Water-Tree Resistability of UV-XLPE from Hydrophilicity of Auxiliary Crosslinkers.

The water-resistant characteristics of ultraviolet crosslinked polyethylene (UV-XLPE) are investigated specially for the dependence on the hydrophilicities of auxiliary crosslinkers, which is significant to develop high-voltage insulating cable materials. As auxiliary crosslinking agents of polyethylene, triallyl isocyanurate (TAIC), trimethylolpropane trimethacrylate (TMPTMA), and N,N'-m-phenylenedimaleimide (HAV2) are individually adopted to prepared XLPE materials with the UV-initiation crosslinking technique, for the study of water-tree resistance through the accelerating aging experiments with water blade electrode. The stress-strain characteristics and dynamic viscoelastic properties of UV-XLPE are tested by the electronic tension machine and dynamic thermomechanical analyzer. Monte Carlo molecular simulation is used to calculate the interaction parameters and mixing energy of crosslinker/water binary systems to analyze the compatibility between water and crosslinker molecules. Water-tree experiments verify that XLPE-TAIC represents the highest ability to inhibit the growth of water-trees, while XLPE-HAV2 shows the lowest resistance to water-trees. The stress-strain and viscoelastic properties show that the concentration of molecular chains connecting the adjacent lamellae in amorphous phase of XLPE-HAV2 is significantly higher than that of XLPE-TAIC and XLPE-TMPTMA. The molecular simulation results demonstrate that TAIC/water and TMPTMA/water binary systems possess a higher hydrophilicity than that of HAV2/water, as manifested by their lower interaction parameters and mixing free energies. The auxiliary crosslinkers can not only increase the molecular density of amorphous polyethylene between lamellae to inhibit water-tree growth, but also prevent water molecules at insulation defects from agglomerating into micro-water beads by increasing the hydrophilicity of auxiliary crosslinkers, which will evidently reduce the damage of micro-water beads on the amorphous phase in UV-XLPE. The better compatibility of TAIC and water molecules is the dominant reason accounting for the excellent water resistance of XLPE-TAIC.

How does natural resource dependence affect public education spending?

The "resource curse" phenomenon has been the subject of extensive research, with its causes and transmission mechanisms primarily examined from the perspectives of economic development and rent seeking. Education is a major factor contributing to economically sustainable development, owing to its potential for improving cognition and skill levels and thereby enhancing worker productivity. The crowding-out or crowding-in effect of natural resource dependence on public education spending has been identified as one of the key mechanisms of the resource curse or blessing. Using panel data from 31 Chinese provinces, this empirical study revealed a positive correlation between natural resource dependence and public education expenditure, demonstrating the impact of the crowding-in effect, exerted by natural resource dependence, on public education expenditure. Abundant natural resources can provide funds for education expenditure. The sample was further divided into eastern and central and western regions. The results indicate that the crowding-out effect of natural resource dependence only affects public education expenditure in the Eastern region, while the crowding-in effect of natural resource dependence on public education expenditure in the central and western regions. Research shows that the regional differences of crowding-out or crowding-in effect are very obvious, so the government should adopt transfer payment to promote balanced regional development. Better economic and social policies will help to translate wealth from natural resources into economic growth. Thus, a "resource blessing" may emerge to replace the "resource curse." Fairly distributed and higher quality education will enhance human capital, thereby promoting economic growth from its current resource-driven pattern to a knowledge-driven pattern.

[Assessment on the clinical efficacy and safety of xiezhuo chubi recipe in treating hyperuricemia].

OBJECTIVE: To observe the clinical efficacy and safety of Xiezhuo Chubi Recipe (XCR) on hyperuricemic patients. METHODS: 99 patients with hyperuricemia were randomly assigned to the XCR group, the Benzbromarone group, and the blank control group. Patients in the XCR group took XCR, one dosage daily, twice per day. Patients in the Benzbromarone group took Benzbromarone Tablet (50 mg each tablet, once per day). Patients in the blank control group were not treated with any drug, but only with clinical observation. Twenty days consisted of one course of treatment. The laboratory data including uric acid, blood routines, urine routines, the liver function, and the renal function were statistically analyzed before and after treatment. RESULTS: The blood uric acid decreased in the three groups after treatment (P<0.05). The total effective rate was 85.71% in the XCR group, 92.86% in the Benzbromarone group, and 23.33% in the blank control group. There was no statistical difference between the XCR group and the Benzbromarone group (P>0.0167). There was no significant difference in the safety indices such as blood routines, urine routines, liver functions, and renal functions of the XCR group between before and after treatment (P>0.05). CONCLUSION: XCR could effectively reduce the uric acid level with higher safety.