Continuum robot has become a research hotspot due to its excellent dexterity, flexibility and applicability to constrained environments. However, the effective, secure and accurate path planning for the continuum robot remains a challenging issue, for that it is difficult to choose a suitable inverse kinematics solution due to its redundancy in the confined environment. This paper presents a collision-free path planning method based on the improved artificial potential field (APF) for the cable-driven continuum robot, in which the beetle antennae search algorithm is adopted to deal with the optimal problem of APF without the necessary for velocity kinematics. In addition, the local optimum problem of traditional APF is solved by the randomness of the antennae’s direction vector which can make the algorithm easily jump out of local minima. The simulation and experimental results verify the efficiency of the proposed path planning method.

With the characteristics of full autonomy and no accumulated errors, polarisation navigation shows tremendous prospects in underwater scenarios. In this paper, inspired by the polarisation vision of aquatic organisms, a novel point-source polarisation sensor with high spectral adaptability (400 nm–760 nm) is designed for underwater orientation. To enhance the environmental applicability of the underwater polarisation sensor, a novel sensor model based on the underwater light intensity attenuation coefficient and optical coupling coefficient is established. In addition, concerned with the influence of light intensity uncertainty on sensor performance underwater, an antagonistic polarisation algorithm is adopted for the first time, to improve the accuracy of angle of polarisation and degree of polarisation in the low signal-to-noise ratio environment underwater. Finally, indoor and outdoor experiments are carried out to evaluate the performance of the designed polarisation sensor. The results show that the designed point-source polarisation sensor can acquire polarised light and be used for heading determination underwater.

This work demonstrates a double-step method, a simple chemical bath deposition and an in situ polymerization process, to synthesize the stable structure of a composite of Polyaniline/BiVO4/cellulose aerogel (PBC) in wastewater treatment. The poor stability of the carrier catalyst was improved significantly by forming a dense film of polyaniline (PANI) through polymerization on BiVO4/cellulose aerogel (BC). The developed three-dimensional porous structure enhanced photocatalytic stability. For instance, photocatalytic degradation of a dye, methylene blue, reached to 91.67% under the eight times successive irradiation of the visible light. The resulted fine performance could be owed to the strong adsorption of cellulose aerogel, uniform spreading of BiVO4, and the speedy electron separation efficiency of PBC. Moreover, the photocatalytic mechanisms including the role of the free radicals (•OH and •O2−) of the developed PBC were also discussed. The novel structure may present a new insight into the development of the carrier catalyst.

The dipeptide dl-methionyl-dl-methionine (Met-Met) has extremely low water solubility and better absorption than other methionine sources (such as dl-methionine and l-methionine) available in the market. Therefore, six diets (D1, D2, D3, D4, D5 and D6) containing 0, 0·07, 0·15, 0·21, 0·28 and 0·38 % Met-Met were formulated to investigate the effects of Met-Met in juvenile Nile tilapia, Oreochromis niloticus (17 g initial body weight). The results indicated that percentage weight gain and specific growth rate of fish fed with D2 and D3 diets were higher than those fed with D1, D4–D6 diets. The levels of total essential amino acid in whole body of fish fed with D3 and D4 diets were significantly higher than those fed the D1 diet. Superoxide dismutase activity and malondialdehyde content have no significant difference in fish fed the diet with or without Met-Met supplementation. Majority of reads derived from the fish intestine belonged to members of Fusobacteria, followed by Bacteroidetes and Proteobacteria. Diversity of intestinal microbiota and total antioxidant capacity in fish fed with D3 diet was significantly higher than that of other groups. Based on the growth results, the authors conclude that the optimal level of Met is 0·61 % Met with the addition of 0·15 % Met-Met for grower-phase O. niloticus.

