Search

Sensory data about most natural task-relevant variables are entangled with task-irrelevant nuisance variables. The neurons that encode these relevant signals typically constitute a nonlinear population code. Here we present a theoretical framework for quantifying how the brain uses or decodes its nonlinear information. Our theory obeys fundamental mathematical limitations on information content inherited from the sensory periphery, describing redundant codes when there are many more cortical neurons than primary sensory neurons. The theory predicts that if the brain uses its nonlinear population codes optimally, then more informative patterns should be more correlated with choices. More specifically, the theory predicts a simple, easily computed quantitative relationship between fluctuating neural activity and behavioral choices that reveals the decoding efficiency. This relationship holds for optimal feedforward networks of modest complexity, when experiments are performed under natural nuisance variation. We analyze recordings from primary visual cortex of monkeys discriminating the distribution from which oriented stimuli were drawn, and find these data are consistent with the hypothesis of near-optimal nonlinear decoding., Sensory data about most natural task-relevant variables are entangled with task-irrelevant nuisance variables. Here, the authors present a theoretical framework for quantifying how the brain uses or decodes its nonlinear information which indicates near-optimal nonlinear decoding.

To analyze the clinical phenotype and MYH7 gene variant in a Chinese pedigree affected with hypertrophic cardiomyopathy (HCM).The proband was screened for variant of 96 cardiomyopathy-associated genes by exonic amplification and high-throughput sequencing. Candidate variant was verified by Sanger sequencing among 300 healthy controls as well as family members of the proband. Co-segregation analysis of genotypes and clinical phenotypes was carried out for the pedigree. Clustal X software was used to analyze the sequence conservation of the variant among various species, and its pathogenicity was predicted by using bioinformatics software.6 out of 12 members from this pedigree were found to harbor heterozygous c.4124AG (p.Tyr1375Cys) variant of the MYH7 gene, among whom five were diagnosed with HCM. The remaining one had failed to meet the diagnostic criteria for HCM, but had abnormal ECG. The same variant was not found in the 300 healthy controls. Amino acid sequence analysis showed that the variant is located in a highly conserved region, and bioinformatics analysis predicted that this variant may affect protein function and has a deleterious effect. Based on the American College of Medical Genetics and Genomics (ACMG) guidelines, the variant was predicted to be likely pathogenic (PM2+ PP1_Moderate+PP3+PP5).The c.4124AG (p.Tyr1375Cys) variant of the MYH7 gene probably underlay the pathogenesis in this pedigree. Above finding has important value for the early diagnosis of patients with HCM.

The mutation MYBPC3–E334K is a culprit mutation of hypertrophic cardiomyopathy (HCM). The pathogenicity of MYBPC3–E334K is conflicting in ClinVar because of the limited segregation data and the relatively high frequency in gnomAD (0.03% overall, with 0.3% in East Asians and 0.8% in Japanese). The main aim is to clarify the clinical importance and phenotype–genotype correlations in subjects with or without MYBPC3–E334K alone. The prevalence of MYBPC3–E334K was sequenced in 1017 HCM unrelated probands. The clinical features, morphology phenotypes, and electrical phenotypes were further analyzed according to the phenotype and genotype status in families with single-mutation MYBPC3–E334K. Nine of 1017 (0.88%) unrelated HCM probands were detected harboring MYBPC3–E334K, and three of them harbored a second variant in sarcomere protein gene. Family study and co-segregation analyses indicated that patients with single-mutation MYBPC3–E334K showed autosomal dominant mode of inheritance with incomplete penetrance. The overall disease penetrance was 52.6%, and the disease penetrance was higher in males than in females (100% in men vs 25% in women, p = 0.003). The mean age at diagnosis of males was approximately 25 years younger than females (36.57 ± 18.65 vs 62.33 ± 12.10, p = 0.062). The variant MYBPC3–E334K was classified as a likely pathogenic variant, and a second sarcomere variant did not reveal obvious cumulative effects. The patients harboring single-mutation MYBPC3–E334K had incomplete penetrance, and males demonstrated higher penetrance and early onset HCM than females. A second sarcomere variant did not reveal obvious cumulative effects.

