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When a penetrator with enhanced lateral effect (PELE) impacts on a reinforced concrete (RC) target, the target is damaged with a large opening. An understanding of how PELE projectile parameters affect the opening dimension, is essential for effective design of the PELE projectile. In this study, under the condition that the impact velocity and target parameters (strength and thickness) were fixed values, the important influence factors of the PELE (jacket wall thickness B, jacket material strength Y 1 , filling material strength Y 2 and angle of monolithic jacket θ) were determined by a dimensional analysis. Tests and simulations of the PELE penetrating the RC target were conducted to analyze the influence of these factors on opening diameter ( D ¯ , an equivalent diameter under relative kinetic energy). Based on the test and simulation results, it is found that the influence of these factors B, Y1 and θ on the deformation mode of the jacket shows a similar trend: as values of the three factors decrease, the jacket deforms from small bending deformation to large one, and then to curling deformation. This causes the opening diameter to first increase with the decrease of these three factors, and then decreases. It is well known that the bending resistance of the jacket is related to these factors B, Y1 and θ. Therefore, a plastic limit bending moment (M0) of the jacket was quoted to characterize the influence of these factors on the bending deformation of the jacket and the opening diameter of the target. The influence factor Y 2 causes D ¯ to first increase with the increase of Y 2 , and then decreases. A formula was developed to predict the opening diameter, whose influence parameters were considered in a dimensionless way. It has been shown that the dimensionless opening diameter D ¯ / d 1 is dependent on two dimensionless parameters Q = d 1 3 f c M 0 and G = f c Y 2 , where d 1 and f c are the outer diameter of the projectile and the compressive strength of the target, respectively.

Impact velocity (v0), target strength (fc) and target thickness (hc) are important factors affecting opening damage ( D ¯ ) of PELE penetration into RC target. In this paper, based on the three influence factors of v0, fc and hc, experimental and numerical simulation studies on PELE penetration into RC target were carried out. The study results show that: (1) Since interaction force (or penetration resistance) between projectile and target is positively correlated with v0 and fc, with the increase of v0 and fc, deformation mode of jacket is changed from small bending deformation to large bending deformation and then to curling deformation. Therefore, the variation of jacket deformation mode causes opening diameter of RC target to increase first and then to decrease. It is found that the two factors approximately satisfy a quadratic function relationship, respectively. (2) For PELE projectile penetrating RC targets with thickness of 80–400 mm, the opening diameter of six sets of RC targets grows from 240 to 500 mm, and hc with D ¯ approximately satisfy a linear relationship. (3) Based on the above study results, the relationship between two dimensionless parameters ( I = m v 0 2 d 1 3 f c and H = h c l ) and dimensionless opening diameter ( D ¯ / d 1 ) was determined. Combined with the results of previous research, a dimensionless opening diameter model D ¯ d 1 = f 1 ( Q , G , I ) f 2 ( H ) was established. By tests verified, the test results are all within ±10% error of the theoretical model, which verifies the accuracy of the model.

A new aerotolerant strain of Clostridium beijerinckii LY-5 was isolated from the pit mud of the Chinese Baijiu-making process for butanol production. Plackett-Burman design and artificial neural network were used to optimize the fermentation medium and a total of 13.54 ± 0.22 g/L butanol and 19.91 ± 0.52 g/L ABE were attained under aerotolerant condition. Moreover, distillers' grain waste (DGW), the main by-product in the Baijiu production process, was utilized as potential substrate for butanol production. DGW was hydrolyzed by α-amylase and glucoamylase and then fermented after a detoxifying process of overliming. Butanol and ABE concentrations were 9.02 ± 0.18 and 9.57 ± 0.19 g/L with the yield of 0.21 and 0.23 g/g sugar, respectively. The higher ratio of butanol to ABE might be caused by the inhibitors in DGW medium affecting the metabolic pathways of C. beijerinckii LY-5 and approximately 1.48 ± 0.04 g/L isopropanol was found at the end of fermentation. This work highlights the feasibility of using DGW as a promising feedstock for butanol production by a new aerotolerant strain of C. beijerinckii LY-5, with benefit to the environment.