Paediatric Mycoplasma pneumoniae pneumonia (MPP) is a major cause of community-acquired pneumonia in China. Data on epidemiology of paediatric MPP from China are little known. This study retrospectively collected data from June 2006 to June 2016 in Beijing Children's Hospital, Capital Medical University of North China and aims to explore the epidemiological features of paediatric MPP and severe MPP (SMPP) in North China during the past 10 years. A total of 27 498 paediatric patients with pneumonia were enrolled. Among them, 37.5% of paediatric patients had MPP. In this area, an epidemic took place every 2–3 years at the peak, and the positive rate of MPP increased during these peak years over time. The peak age of MPP was between the ages of 6 and 10 years, accounting for 75.2%, significantly more compared with other age groups (χ2 = 1384.1, P < 0.0001). The epidemics peaked in September, October and November (χ2 = 904.9, P < 0.0001). Additionally, 13.0% of MPP paediatric patients were SMPP, but over time, the rate of SMPP increased, reaching 42.6% in 2016. The mean age of paediatric patients with SMPP (6.7 ± 3.0 years old) was younger than that of patients with non-SMPP (7.4 ± 3.2 years old) (t = 3.60, P = 0.0001). The prevalence of MPP and SMPP is common in China, especially in children from 6 to 10 years old. Paediatric patients with SMPP tend to be younger than those with non-SMPP. MPP outbreaks occur every 2–3 years in North China. September, October and November are the peak months, unlike in South China. Understanding the epidemiological characteristics of paediatric MPP can contribute to timely treatment and diagnosis, and may improve the prognosis of children with SMPP.

Nutrition therapy is considered an important treatment of burn patients. The aim of the study was to delineate the nutritional support in severe burn patients and to investigate association between nutritional practice and clinical outcomes. Severe burn patients were enrolled (n 100). In 90 % of the cases, the burn injury covered above 70 % of the total body surface area. Mean interval from injury to nutrition start was 2·4 (sd 1·1) d. Sixty-seven patients were initiated with enteral nutrition (EN) with a median time of 1 d from injury to first feed. Twenty-two patients began with parenteral nutrition (PN). During the study, thirty-two patients developed EN intolerance. Patients received an average of about 70 % of prescribed energy and protein. Patients with EN providing <30 % energy had significantly higher 28- d and in-hospital mortality than patients with EN providing more than 30 % of energy. Mortality at 28 d was 11 % and in-hospital mortality was 45 %. Multiple regression analysis demonstrated that EN providing <30 % energy and septic shock were independent risk factors for 28- d prognosis. EN could be initiated early in severe burn patients. Majority patients needed PN supplementation for energy requirement and EN feeding intolerance. Post-pyloric feeding is more efficient than gastric feeding in EN tolerance and energy supplement. It is difficult for severe burn patients to obtain enough feeding, especially in the early stage of the disease. More than 2 weeks of underfeeding is harmful to recovery.

A series of CoCrFeNiMox (x = 0.2, 0.4, 0.6, 0.8, 1.0, and 1.2) high-entropy alloys were designed to develop a eutectic high-entropy alloy system and to acquire a superfine eutectic structure. The results show that for the CoCrFeNiMox alloys, with the increase of Mo content from 0.2 to 1.2, the microstructures shift from a typical dendrite structure to a hypoeutectic microstructure (x = 0.6), and then to a fully eutectic microstructure (x = 0.8) with a lamellar spacing only 110 nm, and finally culminate in the hypereutectic structure (x = 1.0, x = 1.2). The XRD results show that CoCrFeNiMox alloys have a single FCC phase when x is 0.2 or 0.4. When Mo content is over 0.6, it begins to separate Cr9Mo21Ni20 intermetallic compounds. The hardness of the CoCrFeNiMox alloys is increasing significantly from 172.8 to 763.7 HV with the increase of Mo content. Meanwhile, the fracture strength increased but the ductility decreases. Among these alloys, the CoCrFeNiMo0.6 alloy shows excellent integrated mechanical properties of compressive fracture strength and strain, which are 2051 Mpa and 23%, respectively.

