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The apical hook protects the meristems of dicot seedlings as they protrude through the soil; multiple factors, including phytohormones and light, mediate apical hook development. HOOKLESS1 (HLS1) plays an indispensable role, as HLS1 mutations cause a hookless phenotype. The ETHYLENE INSENSITIVE3 (EIN3) and EIN3-LIKE1 (EIL1) transcription factors integrate multiple signals (ethylene, gibberellins, and jasmonate) and activate HLS1 expression to enhance hook development. Here, we found that Arabidopsis thaliana PHYTOCHROME INTERACTING FACTOR (PIF) transcription factors act in parallel with EIN3/EIL1 and promote hook curvature by activating HLS1 transcription at a distinct binding motif. EIN3/EIL1 and PIFs can promote hook formation in the absence of the other. Jasmonate represses PIF function to inhibit hook development. Like EIN3 and EIL1, MYC2 interacts with PIF4 and hampers its activity. Acting together, EIN3/EIL1 and PIFs alleviate the negative effects of jasmonate/light and facilitate the positive effects of ethylene/gibberellins. Mutating EIN3/EIL1 and PIFs causes a complete hookless phenotype, marginal HLS1 expression, and insensitivity to upstream signals. Transcriptome profiling revealed that EIN3/EIL1 and PIFs additively and distinctly regulate a wide array of processes, including apical hook development. Together, our findings identify an integrated framework underlying the regulation of apical hook development and show that EIN3/EIL1 and PIFs fine-tune adaptive growth in response to hormone and light signals.

In an energy harvesting powered cooperative cognitive radio network, secondary users are mostly distributed in mobile environments. It is necessary to design an optimal policy to maximize secondary throughput. In this paper, we focus on maximizing the long-term secondary throughput by providing the secondary users two modes to choose at the start of each time slot. Under the partially observable Markov decision process framework, we propose an optimal mode selection policy for the distributed secondary users. Finally, we explore the influence of different parameters on the proposed policy with numerical simulations.

Background: Pulmonary Langerhans cell histiocytosis (PLCH) is an interstitial primary pulmonary disease, characterized by Langerhans cell proliferation. It is easily misdiagnosed in children. This study aimed to characterize the clinical manifestations and features of PLCH by retrospective analysis. Methods: A retrospective analysis was performed in 117 PLCH patients out of 338 LCH patients who were admitted in our center from November 2006 to October 2013. Variables between two groups were compared by Mann-Whitney U-test and Chi-square test. Kaplan-Meier curves were constructed to compare the survival rates and Cox regression to evaluate the effect of risk factors. Results: The median age of PLCH group was significantly lower than that of non-PLCH group (18.63 months vs. 43.4 months, P< 0.001). All PLCH children had other organ involvement and only 11 cases (9.4%) had respiratory symptoms. The most common radiologic finding was cystic lesions (29 cases, 24.8%). Pulmonary function abnormalities were dominated by obstructive ventilatory dysfunction (63 cases, 82.9%). The 5-year overall survival (OS) of PLCH children was 93.6% ± 2.3% and the event-free survival (EFS) was 55.7% ± 5.2%. Among the 38 cases with progressed or relapsed disease, five cases (13.2%) were due to progression or recurrence of lung damage. The 5-year OS of PLCH children with "risk organ" involvement was significantly lower than those without "risk organ" involvement (86.0% ± 4.9% vs. 100%, χ2= 8.793, P= 0.003). The difference of EFS between two groups was also significant (43.7% ± 7.7% vs. 66.3% ± 6.5%, χ2 = 5.399, P= 0.020). The "risk organ" involvement had a significant impact on survival (hazard ratio = 1.9, P= 0.039). Conclusions: PLCH mainly occurs in young children, and only a small percentage of patients have respiratory symptoms. They generally have other organ involvement. Most of PLCH children have a good prognosis and most lung lesions could have improved or stabilized. Management of "risk organ" involvement is the key point to improving EFS. Key words: Children; Langerhans Cell Histiocytosis; Lung

A resonant integrated optical gyroscope (RIOG) based on silicon nitride (Si3N4) waveguide ring resonator (WRR) with single-polarization performance is proposed and demonstrated. The Si3N4 WRR has high polarization-dependent loss and can maintain a single polarization state, thereby avoiding other polarization modes from affecting the performance of the RIOG. In this paper, we design and fabricate a Si3N4 WRR with a bending radius of 8 mm, which shows excellent single-polarization performance is demonstrated at different temperatures. Finally, a long-term bias stability (3600s) of 0.68°/s in an integration time of 164s are successfully demonstrated. To the best of our knowledge, this is the first reported to date for the Si3N4 WRR-based RIOG.

