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We show that the central limit theorem for linear statistics over determinantal point processes with $J$-Hermitian kernels holds under fairly general conditions. In particular, We establish Gaussian limit for linear statistics over determinantal point processes on union of two copies of $\mathbb{R}^d$ when the correlation kernels are $J$-Hermitian translation-invariant., Comment: 18 pages

Transmission accuracy is one of the most important parameters in ball screw mechanism (BSM); however, very few researches can be found on the transmission error modeling for BSM. Therefore, on the basis of the converting principle of the errors in the normal and axial direction proposed in this paper, this paper proposes a new model to predicate the transmission accuracy of BSM considering the manufacturing errors, installation errors, as well as the transmission error due to different loading status. After the error analysis and calibration of a transmission accuracy measuring system, the transmission accuracy measurement of a typical BSM under five different preloading levels is performed. The experimental results show that the difference compared with the analytical solution is 21.6% under no preload condition, and is less than 11% under preload condition, largely owing to the uneven distribution of clearance can increase the travel deviation. Further analysis shows that the eccentricity error is the dominant factor leading to the periodic fluctuation of the transmission error. More importantly, the travel deviation increases with increasing preload, which indicates the transmission accuracy of the BSM deteriorates when the load increases.

Background Hirschsprung-associated enterocolitis (HAEC), one of the most significant causes of morbidity and mortality for patients with Hirschsprung disease (HSCR), can occur before and after radical surgery. This study aims to identify the risk factors for HAEC before and after Soave. Methods A retrospective study of 145 patients with HSCR treated by transanal or combination with laparoscopic or laparotomy Soave procedure between January 2011 and June 2021 was performed. Data were retrieved from the medical records. HAEC was defined as the presence of clinical signs of bowel inflammation and requiring treatment with intravenous antibiotics and rectal irrigation for at least two days in the outpatient or inpatient department. Univariate analysis and multivariate regression models were used to identify risk factors for developing pre-and postoperative HAEC. Results The incidence of pre-and postoperative HAEC was 24.1% and 20.7%, respectively. More than 90% of the patients with the first episode of postoperative HAEC occurred within the first year after Soave. Long-segment aganglionosis was the independent risk factor for developing preoperative HAEC ([OR] 5.8, Cl 2.4–14.2, p p = 0.003). Conclusions Long-segment aganglionosis was the independent risk factor for the development of preoperative HAEC, and the history of preoperative HAEC was strongly associated with developing HAEC after Soave. Level of Evidence Level III

Background A major hand-foot-and-mouth disease (HFMD) pathogen, coxsackievirus A16 (CVA16), has predominated in several of the last 10 years and caused the largest number of HFMD outbreaks between 2011 and 2018 in China. We evaluated the efficacy of maternal anti-CVA16 antibody transfer via the placenta and explored the dynamics of maternal and natural infection-induced neutralizing antibodies in children. Methods Two population-based longitudinal cohorts in southern China were studied during 2013–2018. Participants were enrolled in autumn 2013, including 2475 children aged 1–9 years old and 1066 mother-neonate pairs, and followed for 3 years. Blood/cord samples were collected for CVA16-neutralizing antibody detection. The maternal antibody transfer efficacy, age-specific seroprevalence, geometric mean titre (GMT) and immune response kinetics were estimated. Results The average maternal antibody transfer ratio was 0.88 (95% CI 0.80–0.96). Transferred maternal antibody levels declined rapidly (half-life: 2.0 months, 95% CI 1.9–2.2 months). The GMT decayed below the positive threshold (8) by 1.5 months of age. Due to natural infections, it increased above 8 after 1.4 years and reached 32 by 5 years of age, thereafter dropping slightly. Although the average duration of maternal antibody-mediated protection was < 3 months, the duration extended to 6 months on average for mothers with titres ≥ 64. Conclusions Anti-CVA16 maternal antibodies are efficiently transferred to neonates, but their levels decline quickly. Children aged 0–5 years are the main susceptible population and should be protected by CVA16 vaccination, with the optimal vaccination time between 1.5 months and 1 year of age.

Based on the topology analysis of a screw grinder mapping the dressing error of the grinding wheel (DEGW) to the geometric errors of the virtual axis, an improved accuracy model of the screw grinder with 36 geometric errors is established, and an error model of ball screw profile parameters is established according to the forming principle. Then, the Sobol method is performed to analyze the error sensitivity and obtain the crucial geometric errors affecting the profile parameters by considering the individual and intercoupling effect. It is worth mentioning that the overall change of the global sensitivity sum of the crucial geometric errors for lead error (EL) and pitch diameter error (EPD) is 22.9% and 30.2%, respectively, which indicates that the model considering the DEGW has a stronger ability to identify the geometric errors. Lastly, the grinding experiments of ball screw under the adjustment of four grinder geometric errors are conducted. The results show that the crucial geometric error corresponding to the EL and EPD is consistent with the calculation results of the Sobol method, which verifies the effectiveness of the proposed method, and provides a way to trace the machining errors.

The static and dynamic characteristics of a marine sandstone bottom-water heavy oil reservoir include low structural amplitude, small thickness, strong bottom water energy, high watercut rise speed, significant differences in the watercut change law of wells, etc. Due to the complexities of accurate description of the sweep range and ridge shape of high watercut production wells, the evaluation and prediction of the remaining oil distribution is problematic, as well as the feasibility of the adjustment wells. In this paper, we have studied the dynamic characteristics of the water ridge of horizontal production wells in marine sandstone bottom-water heavy oil reservoirs. First, based on the physical simulation experiments, we discuss the overall morphological characteristics of the water ridge after the bottom water rise and the changes caused by the influence of an interlayer, considering the effect of the horizontal production wells and natural water driving. Second, a new method is proposed for calculating the characteristic shape of the water ridge in the heavy oil reservoir in the presence of the bottom water. The new method can be used for quick and accurate calculations of a 3D water ridge shape under horizontal production wells in reservoirs, with or without interlayers. It can also facilitate the quantitative evaluation of the water ridge sweep range of production wells in the high watercut periods. The new method can be applied to predict the remaining oil distribution range and reserves and provide important technical background for development adjustment measures and potential tapping for this type of heavy oil reservoir.

