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SnO2@MWCNT wave absorbent was firstly fabricated via a hydrothermal process followed by heat treatment. Then SnO2@MWCNT/silicone rubber wave-absorbing composites were obtained by solution casting method. XRD, Raman, TGA, XPS, and TEM analyses indicated the successful preparation of covalently bonded SnO2@MWCNT absorbent with encapsulation structure. When the mass fraction of SnO2@MWCNT was 7.5 wt% and the sample thickness was 2.6 mm, the SnO2@MWCNT/silicone rubber wave-absorbing composite displayed the minimum reflection loss (RLmin) of −56.9 dB and effective absorption bandwidth (EAB) of 3.1 GHz. The outstanding wave-absorbing performances of SnO2@MWCNT/silicone rubber wave-absorbing composites could be ascribed to the excellent impedance matching and dielectric loss capability. Furthermore, the corresponding 7.5 wt% SnO2@MWCNT/silicone rubber wave-absorbing composite exhibited heat resistance index (THRI) of 196.3 °C, higher than that of neat silicone rubber (187.4 °C).

Stacked DRAM used as the last-level caches (LLCs) in multicore systems delivers performance enhancement due to its capacity benefit. While the performance of LLC depends heavily upon its block replacement policy, the conventional replacement policy needs redesigning to exploit the best of DRAM cache and avoid its drawbacks. The existing DRAM cache insertion policy blindly forwards victim lines replaced from L3 to the off-chip memory, regardless of the potential for increased hits by placing a fraction of them in the DRAM cache. Nevertheless, a naive design that steers all dirty victims to the DRAM cache introduces excessive writeback traffic, which aggravates capacity misses and DRAM interference. To leverage insertions in terms of writeback or fill requests, we propose a collective writeback and fill policy that adapts to the distinct access patterns of heterogeneous workloads based on runtime misses and writeback efficiency. The synthesis result shows that the new policy has only a small hardware overhead. According to the experimental results on the gem5 simulator, the new policy increases harmonic instruction per cycle throughput by 18%, 11.6%, and 11.7%, respectively, compared with the Always Writeback (AW)–Always Fill policy, Never Writeback Adaptive DRAM Placement policy, and AW Adaptive DRAM Placement policy on 64-MB alloy cache, while the improvement is 19.3%, 13.7%, and 14.5% on 64-MB MissMap cache.

Currently, the standard management for locally advanced prostate cancer (PCa) is still controversial. In our study, we aimed to compare the survival outcomes of radical prostatectomy (RP) versus external beam radiotherapy (EBRT). We conducted analyses with a large cohort of 38,544 patients from the Surveillance, Epidemiology, and End Results (SEER) database (2004–2016). Propensity score matching, Kaplan-Meier method, and Cox proportional hazard regression were used to reduce the influence of bias and compare the overall survival (OS) and cancer specific survival (CSS). Several different sensitivity analyses including inverse probability of treatment weighting and standardized mortality ratio weighting were used to verify the robustness of the results. Totally, 33,388 men received RP and 5,156 men received EBRT with cT3-4N0M0 PCa were included in this study. According to the Kaplan-Meier curves, RP performed better in both OS and CSS compared with EBRT (P

Solar energy as an inexhaustible source of clean energy has attracted more and more attention. As an important way to collect source of energy, solar absorber is widely reported and studied. However, how to efficiently absorb the solar energy in the solar radiation range is a long-term perplexing problem. In this work, we propose a new type of broadband solar energy absorber based on monolayer molybdenum disulfide (MoS2). Tungsten (W) elliptical arrays are introduced into the structure to enhance its absorption. By exciting local surface plasmon resonance (LSPR) between monolayer MoS2 and tungsten elliptical arrays, ultra-broadband solar energy absorber with high absorption rate is obtained. Theoretical calculation by a finite-difference time-domain method (FDTD) shows that absorption with a bandwidth of 1750 nm from about 280 nm to 2030 nm has been achieved. The peak values of resonance wavelength at 1275 nm and 1885 nm are both greater than 99%. Our absorber also has good polarization independence and incidence insensitivity, which provides a theoretical basis for its work in the actual solar environment and possibilities for its application in other solar devices. The inspiration for proposed absorber can also be applied to other transition-metal dichalcogenides (TMDCs).