The nature of source rocks and the pressure-temperature-hydration (P-T-H2O) condition are the two main factors that control the geochemical properties of granites. Therefore, the evolution of P-T-H2O conditions can be used to deduce the tectonic setting of granites. In this paper, we report on three Paleozoic granite plutons along the Shangdan suture that revealed increasing melting temperature and decreasing pressure from 437 to 403 Ma, suggesting a crustal thinning process. The Tieyupu granodiorites (437 ± 4 Ma) display Na-rich adakite affinity, i.e., SiO2 = 69.1–70.1 wt%, Na2O/K2O = 1.9–2.26, positive zircon εHf(t) values (+4.29 to +12.04), and high Sr/Y (137–160) and Y/Yb (9.89–10.25) ratios, implying a garnet-rich residue in their source. In combination with moderate zircon saturation temperatures (814–822 °C), we infer that the Tieyupu granodiorites were formed by melting of Neoproterozoic metabasites under high-pressure (>1.5 GPa) and moderate-temperature (HP-MT) conditions. The Liangchahe granodiorites (415 ± 8 Ma) also display Na-rich adakite affinity, i.e., higher Na2O/K2O (2.16–3.11) and lower Sr/Y (77–88) ratios, and higher zircon saturation temperatures (854–874 °C), and they are interpreted to have been derived from melting of metabasites under moderate-pressure (>1.0 GPa) and high-temperature (MP-HT) conditions. Their variable zircon εHf(t) values (−14.97 to +9.80) and the existence of zircon xenocrysts suggest that the primitive adakitic melts were assimilated by evolved crustal components. The Yaogou monzogranites (403 ± 4 Ma) have the highest K2O/Na2O (0.81–1.00) ratios and total rare earth element (ΣREE; 105–191 ppm) contents, lowest Sr/Y (14–43) ratios, positive zircon εHf(t) values (+6.79 to +12.22), and highest zircon saturation temperatures (891–973 °C), showing they were formed by high-temperature melting of intermediate rocks under low-pressure conditions (

The Early Cretaceous granitoids are widely distributed in the southern North China Craton (NCC), petrogenesis of these rocks is critical to understanding the implications for the Early Cretaceous g...

Anaerobic digestion effluent (ADE) from the anaerobic digestion treatment of citric acid wastewater can be reused as a potential substitute for process water in the citric acid fermentation. However, excessive sodium contained in ADE significantly decreases citric acid production. In this paper, the inhibition mechanism of sodium on citric acid fermentation was investigated. We demonstrated that excessive sodium did not increase oxidative stress for Aspergillus niger, but reduced the pH of the medium significantly over the period 4–24 h, which led to lower activities of glucoamylase and isomaltase secreted by A. niger, with a decrease of available sugar concentration and citric acid production. ADE was pretreated by air-stripping prior to recycle and 18 g/L calcium carbonate was added at the start of fermentation to control the pH of the medium. The inhibition caused by ADE was completely alleviated and citric acid production substantially increased from 118.6 g/L to 141.4 g/L, comparable to the fermentation with deionized water (141.2 g/L). This novel process could decrease wastewater discharges and fresh water consumption in the citric acid industry, with benefit to the environment.

To enhance the heat dissipation of high-power light-emitting diodes (LEDs), corona wind based on corona discharge was promoted. In this paper, we aimed at reinforcing the intensity of corona wind by modifying the needle electrode with graphene solution. To explore the differences in the graphene-coated electrode and the original bare electrode on the electrical characteristics, the intensity of corona wind, and LED heat dissipation, a corona wind cooling system and a thermal test system were built for the experimental study. The results showed that the graphene-coated electrode system could produce corona wind at a lower voltage. In addition, the discharge current of the graphene-coated electrode system is higher than that of the bare electrode system under the same discharge voltage. The graphene-coated electrode system can induce a faster corona wind and the highest speed is about 3.4 m/s, showing that it is more efficient than the bare electrode system in corona wind production. Moreover, the temperature drop of LEDs for the graphene-coated system is greater, which means that the corona wind cooling system can reduce the junction temperature of the LED chips effectively. Ultimately, as the discharge power increases, the average convective heat transfer coefficient increases. Indeed, the result of this paper can be used for the wide variety of the graphene-coated corona wind generator application as a promising technology for the LED heat management.

