[en] The Cr-Ni-Mo-V heat-resistant low-alloy steel is used for VVER reactor pressure vessel material. The neutron irradiation of the reactor will cause the irradiation embrittlement of the RPV material, cause the change of the microstructure of the material, reduce its mechanical characteristics, affect the operating life of the RPV and the safety of the reactor. The irradiation embrittlement mechanism of RPV material is divided into reinforce mechanism and non-reinforce mechanism. Under the neutron irradiation, radiation defects are formed inside the material, and elements such as copper, nickel, manganese and silicon form irradiation-induced clusters, leading to material strengthening and hardening, phosphorus and other impurity elements segregate to the dislocation line, grain boundary or phase boundary, resulting in reduced grain boundary and phase boundary strength. There are synergistic effects of radiation embrittlement between nickel and manganese, nickel and copper, copper and phosphorus. (author)

[en] Highlights: • A novel readily biodegradable chelating ligand was employed to remove heavy metals. • The effects of different conditions on the extraction with GLDA were probed. • Species distribution of metals before and after extraction with GLDA was analyzed. • GLDA was effective for Cd extraction from sludge samples under various conditions. • GLDA offers special insights in the effective removal of heavy metals. - Abstract: Tetrasodium of N,N-bis(carboxymethyl) glutamic acid (GLDA), a novel readily biodegradable chelating ligand, was employed for the first time to remove heavy metals from industrial sludge generated from a local battery company. The extraction of cadmium, nickel, copper, and zinc from battery sludge with the presence of GLDA was studied under different experimental conditions such as contact times, pH values, as well as GLDA concentrations. Species distribution of metals in the sludge sample before and after extraction with GLDA was also analyzed. Current investigation showed that (i) GLDA was effective for Cd extraction from sludge samples under various conditions. (ii) About 89% cadmium, 82% nickel and 84% copper content could be effectively extracted at the molar ratio of GLDA:M(II) = 3:1 and at pH = 4, whereas the removal efficiency of zinc was quite low throughout the experiment. (iii) A variety of parameters, such as contact time, pH values, the concentration of chelating agent, stability constant, as well as species distribution of metals could affect the chelating properties of GLDA

[en] Large scale and homogeneous bunched lead molybdate nanobelts were synthesized via a vertically supported liquid membrane system in the presence of ethylenediamine at room temperature. The typical bunched nanobelts were of length of ca. 300-500 μm, the width of ca. 230-280 nm and the thickness of ca. 90-110 nm. The X-ray diffraction patterns showed that all the obtained PbMoO₄ crystals belonged to tetragonal structure. Scanning electron microscopy images revealed that the positioning of the two compartments in the SLM system, modifier additive and reacting time, highly affect the morphologies and sizes of PbMoO₄ crystals. Room-temperature emission spectra of PbMoO₄ were investigated and the relative photoluminescence intensity of 400 nm was intensified in PbMoO₄ nanobelts. A possible growth mechanism is proposed. (orig.)

[en] Compared with Pressurized Water Reactors, Pulse Reactors show two characters: One is fuel elements with U-Z_rH_X, the other is operation under the condition of low temperature, low pressure and natural circulation. These make it necessary that special analysis tools be used for Pulse Reactors. The author will introduce the steady-state thermal-hydraulic analysis methodology of Pulse Reactors first, then calculate steady-state thermal-hydraulic behavior of a 1 MW Pulse Reactor. At last, comparing the calculated results with foreign results and experimental data, show that this methodology is feasible

[en] The continuous phase transformation from the layered structure to the spinel-like phase seriously degrades the electrochemical properties of Li-rich layered oxides in Lithium-ion batteries. Herein, heterostructured Li-rich cathode materials Li[Li_0.2Ni_0.17Co_0.07Mn_0.56]O₂ in conjunction with different contents of Zr-containing phosphate (ZCP) coating layers were prepared. The structural and electrochemical characterizations reveal that the ZCP surface layer, which not only prevents electrolyte from eroding the Li-rich core and thus suppressing the fast growth of solid electrolyte interface film and charge transfer resistance on the surface of oxide particles, but also enhances the structural and thermal stabilities of the electrode. As a result, the 3 wt.% coated sample delivers an initial discharge capacity of 216 mAh g⁻¹ with a coulombic efficiency of 80%, compared to 202 mAh g⁻¹ and 71%, respectively, for the bare sample. Particularly, the coated sample demonstrates excellent cycling stability with a capacity retention of 91% within 100 cycles, and higher thermal stability.

