| 1. |
- Szymanski, J. J., et al.
(författare)
-
A study of the decay mu –> e gamma by the MEGA experiment
- 1996
-
Ingår i: Proceedings, 9th Meeting, DPF'96, Minneapolis, USA, August 11-15, 1996. Vol. 1, 2.. ; , s. 1450-1452
-
Konferensbidrag (refereegranskat)
|
|
| 2. |
- Hoganson, C W, et al.
(författare)
-
A hydrogen-atom abstraction model for the function of Y-Z in photosynthetic oxygen evolution
- 1995
-
Ingår i: Photosynthesis Research. - 0166-8595. ; 46:1-2, s. 177-184
-
Tidskriftsartikel (refereegranskat)abstract
- Recent magnetic-resonance work on Y-Z suggests that this species exhibits considerable motional flexibility in its functional site and that its phenol oxygen is not involved in a well-ordered hydrogen-bond interaction (Tang et al., submitted; Tommos et al., in press). Both of these observations are inconsistent with a simple electron-transfer function for this radical in photosynthetic water oxidation. By considering the roles of catalytically active amino acid radicals in other enzymes and recent data on the water-oxidation process in Photosystem II, we rationalize these observations by suggesting that Y-Z functions to abstract hydrogen atoms from aquo- and hydroxy-bound manganese ions in the (Mn)(4) cluster on each S-state transition. The hydrogen-atom abstraction process may occur either by sequential or concerted kinetic pathways. Within this model, the (Mn)(4)/Y-Z center forms a single catalytic center that comprises the Oxygen Evolving Complex in Photosystem II.
|
|
| 3. |
- Sargeson, A. M., et al.
(författare)
-
Names and symbols for the transfermium elements
- 1997
-
Ingår i: Pure and Applied Chemistry. - : Walter de Gruyter GmbH. - 0033-4545 .- 1365-3075. ; 69:12, s. 2471-2473
-
Tidskriftsartikel (refereegranskat)abstract
- The recommendations (ref. 1) of the Commission on Nomenclature of Inorganic Chemistry (CNIC) on the nomenclature of the transfermium elements (101-109, inclusive) were considered by the IUPAC Bureau at Guildford (UK) in September 1995. As a result of the various criticisms of the recommendations and theway that they had been processed, the Bureau decided to adopt the recommendations as provisional and to circulate them to national/regional nomenclature centres in the normal way, with notices to be published innational/regional chemistry journals and magazines, requesting submission of comments to CNIC. In particular, the National Adhering Organizations (NAOs) were invited to express their views concerning the extant proposals for the names of these elements and the principles and traditions used to derive them. The response from the general chemical community was small, and the bulk of the replies came from nuclear scientists.
|
|
| 4. |
- Kou, Shao Quan, et al.
(författare)
-
Numerical simulation of the cutting of inhomogeneous rocks
- 1999
-
Ingår i: International Journal of Rock Mechanics And Mining Sciences. - 1365-1609 .- 1873-4545. ; 36:5, s. 711-717
-
Tidskriftsartikel (refereegranskat)abstract
- In this study, the possible modes of crack initiation and propagation leading to chip formation in rock cutting are studied numerically by using a rock failure process analysis code referred to as RFPA. By using this approach, additional information is obtained on the tool-rock interaction and the failure mechanisms of rock under mechanical tools.
|
|
| 5. |
|
|
| 6. |
|
|
| 7. |
- Tang, C. A., et al.
(författare)
-
A theoretical model for Kaiser effect in rocks
- 1997
-
Ingår i: Pure and Applied Geophysics. - : Springer Science and Business Media LLC. - 0033-4553 .- 1420-9136. ; 150:2, s. 203-215
-
Tidskriftsartikel (refereegranskat)abstract
- The mechanism of Kaiser effect was studied with the aid of a damage model for rock. Recognizing that the AE counts are transient elastic waves due to local damage of the rock, the quantitative relation between AE counts and statistical distribution of the local strength of the rock has been established. Subsequently, according to Damage Theory, an expression for Kaiser Effect under uniaxial stress state was derived from the model. This is found to be in good agreement with the experimental results.
|
|
| 8. |
- Tang, C.A., et al.
(författare)
-
Crack propagation and coalescence in brittle materials under compression
- 1998
-
Ingår i: Engineering Fracture Mechanics. - 0013-7944 .- 1873-7315. ; 61:3-4, s. 311-324
-
Tidskriftsartikel (refereegranskat)abstract
- Two particular cases concerning crack propagation and coalescence in brittle materials have been modeled by using the rock failure process analysis code, RFPA2D, and the results have been validated by reported experimental observations. Firstly, axial compression of numerical samples containing a number of large, pre-existing flaws and a row of suitably oriented smaller flaws are simulated. It has been confirmed that under axial compression, wing-cracks nucleate at the tips of the pre-existing flaws, grow with increasing compression, and become parallel to the direction of the maximum far-field compression. However, coalescence of the wing-cracks may be in either tensile mode or shear mode, or a combination of both modes. The numerical results show qualitatively a reasonably good agreement with reported experimental observations for samples with similar flaw arrangements. The numerical results demonstrate that, with a confining pressure, the crack growth is stable and stops at some finite crack length; whereas a lateral tensile stress even with a small value will result in an unstable crack growth after a certain crack length is attained. Secondly, failure mode in a sample containing inhomogeneities on grain scale has also been simulated. The results show that the failure mode strongly depends on the mechanical and geometric properties of the grains and inclusions
|
|
| 9. |
|
|
| 10. |
|
|