This article presents a model to characterize the lateral expansion of metal cylinder expanded by polymer filler and analyzes the influencing factors to the expansion. Based on the elastoplastic th...

Two semi-crystalline polymers: polyethylene and polyamide 66 are selected for experiments over a wide range of strain rates (10−2–1 s−1 and 1000–4000 s−1) at indoor temperature. The Young modulus a...

The constant strain rate loading and dynamic stress equilibrium are prerequisites for ensuring the experimental data of the Split Hopkinson Pressure Bar (SHPB). In order to achieve this requirement, a proper pulse shaper dimensions were used in the experiment. For this purpose, the pulse shaper diameter, thickness and strength and the strike bar length and its velocity on the incident pulse are studied by ∅80mm SHPB apparatus. Then, the parameters affecting the two key inflection points and three loading areas of the incident pulse are discussed. In addition, the improved methods for two typical non-constant strain rate waveforms for the concrete experiments are obtained based on the regular pulse shaping. Moreover, SHPB experiments are conducted for concrete by employing different pulse shaper dimensions. The results show that more valid data can be obtained by employing the pulse shaper with large thickness when the strain rate is non-constant during the experiment. The conclusions and method provide guidance for selecting pulse shaper for concrete SHPB experiments.

High heat flux electronics have encountered difficulties in thermal management. There are some shortcomings in traditional cooling methods. Ionic wind cooling technology based on electrohydrodynamic (EHD) has unique advantages. There are by-product hazards and speed raising limits in the reported ionic wind generators. An electromagnetic field and nanomaterials improved ionic wind cooling system is designed for environment-friendly improvement and thermal management application. The proposed cooling system is optimized experimentally to increase the ionic wind intensity and reduce ozone generation. The results indicate that adding a magnetic field changes the movement trajectory of charged particles and thus regulates the distribution of the flow field. In the macroscopic sense, the ionic wind intensity is also improved, and the greater the magnetic flux density is, the more obvious the effect is. A maximal improvement of 58.6% was obtained. The ionic wind velocity increases by 0.71 m/s due to the synergistic effect of a magnetic field. Meanwhile, the O3 concentration decreased by more than 95% using both the magnetic field and the carbon nanotubes. When the cooling system is applied to a high-power light-emitting diode (LED) chip for thermal management, the cooling effect is remarkable. The results provide an important theoretical basis for the application of EHD technology in the thermal management of electronic devices.

Miniaturization has become the development trend of light-emitting diodes (LEDs), which results in a significant increase in heat flux production and operating temperature. The accumulated heat should be dissipated effectively to ensure that the chip can work properly. The conventional cooling techniques have now reached their limits in heat removal rates. A new cooling device coupled thermoelectric cooling (TEC) with corona wind cooling (CWC) was proposed and optimized experimentally based on the second law of thermodynamics and the principle of entropy generation minimization. The results indicate that a better cooling effect and a high coefficient of performance value is obtained by turning on the TEC near the heat source firstly and adjusting the CWC power at the hot side. Increasing the input power of TEC and keeping the total cooling power unchanged, another 4.7% improvement is obtained with the highest heating power of 14 W. The target temperature can be maintained at an acceptable level (＜80 °C) if the TEC and CWC are well coupled. However, the coupling effect between TEC and CWC will be worse when the input power is large. A higher output luminous flux will be obtained when the LED chip works in the constant current mode due to the good coupling between CWC and TEC. The luminescence intensity and chromaticity properties are improved significantly. The principal component analysis (PCA) also indicates excellent comprehensive performance. The results verify the feasibility of a novel cooling device coupled TEC with CWC in cooling high heat flux electronics.