Background Light-chain (AL) amyloidosis is the most common type of systemic amyloidosis with poor prognosis. Currently, the predictors of cardiac involvement and prognostic staging systems are primarily based on conventional echocardiography and serological biomarkers. We used three-dimensional speckle tracking echocardiography (STE-3D) measurements of strain, hypothesizing that it could detect cardiac involvement and aid in prediction of mortality. Methods We retrospectively analysed 74 consecutive patients with biopsy-proven AL amyloidosis. Among them, 42 showed possible cardiac involvement and 32 without cardiac involvement. LV global longitudinal strain (GLS), global radial strain, global circumferential strain and global area strain (GAS) measurements were obtained. Results The GLS and GAS were considered significant predictors of cardiac involvement. The cut-off values discriminating cardiac involvement were 16.10% for GLS, 32.95% for GAS. During the median follow-up of 12.5 months (interquartile range 4–25 months), 20 (27%) patients died. For the Cox proportional model survival analysis, heart rate, cardiac troponin T, NT-proBNP levels, E/e’, GLS, and GAS were univariate predictors of death. Multivariate Cox model showed that GLS ≤ 14.78% and cardiac troponin T ≥ 0.049 mg/l levels were independent predictors of survival. Conclusions STE-3D measurements of LV myocardial mechanics could detect cardiac involvement in patients with AL amyloidosis; GLS and cardiac biomarkers can provided prognostic information for mortality prediction.

Xueli Zhao,1 Xuanying Wang,1 Jing Wang,1 Jiani Yuan,1 Juan Zhang,1 Xiaoli Zhu,1 Changhui Lei,1 Qianli Yang,1 Bo Wang,1 Feng Cao,2 Liwen Liu1 1Department of Ultrasound of Xijing Hospital, Xijing Hypertrophic Cardiomyopathy Center, Fourth Military Medical University, Xi’an 710032, People’s Republic of China; 2Department of Cardiology, Chinese PLA General Hospital, Beijing 100700, People’s Republic of ChinaCorrespondence: Liwen Liu Email liuliwen@fmmu.edu.cnIntroduction: Currently, the unsatisfactory treatment of cardiac hypertrophy is due to the unbridled myocardial fibrosis. Melatonin has been demonstrated to ameliorate cardiac hypertrophy and its accompanied fibrosis in previous studies. But it is not clinically appealing due to its short-lasting time against the hostile microenvironment when administered orally.Methods: Herein, to address this, poly (lactide) polycarboxybetaine (PLGA-COOH) accompanied by cardiac homing peptide (CHP) and superparamagnetic iron oxide nanoparticles (SPIONs) were used to establish a novel drug delivery and transportation strategy for melatonin via a facile two-step emulsion method. This study characterized these nanoparticles (CHP-mel@SPIONs) and tested their delivery to the hypertrophied heart and their effect on myocardial hypertrophy and fibrosis in an animal model of pressure overload-induced cardiac hypertrophy.Results: The engineered magnetic nanoparticles of CHP-mel@SPIONs were spherical (diameter = 221 ± 13 nm) and had a negative zeta potential of − 19.18 ± 3.27 mV. The CHP-mel@SPIONs displayed excellent drug encapsulation capacities of SPIONs (75.27 ± 3.1%) and melatonin (77.69 ± 6.04%) separately, and their magnetic properties were characterized by constructing magnetic hysteresis curves and exhibited no remnant magnetization or coercivity. The animal experiments showed that compared with mel@SPIONs, CHP-mel@SPIONs accumulated more in the heart, especially in the presence of an external magnetic field, with in vivo echocardiography and RT-PCR and histological assessments confirming the amelioration of the myocardial hypertrophy and fibrosis with low drug doses.Conclusion: This simple biocompatible dual-targeting nanoagent may be a potential candidate for the guided clinical therapy of heart disease.Keywords: magnetic targeting, cardiac homing peptide, cardiac hypertrophy, melatonin, myocardial fibrosis