The first-wall materials and components are the most thermally loaded in-vessel components of a fusion machine, which are required to survive at high heat fluxes induced by the intense plasma bombardment. As a candidate material, the W/Cu composite was investigated from the aspects of choosing a feasible and preferable welding method for high performance and high strength. For this, a strong confinement thermal explosive welding technology was proposed to solve the key problems in producing high-quality W/Cu composite material without damage and shock-induced defects. The microstructural evolution of the welding interface was observed and analyzed in the paper. Combining with the numerical simulation, the evolution mechanism of the bonding interface and the changing rule of the grain structure of the material were studied. This comprehensive research allows to provide a new perspective for preparing high-quality W/Cu composite.

Objective To analyze the clinical characteristics, prognosis factors and risk factors of chronic active Epstein-Barr virus infection in children. Study design Observational analysis of baseline data and follow-up evaluation data of children with chronic active Epstein-Barr virus infection in our center between January 1, 2016 and December 31, 2019; they were followed through June 30, 2020. Results There were 96 children with chronic active Epstein-Barr virus infection (50 male and 46 female children), with the median age of 6.7 years (range from 0.6 to 17.6 years) at diagnosis. The median follow-up time was 16.5 months. The 3 most common clinical manifestations were fever, lymph node enlargement, and hepatomegaly or splenomegaly. Thirty-three patients (36.3%) also had a diagnosis of hemophagocytic lymphohistiocytosis (HLH). Epstein-Barr virus infected only T lymphocytes, natural killer cells, or both T- and natural killer-cell types in 15 (33.3%), 17 (37.8%), and 13 (28.9%), respectively. At the end of follow-up, 26 children had died, 60 survived, and 10 were lost to follow-up. Generally, progression-free survival was 69.8% ± 2.4%. The level of interleukin (IL)-6 and IL-10 and the combination of younger age and lower pathologic grade at diagnosis were independent prognostic factors by Cox regression analysis (P = .009 and .018, respectively). Conclusions Children with lower levels of IL-6 and IL-10, or with younger age and lower pathologic grades, generally had favorable outcomes at the terminal point of follow-up, indicating better prognostic signs.

In this work, explosive welding was introduced to manufacture Ag coating on Fe substrate. The microstructure evolutions of the Ag/Fe joint interface and the associated governing mechanisms during the collision process, were investigated by a comprehensive study combined advanced characterizations and smoothed particles hydrodynamics simulations. It was concluded that the self-developed explosive welding process enabled to attain high-quality Ag coatings effectively, certified by absence of geometric defects at the Ag/Fe interface and the surface of Ag foil. The simulation accurately reproduced the wavy interface and vortex structure observed in experiment. From this, the evolution of the wave was reconstructed and the formation mechanism of the vortex was revealed. The microstructure analyses revealed a remarkable diversity of the grain structure near the Ag/Fe interface. The equiaxed fine grains related to dynamic recrystallization were formed in the vicinity of the interface and also within the vortex. The grains of the Fe matrix slightly away from the interface became elongated, which reflected well the deformation features. Meanwhile, the columnar grains induced by molten and re-solidified processes were observed at the vortex boundary. The variation of these grain structures was responsible for the inhomogeneity of nanoindentation hardness distribution.

