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The underhand cut-fill backfill mining manner (UCFBMM) is widely employed in nonferrous metallic mines, and stability of the artificial backfill top plate directly determines the safety of operators and equipment, which puts forward higher requirements on fill's bending properties. The purpose of the current research is to advance steel-fiber reinforced cemented tailings backfills' (SFCTBs') mechanical features by employing steel fibers. 17 groups of specimens were prepared by considering the effects of diverse steel fiber doping and magnetic induction strength on SFCTB's bending properties. Steel fiber reinforced SFCTB's bending evolution was studied by utilizing three-point bending tests, SEM interpretations, and X-ray computed tomography. Lab findings exhibited that directional distribution of steel fibers was effective in increasing SFCTB's flexural strength, and the flexural strength was positively correlated with fiber doping and magnetic induction strength. The presence of steel fibers and their directional distribution well inhibited crack development, and thus the crack resistance and toughness of SFCTBs, enabling them to bear greater tensile force. The unadulterated steel fiber reinforced SFCTBs showed sudden fracture when reaching the peak load, while the steel fiber adducted SFCTB specimens showed the characteristics of good ductility. Due to gravity and magnetism, steel fibers were distributed at the bottom of SFCTBs and showed a directional distribution along the length of the specimens. Besides, SFCTBs produced further CSH-gels and Aft in process of hydration. The overall outcomes of the current study could run an academic guide to construction of artificial backfilling roofs in UCFBMM in terms of cost and operational stages. • The magnetic induction intensity effect of cemented tailings backfill (CTB) was considered in three-point bending test. • Fiber's directional distribution has a significant impact on increasing steel fiber CTB's flexural strength. • The presence of steel fibers and their directional distribution well inhibited crack development. [ABSTRACT FROM AUTHOR]

How do neuronal subtypes emerge during development? Recent molecular studies have profiled existing neuronal diversity, but neuronal subtype genesis remains elusive. The 15 types of mouse retinal bipolar interneurons are characterized by distinct functions, morphologies, and transcriptional profiles. Here, we develop a comprehensive spatiotemporal map of bipolar subtype genesis in the murine retina. Combining multiplexed detection of 16 RNA markers with timed delivery of 5-ethynyl uridine (EdU) and bromodeoxyuridine (BrdU), we analyze more than 30,000 single cells in full retinal sections to classify all bipolar subtypes and their birthdates. We find that bipolar subtype birthdates are ordered and follow a centrifugal developmental axis. Spatial analysis reveals a striking wave pattern of bipolar subtype birthdates, and lineage analyses suggest clonal restriction on homotypic subtype production. These results inspire a hierarchical developmental model, with ordered subtype genesis within lineages. Our results provide insight into neuronal subtype development and establish a framework for studying subtype diversification. [Display omitted] • Birthdates of retinal bipolar subtypes are patterned across space and time • Subtype birthdate patterns are consistent with a hierarchical genesis model • Late retinal lineages are biased against homotypic bipolar subtype production West et al. employ multiplexed detection of RNA markers to map the precise locations and birthdates of all bipolar interneuron subtypes in mouse retinal sections. They discover patterns among subtype birthdates in space and time and that retinal lineages are biased in subtype composition, together suggesting hierarchical development of subtype diversity. [ABSTRACT FROM AUTHOR]

Abstract: The effect of synthetic diesel fuel made from natural gas (Gas to Liquid, GTL) on the engine performances (such as power, efficiency and emission) was carried out on one Euro III common rail (CR) heavy duty (HD) diesel engine without any modification. The results showed that the engine fueled with GTL had some variations compared with the one fueled with petroleum-based low sulfur diesel fuel (sulfur content less 50ppm). The maximum torque and power were decreased by 1.3% and 1.9%, respectively. The specific fuel consumption increased in volume but had no change in mass. Under the load characteristics, the NOx, CO and THC were reduced by 13%, 55% and 55%, respectively. During the ESC cycle test, the NOx, CO, THC and PM were reduced by 5.2%, 19.3%, 19.8% and 33%, respectively. [Copyright &y& Elsevier]

Abstract: Gas-to-liquids (GTL) as an alternative to diesel is considered to be one of the technical options to reduce petroleum consumption in the on-road transportation sector. Between May and August 2007, a joint demonstration program by Tsinghua University, Beijing Transit, Cummins Corporation and Shell Corporation was carried out in Beijing. The program focused on the supply systems and vehicle use of GTL fuel. The demonstration fleet was formed by four transit buses fueled with GTL and four with diesel. It was demonstrated that GTL has good compatibility with diesel in terms of fuel supply system and vehicle use. This paper compares the energy consumption and GHG emissions of diesel and GTL fuel supply chains by life cycle analysis based on demonstration results. The results indicate GTL’s large range (reported 54–70%) in synthesis efficiency, as the key factor in determining energy consumption and GHG emissions within the GTL fuel supply chain. For the probable case (GTL synthesis efficiency: 65%), the life cycle energy consumption and GHG emissions of GTL fuel are 42.5% and 12.6% higher than that of diesel. For two sensitivity analysis cases (GTL synthesis efficiency: 54% and70%), energy consumptions are 74.2% and 31.2% higher and GHG emissions are 27.3% and 7.4% higher than that of the diesel fuel supply chain. If the efficiency of the GTL synthesis process is improved to 75%, then the GHG emissions level of the GTL fuel supply chain can be reduced to the same level as the diesel fuel supply chain. [Copyright &y& Elsevier]

This paper is to present a test platform for automotive fuel cell systems and report some test results on this platform. The test platform was developed based on a test bed of internal combustion engine with a dynamometer, the dynamometer acted as both a load and a measurement instrument. A fuel cell engine, a DC/DC converter and an induction traction drive motor with a DC/AC inverter were integrated to a system and were tested in the platform. Test results of one fuel cell system showed that the efficiency was 41% (LHV) while 50 kW of electrical power is produced in the engine; the cell current density was 400 mA/cm2 when 0.65 V of average cell voltage is obtained in the stacks; the maximum mechanical power of the fuel cell system was 41 kW, and the best specific fuel consumption was 102 g/kWh. This test platform is feasible for evaluating all components of fuel cell systems, such as stacks, parasitic powers, engines, DC/DC converters and traction drive motors; and in this platform it is convenient to uncover problems of electromagnetism compatibility in the fuel cell systems before being mounted into vehicles. [Copyright &y& Elsevier]