Humans can often handle daunting tasks with ease by developing a set of strategies to reduce decision making into simpler problems. The ability to use heuristic strategies demands an advanced level of intelligence and has not been demonstrated in animals. Here, we trained macaque monkeys to play the classic video game Pac-Man. The monkeys’ decision-making may be described with a strategy-based hierarchical decision-making model with over 90% accuracy. The model reveals that the monkeys adopted the take-the-best heuristic by using one dominating strategy for their decision-making at a time and formed compound strategies by assembling the basis strategies to handle particular game situations. With the model, the computationally complex but fully quantifiable Pac-Man behavior paradigm provides a new approach to understanding animals’ advanced cognition.One-Sentence SummaryMacaque monkeys play Pac-Man with strategy-based hierarchical decision making, a cognitive capacity hitherto unknown in them.

Background The correlations between genotype and phenotype in hypertrophic cardiomyopathy (HCM) have not been established. Mutation of α-actin gene (ACTC1) is a rare cause of HCM. This study aimed to explore novel genotype–phenotype correlations in HCM patients with the variants in ACTC1 and myosin-binding protein (MYBPC3) genes in three unrelated Chinese families. Methods Clinical, electrocardiographic, and echocardiographic examinations were performed in three Han pedigrees. Exon and boarding intron analysis of 96 cardio-disease-related genes was performed using second-generation sequencing on three probands. The candidate variants were validated in 14 available family members and 300 unrelated healthy controls by bi-directional Sanger sequencing. The pathogenicity and conservation were calculated using MutationTaster, PolyPhen-2, SIFT, and Clustal X. Pathogenicity classification of the variants was based on American College of Medical Genetics and Genomics (ACMG) guidelines. Results Nine members fulfilled diagnostic criteria for HCM with clinical characteristics, electrocardiographic, and echocardiographic findings. Two candidate variants in ACTC1 p.Asp26Asn (ACTC1-D26N) and MYBPC3 p.Arg215Cys (MYBPC3-R215C) were identified in patients. Only ACTC1-D26N strongly co-segregated with the HCM phenotype. Seven patients who harbored variant ACTC-D26N only were diagnosed with non-obstructive HCM, and four of these patients exhibited a triphasic left ventricular (LV) filling pattern. Two patients carrying both ACTC1-D26N and MYBPC3-R215C variants showed a higher LV outflow tract pressure gradient. Bioinformatics analysis revealed that the two variants were deleterious and highly conserved across species. According to ACMG guidelines, ACTC1-D26N is classified as a likely pathogenic mutation. The second variation MYBPC3-R215C may function as a genetic modifier, which remains uncertain here. Conclusions Novel p.(Asp26Asn) mutation of ACTC1 was associated with HCM phenotype, and the penetrance is extremely high (∼81.8%) in adults. The second variation, MYBPC3-R215C may function as a genetic modifier, which remains uncertain here.

Danon disease is an X-linked glycogen storage disease characterized by skeletal myopathy, cardiomyopathy and intellectual impairment. It is caused by a loss-of-function mutation in the lysosome-associated membrane protein-2 (LAMP2) gene. In the present study, exon and boarding intron analysis of 96 cardio disease-associated genes was performed in 770 patients with hypertrophic cardiomyopathy (HCM) using second-generation sequencing. Next, the identified mutations were confirmed in family members of the patients and 300 healthy controls. Detailed clinical, electrocardiographic (ECG) and echocardiographic findings were recorded. A pathogenic mutation in LAMP2 was identified in 7 patients who phenotypically presented with HCM. A total of four patients had a fragmented QRS complex (fQRS) on surface ECG. In addition, two patients presented with ventricular preexcitation with a short PR interval. Compared with the patients with protein kinase AMP-activated non-catalytic subunit γ2 syndrome and Fabry disease, the 7 patients with Danon disease presented at an earlier age, had a smaller left atrial size, a thinner maximal left ventricular wall thickness and a lower probability of pacemaker implantation. Compared with 12 sex- and age-matched patients with sarcomere-protein mutations, the 4 patients with Danon disease had a lower left ventricular outflow tract gradient and worse diastolic function. The present study provided a comprehensive comparison of different pathologies presenting with HCM and reported on features of early-onset Danon disease, including the characteristic preexcitation and fQRS on ECG. This may provide valuable information that may be utilized for the early diagnosis and treatment of patients with Danon disease. The present study was registered as a clinical trial with ClinicalTrials.gov (Sep. 2, 2016; registry no. NCT02888132).

