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Arguments are presented for the necessity of integrating diagnostics and supervision in technological machines. An example of integrated diagnostics and supervision of the machine tool main drive, based on an expert system and neural network, is shown. Problems of intelligent thermal displacement supervision and questions related to practical supervision of machining centres are presented. 相似文献
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The ontogeny of the myotome was investigated using [3H]thymidine or Brdu treatment in conjunction with 1,1', di-octadecyl-3, 3, 3', 3',-tetramethylindo-carbocyanine perchlorate (DiI) labeling and expression of specific markers. We have identified a subset of early post-mitotic cells that is present in the dorsomedial aspect of epithelial somites and is homogeneously distributed along their entire rostrocaudal extent. The post-mitotic quality of this cell subset enabled us to trace their fate in time-course experiments. Following initial somite dissociation, this epithelial post-mitotic layer bends underneath the medial portion of the nascent dermomyotome. Then, these cells progressively lose epithelial arrangement and migrate in a rostral direction where they accumulate temporarily. Subsequently, these early post-mitotic precursors extend processes that reach both rostral and caudal edges of each segment. Medial somite-derived myofibers also fill the entire mediolateral extent of the segment and reach the dorsomedial lip of the dermomyotome, thus forming the primary myotome. During this process, their large nuclei localize to a narrow stripe in the middle of the nascent myotome. Consistent with the proliferation studies, DiI labeling of the medial epithelial somite cells gave rise to a primary myotomal structure, and continuous pulsing of the DiI-injected embryos with radioactive thymidine revealed that these fibers indeed developed from post-mitotic progenitors. As these early post-mitotic cells that arise prior to somite dissociation are the first wave of progenitors that constitutes the myotome, we have termed them avian muscle pioneers. We propose that the primary myotome formed by the muscle pioneers constitutes a longitudinal scaffold that serves as a substrate for the addition of subsequent waves of myotomal cells. 相似文献
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C. J. Boehlert D. S. Dickmann NY. N. C. Eisinger 《Metallurgical and Materials Transactions A》2006,37(1):27-40
The grain size, grain boundary character distribution (GBCD), creep, and tensile behavior of INCONEL alloy 718 (IN 718) were
characterized to identify processing-microstructure-property relationships. The alloy was sequentially cold rolled (CR) to
0, 10, 20, 30, 40, 60, and 80 pct followed by annealing at temperatures between 954 °C and 1050 °C and the traditional aging
schedule used for this alloy. In addition, this alloy can be superplastically formed (IN 718SPF) to a significantly finer
grain size and the corresponding microstructure and mechanical behavior were evaluated. The creep behavior was evaluated in
the applied stress (σ
a
) range of 300 to 758 MPa and the temperature range of 638 °C to 670 °C. Constant-load tensile creep experiments were used
to measure the values of the steady-state creep rate and the consecutive load reduction method was used to determine the values
of backstress (σ0). The values for the effective stress exponent and activation energy suggested that the transition between the rate-controlling
creep mechanisms was dependent on effective stresses (σ
e
=σ
a
σ0) and the transition occurred at σ
e
≅ 135 MPa. The 10 to 40 pct CR samples exhibited the greatest 650 °C strength, while IN 718SPF exhibited the greatest room-temperature
(RT) tensile strength (>1550 MPa) and ductility (ε
f
>16 pct). After the 954 °C annealing treatment, the 20 pct CR and 30 pct CR microstructures exhibited the most attractive
combination of elevated-temperature tensile and creep strength, while the most severely cold-rolled materials exhibited the
poorest elevated-temperature properties. After the 1050 °C annealing treatment, the IN 718SPF material exhibited the greatest
backstress and best creep resistance. Electron backscattered diffraction was performed to identify the GBCD as a function
of CR and annealing. The data indicated that annealing above 1010 °C increased the grain size and resulted in a greater fraction
of twin boundaries, which in turn increased the fraction of coincident site lattice boundaries. This result is discussed in
light of the potential to grain boundary engineer this alloy.
INCONEL is a registered trademark of Special Metals Corp., Huntington, WV.
This article is based on a presentation made in the symposium entitled “Processing and Properties of Structural Materials,”
which occurred during the Fall TMS meeting in Chicago, Illinois, November 9–12, 2003, under the auspices of the Structural
Materials Committee. 相似文献
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PG Brusov AN Kuritsyn NY Urazovsky ML Tariverdiev 《Canadian Metallurgical Quarterly》1998,163(9):603-607
We prospectively analyzed our experience with operative videothoracoscopy (OVT) performed in a field military hospital in cases of penetrating firearms wounds of the thorax (PFAWT) sustained in Chechnya. From February to April 1996, we treated 206 wounded patients, of whom 37 (18.0%) had sustained chest injuries. PFAWT were present in 23 soldiers, accounting for 62.2% of all chest injuries. Twelve injuries were confined to the thorax, eight patients had associated injuries, and three soldiers had thoracoabdominal injuries. Nineteen patients had pleural drainage performed during medical evacuation. The thoracic injuries were right-sided (17), involved bullets or shell splinters (23); were through and through (16), represented solitary wounds (19), and were associated with internal organ injuries (21). Fifteen patients had indications for OVT when they were delivered from the battle-field 1.5 to 22 hours after injury. All patients manifested signs of hemorrhagic shock and hemodynamic instability. Indications for OVT were ongoing intrapleural bleeding (6), clotted hemothorax (6), or marked air leakage (3) preventing lung inflation with the OP-02 apparatus (field modification). OVT revealed 12 lung wounds, nine of which were multiple wounds, pleural bleeding in 6 patients, clotted hemothorax in 11 patients, and foreign bodies in 5 patients. Two patients underwent thoracotomy, one for suspicion of heart injury and the second because we could not adequately visualize and control bleeding revealed at OVT to be from the intercostal artery in the left costovertebral angle. Eight of 23 patients had no indication for operative videothoracoscopy and were managed with continued pleural aspiration and drug therapy. Wedge resection of the lung using an Endo-GIA-30 stapler was necessary in two patients because of parenchymal destruction and bleeding. Evacuation of clotted blood by fragmentation and aspiration was satisfactory in all cases. Satisfactory manual suturing of selected lung injuries was obtained largely with intracorporeal knot tying. The duration of the procedures ranged from 40 to 90 minutes. No morbidity nor mortality was encountered in patients undergoing OVT. Postoperative pain was minimized by using OVT placement of catheters in the chest wall soft tissue with local administration of 2% Trimecain. Patients were able to stand in 10 to 12 hours and to walk by the end of the first postoperative day. All patients who underwent OVT were evacuated without drains by the third or fourth postoperative day, all tolerating sitting and standing positions. We conclude that early OVT in the military field hospital for continued bleeding, clotted hemothorax, and continued major air leakage has several advantages in military patients with PFAWT: early definition and management of organ injury; identification and control of bleeding in most instances; earlier and more accurate assessment for thoracotomy; vigorous lavage and removal of projectiles such as bone fragments and evacuation of clotted hemothorax; early debridement with suture closure of the thoracic wall canal; and minimal postoperative pain with dramatically reduced suppurative sequelae and bronchopleural fistulae. 相似文献
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