Herein, a self-assembled RuO2@IrOx core-shell heterostructure nanocomposite is designed and constructed to mediate oxygen evolution activity and sufficient durability. Enhanced by synergistic interactions of heterojunction between RuO2 and IrOx, the RuO2@IrOx nanocomposite reveals lower overpotential (215 mV at 10 mA cm−2) than RuO2 (260 mV at 10 mA cm−2) and IrO2 (316 mV at 10 mA cm−2). After assembled into a homemade single-cell PEM water electrolyzer, a lower cell voltage of 1.683 V at 1 A cm−2 for RuO2@IrOx anode is obtained, compared with RuO2 (1.715 V at 1 A cm−2) and IrO2 (1.748 V at 1 A cm−2). Additionally, the RuO2@IrOx anode shows good stability at 1 A cm−2 over a 300 h stability test due to the effective protection of IrOx shell. This work offers an effective strategy to design and construct high efficient and long-term stable catalysts simultaneously.

A mid-infrared formaldehyde (H2CO) detection system was demonstrated using a continuous-wave distributed-feedback interband cascade laser (DFB-ICL) emitting at 3.6 μm as light source and an assembly F-P cavity with 20 m effective optical path length as gas chamber. The laser and the cavity were locked to the H2CO absorption peak simultaneously by an electro-optic modulation based automatic Pound-Drever-Hall (PDH) scheme which consist of two steps: dynamic PDH locking and continuous PDH locking. Before continuous PDH locking, the dynamic PDH locking was conducted to acquire the H2CO absorption spectrum and calibration the locking frequency. Then, the cavity transmitted intensity was detected continuously to characterize the gas concentration. H2CO measurements were conducted to evaluate the performance of the sensor system. A linear relationship was observed between the voltage of the absorption signal and the H2CO concentration within the range of 0–6 ppm. Based on Allan deviation analysis, a minimum detection limit of 5.8 ppb was achieved with an averaging time of 30 s.

Error measurement of a rotary axis is the key to error compensation and to improving motion accuracy. However, only a few instruments can measure all the motion errors of a rotary axis. In this paper, a device based on laser collimation and laser interferometry was introduced for simultaneous measurement of all six degrees-of-freedom motion errors of a rotary axis. Synchronous rotation of the target and reference rotary axes was achieved by developing a proportional&ndash, integral&ndash, derivative algorithm. An error model for the measuring device was established using a homogeneous transformation matrix. The influences of installation errors, manufacturing errors, and error crosstalk were studied in detail, and compensation methods for them were proposed. After compensation, the repeatability of axial and radial motion errors was significantly improved. The repeatability values of angular positioning error and of tilt motion error around the y axis and x axis were 28.0&Prime, 2.8&Prime, and 3.9&Prime, The repeatability values of translational motion errors were less than 2.8 &mu, m. The comparison experiments show that the comparison errors of angular positioning error and tilt motion error around the y axis were 2.3&Prime, and 2.9&Prime, respectively. These results demonstrate the effectiveness of our method and the error compensation model.

Target assignment problem has always been the focus of scholars. The solution of target problem belongs to classical mathematical problem. This paper combines ant colony algorithm with artificial fish swarm algorithm by understanding intelligent algorithm. The concept of crowding degree is introduced into fish swarm algorithm. In the early stage of the algorithm, the dispersion is large, avoiding premature maturity. In the later stage, the convergence speed of the algorithm is faster and the time is saved. Compared with other algorithms, the hybrid algorithm has the characteristics of strong optimization ability and fast speed.