The fundamental evolution mechanisms of many important phenomena accompanying explosive welding of metal foils remain a subject of open discussion, due to the extreme difficulties of in-situ observations. In this work, a comprehensive study combined SPH (smoothed particles hydrodynamics) simulation and advanced characterization was performed to investigate the interfacial evolutions, nano-mechanical properties, and the associated governing mechanisms in Cu foil/Fe welding system. Based on the simulation results, a detailed evolution model of the wave formation was given, and a new explanation for the vortex formation was proposed. The microstructure analyses revealed that the grain structures adjacent to the joining interface were dramatically changed, where two different morphologies of equiaxed and columnar grains were detected at Fe and Cu side, respectively, and the vortex area was built of ultra-fine equiaxed nanometer grains. These microstructure changes were correlated very well with the nano-mechanical properties, and the perplexing evolution processes can be explained by dynamic recovery and recrystallization accompanied by different degrees of crystal growth and deformation. The predicted widths of recrystallization layer and hardened layer agree well with the experimental results, suggesting that the SPH simulation allows predicting the microstructure evolution during the high speed impact welding process in a quantitative way.

Experiments were conducted to study the underwater explosion performance of emulsion explosives (EE) after hot water bath. Spherical charges of EE with different sensitizers and hot water bath were prepared and tested. As for as-prepared charges, the detonation velocity experiments and underwater explosion experiments were carried out and the crystallization ratio was measured and calculated by the dissolution and neutralization method. The results showed an inverse relationship between explosion parameters (pressure peak, specific impulse, detonation velocity and specific total energy) and heating time. It also revealed that the effective explosive weight of EE was reduced with long time of hot water bath. Moreover, the crystallization ratio and the decreasing rate of explosion parameters of EE sensitized by NaNO2 were apparently higher than EE containing physical sensitizers (glass microballoon and perlite), which was attributed to the different destruction mechanism of EE. After 6-hour hot water bath, the EE containing physical sensitizers still retained detonator sensitivity and more than 80 % of specific total energy. Meanwhile, the crystallization ratio was less than 20 %. Whereas, the EE sensitized by NaNO2 lost the detonator sensitivity and the crystallization ratio of EE was also above 40 %.

The bubbling method has been refined to produce vaterite with both high productivity and purity for its promising applications. This involves: a) adding an adequate amount of ammonia water to achieve maximum precipitation of Ca2+, b) refining CO2 bubble sizes into microns by a designed gas disperser, and c) using optimal final pH condition and CO2 flow rate to obtain vaterite with both high productivity and purity. In addition, the conservation of vaterite was also investigated by exposing vaterite to two moist environments. The results show that 95.1 % pure vaterite can be produced with 88.8 % yield at a final pH value of 8.6 and CO2 flow rate of 11 l min−1. The corresponding vaterite particles mostly have a hollow structure. The conservation of vaterite is very sensitive to moisture, and it transforms into calcite gradually depending on the moisture content.

Experiments were conducted to study the underwater explosion performance of titanium hydride/RDX-based (TiH2/RDX) composite explosive. Cylinder charges with different TiH2 particle sizes and contents were prepared and tested. Explosion parameters like peak overpressure, impulse, shock energy, and bubble energy were analyzed. It was notable that underwater explosion performance of TiH2/RDX composite explosive was promoted by addition of small particle size TiH2 (D50=0.96 μm), in which case increasing TiH2 content also showed a favorable effect. The maximum increments of specific initial shock energy, bubble energy, and total energy were 10.5%, 6.4%, and 7.1% respectively. However, with bigger TiH2 particle sizes (D50=20.78 μm, D50=136.74 μm), the explosion parameters and the TiH2 content showed a negative relationship, which reveals that TiH2 particle size plays an important role in determining the reactivity of TiH2. Meanwhile, the interaction between TiH2 particle size and content was significant.

A recent study showed that the properties of recycled concrete aggregates (RCAs) can be significantly improved by acetic acid treatment. This study demonstrates that a useful product, vaterite, a metastable polymorph of calcium carbonate, can be produced from the waste solution of this treatment through an improved pH swing method. The salient feature of this improved method is that ethanol is added into the waste solution to not only prohibit the phase transformation of vaterite, but also to suppress the ionization of the regenerated acetic acid. This method allows not only more vaterite to be produced, but also more acetic acid to be regenerated from the waste solution through a CO 2 bubbling method. Meanwhile, CO 2 can be permanently stored in the produced vaterite to achieve sustainable CO 2 sequestration. Experimental results confirm that near-pure vaterite can be produced from the waste solution by adding 20% ethanol into the waste solution. 1 kg RCAs can be used to produce about 76.6 g vaterite and permanently store 33.7 g CO 2 by using this new method. The potential application of the produced vaterite as an internal curing agent for high performance concrete has also been demonstrated.

