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The sodium smelting of vanadium–titanium magnetite can achieve the comprehensive utilization of Fe, V, and Ti. However, the generation of alkaline slag during this process may cause damage to refractory materials. The wettability and corrosion behavior of alkaline slag on three types of refractory (MgO–C, SiC, and high alumina refractory) substrates were investigated at temperatures up to 1200 °C. The effects of duration on the wettability of molten slag on SiC substrates were also investigated. Results showed that the high alumina refractory exhibited better wettability with the molten slag than the others, and thus, it is easier to be corroded. The results of scanning electron microscopy coupled with energy dispersive spectroscopy showed that MgO–C and high alumina refractory substrates were severely eroded. There was a visible and regular interfacial reaction layer between the slag and SiC refractory substrate, which was produced by the redox reaction between the metal oxides in the slag and the SiC refractory substrate. With the increase in holding time, the interface layer expands and silico-ferrite phases are generated at the interface. The redox reaction between Fe2O3and SiC substrate is the main reason for the corrosion. By comparing the differences in wettability and corrosion behavior between the alkaline slag from sodium smelting of vanadium–titanium magnetite and MgO–C, SiC and high alumina refractories, it is concluded that SiC refractory has good corrosion resistance to the slag. Iron oxides in the slag accelerate the oxidation rate of SiC refractory.

The optimal width of resection margin (RM) for hepatocellular carcinoma (HCC) remains controversial. This study aimed to investigate the value of imaging tumor capsule (ITC) and imaging tumor size (ITS) in guiding RM width for patients with HCC.

Valve-induced flow characteristics were often concerned in many fluid transportation and control industries. In this paper, the eccentric jet-flow characteristics induced by a gate valve have been studied by considering the influence of valve opening regulation. The experimental setup of monitoring the downstream pressures along the pipeline was developed, and corresponding numerical simulation was employed. The downstream-monitoring pressure distribution caused by valve opening regulation was investigated to verify the flow simulation. The generation mechanism of eccentric jet-flow was revealed as a strong pressure gradient caused by the throttling effect at the valve throat. It was found that the eccentric jet-flow evolved in the pipeline was accompanied by shearing vortices, extremely under a small valve opening. The pressure and axial velocity distributions at various downstream cross-sections of the eccentric jet-flow evolving in the pipeline were analyzed. The axial velocities on four monitoring lines in downstream cross-sections were extracted, and the radial location of the maximum axial velocity was derived to assess the eccentric characteristics of jet-flow. A dimensionless parameter of velocity eccentric ratio was introduced to quantify the eccentric intensity of the evolving jet-flow in the downstream pipeline, and its correlation with the pipeline length could be adequately expressed by a natural decreasing exponential curve via fitting analysis. By virtue of that correlation, the critical pipeline length was proposed that can be used as the judgment to the terminal of the eccentric jet-flow evolving in the downstream pipeline. This study was helpful to characterize the valve-induced flow characteristics in scientific research and provide useful insight into fluid and mechanical engineering.

Axial flow check valves are primarily employed to regulate the unidirectional flow of fluids within pipelines, preventing backflow or reverse flow. The design of this type of check valve ensures its opening in the direction of fluid flow and closing in the case of reverse flow, thereby ensuring that fluid within the pipeline system can only move in the predetermined direction. This paper establishes a three-dimensional physical model of the axial flow check valve with the length of 2050 mm, the height of 2200 mm and the inlet/outlet diameter of 1716 mm. Dynamic characteristics of the flow field during the closing process of axial flow check valve under different pressure difference were studied using dynamic mesh technology and User Defined Function. The vibration of the valve stem of the axial flow check valve was predicted and analyzed through fluid-structure coupling. Additionally, a fluid-structure coupled approach is employed to predict and analyze the vibration of the valve stem in axial flow check valves. The results indicate that with an increase in the pressure difference at the inlet and outlet, the time required for the check valve to close decreases, leading to an acceleration in the valve disc’s velocity. Simultaneously, the fluid forces exerted by the flow field on the valve stem the increase, resulting in more significant vibrations. Among these vibrations, the first three natural modes have the most substantial impact on the valve stem. To prevent damage to the valve stem, efforts should be made to minimize the influence of these first three modes on axial flow check valves. This study provides valuable recommendations and support for preventing damage to the valve stem in operational scenarios involving axial flow check valves.

Here, we propose the use of carboxyl-functionalized ionic liquid, [Hbet][Tf2N], to separate the fission products from spent nuclear fuels. This innovative method allows the selective dissolution of neutron poisons, lanthanides oxide, as well as some fission products with high yield, leaving most of the UO2matrix and minor actinides behind in the spent nuclear fuel and accomplishing the actinides recovery as a group. Water-saturated [Hbet][Tf2N] can dissolve lanthanides oxide from simulated spent nuclear fuel with a dissolution ratio of 100% at 40 °C. However, the dissolution of uranium is almost negligible (<1%) under the same conditions. This big difference in dissolution provides a novel separation approach to spent nuclear fuel recycling and may open new perspectives for spent nuclear fuel reprocessing. The recovery of Nd and U from metal-loaded ionic liquids and the recyclability of the ionic liquid [Hbet][Tf2N] have also been investigated. Furthermore, a U/xvalue related to the lattice energy Uof metal compound MxOyis used to elaborate the solubility. This work represents the first case for efficient fission products removal by selective dissolution, avoiding the complete dissolution of spent nuclear fuel, the producing of the large high-level radioactive waste, and reducing environmental hazards.