[en] The computer codes, calculation models, transient results, sensitivity research, design improvement, and safety evaluation used in accident analysis for PRC-II Reactor (The Second Pulsed Reactor in China) are introduced. PRC-II Reactor is built in big populous city, so the public pay close attention to reactor safety. Consequently, Some hypothetical accidents are analyzed. They include an uncontrolled control rod withdrawal at rated power, a pulse rod ejection at rated power, and loss of coolant accident. Calculation model which completely depict the principle and process for each accident is established and the relevant analysis code is developed. This work also includes comprehensive computing and analyzing transients for each accident of PRC-II Reactor; the influences in the reactor safety of all kind of sensitive parameters; evaluating the function of engineered safety feature. The measures to alleviate the consequence of accident are suggested and taken in the construction design of PRC-II Reactor. The properties of reactor safety are comprehensively evaluated. A new advanced calculation model (True Core Uncovered Model) of LOCA of PRC-II Reactor and the relevant code (MCRLOCA) are first put forward

[en] A356 alloy reinforced with carbon nanofibers (CNFs) was fabricated by high-intensity ultrasonic vibration processing. The microstructure and mechanical properties were investigated. The distribution of CNFs became more and more uniform with the increase of ultrasonic power, and the mechanical properties of nanocomposites were significantly enhanced accordingly. The yield strength (YS), ultimate tensile strength (UTS), and microhardness of the nanocomposite increased by 38.3, 21.9, and 43.2 pct, respectively, at a CNF content of 0.9 wt pct compared with the matrix without CNF addition. The improvement in mechanical properties was the effect of CNFs on the thermal expansion mismatch strengthening of the nanocomposite, the grain refinement of the nanocomposite, and the load transfer from the matrix to the nanofibers.

[en] Short communications only

[en] The continuous cooling transformation (CCT) behaviors of CLAM (China Low Activation Martensitic) steel were studied, the CCT diagram was constructed, and the influence of cooling rates on the microstructures was also investigated. The microstructures were investigated using optical microscopy (OM) and microhardness tests were also carried out. The results showed that CLAM steel possessed high hardenability and there were ferrite and martensite transformation regions only. The maximum cooling rate to form ferrite microstructure was found to be 10–12 K/min. In order to obtain fully ferrite microstructure, the cooling rate should be lower than 1 K/min. The CCT diagram also gave relevant parameters such as the transformation temperatures, i.e., A_c1, A_c3, M_s and M_f were 1124 K, 1193 K, 705 K and 593 K, respectively. The diagram made it possible to predict the microstructures and properties of CLAM steel with different cooling rates

[en] Objective: To evaluate the clinical efficacy of CT-guided ¹²⁵I seed implantation in treating pelvic and retroperitoneal malignant tumors. Methods: CT-guided ¹²⁵I seed implantation was carried out in 23 patients with pelvic or retroperitoneal malignant tumors. Helical CT examination of abdomen or pelvic cavity was employed in all patients one week before the treatment, the image data were transferred to a computerized three-dimensional (3-D) tumor treatment planning system (TPS), the contour of target areas as well as the important organs around the tumor such as the bladder, bowel, large blood vessels, etc. were sketched. 3-D reconstruction of the target and the related profile was conducted. The radiation dose of target areas, the particle number and the particle space alignment were determined. The patients were followed up for 4 months to check the local treatment effect, the toxic and side effects of digestive tract and urinary system, the changes in pain and local tumor remission. Results: Of the 23 patients in this series, 16 had pain in the sacrococcygeal or lower back region before treatment. After treatment pain relief was obtained within 5-14 days, the effective rate was 87.5%, the short-term improvement for local pain was very remarkable. The 2-month and 4-month local control effective rates (CR+PR) were 47.8% (11/23) and 43.5% (10/23) respectively. During the follow-up period, no complications such as abdominal pain, pain in urination, radioactive enteritis, or bone marrow suppression, etc. occurred. Conclusion: This preliminary study shows that brachytherapy of CT-guided percutaneous ¹²⁵1 seed implantation is safe and effective for the treatment of pelvic and retroperitoneal malignant tumors. For the pelvic and retroperitoneal malignant tumors that are inoperable or postoperative recurrent, or that show poor response to pure radiotherapy and chemical therapy, this treatment is an effective and remedial therapeutic means, besides, it can effectively improve the quality of life of patients and improve the local control rate of tumor. (authors)