Background Hemophagocytic lymphohistiocytosis (HLH) is a rare potentially fatal illness characterized by impaired natural killer and cytotoxic T cell function. Chronic granulomatous disease (CGD) is an inherited immune deficiency caused by a defect in the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase complex. CGD patients display an increased susceptibility to infection with bacteria and fungi. Repeated infections lead to an increased risk for developing HLH. The case of CGD with repeated Salmonella septicemia complicated with HLH is very rare, and the CGD mutation identified has not been reported. Case presentation A 3-year-old boy was admitted to our hospital for fever, hepatosplenomegaly and pancytopenia. According to the clinical manifestations and laboratory results, hemophagocytic lymphohistiocytosis (HLH) was diagnosed. Blood and bone marrow culture confirmed septicemia due to Salmonella Typhimurium. On the basis of antiinfection treatment, methylprednisolone was used to control HLH. After treatment, the clinical symptoms and laboratory results improved. Gene analysis showed a novel hemizygous CYBB gene mutation: c.302A > G (p.H101P). Combined with a past history of recurrent infection, the child was diagnosed with HLH secondary to CGD triggered by septicemia. Conclusions In case of a known (or highly suspected) CGD with a documented infection, clinical or biological features of HLH should encourage the physician to make possible to confirm or not the HLH. Therefore, to initiate the adequate treatment in association with anti-infective therapy.

X-linked inhibitor of apoptosis (XIAP) deficiency caused by mutations in the XIAP/BIRC4 gene is a rare inherited primary immunodeficiency also known as X-linked lymphoproliferative syndrome type 2 (XLP2). Hematopoietic stem cell transplantation (HSCT) is currently the only curative strategy available. However, few studies of haploidentical HSCT have been published regarding the outcomes in patients with this syndrome. We evaluated the XIAP gene analysis and clinical characteristics of four Chinese patients with XIAP who underwent haploidentical HSCT. The mutations in the two of four patients had not yet been reported in the literature. All of the patients had recurrent hemophagocytic lymphohistiocytosis but did not have a good matched donor and underwent haploidentical HSCT at BCH in China between September 2016 and December 2018. All four patients received antithymocyte globulin with fludarabine-based regimens. Two patients underwent reduced intensity conditioning (RIC), and the other two received modified myeloablative conditioning (MAC) regimens. Three of the four patients survived. Three patients experienced complications with mixed chimerism. One of the four patients who underwent RIC had early graft loss and then developed grade IV acute graft-versus-host disease (GVHD) after donor lymphocyte infusion with bone marrow. The two patients who received MAC survived with no or mild GVHD, even though one of them developed hepatic veno-occlusive disease in the early stage of transplantation. Haploidentical HSCT may be a treatment option for patients with XIAP deficiency who lack a good matched donor. More studies are needed to determine whether modified MAC with reduced toxicity is more suitable for haploidentical transplantation.

MPIG6B has orthologous physiological effects in human and mice, which regulates platelet production and function. For this reason, germline loss-of-function mutations in this gene cause congenital thrombocytopenia that is associated with bone marrow fibrosis, organomegaly and subsequent anemia. This was described in a consanguineous Arabian family with a novel truncation mutation (p.C108*) in chromosome 6, open reading frame 25 gene, also known as MPIG6B. In our case, we identified a homozygous frameshift variation (c.392delC,p.P134Lfs*10) in a ten-month-old boy presenting with signs of pallor, splenomegaly and resistant hemocytopenia. Interestingly, this is a new form of a MPIG6B variation, which could disrupt the effector protein for the key hematopoiesis regulators. This report adds to the growing number of mutations causing complex clinical manifestations associated with pancytopenia and splenomegaly in children.