The Bi4Te3 films with well-ordered orientation and microstructure were successfully prepared on SiO2 substrate by a vacuum thermal evaporation deposition technique for the first time. We discussed the effects of evaporation temperature and substrate temperature on the phase and its well-ordered growth of Bi4Te3 films. The formation of Bi4Te3 phase is owing to the differences of the saturated vapor pressure. The thermoelectric transport properties of the Bi4Te3 films were investigated and the (00l)-oriented nanopillars array film has a better electrical transport performance, whose value of PF is 0.032 mWm−1 K−2 at 339 K, approaching twice that of the non-oriented ordinary film. The enhanced electrical properties of Bi4Te3 films could be achieved via the high-crystallinity well-controlled (00l)-oriented nanopillars array.

Sn–Ag–Cu solder interconnects were made by solidifying the solder balls in a magnetic field and subsequently tested for their electromigration behavior. The orientation of the tin grains was analyzed by electron backscattered diffraction. It was found that the c-axis of Sn grain tended to rotate away from the direction of the magnetic field during solidification, resulting in an enhanced electromigration resistance for the solder joint when the current was applied along the direction of the magnetic field, as evidenced by a smaller electromigration-induced polarity effect in the growth of the interfacial intermetallic compound. Such a reduced polarity-effect of electromigration is shown to agree well with the anisotropy in the diffusivity of the active diffusion species, Cu, in the tetragonal Sn. The difference of free energy change caused by the anisotropy in the magnetic susceptibility of the tetragonal Sn during solidification is suggested to be the main factor for this phenomenon.

The computation of compressible flows becomes more challenging when the Mach number has different orders of magnitude. When the Mach number is of order one, modern shock capturing methods are able to capture shocks and other complex structures with high numerical resolutions. However, if the Mach number is small, the acoustic waves lead to stiffness in time and excessively large numerical viscosity, thus demanding much smaller time step and mesh size than normally needed for incompressible flow simulation. In this paper, we develop an all-speed asymptotic preserving (AP) numerical scheme for the compressible isentropic Euler and Navier-Stokes equations that is uniformly stable and accurate for all Mach numbers. Our idea is to split the system into two parts: one involves a slow, nonlinear and conservative hyperbolic system adequate for the use of modern shock capturing methods and the other a linear hyperbolic system which contains the stiff acoustic dynamics, to be solved implicitly. This implicit part is reformulated into a standard pressure Poisson projection system and thus possesses sufficient structure for efficient fast Fourier transform solution techniques. In the zero Mach number limit, the scheme automatically becomes a projection method-like incompressible solver. We present numerical results in one and two dimensions in both compressible and incompressible regimes.

The aim of the present study was to evaluate the feasibility of an antimicrobial peptide, cecropin A(1-11)-D(12-37)-Asn (CADN), as an alternative to antibiotic growth promoter (AGP) in poultry diets. A total of 1500 14-d-old indigenous male chickens (222 (sd 13) g) were randomly allocated to five groups with five replicate cages of sixty birds each, and fed ad libitum five grower diets and subsequently five finisher diets for 14 d each. The diets were made up by supplementing their basal diets with a CADN liquid sample (CADNL) at 0, 2, 4, 6 and 8 ml/kg, respectively. During the feeding period, a metabolic experiment was carried out to determine the apparent digestibility of diethyl ether extract, nitrogen retention and apparent metabolisable energy of the diet sample fed to each cage of chicks. At the end of the feeding experiment, one chick from each cage was killed for bacteriological, light microscopic and scanning electron microscopic examination of the intestinal villi. CADN had a negative linear, positive quadratic and negative linear effect on feed intake (F), weight gain (G) and feed:gain ratio (F:G), respectively, for the growers; it had a quadratic effect on F, G or F:G for the finishers; it increased nutrient utilisation for both growers and finishers; it decreased aerobic bacterial counts in both jejunal and caecal digesta in a dose-dependent manner; it enhanced intestinal villus heights in a dose-dependent manner and made the duodenum villi of the CADNL8 group at 42 d appear as a netted leaf-like structure. CADN is therefore a possible alternative to AGP in broiler feeds.