International audience; Image classification is still a hot and challenging task in the field of computer vision. With the combination of traditional CNN and Gabor CNN, we designed color-texture convolutional neural networks. We believe that color and texture is the most important feather to describe an object. So the original image, which main consist of color information, and the image processed by Gabor, which contain the texture information, input two stream networks separately is a natural idea. And merging the output of two stream at the end of network to complete the task of classification. We design a simple but effective network structure and test it on Cifar-10, STL-10 and NWPU-RESISC45 dataset. The result shows that the network achieve a well accuracy and proves that our idea is feasible

Acquired docetaxel (Doc) resistance in hormone-refractory prostate cancer (HRPC) remains an ongoing clinical challenge, resulting in failed chemotherapy and tumor recurrence. However, the mechanism of Doc-resistance development in prostate cancer cells is still unclear. Here, we observed a subpopulation of prostate cancer cells, in both Doc-resistant cell lines and the tumors of patients with HRPC, which show stem cell markers and greater tumorigenic potential. Those stem-like prostate cancer cells show high expression of ABCB1, which encodes multidrug resistance-related protein P-glycoprotein, leading to the Doc-resistance in prostate cancer. Moreover, we found that Notch signaling pathway activation in Doc-resistant cell lines and tumor tissues of patients with HRPC correlated with tumorigenicity and the development of Doc resistance. Here, we revealed that a combination of Doc and a Notch signaling inhibitor overcomes Doc resistance and increases the survival of mice with Doc-resistant xenografts. Therefore, targeting the Notch signaling pathway may be a promising strategy to overcome the Doc-resistant cancer in the clinic.

Modular inversion is an important step in Elliptic Curve Cryptography (ECC). Itoh-Tsujii's algorithm (ITA) is a commonly applied modular inversion algorithm. This paper proposes a novel architecture of modular inversion implementation based on ITA. The modular multiplier and 2n units are modified into non-iterative logic to increase clock frequency. Least-clock-cycle-ITA and High-speed-ITA architectures are proposed to minimize latency in different situations. Both architectures are implemented on FPGA Virtex-5. LCC-ITA completes modular inversion in 9 clock cycles with maximum clock frequency 126.1MHz, while HS-ITA completes two modular inversions in 20 clock cycles with maximum clock frequency 177.6MHz. The performance of the proposed architectures is 56% and 134% higher than the best work before.

The rotary axis is the basis for rotational motion. Its motion errors have critical effects on the accuracy of the related equipment, such as a five-axis computer numerical control machine tool. There are several difficult problems in the implementation of high-precision and fast measurement of the multi-degree-of-freedom motion errors of a rotary axis. In this paper, a novel method for the simultaneous measurement of five-degree-of-freedom motion errors of a rotary axis is proposed, which uses a single-mode fiber-coupled laser with a full-circle measuring range. It has the advantages of high efficiency, low cost, and it requires no decoupling calculation. An experimental system was built and a series of experiments were performed. The standard deviation of stability for 60 min of the five-degree-of-freedom measurement is 0.05 arcsec, 0.06 arcsec, 0.04 μm, 0.03 μm, and 0.19 arcsec, respectively. The repeatability deviation of measuring an indexing table is ± 3.4 arcsec, ± 4.6 arcsec, ± 2.6 μm, ± 2.4 μm, and ± 3.2 arcsec. The maximum deviation of comparison is 3.9 arcsec and 3.2 arcsec. These results demonstrate the effectiveness of the proposed method; thus, a new approach of simultaneous measurement of the multi-degree-of-freedom motion errors of a rotary axis is provided.

Rotary axis is the reference component of rotation motion. Angular position error is the most critical factor which impair the machining precision among the six degree-of-freedom (DOF) geometric errors of rotary axis. In this paper, the measuring method of angular position error of rotary axis based on laser collimation is thoroughly researched, the error model is established and 360 ° full range measurement is realized by using the high precision servo turntable. The change of space attitude of each moving part is described accurately by the 3×3 transformation matrices and the influences of various factors on the measurement results is analyzed in detail. Experiments results show that the measurement method can achieve high measurement accuracy and large measurement range.

