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Using low-cost nonprecious metals to replace Pt as hydrogen evolution reaction (HER) electrocatalyst is promising, but still limited by their efficiency and stability. Herein, with low-cost dicyandiamide and metal salts as precursor, FeCo alloy nanoparticles encapsulated in nitrogenated carbon nanotubes (FeCo-NCNTs) were facially synthesized as efficient HER electrocatalyst. Addition of iron as second element, though not facilitating the formation of carbon nanotube, was utilized to improve the physicochemical properties of metals. Via optimizing the atomic molar ratios of Fe/Co nanoparticles, the optimal Fe0.4Co0.6-NCNTs with thin carbon shell (c.a. 5–10 layer) and equally distribution of embedded alloy nanoparticles was found with outstanding HER activity. To achieve a current density of 10 mA cm−2, only overpotential of 50 mV, 157 mV and 202 mV were needed in acidic (0.5 M H2SO4), alkaline (1 M KOH), and neutral solutions. Its higher electrochemically active surface areas and lower electron transfer resistance may contribute to the excellent electrocatalytic HER. Furthermore, the illustrated current density slightly changed over 20 h, suggesting excellent stability. Hence, the present method provides cost-effective, high efficiency, and stable materials in developing the sustainable energy conversion systems.

Seat suspension is one of a most important part of a vehicle, also it significantly affects the comfortableness of cars. Compared with traditional dampers, magneto-rheological ones can achieve the condition with continuous adjustable damping force. Compared with electro-rheological fluid, magneto-rheological ones have some merits including noise defending, large damping forces and fast response etc. Based on magneto-rheological dampers, the structural parameters were calculated and characteristic test was conducted. Constant amplitude of 5mm and frequency of 1hz were applied. As the current was respectively changing, the peak of damping forces changed correspondingly. In order to figure out a model, which can illustrated the influence of damping force on current, researchers also identify the magneto-rheological dampers using support vector regression. In this paper, research related with fuzzy control of seat-suspension system has been done by using a Matlab simulation model, so as to verify the damping forces can be adjustable and it has priority on vibration attenuation.

Actuator is a very important part of vehicle active control suspension. Based on the analyses of traditional passive suspension and active suspension system, a novel vehicle active suspension with Electro-Hydrostatic Actuator (EHA) is put forward. The system consists of two parts: spring and actuator with variable control force. The actuator includes hydraulic cylinder, hydraulic pump, controller, etc. According to bond graph principle, bond graph model of EHA active suspension are built. In addition, sky-hook controller and fuzzy logic controller are designed and sky-hook control and fuzzy control active suspension are simulated using MATLAB tools. The prototype and test rig of EHA active suspension are developed and bench tests are carried out. The simulation and experimental results show that sky-hook control and fuzzy control active suspension with EHA provide better ride comfort and stability than passive suspension system.

A wide variety of unusual mantle has been reported from podiform chromitite orebodies Cr-31 and Cr-74 in the Luobusa (罗布莎) ophiolite, Tibet. A detailed investigation of chromitite orebody Cr-11, located in the Kangjinla (康金拉) district at the eastern end of the ophiolite, has revealed many of the same minerals, including diamond, moissanite, and some native elements, alloys, oxides, sulphides, silicates, carbonates, and tungstates. This orebody is particularly rich in diamonds, with over 1 000 grains recovered from about 1 100 kg sample of chromitite. More detailed studies and experiments are needed to understand the origin and significance of these unusual minerals because they have not been found in situ. It is a great breakthrough in mineralogical research that we have picked up more than 40 kinds of minerals from the Kangjinla chromite deposit in Luobusa. It is notable that a large amount of diamonds were firstly discovered from the Kangjinla chromite deposit as well as many other unusual minerals, such as moissanites, rutiles, native irons, and metal alloys. Especially, that diamond was found again in different chromitites in the same ophiolite belt provided new key evidence for discussing the origin of the diamond and the hosted chromitite and ophiolite. The mantle mineral group in Tibet has great significance in mineralogy and geodynamics.

