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101.
Based on his presidential address delivered at the annual meeting of the American Psychological Association (APA) in 1982, the author urges APA's commitment to 3 tasks: (1) a continuing study of the intellectual and social influences, inside and outside psychology, that have shaped and continue to shape its directions, (2) an active program to increase the public's understanding of what psychology is and what psychologists do, and (3) a formal involvement at the level of national policy in issues where psychological knowledge and skills are relevant. (70 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
102.
In order to assess the potential of urania-yttria fluorite-type solid solutions as electrodes for high-temperature electrolysis of steam, oxygen evolution and dissolution reactions have been studied at the (U0.7Y0.3)O2+x/YSZ interface. A current-interruption technique was used to separate overpotential and resistive potential drop. In oxygen and air the overpotential-current curves obey the Tafel law, suggesting that a charge-transfer process is rate determining. Activation energies of 120 kJ mole?1 and 165 kJ mole?1 were obtained for the cathodic reaction in oxygen and air respectively. The capacitance obtained from galvanostatic transients varied with potential, temperature, and oxygen partial pressure. The average value of n, the number of electrons involved in the overall charge-transfer reaction, was determined to be 4.01 from reversible potential measurements. The overpotential losses are small for porous electrodes at high po2. A mechanism for the oxygen transfer reaction has been proposed and its limitations discussed. 相似文献
103.
A high-throughput screening method for the determination of aqueous drug solubility using laser nephelometry in microtiter plates 总被引:2,自引:0,他引:2
The determination of aqueous solubility in a high-throughput screening environment is invaluable in the selection of the most promising potential drug candidates. We describe a fast method based on laser nephelometry that can determine the solubility of potential drug candidates (usually from combinatorial chemistry) supplied as dimethyl sulfoxide (DMSO) solutions in 96-well plates. In the sample, the percent DMSO is kept constant allowing direct comparison of results. The nephelometric method has been shown to produce results equivalent to those produced by an HPLC method and to be largely unaffected by colored solutions. 相似文献
104.
E Ellen Billett R Bevan B Scanlon K Pickering B Gibbons 《Journal of the science of food and agriculture》1996,70(3):396-404
Monoclonal antibodies were produced using chicken smooth muscle desmin as the immunogen and one antibody, 4B4/B2, was found to be reactive with desmin from chicken, turkey, pheasant and duck but not from lamb, beef and pork. This antibody reacts with poultry desmin from both smooth muscle and skeletal muscle, allowing its use for the detection of poultry meat in other meats. In addition to reacting with intact forms of this cytoskeletal protein (apparent subunit molecular size 54 kDa), 4B4/B2 also reacts with degradation products of desmin (30–40 kDa), thus enhancing its use for speciation purposes. When the antibody is used in an indirect ELISA involving antigen-coated plates, it can detect <0·04 μg ml−1 poultry desmin. As desmin is one of the most insoluble proteins in cells, it is an ideal marker for speciation. Desmin-enriched samples can be produced from chicken meat and chicken/red meat mixtures by differential extraction, culminating with the solubilisation of desmin in 8M urea. These extracts can be analysed using the ELISA system, routinely detecting chicken at the 100 g kg−1 mixed meats level. Alternatively, Western blots of the samples, resolved by 100 g kg−1 SDS PAGE, can be probed with 4B4/B2 allow-ing detection at the 20 g kg−1 mixed meats level. This monoclonal antibody rep-resents a standard reagent of unlimited supply which can, for the first time, detect a defined insoluble protein in poultry speciation assays. Preliminary applications indicate that it is superior to other reagents and demonstrate that desmin has the potential to be a valuable marker for speciation. 相似文献
105.
Performance comparison of space-time coding techniques 总被引:3,自引:0,他引:3
Simulation results for the comparative performance of a number of space-time coding (STC) schemes in a multiple-input-multiple-output (MIMO) channel are presented and compared with a single-antenna benchmark and two-antenna space-time transit diversity (STTD) scheme. Both the space-time trellis coding (STTC) and BLAST approaches offer high spectral efficiencies, but STTC outperforms BLAST in terms of its power efficiency 相似文献
106.
Banerjee A. Wise R.L. Plumton D.L. Bevan M. Pas M.F. Crenshaw D.L. Aoyama S. Mansoori M.M. 《Electron Devices, IEEE Transactions on》2000,47(3):584-592
Fabrication of rapid thermal nitrided HSG transformed crown capacitor storage cells incorporating an ultrathin low pressure chemical vapor deposition (LPCVD) Ta2O5 and Si3N 4/SiO2(NO) dielectric is proposed. 256 Mb array with HSG crown cells of 0.3 μm diameter×0.6 μm height and 49 A Teff showed an area enhancement factor of 1.7 (relative to untransformed crown cell). Cmin/Cmax ratio of >0.95, and capacitance of 16.7 fF/cell is obtained. A measured leakage current density of 0.7 nA/cm2 at 1.2 V is reported. Metal-oxide-semiconductor capacitor (MOSCAP) devices with HSG electrodes for 1 Gb application are characterized using capacitance-voltage (C-V) and current-voltage (I-V) analyses. Detailed HSG grain characterization results are presented with correlation to the electrical behavior of the devices. Devices are formed using LPCVD Ta2O5 and/or Si3N4 dielectric. HSG films formed from 4×1020 atoms/cc phosphorus doped amorphous silicon show depletion in C-V behavior. It is shown that phosphine doping of HSG film is required to avoid depletion. Process selectivity of the UHV/CVD HSG transformation mechanism applied to thermal oxide and nitride field dielectrics is fully explored. Selectivity limits for different types of dielectric are also presented. Effect of critical parameters such as a-Si dopant concentration, HSG incubation time, anneal conditions, and a-Si layer thickness on HSG transformation are discussed for 1 Gb crown cells 相似文献
107.