Event detection aims to detect events from text by locating event triggers and classifying them into predefined event types. Current state-of-the-art event detection methods benefit from integration of syntactic dependency into graph convolutional network (GCN). Despite the great success of GCN-based event detection methods, there are still two problems. Firstly, most GCN-based methods are designed as stacked structure to capture high-order contextual information, which will result in over-smoothing problem; secondly, dependency type information are not fully utilized in current GCN-based methods due to severe sparsity problem of some dependency types. In this paper, we propose P ath-Aware G raph C onvolutional N etwork (PGCN) model, shedding lights on simultaneously tackling these two problems. Specifically, PGCN is designed as flat structure to avoid over-smoothing problem, while path-aware aggregation is proposed to capture all-order contextual information and integrate dependency type information into feature space at the same time. Moreover, to deal with sparsity problem of some path types, we further adopt latent factor decomposition (LFD) technique by sharing parameters among different kinds of path. Our method is verified on the benchmark ACE 2005 English dataset. Experimental results show that our method gets 1.4% improvement on F1 score over state-of-the-art method, and performs more stably than other GCN-based methods with separate random initializations.

The laser-MAG hybrid welding in horizontal-vertical (PC) position was used to study the effect of different groove types on the quality of a root weld. Six combinations of bevel angles (50° + 0° (represents the groove angle of upper plate and lower plate respectively), 45° + 5°, 40° + 10°, 35° + 15°, 30° + 20°, and 25° + 25°) and root face sizes of 2 to 4 mm were designed. Hannover analyzer was used to collect electrical signals to analyze the stability of the horizontal-vertical position welding process. The results show that different combinations of groove angle have achieved one-sided welding with root formation. The groove angle has an obvious effect on the weld inclination and molten weld metal flowing down. The combination of bevel angles in which that of the lower plate is smaller than that of the upper plate was more conducive to avoid welding defects such as weld inclination and molten weld metal flowing down. The best groove angle combination was 30° + 20°, which allowed one-sided welding with root formation using a 4-mm root face.

The lack of highly permeable and selective separation membranes hampers the application of the energy-efficient membrane separation process for water remediation and CO2 capture in molecular scale. Nanoparticles have been widely applied for tailoring pore structures and surface properties of the molecular separation membranes, thereby enhancing separation performance. However, limited by non-ideal nanoparticle aggregation, it remains a big challenge to fabricate such membranes on a large scale. Herein, we designed a kind of highly dispersed nanoparticles through grafting poly(sodium-p-styrenesulfonate) (PSS) on metal organic frameworks UiO-66 and deployed them for tailoring structure of polyelectrolyte membrane (PEM) for water remediation and Pebax (PEBA) symmetrical membranes for CO2 capture, respectively. Because of electrostatic interaction, the PSS-grafted-UiO-66 (UiO-66-PSS) demonstrated nearly 100% dispersion in water and had an average particle size around 200 nm. Most interestingly, the introduction of the UiO-66-PSS finely tailored the affinity between membranes and target molecules, and the molecular structure of both PEM and PEBA membranes, thereby tripling the permeances of the membranes and slightly improving the selectivity of the membranes meanwhile. The PEM/UiO-66-PSS membranes demonstrated pure water permeance as high as 27.3 L m−2 h−1 bar−1 with MgSO4 rejection above 98.7%. For CO2 capture, the PEBA/UiO-66-PSS membranes exhibited 414.5 barrer with selectivity about 53.8. Taken together, the highly dispersed UiO-66-PSS shows strong promise in constructing molecular separation membranes with high separation performance for environmental remediation. The highly dispersed PSS-grafted-UiO-66 finely tailored membrane structures of PEM membranes and the PEBA membranes and enhanced affinity between the target molecules and the aforementioned membranes, thereby tripling membrane permeances and improving the membrane selectivity slightly. The obtained PEM/UiO-66-PSS membranes and PEBA/UiO-66-PSS membranes show strong promise in water remediation and CO2 capture, respectively.

Currently, the application of mobile ground robots spans a range of fields from surveillance, search and rescue, exploration, agriculture, military among others. In unstructured and dangerous environments such as disaster scene, military fields or chemical spray in agricultural farms, the experience and intelligence of the operator are necessary for making complex decisions beyond the autonomy of the robot. In such cases, teleoperation allow the operator to guide the robot in achieving complex task from a safe location. The effectiveness with which the operator controls the robot depends on, among others, operator’s awareness of the robot’s environment, the quality of communication link, the robustness of robot’s control system and experience of the human operator. Ground mobile robots form the basis of this work since they are applicable in many fields and mostly operate in dynamic environments that require additional guidance from a human operator. This study reviews research work on mobile robot teleoperation systems, and puts more emphasis on the architecture, communication link and situation awareness creation. Moreover, future trend in mobile robot teleoperation is also put forward in this review to give ground for new research work in this field. Based on the sited literature, it is noted that making the operator feel present in the robot’s environment through sufficient visual and force feedback as well as use of good quality network, significantly improve the navigation efficiency and task achievement of mobile ground robots.

To investigate the effect of gas dispersing carbon nanotubes (CNTs) and hot pressing method on the transparency and the conductivity of thin films, the free arc was used to disperse the CNTs in a high dispersion rate, and the dispersed CNTs were rapidly pressed into the surface of the PET film by hot pressing to obtain electrical conductivity. The relationship between the light transmission and sheet resistance of the film was studied by changing the deposition time and the presence or absence of electrostatic adsorption. It was found that the CNTs modified film still retains good electrical conductivity (sheet resistance up to 6 × 104 Ω, light transmittance 69%) through the cleaning of surfactants and ultrasonic waves, which proves that hot pressing is a simple physical method to achieve effective combination of CNTs and films.

