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Generally, there is a seismogenic process before rockbursts occurrence, accompanied by formation of a great amount of micro-cracks and release of micro-seismic energy (micro-seismic precursor). The micro-seismic precursory information can be captured by micro-seismic monitoring equipment. As the micro-seismic activities are of temporal priority and spatial consistency with rockbursts events, the rockburst-prone zone can be predicted accurately. Firstly, Based on the great number of rockbursts events recorded during construction of the headrace tunnels of Jinping II Hydropower Station, the characteristics and mechanism of rockbursts and the role of geological structures are summarized in this essay. And a method was presented that the micro-seismic monitoring technology was employed in rockburst monitoring and early warning during construction of the deep-buried headrace tunnels. Full-time continuous monitoring of micro-seismic activities was realized. Comparison analysis was conducted between the rockbursts and microseismic monitoring results according to the site condition. The relationship between the spatial and temporal evolution of microseismic activities and rockbursts was revealed. The rockbursts analysis, monitoring and early warning practices indicate that: In deep-buried rock tunnels, the tempo-spatial distribution of rockbursts and rockburst intensity follow a certain law. A certain correlation exists between the occurrence of rockbursts and the influencing factors, such as the geological structure, construction method, and excavation disturbance, among which the geological structure plays a crucial role. The engineering practices in this study have proven that application of the microseismic monitoring technology in rockburst monitoring and early warning for deep-buried rock tunnels is feasible and the results are reasonably accurate, which changes the traditional viewpoint that the rockburst is unpredictable. The study in this essay provides a new research idea in rockburst prediction and safe construction for tunnels.

A consistently diamagnetic persistent current (PC) of period halving ( Φ 0 /2-current) observed in mesoscopic rings is in apparent contradiction with the theoretical prediction of barely exclusively paramagnetism . By developing a super-cell method, we analytically and numerically study the magnetic response mechanics of non-interacting mesoscopic rings in both the absence and presence of random disorder. A maximal paramagnetic and/or diamagnetic PC is obtained in primary Φ 0 - and/or Φ 0 /2-period, exhibiting a remarkable quantum size effect. It is shown that for lower free energy, an electron circling the ring accumulates an additional phase on each inter-channel transition induced by magnetic flux, leading to the period halving and the paramagnetic–diamagnetic transition. Our results can well mediate the disputes between the experiments and theory.

To improve the knowledge of nematode communities in the Liaohe estuary, the spatiotemporal variations of free-living nematode communities (density, diversity and trophic structure) in the protected zone (PZ) and the development zone (DZ) were seasonally studied. Soil nematode communities were analysed at the depths of 0–10 and 10–20 cm. The results showed that bacterial feeder nematodes were the most abundant trophic groups in both depths and at both sites. Nematode abundance and plant-parasitic nematodes maturity index/maturity index in the DZ were higher than that in the PZ ( p p

The recent development of silicon-based microreactors requires conventional catalyst carriers to be trimmed down to the sub-micrometer regime while keeping their complex geometrical shapes unchanged. In this work, we use a “top-down” etching approach to fabricate Al 2 O 3 nano-trilobe carriers from the inter-channel parts of pseudo-hexagonally arranged one-dimensional channels of anodic alumina membranes. With a dilute NaOH (0.04 M) etchant and prolonged etching time (1.5 h), highly regulated Al 2 O 3 nanocarriers have been prepared into two major forms: well-aligned (bundles) and freestanding trilobes. It has been found that the Al 2 O 3 nano-trilobes are generated only on the upward facing of the membranes owing to the support provided by less etched membrane underneath and a less vibrant region in fluid exchange. The etching process can be described as a nucleophilic reaction that involves an attachment of hydroxyl ions to Lewis acid sites of aluminum cations. The amorphous as-prepared nano-trilobes can be further heat-treated to any crystallographic phases. For example, phase pure polycrystalline θ-Al 2 O 3 nano-trilobes have been prepared at 1000 °C in laboratory air. Future applications of these nanocarriers have also been discussed.

Double-C 60 -end-capped poly(ethylene oxide) (FPEOF) was reinforced with acid-treated multi-walled carbon nanotubes (MWNTs). The storage modulus of FPEOF was significantly enhanced, whereas the crystallization behavior was not significantly affected upon the incorporation of MWNTs. Fourier transform infrared spectroscopy showed the existence of hydrogen-bonding interactions between the ether oxygen atoms on FPEOF and proton-donating functionalities on the MWNTs, leading to a strong matrix-filler interfacial adhesion. The low-temperature storage modulus of a FPEOF/MWNT composite (6.0 GPa) is more than twice that of a poly(ethylene oxide)/fluorinated single-walled carbon nanotube composite (2.5 GPa) with the same nanotube loading of 4 wt%. The thermal stability of FPEOF is also improved by the addition of MWNTs.

In situ functionalized multi-walled carbon nanotube (MWNT)/Phenoxy composites were prepared by melt mixing Phenoxy with MWNT and 1-(aminopropyl)imidazole (NIm). Composites with 4.8 wt% or more of in situ functionalized MWNT show higher storage modulus than Phenoxy, provided a sufficient amount of NIm was used to aid in the dispersion of the hydrophobic MWNTs in the hydrophilic Phenoxy matrix.

A simple and reliable method has been developed for the controlled growth of well-aligned carbon nanotubes patterns with different sizes and shapes on a silicon substrate. A patterned film of sputtered cobalt on the silicon was prepared by a lift-off process, and the carbon nanotubes were grown via chemical vapor deposition using ethylenediamine as a precursor. The carbon nanotubes are vertically aligned with high density within the micro patterns. The diameter of carbon nanotubes is determined by the thickness of cobalt film while the length of the nanotubes can be controlled by varying the reaction time. The bamboo-like multi-walled carbon nanotubes have been observed by high-resolution transmission electron microscopy. The micro-Raman spectrum further confirmed the graphitic structure of the nanotubes. The potential application of the carbon nanotubes to flat-panel displays is demonstrated by the ability to provide stable high field-emission current densities.

Many aspects of high temperature electrolysis cell operation have been studied experimentally in recent years, including the freezing and melting of electrolyte, the dissolution of added solute material, replacement of anodes and the degradation of the cell's top crust. The present paper reviews this work for the specific case of aluminium electrolysis cells and describes a mathematical model for the cell enthalpy balance which allows the combined effect of all the process kinetics to be observed over time. Comparison of model predictions with dynamic industrial cell measurements is performed where possible, and this demonstrates the importance of interfacial heat transfer from the electrolyte to the cell walls and to feed materials—alumina and anode carbon. The model is then applied to the analysis of generic energy imbalances in a modern industrial electrolysis cell. The causes of these energy imbalances are identified and the consequences for cell performance are predicted using the model. Key issues in the modelling of electrolysis cells identified from these applications, include the importance of different time-scales in mathematically stiff systems, and the unusual behaviour of electrolyte superheat under certain energy imbalance conditions.