A penetrator with enhanced lateral effects (PELE), which is a particular thin-walled structure, is characterized by a low-density filling material surrounded by a high-density jacket material. When the PELE projectile penetrates a concrete target, the target is destroyed by its thin-walled jacket to a large opening. An analytical model describing deformation mode of the jacket during the penetration process is presented. Due to opening diameter of target plate is larger than projectile diameter under condition of a thin concrete target, a relationship between opening diameter of target plate and projectile diameter, based on existing experimental results of ridge projectile penetrating thin concrete target, is formulated. The relationship combined with the analytical model is used to predict opening diameter of concrete target. A quantitative comparison between the jacket deformation mode obtained from analytical results and experimental results is made to validate the accuracy of the analytical model proposed. As a result, the analytical results exhibit good correlation with experimental observations in terms of the opening diameter of target plate and the deformation mode of projectile jacket. In addition, the influence mechanism of three factors (jacket strength, impact velocity, and target thickness) on the opening diameter is analyzed. The jacket strength affects the opening diameter by changing the plastic limit bending moment of the jacket. Even though the impact velocity affects the opening diameter by changing the interaction force between the jacket and the target, it is equivalent to indirectly changing the jacket strength. However, the target thickness affects the opening diameter by changing the penetration time.

Geochemical variations in granitic rocks may be controlled by their source rocks, melting reactions and subsequent magmatic processes, which resulted from various geodynamic processes related to subduction, collision, or slab break-off. Here we report new LA–ICP-MS zircon U–Pb ages and Hf isotopes, whole-rock chemistry and Sr–Nd isotopes for the late Early Cretaceous quartz diorite, granodiorite and monzogranite in the Gaoligong belt, southeastern Tibet Plateau. The zircon U–Pb dating yield ages of 113.9 ± 1.6, 111.7 ± 0.8, and 112.8 ± 1.7 Ma for the quartz diorite, granodiorite, and monzogranite, respectively, which are coeval with bimodal magmatism in the central and northern Lhasa sub-terrane. There are the distinct sources regions for the quartz diorite and granodiorite–monzogranite association. The quartz diorites are sodic, calc-alkaline and have high Mg# (52–54) values. They also have elevated initial 87Sr/86Sr (0.707019 to 0.709176) and low eNd(t) (− 5.16 to − 7.63), with variable zircon eHf(t) values (+ 5.65 to − 9.02). Zircon chemical data indicate a typical crustal-derived character with high Th (142–1260 ppm) and U (106–1082 ppm) and moderate U/Yb ratios (0.30 to 2.32) and Y content (705–1888 ppm). Those data suggest that the quartz diorites were derived from partial melting of ancient basaltic lower crust by a mantle-derived magma in source region. The granodiorite–monzogranite association has high-K calc-alkaline, weakly peraluminous characters. They show lower Nb/Ta (5.57 to 13.8), CaO/Na2O (0.62 to 1.21), higher Al2O3/TiO2 (24.4 to 44.4) ratios, more evolved whole-rock Sr–Nd and zircon Hf isotopic signatures, all of which suggest derivation from mixed basaltic and metasedimentary source rocks in a deep crustal zone. We propose that the granitic magmatisms at ca. 113–110 Ma in the Gaologong belt was triggered by the slab break-off of Bangong–Nujiang Tethyan oceanic lithosphere.

The Tengchong Block of Southwestern China is key to tracing the eastward subduction of Neo-Tethys and collision between Indian and Asian continents. The block contains a magmatic belt that represents the southeastward continuation of the Gangdese belt, produced by the eastward subduction of eastern Neo-Tethyan oceanic lithosphere. In this paper we present geochemical and geochronological data of Late Cretaceous to Early Paleocene (~ 64 Ma) granitic rocks of the Guyong and Husa batholiths in the Tengchong Block. These can be subdivided into high-silica peraluminous granites and low-silica metaluminous granodiorites, and all belong to the high-K calc-alkaline series, are enriched in LILE, and depleted in HFSE. The Guyong granitoids have high initial Sr ratios of 0.706511–0.711753, negative e Nd (t) values of − 9.2 to − 11.6, two-stage model ages of 1.39–1.55 Ga, and Pb isotopic compositions that indicate a crustal affinity. The Husa granodiorites also have high initial Sr ratios of 0.716496, negative e Nd (t) value of − 16.5, two-stage model age of 1.89 Ga, variable e Hf (t) values of 3.4 to − 18.1 and Pb isotopic compositions similar to lower crustal values. These geochemical and isotopic data indicate that the Guyong granitoids were likely derived from partial melting of ancient crustal metapelite or mixed pelite-greywacke sources, while the Husa granodiorites were derived from the partial melting of lower crustal mixed sources involving metasedimentary and metaigneous rocks. To understand the thermal state and architecture of the Late Cretaceous to Early Paleocene magmatic arc crust, the crust-derived intermediate to acidic igneous rocks of the southern-central Lhasa and Tengchong blocks and eastern Himalayan syntaxis are compared. We infer that partial melting of crust occurred at great depth in the southern Lhasa Block, intermediate depths in the eastern Himalayan syntaxis, and shallow depths in the central Lhasa and Tengchong Block. Sr/Y ratios indicate that the Tengchong Block was characterized by thin crust, while the eastern Himalayan syntaxis and northernmost part of southern Lhasa Block contained crust of normal thickness, and the southernmost part of the southern Lhasa Block contained thickened crust.