We have demonstrated a method for active modulating terahertz wave using CsPbBr3 perovskite quantum dots (QDs)–embedded double-C metallic metamaterial unit cells. The resonance response frequency of the proposed CsPbBr3 perovskite QDs-embedded metamaterial can be tuned by varying the external applied photoexcitation intensity. By doing so, we measured the dynamic terahertz wave transmission modulation and demonstrate tuning of the terahertz wave resonant response based on the optical pump fluences. The modulation speed and depth of the modulator are 5 MHz and 88.3%, respectively. Our results indicate the importance of manipulating the terahertz wave for future wireless communication.

The eye is the most important sensory organ of the human body, and the cornea and anterior chamber are very important components In surgeries like vision correction, it is necessary to know the accurate corneal thickness and anterior chamber depth of human eyes. Their accurate measurement cannot only provide a reference for doctors, but also provide a strong guarantee of surgical results. In order to achieve high-precision measurements of human corneal thickness and anterior chamber depth, we develop an equivalent human-eye optical system and a measurement method for the thickness. This method designs an equivalent double-membrane system to simplify the physiological structure of the cornea and anterior chamber of the human eye and irradiate the double-membrane system through laser. The reflected light returns to the laser cavity and the original light self-mixing interference, and a photodetector collects and processes the interference signals to obtain the corneal thickness and anterior chamber depth. The correctness of the theoretical calculations is verified by the experimental system, and the measurement accuracy can reach the micrometer level.

To improve the path tracking accuracy and yaw stability of distributed drive autonomous vehicles (DDAVs) under extreme working conditions, a cooperative lateral motion control method based on the dynamic boundary is proposed to prevent different road adhesion conditions from affecting the motion stability of DDAVs. Based on the analysis of the DDAV lateral dynamics system coordination mechanism, a dynamic boundary considering the pavement adhesion coefficient is proposed, and the Lateral Motion Synergistic Control System (LMSCS) is designed. The LMSCS is divided into the coordination, control, and executive layers. The coordination layer divides the control domain into the stable, quasi-stable, and unstable domains by the dynamic boundary, and coordinates the control strength of the path following control and yaw stability control. In the control layer, the path following control and yaw stability control laws are designed based on the global fast terminal sliding mode. The executive layer estimates the expected steering wheel angle and expected additional wheel torque. Joint simulations under double line shifting conditions confirmed that LMSCS reflects the impact of the road attachment conditions and improves the path tracking accuracy and vehicle yaw stability. The LMSCS has better overall performance than existing lateral motion control methods.

In underground coal mining, frequent dynamic disturbances adversely affect the stability of coal pillars. Thus, it is essential to understand the dynamic mechanical behaviour of coal under repeated impact loads. In this paper, a cone-shaped striker bar with a length of 200 mm was designed for a split Hopkinson pressure bar (SHPB) system, and repeated impact experiments of coal were carried out with this system. Based on three-wave theory, original voltage signals were recorded during the tests and then processed to study the changes in the dynamic stress-strain curves with the number of impacts. Relationships between the dynamic compressive strength, peak strain, and the number of impacts were analysed. Meanwhile, the failure mode and fracture mechanism of coal under repeated impact loads were discussed. It was found that as the number of impacts increases, the peak strain increases but the dynamic strength decreases. Furthermore, the studied coal specimens present two typical failure modes under these conditions, including axial splitting failure and hoop tensile failure. Based on the ultimate fracture modes of the specimens, two crack group failure models are established to reveal the fracture mechanism of coal under repeated impact loads. This study can make a deep understanding about the failure mechanism of coal pillar’s instability induced by impact load.

Grouting has been widely adopted in disaster management related to tunneling. Since completely and strongly weathered granite is problematic stratum in tunneling construction, grouting simulation tests were carried out to investigate the grout diffusion pattern with various particle size distributions and grouting pressures. Injected grout mass and characteristics of the consolidating body were obtained to reveal the mechanism of the grouting process. Permeation, compaction, fracture, and their mixed diffusion pattern were defined, and the different diffusion patterns were distinguished by the particle size distribution and grouting pressure. The compaction pattern and the permeation pattern have the lowest and highest injected grout mass, respectively. Injected grout mass increased with the increment of grouting pressure. Particle size distribution and grouting pressure determine the grout diffusion pattern. The permeation-dominated pattern can be distinguished from compaction and fracture pattern by D10, while the compaction and fracture patterns are differentiated by D60. The grout diffusion pattern is determined by grouting pressure in the specific strata though it has no relationship with the groutability. Permeation pattern has the highest reinforcement effect with a “sandcrete” structure, the compaction pattern has the lowest reinforcement effect with compaction effect, and the fracture pattern enhances strata by compaction and skeleton support. Finally, a criterion was obtained to forecast the completely and strongly weathered granite’s grout diffusion pattern, which was confirmed by the grouting engineering.

Streptomyces is currently the main producer of microbial pharmaceuticals from its secondary metabolites as natural products. It will be more beneficial if the promoters, which are particularly strong during the secondary metabolism of Streptomyces, are used to drive the efficient production of desired natural products with the coordination of bacterial growth. Here, in an industrial natamycin producer Streptomyces chattanoogensis L10, a strong promoter groESp was identified for this purpose based on the comparative proteomic analysis of the primary and secondary metabolism. With a constitutive promoter ermEp* as a control, the activity of groESp was weak in the primary metabolism, but about sixfold higher than ermEp* in the secondary metabolism, when the representative antibiotic natamycin was highly produced. Furthermore, when ScnRII, a pathway-specific positive regulator in natamycin biosynthesis, was expressed under groESp, the productivity of natamycin was about 20% higher in the secondary metabolism than that from ermEp*, but had no discrimination in the early 2 days. Thus, we showed that proteomics is an effective alternative way to identify promoters for the high yield of natamycin in S. chattanoogensis, and this strategy can be widely adaptable to other Streptomyces species for the full development of secondary metabolites with promising bioactivities.