Background: For localized prostate cancer (PCa), radical prostatectomy (RP) and radiotherapy (RT) are two standard interventions to decrease PCa mortality. Contemporary studies contained the elderly people, analyses focusing on patients over 75 years old were still lacking. Method: In the Surveillance Epidemiology and End Results (SEER) database (2004-2015), old people over 75-year-old with cT2 stage were selected in our research. Multivariable Cox proportional hazard models were used to analyze cancer-specific mortality (CSM) and overall mortality (OM) after adjustment. The propensity score matching was performed to assume the randomization. An instrument variate (IVA) was used to calculate the unmeasured confounders. Results: It showed that RP is superior to RT in OM and CSM after adjustment for covariates (hazard ratio [HR] = 0.54, 95% CI = 0.47-0.62, p

The tunicamycins constitute a delicate mimic of the bisubstrate intermediates of N-acetyl-D-hexosamine-1-phosphate translocases and thus inhibit bacterial cell-wall synthesis and the N glycosylation of eukaryotic proteins. An efficient approach to the synthesis of this unique type of nucleoside antibiotics is now reported and features the assembly of five modules in a highly stereoselective and robust manner. A Mukaiyama aldol reaction, intramolecular acetal formation, gold(I)-catalyzed O and N glycosylation, and final N acylation were used as the key steps.

Tunicamycin is a Streptomyces-derived inhibitor of eukaryotic protein N-glycosylation and bacterial cell wall biosynthesis, and is a potent and general toxin by these biological mechanisms. The antibacterial activity is dependent in part upon a π-π stacking interaction between the tunicamycin uridyl group and a specific Phe residue within MraY, a tunicamycin-binding protein in bacteria. We have previously shown that reducing the tunicamycin uridyl group to 5,6-dihydrouridyl (DHU) significantly lowers its eukaryotic toxicity, potentially by disrupting the π-stacking with the active site Phe. The present report compares the catalytic hydrogenation of tunicamycin and uridine with various precious metal catalysts, and describe optimum conditions for the selective production of N-acyl reduced tunicamycin or for tunicamycins reduced in both the N-acyl and uridyl double bonds. At room temperature, Pd-based catalysts are selective for the N-acyl reduction, whereas Rh-based catalysts favor the double reduction to provide access to fully reduced tunicamycin. The reduced DHU is highly base-sensitive, leading to amide ring opening under mild alkaline conditions.

International audience; As an important research topic in computer vision, abnormal detection has gained more and more attention. In order to detect abnormal events effectively, we propose a novel method using optical flow and deep autoencoder. In our model, optical flow of the original video sequence is calculated and visualized as optical flow image, which is then fed into a deep autoencoder. Then the deep autoencoder extract features from the training samples which are compressed to low dimension vectors. Finally, the normal and abnormal samples gather separately in the coordinate axis. In the evaluation, we show that our approach outperforms the existing methods in different scenes, in terms of accuracy.

International audience; Human action recognition is an important topic in the field of computer vision. We use Gabor filter in 3D CNNs models in recognizing action. Convolutional neural networks (CNNs) are a type of deep learning models, which is an efficient recognition model and has a unique superiority in image processing. Three dimension convolutional neural networks can well analyze action from video data. Gabor filter is a special convolution kernel. Its performance in feature extraction is outstanding. We test out model by KTH dataset and achieve a well result.