Ionic wind technology is a right candidate for the thermal management of electronic devices. However, some highly-oxidizing substances are produced during corona discharge, which can destroy the electrode and shorten its service life. In the present work, nanomaterials were coated on the surfaces of needles, which act as emitting electrodes. The generation characteristics of ionic wind and the working durability of an ionic wind generator (IWG) were compared experimentally. The generator modified by nanomaterials was subsequently used to cool high-power LED chips, and the changes in the optical properties of the chips were studied. The results indicate that the electric field intensity and corona current increased after the application of the nanomaterials. The nanomaterials-decorated IWG performed better in operating durability than the original prototype. When the nanomaterials-decorated IWG was applied to cool LEDs, the case temperature at a discharge power of 3 W was reduced by 5.8 °C compared with the original generator. The luminous flux output increased by 28 lm and took less time to reach a stable working state. The ionic wind velocity and the energy conversion efficiency of the system were also greatly improved. This study provides a potential solution for the efficient thermal management of electronic devices.

The performance of a heat dissipation system that consists of a thermoelectric cooler (TEC) and corona wind generator is investigated. The combined thermoelectric cooling and corona discharge power on the system performance are explored via experiment and analytical analysis. The corona wind cooling system is optimized to achieve a higher corona wind velocity. Utilizing the TEC operating temperature, corona wind velocity, and power consumption, the study reveals that the proposed cooling system efficiency can be improved with an increase in these physical parameters. However, its performance reaches an optimal value once the Fourier conduction became a dominate factor when compared to the Peltier and Joule heating effects within the semiconductor elements of a TEC. Considering the cooling effect and power consumption, the optimal TEC and corona discharge power are determined to both be 1 W. The COP value of the proposed coupling system and the decrease of temperature are found to increase by 39.5% and 40%, respectively, indicating that the cooling efficiency of the system is improved after coupling. The knowledge gained from this study will provide a better understanding of various system parameters, including cooling temperature, power consumption and flow velocity in thermal management technology, as they are closely related in the field of electronic cooling system design.

SUMMARY Avian tuberculosis is a contagious disease affecting various domestic and wild bird species, and is caused by Mycobacterium avium. It is reported extremely rarely in commercial poultry flocks and has not been reported in commercial domestic ducks to date, with domestic ducks reported to be moderately resistant to M. avium infection. Here, we report the outbreak of avian tuberculosis in commercial Pekin duck (Anas platyrhynchos domestica) flocks. Postmortem and histopathologic findings included nodules presenting in the visceral organs of ducks, and granulomas with central caseous necrosis surrounded by infiltrating lymphocytes. The M. avium pathogen was isolated and further identified by Ziehl-Neelsen staining and PCR based on insert sequence IS901 and the 16S rRNA gene. We highlight that avian tuberculosis not only has economic significance for the duck industry, but also presents a potential zoonotic hazard to humans.

Miniaturization and high integration are two important factors hindering the further development of electronic devices. The generated heat flux has been increasing, thus requiring efficient cooling systems. The corona wind cooling technology has significant advantages and is likely a new effective solution for cooling electronics. A high-performance solid-state fan (SSF) based on corona discharge was designed and optimized. Carbon nanotubes and catalysts are used to modify the SSF in order to reduce ozone generation and cool a high power light-emitting diode (LED) chip. The experimental results indicate that the needle electrode arrangement, discharge polarity, temperature and relative humidity have a significant effect on the performance of the SSF. The positive corona, high environmental temperature and low relative humidity are beneficial to the original SSF. The modified SSF decreased the initiation voltage by half, increased the velocity by 13%, and reduced ozone production by more than 90%. The greener SSF showed better working durability and cooling performance, which reduced the case temperature by another 6 ℃ compared to the original one.

