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The power consumption of ultrasonic anemometers in engineering application has always been too high, which could limit their application in the long-time field measurement for wind speed. To solve the above problem, an ultrasonic anemometer with low power consumption, which employs the time-difference method to measure wind speed, has been designed in this paper. The ultra-low-power microprocessor STM32L476 is adopted as the core processor and low-power chips are used extensively in peripheral circuits. The whole circuit consists of power circuit, ultrasonic wave transmitter, signal receiver and memory chip. Besides, it can work in both online mode and self-contained mode. Simultaneously, Kalman filter algorithms have been employed to reduce data errors. It has been indicated in many experiments that the anemometer has lower power consumption, as well as higher precision.

The mechanical properties of a new Fe41Co7Cr15Mo14Y2C15B6 bulk glassy alloy were studied by impact bending, compression, and hardness tests carried out at room temperature. The compressive fracture strength, elastic strain to fracture, Young’s modulus and Vickers hardness were measured to be 3.5 GPa, 1.5%, 265 GPa, and 1253 kg mm−2, respectively. The fracture mode of the glassy alloy under uniaxial compression is different from those of other bulk metallic glasses in that this fracture mode causes the samples to be broken, in an exploding manner, into a large number of micrometer-scale pieces. The fracture mechanisms of this bulk glassy alloy under bending and uniaxial compression are discussed based on the observation of the fracture surfaces. Vickers indentation tests indicate that the structure of the glassy ingot may be inhomogeneous.

Various forms of damage, such as cracks, breakages and dislocations of shield tunnel segments, exert negative effects on the structure stress during the operation of a tunnel. Based on the water gushing accident that occurred in a section of a shield tunnel between North Street Station and Wulukou Station of a Xi’an subway, the segment damage caused by water gushing and the sources of damage were analyzed through field investigation, ground penetrating radar (GPR) detection, ultrasonic crack detection and displacement monitoring. Two treatment schemes are proposed on that basis: the balloon injection for concrete structures (BICS) method was used in the treatment of segment cracks, while reinforcing steel mesh and high-performance polymer mortar were used to treat the dislocation. The evaluation indicates that the treatment plans have met the expectations. Thus, the treatments used for other similar engineering damages can be improved by the results of this study.

To analyze the temperature field of freeze-proof separate lining in cold-region tunnels, based on a tunnel on national highway number 307, the numerical model was established by the finite element software ANSYS, combined with the heat transfer theory using a cylindrical coordinate system. The change law of temperature field of the separate lining was investigated when the ventilation temperatures were -5 deg , -10 deg and -15 deg . The heat insulation effect of separate lining was also analyzed when the diameters of holes in the insulating layer were 5 mm, 10 mm and 15 mm, respectively. The results show that the temperature of lining and rock masses decreases gradually with the decrease of ventilation temperature and that the maximum temperature difference occurs in a closed air layer; considering that the temperature is still above 0 deg . When the ventilation temperature is -15 deg , the separate lining structure can protect the tunnel from freezing damage. The temperature field of the lining changes significantly if the diameters of holes in the insulating layer are large; the temperature of rock masses is -8.5 deg when the diameter is 15 mm, and the structure of the tunnel may suffer freezing damage. The tightness of the insulation layer has significant influence on the heat insulation effect of separate lining.

Transformation of conifer monoculture into mixed conifer—hardwood plantations has been considered as an efficient management practice to sustain forest productivity. However, effects of this management practice on ecosystem carbon sequestration are still unclear. In this study, seedlings of five hardwood species (Michelia macclurei, Castanopsis fissa, Castanopsis sclerophylla, Castanopsis kawakamii and Cyclobalanopsis myrsinaefolia) were planted separately under a Pinus massoniana (Pm) stand, and designated as Pm—Mm, Pm—Cf, Pm—Cs, Pm—Ck and Pm—Cm respectively. After 16 years of establishment, total ecosystem carbon increased by 18.0, 53.8, 25.2, 21.7 and 38.7 t ha-1 in the Pm—Mm, Pm—Cf, Pm—Cs, Pm—Ck and Pm—Cm stands respectively compared with Pm stand. Aboveground carbon storage increased from 97.72 t ha-1 in the Pm stand to 109.52, 131.31, 107.77, 115.76 and 123.37 t ha-1 in the five mixed stands respectively, greatly due to an increase in hardwood tree biomass. Mineral soil carbon stock (0—60 cm) was 55.0 t ha-1 in the Pm stand and 61.0, 72.4, 69.6, 58.6 and 66.8 t ha-1 in the five mixtures respectively. Our results suggested that stand improvement by underplanting could be proposed as forest management option for increasing ecosystem carbon sequestration. Langkah mengubah ladang monokultur konifer kepada ladang campur konifer dan kayu keras merupakan amalan pengurusan yang cekap untuk mengekalkan produktiviti hutan. Bagaimanapun, kesan amalan ini terhadap pensekuesteran karbon ekosistem masih belum jelas. Dalam kajian ini, anak benih lima spesies kayu keras (Michelia macclurei, Castanopsis fissa, Castanopsis sclerophylla, Castanopsis kawakamii dan Cyclobalanopsis myrsinaefolia) ditanam secara berasingan di bawah dirian Pinus massoniana (Pm). Dirian ini masing-masing diberi kod Pm—Mm, Pm—Cf, Pm—Cs, Pm—Ck, and Pm—Cm. Selepas 16 tahun, jumlah karbon ekosistem meningkat sebanyak 18.0 t ha-1, 53.8 t ha-1, 25.2 t ha-1, 21.7 t ha-1 dan 38.7 t ha-1 masing-masing di dirian Pm—Mm, Pm—Cf, Pm—Cs, Pm—Ck dan Pm—Cm. Simpanan karbon atas tanah meningkat daripada 97.72 t ha-1 di dirian Pm ke 109.52 t ha-1, 131.31 t ha-1, 107.77 t ha-1, 115.76 t ha-1 dan 123.37 t ha-1 masing-masing di dirian Pm—Mm, Pm—Cf, Pm—Cs, Pm—Ck dan Pm—Cm, terutamanya akibat pertambahan biojisim pokok. Stok karbon tanah ((0—60 cm) adalah sebanyak 55.0 t ha-1 di dirian Pm dan 61.0 t ha-1, 72.4 t ha-1, 69.6 t ha-1, 58.6 t ha-1 dan 66.8 t ha-1 di lima dirian campur itu. Keputusan kami mencadangkan bahawa penambahbaikan dirian secara tanam bawah dapat disyorkan sebagai pilihan pengurusan hutan bagi meningkatkan pensekuesteran karbon dalam ekosistem.