An unusual group of mantle minerals including about 70–80 species has been recovered from podiform chromitites of the Luobusa ophiolite, Qusong County, Tibet, China. All of the minerals were hand picked from heavy mineral separates of the chromitite. The minerals include diamond, coesite, moissanite, wustite, intermetallic compounds, Os-Ir alloys with diamond inclusions, Fe-silicides, and a new mineral, qusongite. Qusongite is associated with chromian chlorite, calcite, (W,Ti)C and (Ti,W) C alloys, and chromite. It occurs as angular grains generally 4–8 μm in diameter, but some are as large as 0.2 × 0.3 × 0.25 mm. The grains are opaque and steel-gray with a metallic luster and grayish-yellow reflection. The empirical formula (based on 2 atoms) is W 1.006 Cr 0.02 C 0.992 , and the simplified formula is WC. Qusongite has a hexagonal structure and belongs to space group P 6 m 2, with a = 2.902(1) A, c = 2.831(1) A, c:a = 0.9775, V = 20.05 (1) A 3 , Z = 1.

Yarlongite occurs in ophiolitic chromitite at the Luobusha mine (29°5′N 92°5′E, about 200 km ESE of Lhasa), Qusum County, Shannan Prefecture, Tibet Autonomous Region, People's Republic of China. Associated minerals are: diamond, moissanite, wustite, iridium (“osmiridium”), osmium (“iridosmine”), periclase, chromite, native iron, native nickel, native chromium, forsterite, Cr-rich diopside, intermetallic compounds Ni-Fe-Cr, Ni-Cr, Cr-C, etc. Yarlongite and its associated minerals were handpicked from a large heavy mineral sample of chromitite. The metallic carbides associated with yarlongite are cohenite, tongbaite, khamrabaevite and qusongite (IMA2007–034). Yarlongite occurs as irregular grains, with a size between 0.02 and 0.06 mm, steel-grey colour, H Mohs: 5½–6. Tenacity: brittle. Cleavage: {0 0 1} perfect. Fracture: conchoidal. Chemical formula: (Cr4Fe4Ni)Σ9C4, or (Cr,Fe,Ni)Σ9C4, Crystal system: Hexagonal, Space Group: P63/mc, a= 18.839(2) A, c= 4.4960 (9) A, V= 745.7(2) A3, Z= 6, Density (calc.) = 7.19 g/cm3 (with simplified formula). Yarlongite has been approved as a new mineral by the CNMNC (IMA2007–035). Holotype material is deposited at the Geological Museum of China (No. M11650).

The crystal structure of the natural 33R moissanite, recovered as inclusions in chromitites from Luobusa harzburgite in Tibet, was determined from X-ray diffraction data collection by a Nonius CAD-4 four-circle diffractometer. The crystal is trigonal in symmetry with a space group of R3m. Identical to the synthetic specimen, the cell parameters are a = 3.076, c = 83.12 Å for the natural sample. Full-matrix least-squares refinement of the structure, including anisotropic displacement parameters, gave the final R factor of 4.80%. The bond angles and tetrahedral angle variance of the present crystal structure show that the tetrahedra are quite regular in geometry. The distance between two adjacent c double layers, 2.517 ± 0.001 Å, is slightly shorter than the average h–c distance of 2.523 ± 0.001 Å. With 36% hexagonal double layers, the present 33R moissanite is inferred to crystallize at high temperature condition and thus come from a depth beneath Earth’s crust. The structure refinements of this work indicate that the present moissanite exhibits smaller thermal displacement parameters. Most of the Si—C bond distances parallel to the c axis are longer than other distances. This result as well as longer bond distances of Si—C along c axis may be indicative of a weaker covalent bonding force along this direction.