Corona discharge-produced ionic wind has drawn considerable attention as a potential candidate to solve the thermal problems that originate from heat accumulation in small-scale devices, as it has clear advantages over conventional cooling devices. The research and application cases of corona wind technology in the field of local heat transfer enhancement have been increasing in recent years. In this review, the formation process of corona wind and the mechanism of local heat dissipation enhancement are deeply investigated from the perspectives of physics, electricity, and thermodynamics. Related literature published in the past decade that has focused on the application of small-scale corona wind generators (CWGs) in local heat transfer enhancement is classified and discussed. Some important research conclusions are highlighted and used to guide the optimal design of a small-scale corona wind cooling system. The ongoing challenges of the power supply, adverse effects of byproducts, humidity, and electrode deterioration are discussed, and corresponding solutions are put forward. The use of corona wind cooling technology will present opportunities based on the research that has been conducted and its future development tendency.

The miniaturization and high integration of electronic devices require efficient heat transfer enhancement. The solid-state fan (SSF) based on corona discharge is a good candidate. The SSF shows advantages in energy consumption, size, cost, and operability et al. compared to traditional cooling systems. In this paper, a high performance SSF was proposed and developed for heat transfer enhancement. The generation of corona wind in SSF was explored theoretically, and a velocity correction method was proposed. The operating durability was improved under the action of carbon nanotube and manganese dioxide. The structure and electrical parameters of SSF can be optimized to obtain higher corona wind velocity. A 3.96 m/s corona wind velocity was obtained for the optimized SSF. The prototype of SSF shows better cooling performance for both uniform heat flux and hot spot heat flux. A temperature drop of 22.3 °C can be obtained for a light-emitting diode (LED) at the applied voltage of 6 kV, and the luminous flux decreased by only 1.5%, which is a satisfactory result. A coated SSF can increase the corona wind velocity at the same voltage and minimize the ozone generation to prolong the service life.

After the power reform No. 9 was released in March 2015, the state officially released the Opinions on the Implementation of the Reform on the Power Sales Side. From this document, we can see that the openness of sales of social capital to the electricity business, the sales side of the market competition through multiple ways to train the main competitors, the result is more users have the right to choose, sales service quality and user energy levels will significantly improve. With the gradual promotion of the electricity sales market, the national electricity sales companies have been established one after another. In addition to power grid outside the power generation companies, energy-saving service companies and distributed power companies may become the main selling power, while industrial parks, commercial complex, large residential area, industrial and commercial users, large industrial users in the new electricity demand appearing The new changes, some power customers have also self-built distributed power supply, installation of energy storage devices or equipment to participate in the transformation of the electricity market. The main body of the electricity sales market has gradually evolved from the traditional electricity generation main body to the multi-unit main body and emerged new value points. Therefore, the electricity sales companies need to establish a power customer value evaluation method and service mode to adapt to the new electricity reform, Provide supportive decision support.

To produce β-glucosidase by consecutive batch fermentation, a marine Aspergillus niger was immobilized on a natural carrier, towel gourd vegetable sponges. The immobilized mycelia were 0.15 g/g carrier with the immobilized biomass percentage of over 95%. The immobilized mycelia possessed the long durability (22.5 days). The maximum production occurred 1.5 day earlier by the immobilized mycelia than by the free mycelia. β-Glucosidase production of five consecutive batches was over 110 U/mL. At high salinity, the activity and stability of β-glucosidase from the marine A. niger increased remarkable. Immobilizing the marine A. niger on the novel natural carrier achieved the efficient production of β-glucosidase.

