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991.
Shankland TJ 《Science (New York, N.Y.)》1968,161(3836):51-53
Optical absorption and reflectivity measurements on synthetic forsterite show that this silicate has a wide band gap of the order of 8.4 electron volts; thus it resembles other pure insulating oxides such as MgO. For natural olivines, in which divalent cations, mainly Fe(2+), can replace Mg(2+), all the optical absorption bands between the lattice overtones in the infrared and the first excitonic transition at 8.4 electron volts are due to the presence of iron. 相似文献
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DAVID T. ZAMOS vmd CLIFFORD M. HONNAS dvm Diplomate acvs ANTON G. HOFFMAN dvm PhD 《Veterinary surgery : VS》1994,23(3):161-166
Arthroscopic examination of structures within the plantar pouch of the tarsocrural joint was accomplished via portals in both the plantaromedial and plantarolateral aspects of the joint. Flexion and extension of the tarsus while examining the joint through either portal allowed observation of the proximal and plantar aspects of the lateral and medial trochlear ridges, the trochlear groove, the caudal aspect of the distal tibia, and the deep digital flexor tendon (DDFT) in its sheath. From a plantarolateral portal, the plantar talocalcaneal ligament and the plantar aspect of the lateral malleolus could be observed. The caudal aspect of the medial malleolus could not be observed with flexion or extension of the joint from a plantaromedial portal, but in some horses, the caudal aspect of the lateral malleolus could be observed. The dorsolateral and dorsomedial aspects of the plantar pouch were best examined from a portal on the ipsilateral side of the joint. An instrument portal opposite either arthroscope portal allowed access to most regions of the joint except the abaxial surface of the trochlear ridge opposite the instrument. 相似文献
999.
Thirty-five crossbred barrows averaging 14.5 kg initial BW were used in a 5-wk experiment to compare the P availability and nutritional value of a low-phytate hybrid corn (LPC, 0.26% total P, 0.08% phytic acid P) homozygous for the lpa 1-1 allele with a nearly isogenic normal hybrid corn (NC, 0.25% total P, 0.20% phytic acid P). The pigs were fed individually twice daily in metabolism pens. Three semipurified diets were created in which corn was the only source of phytate. Diet 1 contained 72% NC, 0.15% estimated available P (aP) and 0.55% Ca. Diet 2 contained 72% LPC, 0.24% aP, and 0.55% Ca. The only differences between Diets 1 and 2 were the source of corn and the levels of aP. No inorganic P (iP) was added to these diets in order to measure the animal response to the different levels of aP in the corn hybrids. Diet 3 was NC Diet 1 supplemented with iP to equal the level of aP in LPC Diet 2. Diets 4 and 5 were practical corn-soybean meal diets formulated with each corn to meet all minimum nutrient requirements and contained 0.30% aP and 0.65% Ca. For the semipurified diets, pigs fed LPC Diet 2 had higher (P < 0.01) growth performance, bone breaking strength, P absorption and retention, Ca absorption and retention, and N retention than pigs fed NC Diet 1. However, when the NC diet was supplemented with iP to equal the aP in the LPC diet, most criteria were similar (P > or = 0.2), indicating an equal nutritional value for both corn hybrids after adjusting for phytate level. The only treatment difference, other than P excretion, between the practical corn diets supplemented with soybean meal was a higher (P < 0.05) bone breaking strength for pigs fed LPC Diet 5 compared with NC Diet 4. The use of LPC in pig diets reduced P excretion in swine waste by 50 and 18.4% in the semipurified and practical diets, respectively, compared with NC. Using our in vitro procedure designed to simulate the digestive system of the pig, the availability of P for pigs was estimated at 56% for LPC and 11% for NC. 相似文献
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Boekhold A. E. Van Der Zee S. E. A. T. M. De Haan F. A. M. 《Water, air, and soil pollution》1991,(1):479-488
To investigate Cd behavior in a heterogeneous soil, soil samples were taken along a transect in a field. Total Cd content, Cd concentration in solution, and soil properties controlling Cd sorption were measured. The scale and degree of variability of these parameters were assessed using statistical and spectral analysis. No substantial correlation was found between total Cd and Cd in solution. However, with a scaled sorption model that accounts for effects of pH and organic matter content the variability of total Cd was predicted well as a function of measured concentrations and soil properties. Apparently, total Cd contents of this soil are primarily controlled by the organic matter content and pH. 相似文献