Vol.8,

Nonlinear feedback functional method is presented to realize synchronization of hyperchaos in higher dimensional systems. New nonlinear feedback functions and superpositions of linear and nonlinear feedback functions are also introduced to synchronize hyperchaos. The robustness of the method based on the flexibility of choices of feedback functions is discussed. By coupling well-known chaotic or chaotic-hyperchaotic systems in low-dimensional systems, such as Lorenz system, Van der Pol oscillator, Duffing oscillator and Rössler system, ten dimensional hyperchaotic systems are formed as the model systems. It can be found that there is not any noticeable difference in synchronization based on the numbers of positive Lyapunov exponents and of dimensions.

309

306

The properties and the component of HLLW (High Level Liquid Waste) were studied. The genuine saline HLLW is a blue-green liquid without any deposition. Its density and acidity are 1.399 g/ml(23±10°C) and 2.1 mol/L HNO₃, respectively. The activities of ¹³⁷Cs, ⁹⁰Sr, ⁹⁹Tc, ²³⁷Np, ²³⁹Pu, ²⁴¹Am, total a, total β, total γ are determined. The extractabilities of actinides in the genuine HLLW were examined with a five-stage cross extraction experiment. More than 98% of Pu is in Pu⁴⁺ species, and more than 70% of Np is in Np⁴⁺ species. More than 99.97% α-nuclides could be extracted by 30%TRPO-Kerosene in 1 mol/L HNO₃ from the HLLW.

427

The stability of low temperature nuclear heating reactor with various subcoolings of reactor core inlet has been studied by means of simulating experiments. The thermal-hydranlic system and the data acquisition and processing system are presented. Especially, the process of realizing the simulating nuclear feedback is introduced in detail. Finally, the experimental results are discussed in the opinions of nuclear reactor physics and thermal-hydraulics. The conclusion is that the nuclear reactor can operate stably only when the subcooling of reactor core inlet is high enough.

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The microstructure of human tumor necrosis factor alpha (TNF-a) and its mutant (TNF-b) has been investigated by utilizing positron annihilation lifetime spectroscopy, radioiodination of human TNF and L929 cells assay. The experimental results show that the long lifetime (T₂) and corresponding intensity (I₂) of lower ortho-positronium annihilation in TNF-a are longer and less than those in the TNF-b, respectively. It suggests that the TNF-b is smaller in free volume and higher in density than the TNF-a. The TNF-b may maintain a more favorable conformation for binding to TNF receptors, thus increasing its biological activity. It is then concluded that the increases in the cytotoxicity and in the density for the TNF-b result from the decreases in the free volume in the TNF-b.

291

The microdomain structure of segmented polyether polyurethaneureas is investigated by means of positron annihilation lifetime spectroscopy, small-angle X-ray scattering and differential scanning calorimetry. The experimental results show that the decrease in the domain volume and free volume results from the increase in the hard segment (polyuretha-neurea segment) contents as the number-average molecular weight Mn¯ of the soft segments (polyethylene glycol segments) is the same, and that the increase in domain volume and free volume result from the increase in the Mn¯ of the soft segments when the hard segment content is the same or nearly the same. These results demonstrate that positron annihilation lifetime spectroscopy is a sensitive technique to probe the microdomain structure in polymers.

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417

Apoptosis in human acute lymphoblastic leukemia cell line Molt-4 cell and macrophage cell line Ana-1 cell could be induced by fission fragment ¹⁴⁷Pm. The cumulative absorption dose of ¹⁴⁷Pm in cultural cells through different periods were estimated. By using fluorescence microscopy and microautoradiographic tracing it can be found that Molt-4 and Ana-1 cells internally irradiated by ¹⁴⁷Pm, displayed an obvious nuclear fragmentation and a marked pyknosis in immune cell nuclei, as well as DNA chain fragmentation and apoptotic bodies formation. The microautoradiographic study showed that ¹⁴⁷Pm could infiltrate through cell membrane and displayed membrane-seeking condensation in cells. At the same time, the membrane-bounded apoptotic bodies were observed. Experimental results in recent study provide evidence that Molt-4 and Ana-1 immune cells undergo apoptosis while internally irradiated with ¹⁴⁷Pm.

275

N,N,N',N'-tetrabutylmalonamide (TBMA) is synthesized and used for extraction of uranyl(II) ion from nitric acid media in a diluent composed of 50% 1,2,4-trimethyl benzene (TMB) and 50% kerosene(OK). The effects of nitric acid concentration, extractant concentration, temperature, salting-out agent (LiNO₃) and back extraction on distribution coefficients of uranyl(II) ion have been studied. The extraction of nitric acid is also studied. The main adduct of TBMA and HNO₃ is HNO₃ TBMA, and there are more than two kinds of adducts in 3.0 mol/L nitric acid solutions, such as HNO₃•TBMA, (HNO₃)₂•TBMA and (HNO₃)₃•TBMA. The complex formation of uranyl(II) ion, nitrate ion and TBMA (1:2:1) as extracted species is further confirmed by IR spectra of the saturated extraction of uranyl(II) ion with TBMA, and the values of thermodynamic parameters have also been calculated.

450

Computations of air bubble collapse dynamics usually neglect thermal conduction, but recent computations show about a 3-fold reduction in bubble gas temperature if thermal conduction is included. However, an isothermal collapse at ambient temperature is even more likely because the air molecules collide with and stick to the bubble walls during bubble expansion and are not available for compression heating during collapse. The probability of isothermal collapse is shown to depend on the mean free path of the air molecules moving through the H₂O vapor molecules within the bubble during bubble expansion and is sensitive to the lowering of ambient temperature to the freezing point.

310

Total neutron yields and neutron emission rates in the forward direction for 50 MeV/u ¹⁸O-ion on thick Be, Cu, Au targets have been measured using an activation technique. The results indicate that neutron yields and emission rates in the forward direction depend on the atomic number of target nuclei, i.e. the lighter target the greater neutron yield and neutron emission rate. Meanwhile, the neutron yield of ¹⁸O-ion is greater than that of ¹²C-ion when target nucleus and incident energy per nucleon are identical.

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494

The correlation between Al metabolism and senile dementia in animal has been studied by AMS (accelerator mass spectrometry). Three groups of laboratory rats were fed with normal food, food with high Al content, and with enriched Ca and Mg together with high Al, respectively for six to eight months. Mapping test was made to record the degree of wisdom degeneration. Half of the rats were sacrificed and Al contents in various organs were measured by atomic absorption spectroscopy. The rest were injected with ²⁶Al, killed after 5, 10, 15, 25, and 35 d and ²⁶Al contents measured by AMS. The distribution of Al as well as the correlation among the accumulation of ²⁶Al, and the existed Al content and dementia was studied.

342

The partition of uranium(VI) between nitric acid and N,N-diethyldecanamide, C₉H₁₉CON(C₂H₅)₂, (DEDEA) in kerosene has been investigated at various concentrations of nitric acid, extractant and salting-out agent LiNO₃. The mechanism of extraction is discussed in the light of the results obtained. The effect of TBP on the extraction of uranium(VI) with DEDEA has also been considered. There is apparent synergism between these two extractants at low concentration of TBP; however, at higher concentration, distribution ratio decreases.

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