The curve-shaped Chaman transform fault between Pakistan and Afghanistan demarks the western boundary of the Indian plate, which is the locus of many catastrophic earthquakes, and this is poorly studied region to understand the earthquake/fault interaction and hazard assessment. Based on earthquake triggering theory, we investigate a sequence of earthquakes comprising five earthquakes that occurred in the Chaman Fault System since 1892. Our results elucidate that three out of four earthquakes are triggered by the preceding earthquakes. The 1935 earthquake of magnitude Mw 7.7 is somewhat an independent earthquake in this sequence, slightly influenced by the 1892 event. The 1935 earthquake significantly loaded either terminus of its rupture with positive stress, which later triggered the 1975 earthquake with 35% of its rupture length where ΔCFS is above triggering threshold value, and 1990 earthquake with 44% of its rupture length in positive stress lobe, on Ghazaband Fault, in the south lobe. Since the 1935 earthquake significantly increased the ΔCFS on either terminus of its rupture, the 2013 earthquake with magnitude Mw 7.7 occurred on Hoshab Fault in the positive stress zone with 23% of its rupture length where ΔCFS is positive. Moreover, the northern locked segment of CF, the southern segment of GBF, southeastern segment of HF and PAF demonstrate a high value of ΔCFS. It could trigger seismicity in these regions, thus requiring arrangements to mitigate any seismic hazards in future.

Due to the abandonment of roadways after the use of conventional mining techniques, fracture behaviours of the roof of a longwall top coal caving (LTCC) working face significantly differ from general coal mining behaviours. This study examines conditions of the no. 3 LTCC working face of the Shenghua coal mine. By theoretical analyses, analogue simulation tests and numerical calculations, we examined the roof failure characteristics, forces acting on supports, and action characteristics of abutment stress observed in front of a longwall face when an abandoned roadway was installed in front of a cave working face. We formed the following conclusions. First, due to effects of abandoned roadways and roof-caving regions in front of the working face, the roof of the working face exhibited advanced fracture characteristics. Second, stress exerted on the surrounding rock of the working face showed a different distribution pattern than that of the coal mining face, with supporting stress noticeably concentrated at the pillar. Third, as hydraulic supports have been subjected to the impact load of the fractured roof, supports have poorly adapted, with a maximum working resistance of 14,000 kN. These conditions may cause serious accidents due to the supports’ failure or hydraulic cylinders’ breakage. Fourth, based on a statically indeterminate equation and the superposition principle, the critical condition of roof fracturing occurring in front of a working face was measured, and the critical width of an abandoned roadway that spurs advanced fracturing in the working face of the Shenghua coal mine was calculated as 6.2 m. Last, to ensure the stability of the surrounding rock and panel supports, a pre-filling scheme of the abandoned roadway is proposed.

Yolk-shell-structured calcium phosphate microspheres have a great potential for medical applications due to their excellent physicochemical properties and biocompatibility. However, developing a yolk-shell-structured calcium phosphate with high adsorption capability remains a challenge. Herein, a porous yolk-shell-structured microsphere (ATP-CG) of calcium phosphate with high-specific surface area [SBET = 143 m2 g−1, which is approximately three times as high as that of ATP-CL microspheres synthesized by replacing calcium source with calcium l-lactate pentahydrate (CL)] was successfully synthesized by using adenosine 5'-triphosphate disodium salt (ATP) as the phosphorous source and calcium gluconate monohydrate (CG) as calcium source through a self-templating approache. The influences of molar ratio of Ca to P (Ca/P), hydrothermal temperature, and time on the morphology of ATP-CG microspheres were also investigated. It is found that the organic calcium source and organic phosphorous source play a vital role in the formation of yolk-shell structure. Furthermore, a batch of adsorption experiments were investigated to illuminate the adsorption mechanism of two kinds of yolk-shell-structured microspheres synthesized with different calcium sources. The results show that the adsorption capacity of ATP-CG microspheres (332 ± 36 mg/g) is about twice higher than that of ATP-CL microspheres (176 ± 33 mg/g). Moreover, the higher-specific surface area caused by the calcium source and unique surface chemical properties for ATP-CG microspheres play an important role in the improvement of HEL adsorption capability. The study indicates that the as-prepared yolk-shell-structured microsphere is promising for application in drug delivery fields and provides an effective approach for improving drug adsorption capability.

One of the main concerns in rank aggregation tasks for metasearch service is how to retrieve and aggregate the large-scale candidate search results efficiently. Much work has been done to implement metasearch service engines with different rank aggregation algorithms. However, the performance of these metasearch engines can hardly be improved. In this paper, we transform the top-k ranking task into a multi-objective programming problem when user preferences are considered along with user queries. We build an improved discrete multi-objective programming model to make the aggregate rankings satisfy user queries and user preferences both, and then propose a user preferences-based rank aggregation algorithm accordingly. Based on discrete particle swarm optimization algorithm, we improve the encoding scheme, the initialization methods, the position and velocity definition, the integrating updating process, the turbulence operator, and the external archive updating and leader selection strategy to make sure the candidate results that fit the user’s preferences can be located quickly and accurately in a large-scale discrete solution space. We have our proposed algorithm tested on three different benchmark datasets: a public dataset, the real-world datasets and the synthetic simulation datasets. The experimental results demonstrate the efficacy and convergence efficiency of the proposed algorithm over the baseline rank aggregation methods especially when dealing with large amount of candidate results. And when the set of candidate results is of normal size, the proposed algorithm is proved to perform not worse than the baseline methods.

The attitude control problem is addressed for a quadrotor system subject to the modeling uncertainties and unknown disturbances. A novel attitude control scheme is proposed based on nonsingular fast terminal sliding mode (NFTSM) technique. First, the tracking differentiator (TD) is designed to obtain the smooth tracking signal and its derivative. Then, the extended state observer (ESO) is constructed to provide the estimate of the modeling uncertainties and unknown disturbances. With the designed TD and ESO, a novel NFTSM controller is developed such that tracking error converges to zero in finite time. The transient-state and the steady-state performances are both achieved with the new controller. Finally, the simulation and real experiment results verify the effectiveness and superiority of the proposed control method.