Tunicamycins (TUN) are inhibitors of the UDP-HexNAc: polyprenol-P HexNAc-1-P transferase family of enzymes, which initiate the biosynthesis of bacterial peptidoglycan and catalyze the first step in eukaryotic protein N-glycosylation. The TUN are therefore general and potent toxins to both eukaryotes and prokaryotes. Screening a library of synthetic TUN against Bacillus and yeast identified TUN that are antibacterial, but have significantly reduced eukaryotic toxicity. One of these (Tun-15:0) differs from the native TUN control only by the lack of the conjugated double bond in the tunicaminyl N-acyl group. Tun-15:0 also showed reduced inhibition for protein N-glycosylation in a Pichia-based bioassay. Natural TUN was subsequently modified by chemically reducing the N-acyl double bond (TunR1) or both the N-acyl and uridyl double bonds (TunR2). TunR1 and TunR2 retain their antibacterial activity, but with considerably reduced eukaryotic toxicity. In protein N-glycosylation bioassays, TunR1 is a less potent inhibitor than native TUN and TunR2 is entirely inactive. Importantly, the less toxic TunR1 and TunR2 both enhance the antibacterial activity of β-lactams: oxacillin by 32- to 64-fold, comparable with native TUN, and with similar enhancements for methicillin and penicillin G. Hence, the modified TUNs, TunR1 and TunR2, are potentially important as less-toxic synergistic enhancers of the β-lactams.

Thermal imaging technology is an effective means of detecting hazardous gas leaks. Much attention has been paid to evaluation of the performance of gas leak infrared imaging detection systems due to several potential applications. The minimum resolvable temperature difference (MRTD) and the minimum detectable temperature difference (MDTD) are commonly used as the main indicators of thermal imaging system performance. This paper establishes a minimum detectable gas concentration (MDGC) performance evaluation model based on the definition and derivation of MDTD. We proposed the direct calculation and equivalent calculation method of MDGC based on the MDTD measurement system. We build an experimental MDGC measurement system, which indicates the MDGC model can describe the detection performance of a thermal imaging system to typical gases. The direct calculation, equivalent calculation, and direct measurement results are consistent. The MDGC and the minimum resolvable gas concentration (MRGC) model can effectively describe the performance of “detection” and “spatial detail resolution” of thermal imaging systems to gas leak, respectively, and constitute the main performance indicators of gas leak detection systems.

International audience; Human action recognizing nowadays plays a key role in varieties of computer vision applications while at the same time it’s quite challenging for the requirement of accuracy and robustness. Most current computer vision methods focus on algorithms designing classifiers with handcrafted features which are complex and inflexible. To automatically extract both spatial and temporal features, in this paper we propose a method of human action recognition based on sub-data learning which combines the proposed 3D convolutional neural network (3DCNN) with the One-versus-One (OvO) algorithm. We also employ effective data augmentation to reduce overfitting. We evaluate our method on the KTH and UCF Sports dataset and achieve promising results.

SPE water electrolysis is a promising method of hydrogen production owing to its multiple strengths, including its high efficiency, high product purity and excellent adaptability. However, the overpotential of the oxygen evolution reaction process and consumption of Ir during charging in SPE water electrolysis will inevitably result in large energy loss and then high cost. Under these circumstances, we propose a novel 40IrO 2 /Co x Sn (1− x ) O 2 ( x = 0.1, 0.2, 0.3) anode catalyst, where the Co x Sn (1− x ) O 2 support is synthesized by a hydrothermal method and IrO 2 is synthesized by a modified Adams fusion method. After modifying the component of Co x Sn (1− x ) O 2 , the 40IrO 2 /Co x Sn (1− x ) O 2 exhibits an increased specific surface area, electrical conductivity and surface active sites. Moreover, a single cell is fabricated by Pt/C as cathode catalyst, 40IrO 2 /Co x Sn (1− x ) O 2 as anode catalyst and Nafion 117 membrane as electrolyte. The 40IrO 2 /Co 0.2 Sn 0.8 O 2 exhibits the lowest overpotential (1.748 V at 1000 mA cm −2 ), and only 0.18 mV h −1 of voltage increased for 100 h durability test at 1000 mA cm −2 . Consequently, Co x Sn (1− x ) O 2 is a promising anode electrocatalyst support for an SPE water electrolyzer.