Silicon(Si)-rutile separated from the Luobusa podiform chromitite in the Yarlung Zangbo ophiolite of southern Tibet is typically about 50 µm × 50 µm × 200 µm in size and consists mainly of SiO2 and TiO2. The average mineral formula is (Ti0.82Si0.18)O2. Powder X-ray diffraction data show that it is tetragonal in form, and the unit cell dimensions and other parameters are: a = 4. 591(2)A, c = 2.946 (2)A, v = 62.09(5)A3, c/a = 0.6415, with a molar volume about 5% smaller than rutile (JCPDS, 21–1276). The Si4+ ions in silicon rutile are six-coordinated, and are substituted for Ti4+ in the rutile structural sites. The Si-rutile, along with other associated ultra-high minerals discovered in the chromitite, such as octahedral silicate, silicon-magnesium spinel (Si4+ ions are six-coordinated), diamond, and intergrown of SiO2 and FeO phases, probably originated from the transition zone or the lower mantle, and were brought to shallow levels beneath an oceanic spreading ridge by an upwelling superplume.

PGE and base-metal alloy minerals from podiform chromitites of the Luobusa ophiolite, southern Tibet include Os–Ir, Os–Ir–Ru, Pt–Fe, Ir–Ni–Fe, Fe–Ni–Cr, and Fe–Co with highly variable compositions. Small amounts of diamond, graphite, SiC, an unnamed chromium carbide, iron silicide (Fe–Si), and native Fe, Ni, Cr, Au, Cu and Si also are present. The alloys and native elements were recovered primarily from heavy-mineral separates of the chromitites, but some are included in, or attached to, magnesiochromite grains. They are mostly subhedral to anhedral and range in size from about 0.05 to 0.5 mm. Some grains have euhedral crystal forms and others have round shapes, suggestive of melt droplets. Fe–Ni-bearing, Ru-rich PGE alloys, Fe–Ni and Fe–Co alloys and native Fe and Ni in the Luobusa chromitites are interpreted as secondary minerals formed by alteration of PGE sulfides. The Pt–Fe, Os–Ir, and Ir–Ni–Fe alloys, Fe silicide and perhaps the native Si are considered to be xenocrysts from the mantle, transported to shallow depths by a rising plume and then captured by the melts from which the Luobusa chromitites crystallized.

The Luobusa ophiolite of the Yarlung–Zangbo (southern Tibet) suture zone and the Donqiao ophiolite of the Bangong–Nujiang (northern Tibet) suture zone are allochthonous bodies that contain possibly diamond-bearing mantle peridotites and podiform chromitites. The mantle sections in both massifs consist chiefly of harzburgite and diopside-bearing harzburgite with abundant lenses of dunite and chromitite. These ultramafic rocks are more strongly depleted than typical abyssal peridotites and their whole-rock and mineral chemistries suggest formation above a subduction zone. An unusual mineral association (diamond, SiC, graphite, native chromium, Ni–Fe alloy, Cr2+-bearing chromite), indicating a high-pressure, reducing environment, occurs in both the peridotites and chromitites. We suggest that these ophiolites were generated originally in a suprasubduction zone environment and were later carried deep into the mantle along a second subduction zone, at which time the diamonds and other high-pressure minerals were formed. It is not yet clear whether the diamonds formed by high-pressure metamorphism of the oceanic crust or by crystallization from mantle melts, but their occurrence in chromitites and harzburgites suggests a metamorphic origin. During the collision of India with the Eurasian plate, the mantle sections were tectonically emplaced at shallow crustal levels rapidly enough to preserve the diamonds.

Diamonds and other ultrahigh pressure (UHP) minerals have been reported previously from the Luobusa ophiolite of Tibet, but these minerals have thus far been found only as individual grains. Here we report the occurrence of diamond as an inclusion in OsIr alloy and coesite as part of a silicate assemblage rimming a grain of FeTi alloy, both of which were recovered from chromitite. These occurrences confirm the presence of UHP minerals in the Luobusa chromitite requiring minimum pressures of ∼2.8–4 GPa. Individual coesite “crystals” have external form similar to that of stishovite and are polycrystalline, suggesting pseudo morphic replacement and implying a pressure >9 GPa. We propose that the UHP minerals were incorporated into the chromitites in the deep upper mantle or that they have an impact origin; the preponderance of evidence favors the former.