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991.
992.
Lung volumes and quasi-static deflation volume-pressure relationships were measured in male golden hamsters anesthetized with pentobarbital. Volume was measured with a pressure plethysmograph, and pleural pressure was estimated by the use of a water-filled esophageal catheter. Mean body weight +/- SE was 122.3 +/-3.0 g, mean lung weight was 0.74 +/- 0.2 g or about 0.6% of body weight. Mean lung volume at 25 cmH2O transpulmonary pressure (TLC25) was 7.2 +/- 0.14 ml, 9.78 +/- 0.17 ml/g lung weight or 5.92 +/- 0.06 ml/100 g body weight. Mean functional residual capacity was 2.4 +/- 0.06 ml or 33.3% of TLC25. Mean vital capacity was 5.2 +/- 0.13 ml. Mean quasi-static compliance of lung was 0.63 +/- 0.03 ml/cmH2O. Chord compliance of chest wall between lung volumes of 1 and 4 ml above RV was 3.39 +/- 0.53 ml/cmH2O. At FRC, the chest wall recoiled inward, so that pleural pressure was positive (1.4 +/- 0.13 cmH2O) and the lung was resisting further collapse. The slope of the lung's deflation volume-pressure curve changed at FRC, ERV was small (0.36 +/- 0.03 ml), and RV was determined by complete airway closure. Thus the mechanisms determining FRC are unusual and include an influence of airway closure. 相似文献
993.
994.
F Cavalli RW Sonntag HJ Ryssel L Tschopp KW Brunner 《Canadian Metallurgical Quarterly》1976,106(22):754-757
Ten patients with metastatic testicular or ovarian carcinoma were treated with cis-platinum II diaminedichloride. All had received prior chemotherapy with other agents. A therapeutic effect was seen in 7 cases, though it was of short duration in all instances. The drug proved to be very nephrotoxic and caused marked bone marrow depression. The future of this highly effective cytostatic agent, either with different dosage schedules or in combination with other drugs, is discussed. The possibility of new platinum derivatives with a better therapeutic index is also mentioned. 相似文献
995.
1. Tonic labyrinth and neck reflexes were studied separately and in combination in the decerebrate cat with C1 and C2 spinal roots cut. Reflex effects were observed as changes in length of the isotonically loaded medial head of triceps. 2. The tonic labyrinth reflexes acted asymmetrically on the medial head of triceps. Side-down rotation of the head produced shortening in medial triceps, whereas side-up rotations of the head resulted in a lengthening. 3. The tonic neck reflexes acted asymmetrically on the medial head of triceps. Side-down rotations of the neck produced a lengthening of medial triceps, whereas side-up rotations of the neck resulted in shortening. 4. Labyrinth and neck reflexes produce opposite effects on the same limb extensor muscle so that, if the neck innervation is intact, head tilting produces no change in muscle length. 5. It is suggested that the interaction between the labyrinth and neck reflexes contributes to the stability of the trunk, allowing the head to move freely on the body without affecting this stability. Labyrinth and neck reflexes need therefore to be considered together as a single system. 相似文献
996.
Pilsoo?Jeon Kwangjai?LeeEmail author Jaisuk?Yoo Youngmoo?Park Jonghwa?Lee 《Journal of Mechanical Science and Technology》2004,18(10):1712-1721
A method of measuring the thermal diffusivity of semi-infinite solid material at room temperature using photothermal displacement
is proposed. In previous works, within the constant thickness of material, the thermal diffusivity was determined by the magnitude
and phase of deformation gradient as the relative position between the pump and probe beams. In this study, however, a complete
theoretical treatment of the photothermal displacement technique has been performed for thermal diffusivity measurement in
semi-infinite solid materials. The influence of parameters, such as, radius and modulation frequency of the pump beam and
the thermal diffusivity, was studied. We propose a simple analysis method based on the zero-crossing position of real part
of deformation gradient and the minimum position of phase as the relative position between two beams. It is independent of
parameters such as power of pump beam, absorption coefficient, reflectivity, Poisson’s ratio, and thermal expansion coefficient. 相似文献
997.