To develop red emitting phosphors for white LEDs, a series of ZnWO4:xEu3+, ySm3+, zBi3+ (x, y and z are values in mol%, x = 5; y = 0, 0.6; 0 ≤ z ≤ 11) phosphors were prepared by hydrothermal method, and their structures, characteristic photoluminescence properties and energy transfer mechanism were studied in detail. The causes for the morphological changes after doping Sm3+ and Bi3+ ions were also analyzed in our work. It could be determined that all the samples were pure monoclinic ZnWO4. For Bi3+ doped ZnWO4:Eu3+, the dominant emission band located at 617 nm (when λex = 357 nm) was significantly enhanced by the efficient energy transfer (from Bi3+ to Eu3+). In addition, the experiment also found that Bi3+ doped ZnWO4:Eu3+ had a stronger emission than ZnWO4:Eu3+ (without Bi3+ sensitization) excited at 465 nm. This phenomenon appeared in ZnWO4:Eu3+, Sm3+, Bi3+ as well. Thus, we suggest that the introduction of Bi3+ leads to structural distortion that affects the f–f transition of Eu3+ in ZnWO4:RE3+. The obtained results clearly indicate the beneficial influence of introduction of Bi3+ ions on luminescence properties of Eu3+ in our work.

PtCo x bimetallic nanoparticles(NPs) supported on tannin-grafted collagen fiber(CF-BT) have been pre-pared via a novel synthetic strategy, and applied for catalytic hydrogenation of cinnamaldehyde(CAL), a typic unsa-turated aldehyde. The catalysts were systematically and specifically characterized by means of XRD, XPS, TEM-EDX and SEM to clarify the structure-property correlation. It was found that the PtCo x /CF-BT catalysts exhi-bited significantly enhanced catalytic activity and desirable stability in catalytic hydrogenation of CAL, which is ascribed to the synergistic interaction between bimetallic components, the effective dispersion, the anchoring role of CF-BT matrix on bimetallic NPs, as well as the lower mass transfer resistance of the matrix.

L1 cell adhesion molecule (L1CAM) is highly expressed in various types of human cancers, displaying yet unknown molecular mechanisms underlying their oncogenic potential. Here, we found that L1CAM expression was significantly increased in esophageal squamous cell carcinoma (ESCC; n = 157) lesions compared with non-cancerous tissues. High tumorous L1CAM expression significantly correlated with reduced overall survival. Experimentally, L1CAM knockdown led to decreased cell growth, migration, and invasiveness in vitro, whereas overexpression of L1CAM showed the opposite effect. In nude mice, L1CAM depletion attenuated tumorigenesis and ability to penetrate the tissues surrounding ESCC cells. Gene set enrichment analysis (GSEA) and SubpathwayMiner analysis on gene expression profiles (microarray data on ESCC tissues, GSE53625; cDNA microarray data on L1CAM-knockdown ESCC cell line, GSE86268) suggested that L1CAM-co-expression genes were related to cell motility, cell proliferation, and regulation of actin cytoskeleton, validating the above experimental findings. Further mechanistical analysis showed that L1CAM upregulated the expression of the cytoskeletal protein ezrin via activating integrin β1/MAPK/ERK/AP1 signaling and thus led to the malignant phenotypes of ESCC cells. Together, our findings suggest that L1CAM may be employed as a valuable prognosis marker and a therapeutic target for ESCC patients and that L1CAM promotes ESCC tumorigenicity by upregulating ezrin expression.L1CAM promotes growth and invasiveness of ESCC cells in vitro and in vivo. L1CAM upregulates the expression of ezrin by integrin α5β1/MAPK/ERK/AP1 pathway. Ezrin is a key downstream effector in the L1CAM-promoted malignant phenotypes. High expression levels of both L1CAM and ezrin significantly correlated with reduced overall survival. Nuclear L1CAM is an independent prognosis marker for esophageal squamous cell carcinoma.

Bi0.95PO4:0.05Eu3+ phosphors with different structures and morphologies were prepared by a CTAB-assisted hydrothermal method. X-ray diffraction (XRD), scanning electron microscopy (SEM) and photoluminescence (PL) spectrometer were carried out to characterize the samples. The results showed that the amounts of CTAB and the pH values of the precursor solution had a great influence on the structure, morphology and luminescence intensity of the obtained samples. XRD results showed that a structural change from low temperature monoclinic phase (LTMP) to hexagonal phase (HP) happens with increasing the pH values and the amounts of CTAB. Some morphologies changes from octahedron-like to microrods and nano particles could be observed in SEM images. When the amount of CTAB was 2 mmol, the sample showed the highest luminescence intensity at pH = 0.5. Under 395 nm excitation, BiPO4:Eu3+ phosphors displayed red emission centered at 595 nm which corresponded to the 5D0→7F1 transition of Eu3+ ions. The BiPO4:Eu3+ phosphors synthesized by the CTAB-assisted hydrothermal method could be a promising phosphors which emits red light for white LEDs.

With the increasing depth of underground coal mining in China year by year, the problems of the floor heave of roadway become more and more serious. As one of the main forms of the deformation and failure of the surrounding rock in the soft rock roadway, floor heave is the most difficult problem to be solved in the deep mining of coal mines and other underground tunnel engineering. In order to control the floor heave effectively, Chinese scholars have systematically studied the treatment methods of floor heave under various conditions. In this paper, the direct reinforcement method, the indirect reinforcement method and the unloading method are analyzed emphatically, and the comprehensive treatment methods of the grouting bolt combined with reinforcing sidewalls and corners for the floor heave are put forward. After the engineering application of the methods of the grouting bolt combined with reinforcing sidewalls and corners in Baode coal mine, the floor heave of the roadway is controlled at 283 mm and the reinforcement cost of roadway floor is reduced by 40%, which has achieved remarkable technical and economic results. Finally, the prevention and control of floor heave technology is prospected.

