Vol.8,

The complete fusion-fission is separated from the transfer-induced-fission with the fragment folding angle technique. The cross sections and fragment angular distributions for the complete fusion-fission reactions of ¹¹B+²³⁸U(²³⁷Np), ¹²C + ²³⁷Np, ¹⁶O + ²³²Th(²³⁸U) and ¹⁹F+ ²³²Th at near- and sub-barrier energies have been measured. The present fusion and fission standard models can reproduce both the excitation functions and the fragment anisotropies for the systems of ¹¹B+²³⁸U(²³⁷Np) and ¹²C+²³⁷Np; but fail to explain both the experimental data for the other 3 systems simultaneously. The evidence of the entrance-channel dependence of fission-fragment anisotropies is revealed by comparison of the ¹¹B+²³⁷Np and ¹⁶O+²³²Th data. Based on the observations, a new version model of preequilibrium fission is put forward to explain the anomaly.

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In 1994 the first single-photon spectra from the 200 GeV/A S + Au collisions at CERN SPS were reported by WA80 group. Based on these data, it can be proved that as long as there is an instantaneous thermal distribution T(r,t) in an expanding fireball at each instant, the basic mathematical feature of various kinds of photon spectra is that photon yield is approximately an exponential function of the transverse momentum P_T in some region, which is basically irrelevant to the uncertainties enclosed in the theoretical estimations.

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The defects in Si-doped, N-type HB GaAs single crystal irradiated by E_n ≥1 MeV fission neutrons (6.5×10¹⁵cm^-2 and 1.4×10¹⁴cm^-2) have been investigated using positron annihilation lifetime technique. The mono- and di-vacancies were created by irradiation and the tri-vacancies were formed during annealing. The concentration of defects is proportional to the irradiating neutron fluence. Three annealing stages were observed at 250, 450 and 650℃ for the mono-, di- and tri-vacancies, respectively.

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Radiation heat waves play an important role in high-temperature hydro-dynamic phenomena which is very important for laser fusion. Therefore, the propagation of a radiation heat w ave through a thin foil of solid aluminium is observed. The wave is driven by the intense soft-X-ray radiation in acylindrical cavity heated by the intense laser pulse. Experiments are carried out with two beams of λ=1.05μm light from the Shenguang Nd-glass laser facility. The pulse energy is about 600 J and the pulse duration 0.8 ns. Evidence of radiation heat wave is obtained by observing the delayed signal of intense thermal emission from the outside of the foil. The delay is 850 ps for 1.5μm thick foil and the mass ablation rate is about 4.8×10⁵g/(cm²°s)under the X-ray flux of about 1×10¹³ W/cm². Also, the radiation-driven shock waves of (2±1)TPa are observed from different shots in the experiments.

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A simple, engineeringly feasible dynamic method is supposed to control the deuterium-tritium burn process in Tokamak reactors operated in an advanced scenario. The thermal transport of the D-T plasma is described by an anomalous thermal conduction which is a radially increasing function and the central conduction value is proportional to the central temperature of the plasma. The dynamic external heating power is selected to be inversely proportional to certain power function of this temperature. As a result, the D-T burn can undergo in controllable way in different temperature regimes with different power output. Anomalous alpha particle transport effect is taken into account. It can affect the resultant plasma equilibrium, the reactor efficiency, the operation mode and so on.

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The skeleton transference and the retention dynamics of i.v, ¹³⁴Cs are investigated. Results indicate that the retention percentage of ¹³⁴Cs in skeleton could be characterized by R(t) = 0.0029exp(-0.121t) with T_1/2= 5.73 d; the chromosome aberration percentage of somatic bone marrow cells increases obviously, the relationship between injected dose (X in kBq/g) and the chromosome aberration percentage can be expressed as Y = 0.0561X^0.427. It should be noted that sustained elevation of chromosomal aberration rates induced by ¹³⁴Cs can be upto the 47 th d.

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The effects of several Chinese crude drugs including Crocus sativus, Carthamus tinctorius and Ginkgo biloba on Ca²⁺ transmembrane influx in rat aorta rings were studied. Resting ⁴⁵Ca uptake was not markedly altered by these drugs, whereas the ⁴⁵Ca influxes evoked by norepinephrine (1.2µmol/L ) and KC1 ( 100 mmol/L ) in rat aorta rings were significantly inhibited by Crocus and Carthamus in a concentration-dependent manner, not by Ginkgo. The results indicate that extracellular Ca²⁺ transmembrane influx through receptor-operated Ca²⁺ channels and potential-dependent Ca²⁺ channels can be blocked by Crocus and Carthamus.

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