Experimental studies of deflagration flame quenching by crimped ribbon flame arrestors were performed in a circular ducting with propane-air flammable mixture. The corresponding flameproof velocities were determined systemically. The results showed that the channel length, the expansion ratio and the aperture size must be taken into consideration to predict the performance of the crimped ribbon flame arrestors. To explore the relationship between flameproof velocity and arrestor structure, numerical simulations were carried out. The simulated results showed that with the reduction of the hydraulic diameter of the aperture size, the flameproof velocity is increased, which implies the basic angle must be considered when crimped ribbon flame arrestors are used to quench deflagration flame. In addition, the influence of the expansion ratio is of great significance on the efficiency of flame arrestors. The flameproof velocity can be reduced to be a value related to the expansion ratio. Two empirical formulas were derived to exhibit the relation between the flameproof velocity and the characteristics of the flame arrestor, which can be used to predict the performance of crimped ribbon arrestors.

In order to explore a new method for the explosive welding of aluminum alloy to steel, a 5083 aluminum alloy plate and a Q345 steel plate with dovetail grooves were respectively employed as the flyer and base plates. The parameters adopted in the explosive welding experiment were close to the lower limit of weldable window of 5083 aluminum alloy to Q345 steel. The bonding properties of 5083/Q345 clad plate were studied through mechanical performance tests and microstructure observations. The results showed that the aluminum alloy and steel plates were welded under the actions of metallurgical bonding and meshing of dovetail grooves. The tensile shear strength of 5083/Q345 clad plate met the requirements of the bonding strength of Al/Fe clad plate. The interfaces between aluminum alloy and the upper and lower surfaces of dovetail grooves were mainly welded through direct bonding, and discontinuous molten zone emerged in the local region; while the interface between aluminum alloy and the inclined surface of dovetail grooves was bonded by continuous molten layer. The brittle intermetallic compounds FeAl2 and Al5Fe2 were generated at the bonding interfaces of 5083/Q345 clad plate. The fracture surface of the tensile specimen exhibited ductile and quasi-cleavage fractures. Keywords: Explosive welding, Dovetail grooves, Metallurgical bonding, Meshing, Bonding strength

As the only solid detonation product of CHNO negative oxygen balance explosive, the condensed carbon plays an important role in the energy-releasing and working capability by coagulation and phase transition. But the process of condensed carbon transformation has always been controversial because the detonation is so fast and the carbon phase is so complex (amorphous phase, graphite phase, diamond phase, liquid phase, etc.), that spatial and temporal resolution of existing test techniques is difficult to meet the requirements of quantitative analysis. If we can accurately understand the phase transition and coagulation process of carbon condensation during detonation, we can provide effective reference data for the accurate evaluation of explosive energy release process and damage effect, rational design of formula, and accurate correction of non-ideal explosive detonation model.

Achieving high quality tantalum coatings on common metals is still a challenging task, due to potential technical problems such as high differences in melting points and formation of intermetallic compounds. In this work, an improved explosive welding technique was successfully employed to prepare tantalum coatings on a steel substrate, where a special charging structure and a double-layer buffer structure were used to obtain an ideal welding condition. The microstructure analyses of the achieved joints were conducted using electron backscatter diffraction (EBSD), and scanning electron microscope (SEM) cooperated with energy dispersive X-ray spectroscopy (EDS) system. Tensile, three-point bending, and nanoindentation tests were carried out to investigate the mechanical properties. It was concluded that the improved explosive welding technique was a suitable method to produce Ta coatings on steel substrate. In both microstructure observation and mechanical tests, an excellent bonding quality between Ta foil and Q235 plate was confirmed. In addition, a novel vortex structure, good for preventing crack propagation from the brittle melted area, was observed at the Ta/Fe interface. Finally, the corrosion test indicated that the corrosion resistance of Q235 plate was remarkably improved after being coated by Ta foils using explosive welding. Keywords: Explosive welding, Tantalum foil, Steel plate, Corrosion resistance