In this study, a thermo-plastic-martensite transformation coupled model based on the von Mises yield criterion and the associated plastic flow rule is developed to further improve the accuracy of numerical simulation during hot stamping. The constitutive model is implemented into the finite element program ABAQUS using user subroutine VUMAT. The martensite transformation, transformation-induced plasticity and volume expansion during the austenite-to-martensite transformation are included in the constitutive model. For this purpose, isothermal tensile tests are performed to obtain the flow stress, and non-isothermal tensile tests were carried out to validate the constitutive model. The non-isothermal tensile numerical simulation demonstrates that the thermo-plastic-martensite transformation coupled constitutive model provides a reasonable prediction of force-displacement curves upon loading, which is expected to be applied for modeling and simulation of hot stamping.

Studying the true triaxial deformation characteristics and progressive damage behavior of sandstone is of great significance for the stability control of roadways. Both the conventional triaxial test (CTT) and the true triaxial compression test (TTT) were conducted for sandstone to investigate its deformation characteristics and the variation laws of volume strain during the progressive damage process under different confining pressures. The conducted experiments showed that both the axial and lateral strains of the rock prior to failure under CTT conditions increased with increasing confining pressure. However, with increasing intermediate principal stress (σ2) under TTT conditions, both the axial strain, and the lateral strain (ε2) gradually decreased, and the lateral strain (ε3, expansion) first slow down and then accelerated. Moreover, the anisotropic characteristics first gradually weakened and then enhanced. The variation of the volume strain increment and the volume strain rate of rock combined with the acoustic emission activity and a three-dimensional rock theoretical model with microcrack defects were analyzed in detail. During the stable crack growth stage III, the volume strain increment and volume strain rate increased with increasing confining pressure under CTT conditions, while they decrease after the initial increase with increasing σ2 under TTT conditions. During the unstable crack growth stage IV, the volume strain increment increased sharply, while the volume strain rate gradually slowed down with increasing confining pressure under CTT conditions. The internal cracks of the rock were gradually suppressed and the lateral expansion was gradually constrained. The volume strain increment first increased followed by a decrease, and the volume strain rate gradually slowed down after a noticeable acceleration with increasing σ2 under TTT conditions. The internal micro-cracks gradually evolved from inhibition (in the planes parallel to plane 1–2 and plane 2–3) to accelerated expansion (the planes along the σ2 direction), and the lateral deformation first weakened and then strengthened.

Due to coal mining taking place on a large scale in northern China, it is inevitable that wide-spread dewatering occurs in the aquifers overlying the resulting goaf. The purpose of this paper is to protect the groundwater of overlying unconsolidated aquifers. Based on physical model experiment, seepage experiments, and numerical simulation, this paper determines the patterns and distribution of the overburden rocks in the goaf, establishes the correlation between the fracture ratio and the hydraulic conductivity of the rock mass, and characterizes the groundwater flow pattern. The results show that (1) the residual fracture occurring ratio within the residual fracture zone is approximately 1.82 times that of the fracture compaction zone and 1.93 times that of the coal wall support zone; (2) the hydraulic conductivity of the rock mass in different parts of the goaf increases with increasing fracture ratio, the relationship of the two follows a power curve; (3) the predicted groundwater levels from numerical simulation is good fit with the measured and indicates that the hydraulic conductivities derived from seepage experiments are rational. We demonstrate how a laboratory-scale physical model can be used effectively to verify existing conceptual models in such a way that the impact of coal mining on groundwater resources can be predicted for similar regions.

The Thornthwaite moisture index, an index of the supply of water (precipitation) in an area relative to the climatic demand for water (potential evapotranspiration), was used to examine the spatial and temporal variation of drought and to verify the influence of environmental factors on the drought in the Hengduan Mountains, China. Results indicate that the Thornthwaite moisture index in the Hengduan Mountains had been increasing since 1960 with a rate of 0.1938/yr. Annual Thornthwaite moisture index in Hengduan Mountains was between –97.47 and 67.43 and the spatial heterogeneity was obvious in different seasons. Thornthwaite moisture index was high in the north and low in the south, and the monsoon rainfall had a significant impact on its spatial distribution. The tendency rate of Thornthwaite moisture index variation varied in different seasons, and the increasing trends in spring were greater than that in summer and autumn. However, the Thornthwaite moisture index decreased in winter. Thornthwaite moisture index increased greatly in the north and there was a small growth in the south of Hengduan Mountains. The increase of precipitation and decrease of evaporation lead to the increase of Thornthwaite moisture index. Thornthwaite moisture index has strong correlation with vegetation coverage. It can be seen that the correlation between Normalized Difference Vegetation Index (NDVI) and Thornthwaite moisture index was positive in spring and summer, but negative in autumn and winter. Correlation between Thornthwaite moisture index and relative soil relative moisture content was positive in spring, summer and autumn, but negative in winter. The typical mountainous terrain affect the distribution of temperature, precipitation, wind speed and other meteorological factors in this region, and then affect the spatial distribution of Thornthwaite moisture index. The unique ridge-gorge terrain caused the continuity of water-heat distribution from the north to south, and the water-heat was stronger than that from the east to west part, and thus determined the spatial distribution of Thornthwaite moisture index. The drought in the Hengduan Mountains area is mainly due to the unstable South Asian monsoon rainfall time.

Maritime-type glaciers in the eastern Nyainqentanglha Range, located in the southeastern part of the Tibetan Plateau, are an important water source for downstream residents and ecological systems. To better understand the variability of glaciers in this region, we used the band ratio threshold (TM3/TM5 for the Landsat TM /ETM+ and TM4/TM6 for Landsat OLI) to extract glacier outlines in ~1999 and ~2013. After that, we also generated a series of glacier boundaries and monitored glacier variations in the past 40 years with the help of the Chinese Glacier Inventory data (1975) and Landsat TM, ETM+ and OLI data. The total glacier area decreased by 37.69 ± 2.84% from 1975 to 2013. The annual percentage area change (APAC) was ~1.32% a-1 and ~1.29% a-1 in the periods 1975-1999 and 1999-2013, respectively. According to the lag theory, the reaction time is probably about 10 years and we discuss the variations of temperature and precipitation between 1965 and 2011. Temperature and precipitation increased between 1965 and 2011 at a rate of 0.34°C /10a and 15.4 mm/10a, respectively. Extensive meteorological data show that the glacier shrinkage rate over the period may be mainly due to increasing air temperature, while the increasing precipitation partly made up for the mass loss of glacier ice resulting from increasing temperature may also lead to the low APAC between 1999 and 2013. The lag theory suggests that glacier shrinkage may accelerate in the next 10 years. Small glaciers were more sensitive to climate change, and there was a normal distribution between glacier area and elevation. Glaciers shrank in all aspects, and south aspects diminished faster than others.

