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81.
The aim of the JET ITER-like wall project was to provide JET with the plasma facing material combination now selected for the DT phase of ITER (bulk beryllium main chamber limiters and a full tungsten divertor) and, in conjunction with the upgraded neutral beam heating system, to achieve ITER relevant conditions.The design of the bulk Be plasma facing components had to be compatible with increased heating power and pulse length, as well as to reuse the existing tile supports originally designed to cope with disruption loads from carbon based tiles and be installed by remote handling. Risk reduction measures (prototypes, jigs, etc.) were implemented to maximize efficiency during the shutdown. However, a large number of clashes with existing components not fully captured by the configuration model occurred.Restarting the plasma on the ITER-like Wall proved much easier than for the carbon wall and no deconditioning by disruptions was observed. Disruptions have been more threatening than expected due to the reduced radiative losses compared to carbon, leaving most of the plasma magnetic energy to be conducted to the wall and requiring routine disruption mitigation. The main chamber power handling has achieved and possibly exceeded the design targets.  相似文献   
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The stiffness, considered to be the slope of the linear region of the load-displacement chart has been calculated. Linear regression lines between failure load and stiffness were sought. Relatively good correlation (R2=0.88) was found for the unjointed samples, however, less good correlation (R2=0.63) was found for the glued jointed samples and even worse correlation (R2=0.53) was found for the unglued jointed ones. Generally, the stiffness can be considered as a useful indicator for the failure load and failure mode of the particleboard samples. For increased stiffness values the boards tend to fail at higher loads and in a more brittle mode, providing a sudden vertical drop in the load/displacement curves. At values over 456 N/mm `catastrophic' failure modes (instant total failures) were observed (span size of 450 mm and thickness of the boards of 18 mm). However, at values less than 420 N/mm the failure mode was more ductile, described by `smooth' post failure curves. By gluing the joints the stiffness of the structure increases significantly. The failure load also increases but not by an amount that is statistically significant. The failure mode of glued jointed structures seems to be more ductile when compared to unglued ones. This means that after the maximum failure load has been achieved, the boards continue to sustain the load for a longer period of time up to ultimate failure occurs.
2 =0,88), schwache für verleimte Proben (R2=0,63) und noch schw?chere für unverleimte Verbindungen (R2=0,53). Allgemein erwies sich die Steifigkeit der Spanplatten als guter Indikator für die zu erwartende Bruchlast und die Art des Bruchs. Bei erh?hter Steifigkeit erfolgte der Bruch bei h?herer Belastung, war zunehmend spr?der und zeigte als ein pl?tzlicher senkrechter Abfall in der Verformungskurve. Bei Werten oberhalb 456 N/mm erfolgte ein unmittelbares totales Versagen (Katastrophenfall). Bei Werten unterhalb 420 N/mm war der Bruchverlauf z?her mit “sanfterem” Kurvenverlauf nach dem Bruch.
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83.
Immunogenic peptides containing epitopes of the gp120 C4 and V3 regions from human immunodeficiency virus strains MN and EV91 have been studied by nuclear magnetic resonance and molecular modeling and used as immunogens in rhesus monkeys. The results, combined with those for other peptides, suggest a correlation between solution conformation and immunologic cross-reactivity.  相似文献   
84.
OBJECTIVE: To propose a definition for stage IA1 cervical adenocarcinoma, based on the International Federation of Gynecology and Obstetrics (FIGO) staging system, and to determine if patients meeting criteria might be candidates for conservative surgery. METHODS: Two hundred women were diagnosed with early-stage cervical adenocarcinoma from 1982 to 1996. Histopathologic sections were reviewed by a gynecologic pathologist. Medical records were reviewed, and patients included in this study had microscopically identifiable lesions, up to 3 mm invasive depth, up to 7 mm tumor width, and negative margins if cone biopsy was performed. RESULTS: Twenty-one patients with microinvasive adenocarcinoma met criteria for FIGO stage IA1 carcinoma of the cervix. The median (range) follow-up was 76 (30-172) months and median (range) patient age was 38 (24-75) years. Definitive treatment included type II or III radical hysterectomy in 16 cases, simple abdominal or vaginal hysterectomy in four cases, and loop electrosurgical excision procedure in one case; one patient received adjuvant pelvic radiation. The histologic subtypes were endocervical adenocarcinoma in 18 cases, adenosquamous carcinoma in two cases, and clear-cell adenocarcinoma in one case. There was no evidence of parametrial invasion or lymph node metastases in any patient who had radical surgery, and there were no disease recurrences. CONCLUSION: Patients with microinvasive adenocarcinoma who met criteria for FIGO stage IA1 cervical carcinoma had disease limited to the cervix, and conservative surgery, such as cone biopsy or simple hysterectomy, might offer them definitive treatment.  相似文献   
85.
The nanoManipulator system adds a virtual-reality interface to an atomic-force microscope (AFM), thus providing a tool that can be used by scientists to image and manipulate nanometer-sized molecular structures in a controlled manner. As the AFM tip scans the sample, the tip-sample interaction forces are monitored, which, in turn, can yield information about the frictional, mechanical, material, and topological properties of the sample. Computer graphics are used to reconstruct the surface for the user, with color or contours overlaid to indicate additional data sets. Moreover, a force feedback stylus, which is connected to the tip via software, allows the user to directly interact with the macromolecules. This system is being used to investigate carbon nanotubes, DNA, fibrin, adeno- and tobacco mosaic virus. It is now also possible to insert this system into a scanning electron microscope which provides the user with continuous images of the sample, even while the AFM tip is being used for manipulations  相似文献   
86.
The widely marketed Public Key Infrastructure as a means of securing business by electronic means requires communication between individuals. Most business models communicate with groups and relate roles to individual actors. Can these models be resolved efficiently and securely? Are new mechanisms needed or can you re-work existing technologies?  相似文献   
87.
OBJECTIVE: Prolactinomas are frequently treated primarily with dopamine agonists; however, these agents have disadvantages and require life-long therapy. We therefore reassessed transsphenoidal microsurgery as an alternative therapy. METHODS: We reviewed the data for 121 female patients treated surgically for prolactinomas between 1976 and 1979 (Group 1) and 98 patients treated between 1988 and 1992 (Group 2). RESULTS: Of 219 women, 92% with preoperative prolactin (PRL) values of < or = 100 ng/ml and 91% with intrasellar microadenomas experienced initial remission; 80 to 88% of patients with intrasellar macroadenomas or macroadenomas showing moderate suprasellar extension or focal sphenoid sinus invasion experienced remission. Women with PRL values of > 200 ng/ml and those with larger and more invasive adenomas experienced poorer outcomes (37-41% remission). Lower preoperative PRL values and adenoma stage were the best predictors of initial surgical outcomes. At the most recent evaluations, 89% of women who experienced initial remission continued to experience clinical remission; 85% exhibited normal PRL values, and 5% demonstrated mild, asymptomatic, recurrent hyperprolactinemia (PRL values of < 34 ng/ml). In Group 1, 84% of patients continued to experience remission (82% with normal PRL values) after a median follow-up period of 15.6 years. In Group 2, 97% of patients continued to experience remission (88% with normal PRL values) after a median follow-up period of 3.2 years. Lower postoperative PRL values were the best predictors of long-term remission. CONCLUSION: Transsphenoidal microsurgery is an effective alternative to long-term medical therapy for selected patients with prolactinomas. Successful outcomes and long-term remission were achieved in patients with microadenomas and noninvasive macroadenomas.  相似文献   
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