70 Background: Magnetic Resonance Imaging-Transrectal Ultrasound (MRI/TRUS) fusion targeted biopsy (TB) has been demonstrated to increase detection rates (DRs) of prostate cancer (PCa) in repeat-biopsy setting. However, its role in biopsy-naïve men remains controversial. We performed a meta-analysis based on well-designed randomized controlled trials (RCTs) to compare the diagnostic accuracy of MRI/TRUS fusion TB and systematic biopsy (SB) in the detection of PCa in biopsy-naïve men. Methods: A systematic review of PubMed (Medline), Embase, Ovid and the Cochrane Library up to 1st October, 2018 was conducted. The statistical analyses were performed with Revman 5.3. We compared the diagnostic accuracy between the intervention group (assisted with fusion TB) and the control group (SB only) by calculating the risk ratio (RR) with 95% confidence intervals (CIs) of overall PCa and clinically significant PCa (csPCa) DRs. Subgroup analysis was performed to highlight the independent role of MRI/TRUS fusion TB alone or combining fusion TB and SB together in the detection of PCa. Results: Six RCTs with 2187 participants were evaluated for the DRs of overall PCa. Pooled analysis revealed slight higher DRs of 62.7% (687/1095) in the intervention group compared with that of 41.3% (451/1092) in the control group (RR 1.40, 95% CI: 1.00-1.95). Four studies with 962 participants were evaluated for the DRs of csPCa. There is a trend favoring the intervention group which detected more csPCa (42.8%, 206/481) compared with SB in the control group (31.6%, 152/481) but with no significant difference (RR 1.36, 95% CI: 0.95-1.95). Subgroup analysis revealed fusion TB alone with less biopsy cores may equal the DRs of csPCa compared with SB alone (RR 1.24, 95% CI: 0.79-1.93). However, the DRs of overall PCa when combining MRI/TRUS fusion TB and SB was comparable to that applying SB alone (RR 1.48, 95% CI: 0.99-2.22). Conclusions: MRI/TRUS fusion TB may obtain similar csPCa DRs with less biopsy cores. But currently there was no enough evidence showing fusion TB can help significantly improve overall PCa or csPCa DRs compared with SB alone in biopsy-naïve men.

117 Background: To evaluate the association between tertiary Gleason pattern (TGP) 5 and the biochemical recurrence (BCR) in patients with prostate cancer (PCa) of Gleason score (GS) 7 after radical prostatectomy(RP). Methods: This retrospective study collected 387 patients received RP and diagnosed GS 7 (3+4 or 4+3) in the West China Hospital from January 2009 to December 2017.Regardlessly the first Gleason pattern, patients were divide into 2 groups: TGP5 absence and TGP5 presence. Furthermore, we added the primary Gleason pattern to divided patients into 4 groups: GS 3+4, GS 3+4/TGP 5, Gleason 4+3, Gleason 4+3/TGP 5. Cox proportional-hazards models was used to evaluate the association between the status of TGP5 and BCR after adjusting the confounding factors with follow-up time as the underlying time scale. All the analyses were conducted with the use of statistical software packages Rnand EmpowerStats and conducted as two sides and P values less than 0.05 were considered statistical significance. Results: In the results by using Cox proportional-hazards model, regardless the primary Gleason pattern, comparing TGP5 absence (89.7%) and presence (10.3%), the risk of BCR for patients with tertiary Gleason pattern 5 presence was statistically significantly higher than absence (P = 0.02, HR = 2.24, 95%Cl: 1.12-4.49). In terms of the patients with primary Gleason pattern 4, the risk of BCR for patients with Gleason 4+3/TGP5 was statistically significantly higher than Gleason 4+3.(P = 0.02, HR = 2.56, 95%Cl: 1.16-5.67). There was a marked trend that patients with Gleason 3+4/TGP 5 has a higher risk of BCR compared with patients with Gleason 3+4, although there was no statistical difference (P = 0.58, HR = 1.82, 95%Cl: 0.22-14.96). Conclusions: The TGP5 in patients with GS 7 had strong association with the risk of BCR and it was an independent predictor for BCR. This result was more obvious in patients with GS 7 (4+3) in our study. Further researches with larger data size were needed to confirm these funding.