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening disease. In clinical practice, we have observed that some HLH patients who have features of systemic autoinflammatory diseases (SAIDs) exhibit unique clinical manifestations and outcomes different from other HLH patients. We analyzed data from 25 HLH patients who were considered to have SAIDs; data were collected from patients of our center between January 1, 2015 and September 1, 2018. The median age of the patients was 1.75 years. In the early phase, all patients had a fever and 92% of patients had a rash; 96% of patients had high white blood cell count (WBC), C-reaction protein, and erythrocyte sedimentation rate. With progression, the above laboratory results decreased gradually. During the HLH period, we compared SAIDs-related HLH and Epstein-Barr virus (EBV)-related HLH and found that rash was more common (92%, P

Considering a cognitive radio network (CRN) with the energy harvesting (EH) capability, we design a sensing-based flexible timeslot structure for a secondary transmitter (ST). This structure focuses on an unslotted transmission mode between two primary users (PUs). In this structure, the ST can decide whether to transmit data or to harvest energy based on the sensing results. Aiming to maximize the long-term average achievable throughput of the secondary system, we study an optimal policy, including the optimal energy harvesting time as well as the optimal transmit power. To reduce the computational complexity, we also derive an effective suboptimal policy by maximizing the upper bound on the throughput. Finally, simulation results demonstrate that the proposed flexible timeslot structure outperforms the conventional fixed timeslot structure in terms of average achievable throughput.

In millisecond-delay blasting and deep water blasting projects, traditional emulsion explosives sensitized by the chemical sensitizer $$\hbox {NaNO}_{2}$$ often encounter incomplete explosion or misfire problems because of the “pressure desensitization” phenomenon, which seriously affects blasting safety and construction progress. A $$\hbox {MgH}_{2}$$ -sensitized emulsion explosive was invented to solve these problems. Experimental results show that $$\hbox {MgH}_{2}$$ can effectively reduce the problem of pressure desensitization. In this paper, the factors which influence the pressure desensitization of two types of emulsion explosives are studied, and resistance to this phenomenon of $$\hbox {MgH}_{2}$$ -sensitized emulsion explosives is discussed.

An explosive mixture of cyclotrimethylenetrinitramine (RDX) and titanium hydride (TiH2) is introduced. To investigate the explosion characteristics of the composite explosive, charges with various contents of the TiH2 powder are prepared and tested in air explosion experiments. Results show that the peak overpressure, positive duration, and positive specific impulse increase as the content of TiH2 increases from 10 to 20%, as compared to passivated RDX. The peak overpressure, duration, and specific impulse have the largest increase of 6, 9, and 23%, respectively, as compared to passivated RDX, when the TiH2 content is 20%. The effect of the TiH2 particle size is also considered. The charge containing the TiH2 powder with a mean particle size of 4.6 μm shows higher values of the three parameters than that containing 45-μm TiH2 particles under the condition of the same content of TiH2. However, the relationship between the detonation velocity and TiH2 content is a linear inverse proportion, and the particle size of TiH2 has a minor effect on it. Solid explosion products of the TiH2/RDX composite explosive are analyzed by x-ray photoelectron spectroscopy (XPS) and energy dispersive x-ray spectroscopy (EDX). TiO2 is found in explosion products, which is believed to form due to TiH2 oxidation.

Due to the low efficiency problem of cut blasting in rock drivage, a new type of jet cracker is invented. There are three development stages of this new type of radial jet cracker, and each stage has its corresponding experiment, and optimal design will be carried out based on the problems of the previous stage, but experimental principles of these radial jet crackers are still the same. The main structure of the radial jet cracker is circular tube, and there are several shaped rings designed on it, which not only can reduce charge quantity but also raise the utilization ratio of explosive energy. Experimental results show that, with this cracker, the utilization ratio of blasting hole is 98%, and the blasting efficiency and the length of cyclical footage had been improved.

To study underwater explosions, a new type of an underwater pressure sensor using polyvinylidene fluoride as a sensing element is developed and well calibrated. The sensor is then applied in underwater explosion tests of RDX explosives with addition of aluminum in the fiber or powder form. The results show that the peak pressure of shock waves slightly decreases when aluminum is added to RDX, and the peak pressure of the fiber aluminum composite explosive is slightly inferior to that of the explosive containing the aluminum powder at the same measuring positions.