Objectives: This study aimed to assess left ventricular (LV) energy loss (EL), circulation and vortex area using vector flow mapping (VFM) in patients with latent obstructive hyper­trophic cardiomyopathy (LOHCM) and nonobstructive hypertrophic cardiomyopathy (NOHCM). Methods: Fourteen LOHCM patients, 10 NOHCM patients, and 11 healthy individuals were evaluated by transthoracic echocardiography. An offline VFM workstation was used to analyze the LV blood flow patterns and fluid dynamics. The hemodynamic parameters, EL, circulation, and vortex area in 7 cardiac phases were calculated and analyzed. Results: Compared with controls and NOHCM patients, EL was significantly higher in ­LOHCM patients during the rapid ejection phase, slow ejection (SE) phase, and isovolumetric relaxation phase (p < 0.05). LOHCM patients also showed increased circulation during SE compared to the other two groups (p < 0.05). The ability to discriminate between NOHCM and LOHCM was assessed by the area under the receiver-operating characteristic curve (AUC), and EL during SE was found to have the largest AUC (0.964); the best cutoff value was 6.34 J/m3/s, with a sensitivity of 100% and specificity of 80%. Conclusions: The VFM technique can detect abnormal changes of LV EL and vortex characteristics in hypertrophic cardiomyopathy patients. Compared with controls and NOHCM patients, the LOHCM patients have worse systolic and diastolic functions.

The study investigated laser welding with filler wire to determine the effects of wire feeding modes and the height of intersection of the wire and the beam (H) on weld geometry and droplet transfer. Droplet transfer behavior was investigated using high-speed imaging. The results showed that the wire melting changed with wire feeding. The leading wire melted completely and the welding depth and width were greater due to higher levels of energy available to heat the plate in the weld pool. The transfer mode changed to liquid bridge transfer and globular transfer with increased H value. With increasing H, the frequency of droplet transfer and the droplet size varied. At 2 mm H, the droplet transfer was very stable resulting in optimum welding.

Gas–solid chlorination of polyvinyl chloride (PVC) enables environmentally friendly and cost-effective production of chlorinated polyvinyl chloride (CPVC) as a high performance material. For this reaction-controlled process, understanding the correlation between steric effects and selectivity in chlorination is the key to improve product quality and process efficiency. We performed density-functional theory (DFT) calculations on model compounds of PVC chain segments in order to provide a microscopic view of gas–solid PVC chlorination. The micro-selectivity was compared and steric effects were visualized. The results showed that radical substitution in gas–solid PVC chlorination is stereoselective because of steric effects, in which the microstructure-determined local chain conformation plays a governing role. In the chlorination to the first degree, the formation of –CH2–CCl2– is allowed by direct radical substitution because –CHCl– groups are not necessarily sterically blocked; heterotactic triads are the most reactive due to little steric hindrance of its stable conformation. In the chlorination to the second degree, steric effects of the additional chlorine in product lead to much higher reaction barrier for radical substitution. The γ carbon of –CHCl– group and the β carbon of –CCl2– group are sterically blocked. These molecular-level understandings of steric effects and selectivity in radical substitution during gas–solid PVC chlorination suggest that by properly choosing reaction temperature, initiation modes and PVC feedstock, the chlorination progress can be tuned to avoid undesired side reactions and improve product quality.