Large-scale grid-connected photovoltaic generators will cause out-of-limit of voltage deviation. The model of voltage drop caused by loads and voltage rise caused by PV generators are established under different loads or PV distribution modes along the line, and the maximum allowable capacity of PV power injected into the grid without causing over-voltage is calculated, assuming the bus voltage deviation reaching the upper limit. The maximum PV penetration level of typical distribution lines is derived under the condition that PV generators is of the same distribution mode with loads, and the voltage margin at the head end of the line without causing over-voltage is proposed. The results show that over-headlines can carry much more PV power than cables, and over-voltage will be avoided by controlling the PV power according to the connected bus voltage, and suitably lowering the bus voltage will allow more PV to connect into the grid.

A windowed DFT method is proposed for power system frequency measurement involving amplitude modulation. First, an error analysis of conventional DFT based method considering amplitude modulation is given. Second, a noval a window DFT function is proposed method to eliminate these errors is given based on the relation among three consecutive DFT values. Due to its high precision and low required processing effort, the proposed algorithm is a good candidate for online frequency measurement.

High temperature generated by target impact causes projectile austenite phase transformation. At high temperature, the austenite strength decreases rapidly and undergoes phase transformation erosion because of target impact. On this basis, a projectile material model which took phase transformation erosion into consideration was established and then the model was verified. Model simulation showed that after phase transformation erosion the projectile was subjective to tensile and compression instability. Dual-arc head design would significantly reduce projectile penetration resistance and decrease phase transformation influence on projectile stability.

TG analysis was used to investigate the thermal decomposition of switchgrass, which is a potential gasification feedstock. 10 mg switchgrass sample with the particles between 0.45 and 0.70 mm was linearly heated to 873 K at heating rates of 10, 20, 30 K/min, respectively, under high-purity nitrogen. The Kissinger method and three isoconversional methods including Friedman, Flynn-wall-Ozawa, Vyazovkin and Lenikeocink methods were used to estimate the apparent activation energy of switchgrass. With the three isoconversional methods, it can be concluded that the activation energy increases with increasing conversion. The four model free methods reveal activation energies in the range of 70-460 kJ/mol. These activation energy values provide the basic data for the thermo-chemical utilization of the switchgrass.

It was found from the experiment that the high temperature caused by target impact led to projectile austenite phase transformation. Based on this finding, a phase transformation model was established and verified by experiments, which proved the model had a relatively high calculation precision. Then, the model was used for numerical simulation. The result showed that the phase transformation zone was at the projectile head surface and the area increased as the impact velocity increased. The critical impact velocity which would cause phase transformation and affect projectile performance was around 700m/s.

Mycobacterium avium is an important pathogenic bacterium in birds and has never, to our knowledge, reported to be isolated from domestic ducks. We present here the complete genome sequence of a virulent strain of Mycobacterium avium , isolated from domestic Pekin ducks for the first time, which was determined by PacBio single-molecule real-time technology.

To ensure seismic safety of a large span cable-stayed bridge, two alternative pylon shapes and section types were studied. Nonlinear time history analysis was performed in the context. It is found that the A-shaped pylon is much stiffener than the H-shaped pylon in terms of deformation. The steel A-shaped pylon can significantly reduce the seismic demands of the key member including tower drift and moment. A ductile steel link between towers is proposed for the optimization of design in the paper. The A-shaped reinforced concrete tower with ductile steel link was proved to be a relatively balanced plan considering engineering, aesthetic and economic factors.

Summary Background The activation of nuclear factor-kappa B (NF-κB) and NLRP3 inflammasome is involved in neuroinflammation, which is closely linked to Alzheimer's disease (AD). In vivo and in vitro studies have suggested that artemisinin shows antiinflammatory effects in inflammation-related diseases. However, the impacts of artemisinin on AD have not been investigated. Aims In this study, 5-month-old APPswe/PS1dE9 transgenic mice were treated daily with 40 mg/kg artemisinin for 30 days by intraperitoneal injection to evaluate the effects of artemisinin on AD. Results We found that artemisinin treatment (1) decreased neuritic plaque burden; (2) did not alter Aβ transport across the blood–brain barrier; (3) regulated APP processing via inhibiting β-secretase activity; (4) inhibited NF-κB activity and NALP3 inflammasome activation in APPswe/PS1dE9 double transgenic mice. Conclusions The in vivo study clearly demonstrates that artemisinin has protective effects on AD pathology due to its effects on suppressing NF-κB activity and NALP3 inflammasome activation. Our study suggests that targeting NF-κB activity and NALP3 inflammasome activation offers a valuable intervention for AD.

