimens used for small cell lung carcinoma. During the years 1980-1997, 19 cases in which various adjuvant chemotherapies were given after hysterectomy were reported in the literature published in English. METHODS: Adjuvant chemotherapy was administered consecutively to 23 patients with Stage Ib-II small cell cervical carcinoma who had been primarily treated with radical hysterectomy and had adequate bone marrow, renal, and hepatic functions. A combination of vincristine, doxorubicin, and cyclophosphamide alternating with cisplatin and etoposide (VAC/PE) was administered to 14 patients during the years 1988-1996 according to a prospective study protocol. A combination of cisplatin, vinblastine, and bleomycin (PVB) was administered to 8 patients, and another regimen was administered to 1 patient during the years 1984-1988. Prognostic factors were evaluated by analyzing both the data on these 23 patients and the pooled data on the cases retrieved from the literature and our own files. RESULTS: Ten of the 14 patients who received VAC/PE had no evidence of disease during a median follow-up of 41 months, whereas 3 of the 9 who received PVB or another regimen survived. Of the 10 patients who died of their disease, all died of distant metastasis within 10 months after recurrence. Meta-analysis of the pooled data showed that 68% of patients who received regimens containing VAC or PE survived, whereas 33% of patients who received regimens not containing VAC/PE survived (P = 0.0078, log rank test). Seventy percent of patients with no lymph node metastasis at hysterectomy and 35% with lymph node metastasis survived (P = 0.05). All patients who died of disease had extrapelvic metastasis. CONCLUSIONS: Chemotherapies containing VAC or PE are favorable regimens for patients with early stage small cell cervical carcinoma after radical hysterectomy.     

A novel device for detecting the polarization direction of linear polarized light using integrated subwavelength gratings and photodetectors

A solid-state device that can be used to detect the polarization direction of linear polarized light is proposed. The device consists of six transmission gratings with periods in the subwavelength region of the incident light and six photodetectors integrated separately underneath each grating. A variable, defined through the photocurrent ratios of the grating-photodetector pairs, shows a one-to one correspondence with the angle between the electric vector of the incident linear polarized light and the orientation of the gratings' fingers, which is therefore used to determine the polarization direction. An angular resolution of 0.2/spl deg/ can be achieved.     

Quantitative phase contrast imaging of arborescent graft polystyrene by off-axis transmission electron holography

Imaging nanoscale polymer objects in the Transmission Electron Microscope is difficult, because small polymeric objects interact only weakly with intermediate-energy electrons. Heavy element staining can induce significant amplitude contrast, but stains can introduce artifacts that complicate the structure determination at nanometer length scales. This paper explores transmission electron holography for phase contrast imaging of unstained arborescent graft polystyrene nanoparticles. Holography is able to recover significant phase contrast from these particles despite the fact that there is negligible amplitude contrast. Comparative imaging experiments show that off-axis holography provides substantially higher contrast than that generated by the traditional method of transferring phase information to amplitude information via defocus. This effect is a consequence of different lens contrast-transfer behavior in each of these two imaging approaches. Under kinematical conditions when the appropriate mean inner potential is known, the specimen's projected thickness can be directly mapped from the holographic phase image to give a measure of the specimen's three-dimensional shape. Such quantitative imaging shows that individual arborescent graft polystyrene nanoparticles, which are spherical in a good solvent, adopt a flattened shape when deposited on a carbon substrate and allowed to dry.     

Developing hypertext-based learning courseware for computernetworks: the macro and micro stages

In order to design and develop hypertext-based learning courseware for computer networks, one needs to know human learning processes and how hypertext can be used to facilitate learning, to be aware of appropriate instructional theories and models to guide design processes, and to consider pedagogical issues. The instructional systems development approach and the elaboration theory of instruction are introduced as the macro and micro stages of designing hypertext learning courses. The development of a sample course is reported. Discussions and a conclusion are provided     

Characterization of Perina nuda nucleopolyhedrovirus (PenuNPV) polyhedrin gene

The occurrence and metabolic capacities of sulfate-reducing bacteria (SRB) were studied in 23 water samples taken from producing wells at 14 different sites. Oil fields in France, the North Sea, and the Gulf of Guinea were selected and classified according to physicochemical parameters (salinity ranging from 0.3 to 120 g.L-1 and temperature between 29 and 85 degrees C). After the distribution of SRB within oil fields was studied, several strains of SRB were isolated and characterized metabolically. Twenty of the thirty-seven strains were not related to any known species. Most of the identified strains were members of the genera Desulfovibrio and Desulfotomaculum by molecular, morphological, and physiological properties.