A vibrated-bed reactor with an online UV-Vis measuring system was established in order to reveal the dynamic process of UV-enhanced chlorination of polyvinyl chloride (PVC). Influences of temperature, radiation time, and interval time of intermittent initiation on chlorination process as well as the overlapping enhanced effect of adjacent UV radiations were analyzed. By properly controlling the intermittent UV radiation, one can obtain a considerable steady reaction rate during the chlorination process to avoid the temperature runaway due to over-accelerated reaction. Solid-state nuclear magnetic resonance identified the microstructure change of chlorinated PVC particles. The whiteness value after thermal aging was determined to uncover the relationship between thermal stability and double-bond content, where the results accorded with the related theory on polymer dehydrochlorination.

A novel gas-solid method to synthesize chlorinated polyvinyl chloride (CPVC) is realized using a plasma circulating fluidized bed reactor (PCFBR), which decouples the plasma-assisted chlorination process into two steps i) the fast step for chlorination activation in the riser; ii) the slow step for gas-solid chlorination and chlorine migration inside particles in the accompanying bed. Experiments are carried out to investigate the influences of different parameters on the chlorination process. The synthesized CPVC has the chlorine content at about 67.5 wt% with the glass transition temperature of 130.4 °C. The characterization results by Raman Spectra, Py-GC-MS and solid-state 13C-NMR prove that the products have homogeneous chlorine distribution and low content of defect structure in.

The dynamic process of gas-solid chlorination of high-density polyethylene (HDPE) was revealed using a vibrated-bed reactor, where a UV-Vis measurement system was used to record the kinetics of chlorination online. Thermal and UV-enhanced chlorination at fixed temperature below the melting point (Tm) of HDPE were firstly investigated. It was observed that UV irradiation could accelerate the reaction rate. However, all of the prepared chlorinated polyethylene (CPE) products had unchlorinated crystal structures and a limitation of chlorine content. Multi-stage chlorination was hence designed for more homogeneous chlorination and decreasing the residual crystallinity. The differential scanning calorimetry (DSC) results showed effective decrease of the melting enthalpy (ΔHm) while the final reaction temperature was beyond Tm. Meanwhile, the presence of -CH = CH- bonds in the polymer chain revealed by solid-state nuclear magnetic resonance (S-NMR) indicated that the final reaction temperature should not be higher than 150 °C.

Dynamic characteristics of UV enhanced gas–solid PVC chlorination process were revealed by a UV–Vis spectral online analysis method. Experimental results showed an instantaneous increase of the chlorination rate as soon as UV light was affiliated, which demonstrated the intensified effect of UV radiation on PVC chlorination directly. Different affiliation methods of UV light were then studied, proving that continuous UV radiation could enhance the chlorination process significantly while intermittent UV radiation was able to initiate the chlorination reaction once it was conducted. Besides, experiments were carried out to study the influences of parameters on the chlorination process such as UV wavelength, chlorination temperature, partial pressure of chlorine gas and PVC raw materials. Among all the parameters, chlorination temperature and partial pressure of chlorine gas were testified as two key factors to determine the chlorination performance. Thermal analysis of CPVC products showed that their corresponding properties such as the glass transition temperature (Tg) and the homogeneity of chlorine distribution in polymer phase were improved with the increase of chlorine content.

This work presents a new method of catalyst surface modification by using oxygen plasma to change the oxidation state of active sites in metal oxide catalysts. The concentration of V5+ ions on phase-pure M1 MoVNbTeOx catalyst is the key factor of catalytic performance in the oxidative dehydrogenation of ethane (ODHE) process. Based on this variable valence system, oxygen plasma is used to increase the vanadium valence state in consideration of its strong oxidization properties at low temperature. As expected, the oxygen plasma can efficiently increase the V5+/V4+ ratio on the catalyst surface without influencing the M1 phase structure. The catalyst evaluation results confirm that the oxidized catalysts give better performance in the ODHE process, e.g., a 9% increase of ethane conversion using the catalyst treated by 50% O2 plasma compared to the M1 phase catalyst without any post-treatment under the conditions of 673 K and the contact time of 20.7 gcat h molC2H6−1. As a gas–solid method, plasma treatment provides an efficient and mild way for catalyst preparation and modification. It is anticipated that this novel approach can be extended to treat a rich variety of redox catalysts.