An Fe 41 Co 7 Cr 15 Mo 14 C 15 B 6 Y 2 bulk metallic glass with a diameter of 5 mm was prepared with the copper-mold-casting method. The corrosion resistance of this amorphous steel in sulfuric-acid solutions was determined by electrochemical measurements. The passive film formed on the surface of the alloy after immersion in the 0.5-mol/l H 2 SO 4 solution for 1 week was analyzed by X-ray photoelectron spectroscopy (XPS). Electrochemical measurements show that the corrosion resistance of the amorphous steel in the 1 mol/l-H 2 SO 4 solution is superior to a stainless steel (SUS 321), and is almost the same as Ti6Al4V, which shows that the amorphous steel has an excellent corrosion resistance in sulfuric-acid solutions. As the concentration of the sulfuric-acid solutions increases from 0.5 mol/l to 4 mol/l, the corrosion resistance of the amorphous steel decreases. The XPS result reveals that a bilayer structure of protective film formed on the surface of the amorphous steel in a H 2 SO 4 solution. The compositions of the inner part of the film are MoO 2 , Cr 2 O 3 , CoO, and FeO, and those of the outer film are MoO 3 , Cr(OH) 3 , Co(OH) 2 , and Fe(OH) 3 .

The effect of sodium N,N-diethyl dithiocarbamate (SDEDTC) on the corrosion of carbon steel in 0.5mol L hydrochloric acid (HCl) solution was studied using weight loss, potentiodynamic polarisation curves and impedance measurement methods. Experimental results revealed that SDEDTC acted as an inhibitor in acid environments. Moreover, the compound was a mixed-type inhibitor, acting predominantly as a cathodic inhibitor. Inhibition efficiency increased with increasing SDEDTC concentration at different temperatures. The corrosion inhibition mechanism of SDEDTC for carbon steel in HCl solution was also investigated by impedance techniques.

An Fe^sub 41^Co^sub 7^Cr^sub 15^Mo^sub 14^C^sub 15^B^sub 6^Y^sub 2^ bulk metallic glass with a diameter of 5 mm was prepared with the copper-mold-casting method. The corrosion resistance of this amorphous steel in sulfuric-acid solutions was determined by electrochemical measurements. The passive film formed on the surface of the alloy after immersion in the 0.5-mol/l H^sub 2^SO^sub 4^ solution for 1 week was analyzed by X-ray photoelectron spectroscopy (XPS). Electrochemical measurements show that the corrosion resistance of the amorphous steel in the 1 mol/l-H^sub 2^SO^sub 4^ solution is superior to a stainless steel (SUS 321), and is almost the same as Ti6Al4V, which shows that the amorphous steel has an excellent corrosion resistance in sulfuric-acid solutions. As the concentration of the sulfuric-acid solutions increases from 0.5 mol/l to 4 mol/l, the corrosion resistance of the amorphous steel decreases. The XPS result reveals that a bilayer structure of protective film formed on the surface of the amorphous steel in a H^sub 2^SO^sub 4^ solution. The compositions of the inner part of the film are MoO^sub 2^, Cr^sub 2^O^sub 3^, CoO, and FeO, and those of the outer film are MoO^sub 3^, Cr(OH)^sub 3^, Co(OH)^sub 2^, and Fe(OH)^sub 3^. [PUBLICATION ABSTRACT]