Bacterial dissimilatory iron reduction is self-inhibited by the production of ferrous [Fe(II)] iron resulting in diminished iron reduction as Fe(II) accumulates. Experiments were conducted to investigate the mechanisms of Fe(II) inhibition employing the dissimilatory metal-reducing bacterium Shewanella putrefaciens strain CN32 under nongrowth conditions in a system designed to minimize precipitation of ferrous iron minerals. After an initial period (ca. 1 day) of relatively rapid iron reduction, hematite reduction rates were controlled by mass transfer of Fe(II). Experiments in which hematite was equilibrated with Mn(II) prior to inoculation indicated that the observed inhibition was not due to Fe(II) sorption. At longer times, soluble Fe(II) accumulated such that the reaction was slowed due to a decreased thermodynamic driving force. The thermodynamic evaluation also supported the prior conclusion that hydrated hematite surface sites may yield substantially more energy during bioreduction than "bulk" hematite. For well-mixed conditions, the rates of hematite reduction were directly proportional to the biologically available reaction potential. 相似文献
998.
H. H. Ryu M. H. Jeon J. Y. Leem H. J. Song L. P. Sadwick G. B. Stringfellow 《Journal of Materials Science》2006,41(24):8265-8270
Gallium indium phosphide (Ga
x
In1−x
P) epitaxial layers were grown on GaAs substrates by chemical beam epitaxy (CBE) without thermally precracking the group V precursor. Trisdimethylaminophosphine (TDMAP), triisopropylgallium (TIPGa), and ethyldimethylindium (EDMIn) were used as the phosphorus, gallium and indium sources, respectively. Ga
x
In1−x
P was grown without group V precracking for substrate temperatures in the range of 400–520 °C. Above 500 °C, the epilayers had a hazy appearance presumably due to being phosphorus deficit. A strong solid composition dependence on substrate temperature was observed. The samples were In-rich at low growth temperatures and Ga-rich at high growth temperatures. It was possible to grow the Ga
x
In1−x
P epilayers over a large composition range with good morphology and strong photoluminescence. Values of full width at half maximum were as low as 45 meV at 14 K photoluminescence measurements. 相似文献
999.
Sanghun Jeon Jeong Hee Han Junghoon Lee Sangmoo Choi Hyunsang Hwang Chungwoo Kim 《Electron Device Letters, IEEE》2006,27(6):486-488
This letter reports the impact of metal work function (/spl Phi//sub M/) on memory properties of charge-trap-Flash memory devices using Fowler-Nordheim program/erase mode. For eliminating electron back tunneling and hole back tunneling through the blocking oxide during an program/erase operation, a gate with /spl Phi//sub M/ of 5.1-5.7 eV on an Al/sub 2/O/sub 3/-SiN-SiO/sub 2/ (ANO) stack is necessary. Compared to a thickness optimized n/sup +/ poly-Si/ONO stack, a high-work-function gate on an ANO stack shows dramatic improvements in retention versus minimum erase state. 相似文献
1000.
Jae-Soong Lee Joonhee Lee Sunghwan Kim Heonsu Jeon 《Photonics Technology Letters, IEEE》2006,18(15):1588-1590
To improve the overall surface emission efficiency, the structure of a standard GaN light-emitting diode (LED) was modified; the mesa sidewalls were etched at an angle, and deep enough to reach the sapphire substrate. Photoexcitation experiments, including photoluminescence and near- and far-field emission patterns, were performed on LED-like test devices, and results indicated that the angled sidewalls efficiently deflect photons that are initially guided laterally within the GaN epilayer in the off-surface direction. For a sidewall angle of 30/spl deg/, the total surface emission strength was improved by a factor exceeding three. Computer simulations produced results consistent with the experimental observations. 相似文献