In order to resolve the current issues about the backward method of charge and low energy efficiency of explosives, honeycomb structure explosives and double sided explosive cladding were used in the present study. Honeycomb structure explosives are used to ensure the quality of charge. Double sided explosive cladding can clad two composite plates simultaneously. Honeycomb structure explosives and double sided explosive cladding, which significantly reduce the critical thickness of stable detonation of explosives, are used to increase the energy efficiency of explosives and save the amount of explosives. Emulsion explosives with the thickness of 5 mm can be stable detonation. In this paper, the experiment of double sided explosive cladding for two groups of steel of No. 45 with the thickness of 2 mm to steel of Q235 with the thickness of 16 mm and two groups of stainless steel with the thickness of 3 mm to steel of Q235 with the thickness of 16 mm were successfully investigated. Without constraints, the critical diameter of emulsion explosives is 14–16 mm. Compared to the existing explosive cladding method, the consumption of explosives for steel of No. 45 to steel of Q235 and stainless steel to steel of Q235 are reduced by 83% and 77% in the case of cladding the same number of composite plates. The explosive cladding windows and collision velocity of flyer plate were calculated before experiment. It shows that the calculation prefigures exactly the explosive cladding for steel of No. 45 to steel of Q235 and stainless steel to steel of Q235.

A number of polymers have been proposed for use as propellants in space launch and thruster applications based on laser ablation, although few prior studies have either evaluated their performance at background pressures representative of the upper atmosphere or investigated interactions with ambient gases other than air. Here, we use spatially and temporally resolved optical emission spectroscopy to compare three polymers, poly(ethylene), poly(oxymethylene), and glycidyl azide polymer, ablated using a 532 nm, nanosecond pulsed laser under Ar and O2 at pressures below 1 Torr. Emission lines from neutrally and positively charged atoms are observed in each case, along with the recombination radiation at the interaction front between the plasma plume and the background gas. C2 radicals arise either as a direct fragmentation product or by a three-body recombination of C atoms, depending on the structure of the polymer backbone, and exhibit a rotational temperature of ≈5000 K. The Sedov-Taylor point blast model is used to infer the energy release relative to the incident laser energy, which for all polymers is greater in the presence of O2, as to be expected based on their negative oxygen balance. Under Ar, plume confinement is seen to enhance the self-reactivity of the ejecta from poly(oxymethylene) and glycidyl azide polymer, with maximum exothermicity close to 0.5 Torr. However, little advantage of the latter, widely considered one of the most promising energetic polymers, is apparent under the present conditions over the former, a common engineering plastic.

A new aluminized explosive is proposed, and the approach is to replace the aluminum powder in the traditional aluminized explosive with an aluminum film. The purpose is not only to improve mechanical properties and lower the impact sensitivity of traditional aluminized explosives, but also to reduce environmental pollution in the aluminum particle production process. The pressure-time curves of the aluminum film explosive and RDX are measured in underwater explosion experiments. The peak pressure, impulse, shock wave energy, and bubble energy are obtained by analyzing the curves. The results of the study indicate that the peak pressure of the aluminum film explosive is lower than that of RDX. However, the aluminum film explosive maintains a high pressure for a longer period of time. The large amount of energy is found to liberate by subsequent reactions of the Al film with the primary detonation products. The increase in the explosion energy of the aluminum film explosive is based mainly on the increase in the bubble energy.

This article illustrates a method to predict flammability of mixtures containing methane, oxygen, and other inert gases like nitrogen and carbon dioxide based on chemical equilibrium. Calculated adiabatic flame temperature (CAFT) is used as a parameter to determine whether a fuel mixture is combustible or not. Our calculated results are obtained with initial conditions of 1 atm and 298 K. Compared with experimental data reported in the literature, we find that 1,450 K is an appropriate threshold of flammability. Mixtures with adiabatic flame temperatures higher than this value are considered flammable while those lower are judged as nonflammable. Using this criterion, it is convenient for us to predict the flammable zone and prevent the existence of flammable mixtures to ensure security. Showing the CAFT of fuel mixtures with various concentrations in a triangular flammability diagram, we can easily find out the influence of inert gases, oxygen, and soot formation on the mixture's flammability, respectively. © 2014 American Institute of Chemical Engineers Process Saf Prog 34: 31–35, 2015