Ovarian VEGF(165)b expression regulates follicular development, corpus luteum function and fertility
Qiu Y Seager M Osman A Castle-Miller J Bevan H Tortonese DJ Murphy D Harper SJ Fraser HM Donaldson LF Bates DO 《Reproduction (Cambridge, England)》2012,143(4):501-511
Angiogenesis and vascular regression are critical for the female ovulatory cycle. They enable progression and regression of follicular development, and corpora lutea formation and regression. Angiogenesis in the ovary occurs under the control of the vascular endothelial growth factor-A (VEGFA) family of proteins, which are generated as both pro-(VEGF(165)) and anti(VEGF(165)b)-angiogenic isoforms by alternative splicing. To determine the role of the VEGF(165)b isoforms in the ovulatory cycle, we measured VEGF(165)b expression in marmoset ovaries by immunohistochemistry and ELISA, and used transgenic mice over-expressing VEGF(165)b in the ovary. VEGF(165)b was expressed in the marmoset ovaries in granulosa cells and theca, and the balance of VEGF(165)b:VEGF(165) was regulated during luteogenesis. Mice over-expressing VEGF(165)b in the ovary were less fertile than wild-type littermates, had reduced secondary and tertiary follicles after mating, increased atretic follicles, fewer corpora lutea and generated fewer embryos in the oviduct after mating, and these were more likely not to retain the corona radiata. These results indicate that the balance of VEGFA isoforms controls follicle progression and luteogenesis, and that control of isoform expression may regulate fertility in mammals, including in primates. 相似文献
108.
Colloidal self‐assembly provides one promising route to fabricate spatially periodic meta‐materials with novel properties important to a number of emerging technologies. However, colloidal assembly is generally initiated via irreversible step‐changes and proceeds along unspecified, non‐equilibrium kinetic pathways with little opportunity to manipulate defects or reconfigure microstructures. Here, a conceptually new approach that enables the use of feedback control to quantitatively and reversibly guide the dynamic evolution of colloid ensembles between disordered fluid and crystalline configurations is demonstrated. The key to this approach is the use of free energy landscape models to inform feedback control laws that close the loop between real‐time sensing (via order parameters) and actuation (via tunable electrical potentials). This approach, which demonstrates controlled assembly to create ordered materials and perform active reconfiguration, is based on chemical physics that suggest it can be generalized to other microscopic processes. 相似文献
109.
A Split decoding algorithm is proposed which divides each row of the parity check matrix into two or multiple nearly-independent
simplified partitions. The proposed method significantly reduces the wire interconnect and decoder complexity and therefore
results in fast, small, and high energy efficiency circuits. Three full-parallel decoder chips for a (2,048, 1,723) LDPC code
compliant with the 10GBASE-T standard using MinSum normalized, MinSum Split-2, and MinSum Split-4 methods are designed in
65 nm, seven metal layer CMOS. The Split-4 decoder occupies 6.1 mm2, operates at 146 MHz, delivers 19.9 Gbps throughput, with 15 decoding iterations. At 0.79 V, it operates at 47 MHz, delivers
6.4 Gbps and dissipates 226 mW. Compared to MinSum normalized, the Split-4 decoder chip is 3.3 times smaller, has a clock
rate and throughput 2.5 times higher, is 2.5 times more energy efficient, and has an error performance degradation of 0.55 dB
with 15 iterations. 相似文献
110.
Abstract The binary solid + liquid phase diagram has been measured for the water + hydroxylammonium nitrate (HAN) system. The phase diagram is a simple eutectic type with the eutectic at 231.5 K (41.7°C) and a mole fraction HAN of 0.281 (wt fraction HAN - 0.676). The enthalpy of fusion of the HAN was determined from the solid + liquid results to be 11 ± 2 kJ·mol?1. The HAN was obtained from Southwestern Analytical Chemicals, Inc. as an approximately 2.8 molar solution. The water was removed by vacuum drying over a three month time period, but the sample still contained some impurity. The impurity level calculated from the change in melting temperature with fraction melted is 0.040 mole fraction. Chemical analysis indicates the sample contains 0.005 mole fraction HNO3 and 0.007 mole fraction NH4NO3, with N2H5NO3 absent. The remainder of the impurity could be water, but this is not known for sure. We obtained a melting temperature for the impure sample of HAN of 315.9 K (42.7°C). The melting point corrected to zero impurity is 317.7 ± 1 K (44.5°C). 相似文献