The reduction behaviors of FeO·V2O3and FeO·Cr2O3during coal-based direct reduction have a decisive impact on the efficient utilization of high-chromium vanadium-bearing titanomagnetite concentrates. The effects of molar ratio of C to Fe n(C)/n(Fe) and temperature on the behaviors of vanadium and chromium during direct reduction and magnetic separation were investigated. The reduced samples were characterized by X-ray diffraction (XRD), scanning election microscopy (SEM) and energy dispersive spectrometry (EDS) techniques. Experimental results indicate that the recoveries of vanadium and chromium rapidly increase from 10.0% and 9.6% to 45.3% and 74.3%, respectively, as the n(C)/n(Fe) increases from 0.8 to 1.4. At n(C)/n(Fe) of 0.8, the recoveries of vanadium and chromium are always lower than 10.0% in the whole temperature range of 1100–1250 °C. However, at n(C)/n(Fe) of 1.2, the recoveries of vanadium and chromium considerably increase from 17.8% and 33.8% to 42.4% and 76.0%, respectively, as the temperature increases from 1100 °C to 1250 °C. At n(C)/n(Fe) lower than 0.8, most of the FeO·V2O3and FeO·Cr2O3are not reduced to carbides because of the lack of carbonaceous reductants, and the temperature has little effect on the reduction behaviors of FeO·V2O3and FeO·Cr2O3, resulting in very low recoveries of vanadium and chromium during magnetic separation. However, at higher n(C)/n(Fe), the reduction rates of FeO·V2O3and FeO·Cr2O3increase significatly because of the excess amount of carbonaceous reductants. Moreover, higher temperatures largely induce the reduction of FeO·V2O3and FeO·Cr2O3to carbides. The newly formed carbides are then dissolved in the γ(FCC) phase, and recovered accompanied with the metallic iron during magnetic separation.

Extraction of vanadium has been developed to extract vanadium from hydrochloric solutions with high concentration of iron ions. The effects of extraction conditions such as pH values, extraction time and extraction temperature on the distribution ratio of vanadium were investigated. The results showed that the distribution ratio of vanadium increased with the higher pH, the lower temperature and the longer equilibrium time. The distribution ratio reached 25 and the extraction ratio reached 96.2% by single stage extraction. When the organic phase was stripped with 2 mol/L hydrochloric acid at the phase ratio (O/A) 10:1, the vanadium stripping ratio of 98.3% could be achieved.

In the development of low-carbon economy, Shaanxi Province in many respects, such as the energy structure, level of social economic development and capital and technology are facing a series of challenges. But, in the meantime, in other respects, such as reductions in carbon emissions space, advantage of backwardness and rich natural resources etc, Shaanxi has the opportunity of developing low-carbon economy. Accordingly, Shaanxi should develop low carbon economy from the following aspects: optimize energy structure, vigorously promote energy conservation, low carbon technology, developing the tertiary industry and playing the advantage of solar and wind energy.

A planetary cylindrical roller traction drive was developed. It is comprised of a sun roller, three planet rollers, an outer ring, a planet carrier and an input shaft. The sun roller is hollow, and is connected through three segments of logarithmic spiral profile to the input shaft. As the input shaft rotates relative to the sun roller, a wedging action takes place between the input shaft and the sun roller; this makes the sun roller produce a certain amount of radial displacement, so an appreciable amount of normal load is thus generated between the rollers of the planetary traction-drive device. The greater the input torque is, the stronger the strength of the wedging action, and the greater the contact load, and vice versa; so this device is self-actuating. Here, as cylindrical rollers are used in the planetary traction-drive device, the spin motion as would present in the case that tapered rollers are used will not occur. This design offers an alternative way to solve the problem of self-adaptively loading of planetary cylindrical roller traction-drive devices.

Friction drives offer certain advantages over gears. In particular, they generally run more quietly and are easier to manufacture than geared units. The friction drives used in revolving stages call for a large driving radius in order to reduce friction force. In traditional friction drives, the two friction wheels (driving and driven) must be highly and precisely circular. This makes the manufacture of the driven wheel difficult and uneconomical. In this paper, a floating and self-actuating friction drive device was developed with the use of a swinging gearbox. In this device, the driving wheel is floatable, so the driven wheel is permitted to have certain deviation of roundness in the make and certain eccentricity in the installation. This avoids the difficulties in making and installing the driven wheel. This is a strong point in the applications of the revolving stage and other large-scale revolving devices. Meanwhile, this configuration can adaptively generate a normal torque on demand by using a swinging gearbox. This relieves the friction wheels of a continuous and high-stress load, thus prolonging their workability. Also, this paper described the working principles of this new friction drive device and presented a force analysis.

Module floorplanning/placement considering boundary constraints is practical and crucial in modern designs because designers may want to place some I/O involved modules along the chip boundary to minimize both chip area and off-chip connections. In this paper, a boundary information checking algorithm based on a general structure representation, called Generalized Polish Expression (GPE), is proposed. The algorithm, coupled with efficient perturbations in GPE, effectively produces solutions that satisfy both the boundary constraints and small chip area requirement. The experimental results have shown good performance from our approach on several commonly used MCNC benchmarks.