We present a fast Poisson solver on spherical shells. With a special change of variable, the radial part of the Laplacian transforms to a constant coefficient differential operator. As a result, the Fast Fourier Transform can be applied to solve the Poisson equation with operations. Numerical examples have confirmed the accuracy and robustness of the new scheme.

Tesla transformers are widely used in short pulse, repetition pulsed power generators. In this paper, a high repetitive rate intense electron beam accelerator (IEBA) based on high coupling (~1) Tesla transformer, which consists of a primary charging system, coaxial pulse forming line (PFL) charged by Tesla transformer and gas spark switch is described, especially stressed on the high coupling Tesla transformer. By introducing magnetic core to enhance the coupling factor between the primary and secondary windings, the transformer is capable of producing high voltage pulse up to 1.4 MV in approximately 45 µs. A coaxial pulse forming line is closely attached to the transformer that the outer and inner magnetic cores are parts of the PFL's outer and inner conductors respectively. In addition, the parameters of the Tesla transformer and PFL are calculated, including the dimension of the PFL and Tesla transformer. Some experiment results showed that the IEBA is capable of producing electron beams of 300–700 kV/7–13 kA at repetitive rate 100 Hz, with the pulse width 35 ns. The maximal energy efficiency of the Tesla transformer is 83%.

Primers bearing restriction enzyme sites for EcoR I and Hind III were designed according to the known partial cDNA sequence for gibberellin-induced cysteine-rich protein and were then used to amplify the full-length open reading frame (ORF) and signal peptide-truncated fragment of the gcgasa gene. Two fragments with lengths 319 and 238 bp were obtained and were further cloned into plasmid pET-32(a). Following transformation into Escherichia coli BL21(DE3), the fusion proteins were observed to appear at ~26.0 and 25.2 kDa after induction from 1 mmol/l isopropyl-beta-D-thiogalactopyronoside (IPTG). The results of sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) and transmission electron microscopy (TEM) of an ultra-thin section revealed that the presence of signal peptide gave rise to the formation of an inclusion body located in the periplasmic space; however, the absence of signal peptide greatly enhanced the solubility of the target protein. The expressed soluble protein was further purified by Ni2+-NTA affinity chromatography and gel filtration methods.

The role of high current stressing during growth of the P-rich phase at the electroless Ni/Sn interface was examined by transmission electron microscopy. Prior to current stressing, two layers of Ni12P5, columnar Ni12P5 and noncolumnar Ni12P5, were formed after soldering. Upon electric stressing, the two layers of P-rich phase showed opposite growth patterns at the two opposing electrode interfaces. At the cathode, columnar growth of the P-rich phase was greatly enhanced while growth of the noncolumnar layer was inhibited. By contrast, the opposite was found at the anode where the current stressing promoted the noncolumnar growth but suppressed the growth of the columnar layer. Such a strong polarity effect resulted from directional electromigration of the key reaction species, nickel, to and from the interfacial reaction fronts. As a result of the difference in reaction mechanism, overall growth of the P-rich phase was much faster at the cathode during current stressing.

A simple empirical method that extracts the elastic moduli of both thin films and the underlying substrates is proposed and validated by both new nanoindentation experiments and published data. Deconvolution of thin film’s elastic properties from the substrate is achieved by statistical estimation, where a simple function relating the elastic moduli of the thin film and substrate to the film-substrate composite modulus is used to fit the experimental data plotted against the logarithmic indentation depth normalized by film thickness. Experimental data from a wide range of soft and hard films on substrate were used to demonstrate the deconvolution and validate the method. The estimated elastic moduli of thin films and substrates agree well with their corresponding standard values or values obtained by other methods. The advantages of this method are discussed, and recommendations are made on how to design experiments to obtain reliable data for this method.