BACKGROUND Decoloration of dyes is a top priority to enhance biodegradability in color-free wastewater post-treatment. A gas–liquid dielectric barrier discharge (DBD) falling film reactor has been developed as a promising approach to the decoloration of dyes. RESULTS Rhodamine B was employed as a model compound. The effects of residence time of the liquid film with different initial concentrations, oxygen flow rates and oxygen concentrations (using different diluent gases, e.g. argon and nitrogen) were investigated. Longer liquid film residence time and lower oxygen flow rate resulted in higher decoloration efficiency. The decoloration efficiency in oxygen and nitrogen discharge was slightly higher than that in oxygen and argon discharge at the same oxygen concentration. The mechanisms of decoloration and the production of oxidative species are clearly revealed. The highest decoloration efficiency (up to 97.4%) with initial concentration of 50 mg L−1 was obtained in pure oxygen discharge with liquid residence time of 1.9 s at an oxygen flow rate of 100 mL min−1. CONCLUSION The proposed gas–liquid DBD falling film reactor is a promising alternative to advanced oxidation processes (AOPs) for effective treatment of dyes. These results are helpful for further real plasma wastewater treatment. © 2014 Society of Chemical Industry

Experiments were carried out in a vibrated fluidized bed to investigate the dynamic process of UV-enhanced synthesis of chlorinated polyvinyl chloride (PVC) using a gas–solid method, where a UV-Vis online analysis system was used to record the kinetics of chlorination. Meanwhile, a comprehensive mathematical model incorporating the distributed activation energy model was established to describe the hindrance effect of Cl atoms already inserted on the PVC polymer chain on the later insertion during the chlorination process. Each of the hypotheses in the model was validated by the well-designed experiments, and the model predictions matched well with the experimental data under various operating conditions. Sensitivity analyses of three primary operating parameters, that is, temperature, chlorine concentration, and UV intensity, were made for better understanding of the mechanism of PVC chlorination. It is anticipated that the modeling methodology in this work would be also suitable for similar gas–solid reaction systems. © 2014 American Institute of Chemical Engineers AIChE J, 60: 2235–2243, 2014

To evaluate the efficacy and side effects of 1550-nm fractional Er:Glass laser in treating atrophic acne scar.Thirty Chinese patients aged 18-65 with atrophic acne scars on both cheeks received a split-face treatment, one side with four sessions of treatment with fractional 1550-nm Er:Glass laser at 20-day interval and the other with topical asiaticoside cream application three times daily as control. Clinical response and side effects were evaluated by a dermatologist three weeks after each treatment and again 12 weeks after the last laser treatment. In addition, self-evaluation of satisfaction by the patients was done at the end of treatment.The study found that mean scores decrease after treatment was 5.65 ± 4.34 for the treated side and 1.23 ± 3.41 for the control side. The improvement in acne scars after the fractional Er:Glass laser 1550-nm treatment was more significant than the control side (p = 0.0001). The side effects were mainly local skin irritation and erythema, which disappeared within one week.The research results show that the fractional 1550-nm Er:Glass laser is an effective and safe treatment device for atrophic acne scars.