Background Riemerella anatipestifer infection is a contagious disease that has resulted in major economic losses in the duck industry worldwide. This study attempted to characterize CRISPR-Cas systems in the disease-causing agent, Riemerella anatipestifer (R. anatipestifer). The CRISPR-Cas system provides adaptive immunity against foreign genetic elements in prokaryotes and CRISPR-cas loci extensively exist in the genomes of archaea and bacteria. However, the structure characteristics of R. anatipestifer CRISPR-Cas systems remains to be elucidated due to the limited availability of genomic data. Results To identify the structure and components associated with CRISPR-Cas systems in R. anatipestifer, we performed comparative genomic analysis of CRISPR-Cas systems in 25 R. anatipestifer strains using high-throughput sequencing. The results showed that most of the R. anatipestifer strains (20/25) that were analyzed have two CRISPR loci (CRISPR1 and CRISPR2). CRISPR1 was shown to be flanked on one side by cas genes, while CRISPR2 was designated as an orphan. The other analyzed strains harbored only one locus, either CRISPR1 or CRISPR2. The length and content of consensus direct repeat sequences, as well as the length of spacer sequences associated with the two loci, differed from each other. Only three cas genes (cas1, cas2 and cas9) were located upstream of CRISPR1. CRISPR1 was also shown to be flanked by a 107 bp-long putative leader sequence and a 16 nt-long anti-repeat sequence. Combined with analysis of spacer organization similarity and phylogenetic tree of the R. anatipestifer strains, CRISPR arrays can be divided into different subgroups. The diversity of spacer organization was observed in the same subgroup. In general, spacer organization in CRISPR1 was more divergent than that in CRISPR2. Additionally, only 8 % of spacers (13/153) were homologous with phage or plasmid sequences. The cas operon flanking CRISPR1 was observed to be relatively conserved based on multiple sequence alignments of Cas amino acid sequences. The phylogenetic analysis associated with Cas9 showed Cas9 sequence from R. anatipestifer was closely related to that of Bacteroides fragilis and formed part of the subtype II-C subcluster. Conclusions Our data revealed for the first time the structural features of R. anatipestifer CRISPR-Cas systems. The illumination of structural features of CRISPR-Cas system may assist in studying the specific mechanism associated with CRISPR-mediated adaptive immunity and other biological functions in R. anatipestifer. Electronic supplementary material The online version of this article (doi:10.1186/s12864-016-3040-4) contains supplementary material, which is available to authorized users.

Riemerella anatipestifer is an important pathogenic bacterium in waterfowl and other avian species. We present here the genome sequence of R. anatipestifer RCAD0122, a multidrug-resistant strain isolated from infected ducks. The isolate contains at least nine types of antibiotic resistance-associated genes.

Transformation behaviors and texture of Ni47Ti44Nb9 cold-rolled plates were studied by differential scanning calorimetry and X-ray diffraction test. R phase transformation does not occur in Ni47Ti44Nb9cold-rolled plate annealed at 350°C-750°C followed by quenching into the water. Martensite transformation temperature first increases and then decreases with increment of annealing temperature, and the maximum achieves at 700°C. The heat of reverse martensite transformation increases, while hardness decreases as annealing temperature increases. The major texture of cold-rolled plate is {332} and spread from {332} to {110}. When the annealing temperature is above 600°C, the major textures are {332} and {111} recrystallization texture in secondary cold-rolled plate.

On how to properly choose initiation position and parameters of cavity liner structure of multi-mode penetrator shaping. Combine gray relation analysis with simulation of different ways of initiation and different cavity liner structure, we analyze the effect of ways of initiation, the height of cavity liner, height ratio of cone and thickness of cavity liner on forming parameters of shaped charge. We get the sequence of factors which affect the penetrator molding effect. That is charge initiation position>the height of cavity liner>cone height ratio of cavity liner> thickness of cavity liner, which provide a reference method for optimization design multi-mode warhead.