Micro laser propulsion is a new technology with brilliant future. In order to reduce the thruster mass and volume further, laser bar is introduced into the micro laser propulsion field. A new kind of 220 × 20 μm rectangular beam of 808 nm was obtained by oval lens compressing the light of diode at fast axes and slow axes. The effect of laser power, energy and coating thickness of double base propellant on propulsion performance was studied. Propulsion performance of double base propellant under static and dynamic mode shows some different characters. Compared to round beam, the new beam prefers to produce higher impulse. Ablation efficiency of DBP shows better performance in short laser duration. The combination of power density and energy density decides the laser propulsion performance. The new rectangular beam is appropriate for millisecond micro-laser propulsion.

In order to suppress the undesired polarization in the hollow-core photonic-crystal fiber (HCPCF) resonator and reduce the loss of the resonator, we realize a low-crosstalk polarizing resonator with the polarization-correlated phase modulation technique (PCPM). In addition, we put forward a homologous multi-frequency differential detection scheme, with which the backscattering noise and the backreflection noise of the gyro can be well suppressed. Finally, we realize a hollow-core photonic-crystal fiber optic gyro based on the low-crosstalk polarizing resonator and the homologous multi-frequency differential detection. With this novel gyro system, a bias stability of 1.23°/h is successfully demonstrated.

Due to low detonation power and pressure desensitization problems that traditional emulsion explosives encounter in utilization, a hydrogen-based emulsion explosives was devised. This type of emulsion explosives is sensitized by hydrogen-containing material MgH2, and MgH2 plays a double role as a sensitizer and an energetic material in emulsion explosives. Underwater explosion experiments and shock wave desensitization experiments show that an MgH2 emulsion explosives has excellent detonation characteristics and is resistant to pressure desensitization. The pressure desensitization–resistant mechanism of MgH2 emulsion explosives was investigated using scanning electron microscopy.

Preliminarily results on the reaction mechanism of detonation of composite emulsion explosives sensitized by MgH2, which simultaneously plays the role of an energetic material, are presented. Compared to emulsion explosives sensitized by glass microspheres, emulsion explosives sensitized by magnesium hydride have a different reaction mechanism of detonation. The shock wave overpressure, specific impulse, shock wave energy, and bubble energy are all greatly increased with the use of MgH2, and it is noticeable that the shock wave overpressure and shock wave energy increase by 17% and 24%, respectively. In addition, emulsion explosives sensitized by MgH2 improve significantly in terms of detonation velocity and brisance. These emulsion explosives also meet safety requirements.

We investigated the characteristics, frequency, and prognosis of central nervous system (CNS) involvement in patients with hemophagocytic lymphohistiocytosis (HLH).Neurological manifestations were prospectively assessed in 92 children with HLH treated from January 2004 to August 2008 at our center; 82 (89%) had associated viral infections (69 Epstein-Barr virus), one empyema, while no associated disease was identified in the remaining nine. Prior to treatment, all underwent cerebrospinal fluid (CSF) evaluation, brain computer tomography (CT) and/or magnetic resonance imaging (MRI).At diagnosis, 43 (47%) children had CNS involvement. Twelve patients (13%) had neurological symptoms, including seizures, ataxia, coma, cranial nerve palsy, and hemiplegia. All patients improved after 8 weeks of therapy, but one later developed progressive neurological symptoms and six discontinued therapy due to progressive systemic symptoms and/or other reasons. Fifteen patients had CSF abnormalities that all normalized completely after 6 weeks of treatment. Thirty-six patients (39%) had neuroradiological abnormalities; with 5 still under treatment, 15 lost to follow-up, and 16 followed after completion of therapy. Of these 16, 12 improved, 3 were unchanged, and 1 progressed. Among all 21 children with CNS involvement followed after completion of therapy, 10 recovered completely, 10 improved (3 had remaining neuroradiological abnormalities), and 1 progressed clinically and neuroradiologically.Most patients reported here suffered from secondary HLH and since CNS involvement is frequent in HLH, brain MRI at diagnosis is recommended in all HLH patients. Clinical and CSF abnormalities often improved within 8 weeks of therapy, but CT/MRI abnormalities normalized more slowly and less frequently.