Accurate, high-resolution precipitation data is important for hydrological applications and water resource management, particularly within mountainous areas about which data is presently scarce. The goal of the this study was to assess the accuracy of TRMM 3B43 precipitation data from the southwest monsoon region of China between 1998 and 2011 based on the correlation coefficients, regression, and geostatistical methods. We found a strong correlation between TRMM 3B43 data and observational data obtained from meteorological stations, but the TRMM 3B43 precipitation data was consistently lower than that obtained from the weather stations. The TRMM 3B43 data was significantly different from the data obtained by weather stations located in the northwest and northeast regions of the Hengduan Mountains. The spatial distribution of precipitation obtained from TRMM 3B43 was also different from meteorological data, but the deviation was predominantly distributed along the northern longitude and southern latitude. In addition, the TRMM data more accurately reflected the regional precipitation patterns. Our results indicate that the TRMM 3B43 data should be used for hydrological applications and water resource management at meteorological stations that have a sparse and uneven distribution of observation stations in the southwest monsoon region.

According to the results of accelerated tests of acidification corrosion depth and compressive strength of concretes subjected to sulfuric acid environments, the acidification depth laws of concretes were predicted based on the grey system theory. Thus, the remaining compressive strength was calculated when the acidification depth reached the protection layer thickness of concrete structures, which indicates that the limit state of durability failure can be defined based on strength degradation, and the calculation process was illustrated by an example. The calculated results show that the remaining compressive strength values in the durability failure limit state for the concrete structures exposed to pH=2 and 3 sulfuric acid water environments and wet-dry cyclic sulfuric acid environment with pH=2 are 74%, 72%, and 80% of initial strength, respectively. The method provides references for the durability evaluation of concrete structure design under the acidic environments.

To study the pressure fluctuation and vibration in mixed flow pumps, we chose a mixed flow pump with specific speed of 436.1 to measure. The time domains and frequency domain at each monitoring point on diffuser and outlet elbow were analyzed, as well as the vibration frequency domain characteristics at the impeller outlet and near the motor. The results show that the peak value of pressure fluctuation peak decreased gradually with the increase of flow rate. The pressure fluctuation of each monitoring point had periodicity, and the frequency domain dominated by blade passing frequency and multiple shaft frequency. The vibration frequency of each monitoring point occurred at shaft frequency and its multiple shaft frequency. The dominant frequency and the second frequency were distributed in shaft frequency and double shaft frequency.

As mining depth increases, the gas content and pressure of the coal seams increase, and gas emissions from the coal face are significantly higher than those at shallower locations. This is more likely to occur in high-gas multi-seam mines and can result in fatal gas disasters. Therefore, extracting multiple seams with high methane content frequently requires implementing highly efficient methane extraction technique. Yangquan Coalfield, China, was selected as a case study, theoretical analysis on the evolution law of mining-induced overlying strata fracture was conducted, similarity model test was used to determine the gas enrichment areas, the results indicate that the distressed gas in the multi-seam is enriched in high-level and low-level area, based on the gas zoning enrichment law, a technique for coordinated extraction of the distressed gas in the high-gas multi-seam mining is proposed, and the high-level drilling holes are arranged to extract the gas in the high-level enrichment area, while low-level drilling holes are arranged to extract the gas in the low-level area; after the coordinated proposal was implemented, the workface was advanced faster, and coordinated extraction technique can also be used under other conditions for high-gas multi-seam mining.

0.7(0.1BiYbO3-0.9PbTiO3)-0.3 Pb(Mg1/3Nb2/3)O3 (0.7BYPT-0.3PMN) ternary piezoelectric ceramics were prepared by a columbite precursor method. The effects of sintering temperature on the crystalline phase, microstructure, and electrical properties of the ceramics were systematically investigated. There were two phases coexisting in the 0.7BYPT-0.3PMN ceramics sintered at 1100–1250 °C, one is the perovskite host phase with tetragonal symmetry and the other is Yb2Ti2O7 impurity phase. It was observed that, with increasing sintering temperature, the piezoelectric constant d33, dielectric constant er, planar electromechanical coupling coefficient kp, and Curie temperature TC increased initially and then decreased. An apparent structure distortion could also be observed in samples synthesized at high sintering temperature due to the severe volatilization of Pb and Bi. The optimum performances of the material were obtained for samples sintered at 1150 °C with d33 = 100 pC/N, er = 494, kp = 25.4%, and TC = 380 °C, respectively. It can be ascribed to the combined effect of a higher density, structural homogeneity with decreased tetragonality as well as a small amount of pyrochlore phase.

Thirty-six strains of marine actinomycetes were isolated from a sample of marine sediment collected from the Yellow Sea and evaluated in terms of their inhibitory activity on the growth of Aspergillus parasiticus and the production of norsolorinic acid using dual culture plate assay and agar diffusion methods. Among them, three strains showed strong antifungal activity and were subsequently identified as Streptomyces sp. by 16S rRNA gene sequencing analysis. The supernatant from the fermentation of the MA01 strain was extracted sequentially with chloroform and ethyl acetate, and the activities of the extracts were determined by tip culture assay. The assay results show that both extracts inhibited mycelium growth and toxin production, and the inhibitory activities of the extracts increased as their concentrations increased. The results of this study suggest that marine actinomycetes are biologically important for the control of mycotoxins, and that these bacteria could be used as novel biopesticides against mycotoxins.