Melasma is an acquired disorder of symmetrical hyperpigmentation commonly seen in patients with Fitzpatrick skin types III and IV. Various novel therapeutic modalities have emerged to treat melasma. The large-spot low-fluence QS Nd:YAG laser has been widely used in Asia; however, the modality needs to be optimized because of the high recurrence rate. The objective of this study is to explore the clinical efficacy and safety of fractional-mode (Pixel) Q-switched neodymium-doped yttrium aluminum garnet (Nd:YAG) 1064-nm laser for treatment of melasma in Chinese patients. Twenty-seven patients were enrolled and completed all the treatment sessions and the 12-week follow-up. All were treated using the fractional-mode Pixel QS Nd:YAG (1064 nm) laser for eight sessions at a 2–3-week interval. Clinical photographs were taken using the Visia skin analysis imaging system. Two blinded assessors evaluated melasma area and severity index (MASI) scores before and 4 weeks after the final session. Melanin index (MI) and erythema index (EI) was measured before each treatment visit and after the final treatment. The degree of pigmentation and erythema was assessed using a tristimulus color analyzer. Physicians’ global assessment (PGA) and patients’ self-assessment were taken as the subjective assessments. Wilcoxon signed-rank test was performed to evaluate clinical response. Recurrence rate were also evaluated. Mean MASI scores decreased from 12.84 ± 6.89 to 7.29 ± 4.15 after treatment (p = 0.000). Seventy percent of patients got moderate to good improvements after all the treatment. Mean MI decreased significantly from 56.52 ± 23.35 to 32.75 ± 12.91 (p = 0.000). L value increased from 59.21 ± 2.22 before treatment to 61.60 ± 2.40 (p = 0.000) after therapy. The mean score of PGA was 3.76 ± 0.71, indicating a “moderate” clearance of the lesion. In patients’ self-evaluations, 70 % of the patients rated the result as “good” to “remarkable.” Partial recurrence was seen in 40 % patients at the 3-month follow-up. No severe adverse events were observed during the study, and the treatment was well tolerated. The fractional mode (Pixel) QS Nd:YAG 1064-nm laser is an effective and safe treatment for melasma. The recurrence rate was relatively lower than that reported in studies treating with large-spot low-fluence QS Nd:YAG laser.

An online UV–Vis analysis system is established to reveal the dynamic characteristics of plasma-assisted synthesis of chlorinated polyvinyl chloride (CPVC). Dielectric barrier discharge (DBD) plasma is generated in a vibrated-bed reactor intermittently so that the decoupled processes, i.e., the plasma initiated chlorination step and the chlorine migration step, are mimicked and operated repeatedly at atmospheric pressure. The instant chlorine consumption rate shows corresponding cyclic curves, illustrating evident plasma initiation followed by chlorine migration inside particles. The mechanism of process decoupling concept is therefore demonstrated vividly. Under the same power density of plasma, temperature is ascertained as a key factor to influence the PVC chlorination process. PVC particles with smaller sizes tend to be chlorinated easily, while other particle properties such as specific surface area and microstructure also exert complicated effect on the chlorination process. SEM results show that plasma can destroy the film layer on the particle surface, which makes the secondary sub-particles inside a PVC particle expose to the environmental chlorination gas and plasma. A pyrolysis GC–MS analysis helps to identify the molecular structure of CPVC product in terms of the compositions of chlorobenzene and dichlorobenzene in the pyrolized products, which are formed by chlorine atoms bonded on polymer chains.

In this paper, we propose a B-spline collocation method using artificial viscosity for solving singularly perturbed two-point boundary-value problems (BVPs). The artificial viscosity has been introduced to capture the exponential features of the exact solution on a uniform mesh and the scheme comprises a B-spline collocation method, which leads to a tri-diagonal linear system. The design of artificial viscosity parameter is confirmed to be a crucial ingredient for simulating the solution of the problem. A relevant numerical example is also illustrated to demonstrate the accuracy of the method and to verify computationally the theoretical aspects. The result shows that the B-spline method is feasible and efficient and is found to be in good agreement with the exact solution.

Based on the highlight method, this paper builds up the model of the radar target especially the near field. The database of the properties of near field, which is generated by the fuse antenna, is established using FDTD method. Combining simulation of circuit with computing of near field the simulator was made for fuse system. And by means of this simulator the imitative analysis and calculation on fuse system can be more reliable and accurate. In the end the result of time-domain simulation demonstrate that the simulator can be effectively applied in the synthetic test system to the fuse of the weapon system.

In this paper, we use the elementary methods to study the properties of the con- structive set S, and obtain some interesting properties for it.