Cost-effective and scalable preparation of two-dimensional (2D) molybdenum disulfide (MoS2) has been the bottleneck that limits their applications. This paper reports a novel coupled ultrasonication-milling (CUM) process to exfoliate natural molybdenite powders to achieve few-layer MoS2 (FL-MoS2) nanosheets in the solvent of N-methyl-2-pyrrolidone (NMP) with polyvinylpyrrolidone (PVP) molecules. The synergistic effect of ultrasonication and sand milling highly enhanced the exfoliation efficiency, and the precursor of natural molybdenite powders minimizes the synthetic cost of FL-MoS2 nanosheets. The exfoliation of natural molybdenite powders was conducted in a home-made CUM system, mainly consisting of an ultrasonic cell disruptor and a ceramic sand mill. The samples were characterized by X-ray diffraction, UV-vis spectra, Raman spectra, FT-IR, SEM, TEM, AFM, and N2 adsorption-desorption. The factors that influence the exfoliation in the CUM process, including the initial concentration of natural molybdenite powders (C in, 15–55 g L−1), ultrasonic power (P u, 200–350 W), rotation speed of sand mill (ω s, 1500–2250 r.p.m), exfoliation time (t ex, 0.5–6 h), and the molar ratio of PVP unit to MoS2 (R pm, 0–1), were systematically investigated. Under the optimal CUM conditions (i.e., C in = 45 g L−1, P u = 280 W, ω s = 2250 r.p.m and R pm = 0.5), the yield at t ex = 6 h reaches 21.6 %, and the corresponding exfoliation rate is as high as 1.42 g L−1 h−1. The exfoliation efficiency of the CUM mode is much higher than that of either the ultrasonication (U) mode or the milling (M) mode. The synergistic mechanism and influencing rules of the CUM process in exfoliating natural molybdenite powders were elaborated. The as-obtained FL-MoS2 nanosheets have a high specific surface area of 924 m2 g−1 and show highly enhanced electrocatalytic performance in hydrogen evolution reaction and good electrochemical sensing property in detecting ascorbic acid. The CUM process developed has paved a low-cost, green, and highly efficient way towards FL-MoS2 nanosheets from natural molybdenite powders.

The objective of this study is to generate dendritic cell (DC) vaccines by exposing DCs to C6 glioma cancer cell antigenic (tumor) peptides following the exposure of C6 cells to photodynamic therapy (PDT) and acid elution. Effects of these DCs on host immunity were assessed by measuring cytokine induction (following adaptive transfer into rats) and assessing DC-induced cytotoxic T lymphocyte (CTL)-mediated lysis of C6 target cells. Precursor dendritic cells were purified from rat bone marrow and matured in vitro. C6 cells were stimulated with PDT, and adherent cells were acid-eluted to obtain cell surface antigens, whole cell antigens were also isolated from supernatants. C6 cells not stimulated with PDT were also used to isolate antigens by acid elution or freeze-thaw methods for comparison purposes. The isolated antigens from the respective purification methods were used to sensitize DCs for the generation of DC vaccines subsequently transferred into SD rats. Following adoptive transfer, the changes in interleukin (IL)-12, IL-10, and TNF-α expression were measured in rat serum by ELISA. CTL-mediated lysis was assessed using the MTT assay. PDT-generated antigens further purified by acid elution had the greatest stimulatory effect on DCs based on the elevated serum IL-12 and TNF-α levels and decreased serum IL-10 levels. CTL activity in this group was also highest (percent lysis 95.5% ± 0.016) compared with that elicited by PDT-supernatants, acid elution, and freeze-thawing (or the control group), which had 90.2% ± 0.024, 73.3% ± 0.027, 63.6% ± 0.049, or 0.4% ± 0.063 lysis, respectively. PDT significantly enhanced tumor cell immunogenicity. These data suggested that DC vaccines prepared by treating tumor cells with PDT to generate antigen-specific CTL responses can be developed as novel cancer immunotherapeutic strategies.

Based on the problems of Global Education Assistance to Africa (GEAA), and combined with China’s rationale and practice of Education Assistance to Africa, this paper proposes a vision and assumption to improve the GEAA, that is, using the assistance rationale of ‘Africa-based’, ‘equal-relationship’, and ‘mutual-benefits’, through ‘multi-stakeholders cooperation’, ‘multi-modes operation’, and ‘multi-goals achievement’ to build one ‘harmonious world’.

Traditionally, the understanding of the demarcation between indemnity and compensation starts from Rechtswidrigkeit (illegality). However, with the rise of “Erfolgsunrecht theory” and the objective base of negligence, and with the convergence of the theoretic bases of compensation and indemnity, the demarcation between compensation and indemnity is vanishing. This phenomenon should have given rise to our retrospection on the traditional research on the methods of state indemnity, which, at the same time, would be of a big influence on the orientation of the amendments to our State Indemnity Law and how to adopt the legislation on administrative compensation. Hence, it is necessary to reconstruct the elements of state indemnity and administrative compensation.

To study the fundamental characteristics and biosafety of the compound bone morphogenetic protein (BMP) and rhBMP-2/CPC, and to provide a theoretical basis for the compound biologically active artificial bone made of calcium phosphate cement (CPC) and bone morphogenetic protein, simplex CPC was taken as the control group, and the compound with the blending ratio of 1g CPC to 5mg rhBMP-2 was taken as the experimentation group to determine the setting time, compressive strength, acute toxicological and sub acute toxicological properties. The osteogenic characteristic of compound rhBMP-2/CPC was measured by making animal model of radio discontinuous defect. The setting time of the two groups meets the clinical requirements, and the compressive strength of the solidified body of bone cement increases along with increasing the immersion time. Compound rh-BMP-2/CPC has a favorable osteogenic characteristic for animal model of radio discontinuous defect. The fundamental characteristics of the compound rhBMP-2 phosphate bone cement are basically the same as that of CPC, and also have a favorable biosafety and osteogenesis.