Supplemental Digital Content is available in the text, Background: We performed the network meta-analysis (NMA) and systematic review involved all evidence from relevant trials to compare the efficiency and safety of various types of selective serotonin reuptake inhibitors (SSRI) and phosphodiesterase-5 inhibitors (PDE5i) in patients with premature ejaculation (PE). Methods: We conducted comprehensive searches of peer-reviewed and grey literature. PubMed, the Cochrane Library Central Register of Controlled Trials, Embase were searched for randomized controlled trials published up to June 1, 2017. The primary outcome was intravaginal ejaculation latency time (IVELT) and adverse effects (AEs). We performed pairwise meta-analyses by random effects model and network meta-analysis by Bayesian model. We used the GRADE framework to assess the quality of evidence contributing to each network estimate. Results: Of 3046 titles and abstracts initially identified, 17 trials reporting 5739 participants were included. Considering IVELT in the NMA, paroxetine plus sildenafil and sildenafil alone are both superior to placebo (MD: 1.75, 95% CrI: 0.05 to 3.78; MD 1.43, 95% CrI 0.003 to 2.81). Sildenafil is superior to sertraline (MD: 1.63, 95% CrI: 0.10 to 2.79). Considering AEs, placebo demonstrated obviously lower risk comparing to paroxetine, sildenafil and paroxetine plus sildenafil (OR 0.20, 95% CI: 0.05 to 0.52; OR 0.23, 95% CI: 0.04 to 0.80; OR 0.45, 95% CI: 0.01 to 0.92). Compared with tadalafil plus paroxetine, dapoxetine showed significantly less AEs (OR 0.23, 95% CI 0.02 to 0.96). Conclusions: Our study concluded that although paroxetine plus sildenafil and sildenafil alone both demonstrated significant IVELT benefit compared with placebo, significant increase of AEs risk was also observed. Furthermore, sildenafil alone was superior to sertraline in efficacy with comparable tolerability.

Anomerization, which involves cleavage and formation of the anomeric C-O bond, is of fundamental importance in the carbohydrate chemistry. Herein, the unexpected gold(I)-catalyzed anomerization of glycosyl ortho-alkynylbenzoates has been studied in detail. Especially, crossover experiments in the presence of an exogenous isochromen-4-yl gold(I) complex confirm that the anomerization proceeds via the exocleavage mechanism, involving (surprisingly) the addition of the isochromen-4-yl gold(I) complex onto a sugar oxocarbenium (or dioxolenium) and an elimination of LAu(+) from the vinyl gold(I) complex. The inhibitory effect of the exogenous isochromen-4-yl gold(I) complex when in stoichiometric amount on the anomerization has guided us to disclose an isochromen-4-yl gem-gold(I) complex, which is inactive in catalysis but in equilibrium with the monogold(I) complex and the LAu(+) catalyst. The proposed key intermediate in the anomerization, a transient glycosyloxypyrylium species, is successfully trapped via a cycloaddition reaction with n-butyl vinyl ether as a dienophile. SN2-like substitution of the initially formed glycosyloxypyrylium intermediate has then been achieved to a large extent via charging with acceptors in an excess amount to lead to the corresponding glycosides in a stereoselective manner.

This paper introduces an error-compensation model for our measurement method to measure five motion errors of a rotary axis based on fibre laser collimation. The error-compensation model is established in a matrix form using the homogeneous coordinate transformation theory. The influences of the installation errors, error crosstalk, and manufacturing errors are analysed. The model is verified by both ZEMAX simulation and measurement experiments. The repeatability values of the radial and axial motion errors are significantly suppressed by more than 50% after compensation. The repeatability experiments of five degrees of freedom motion errors and the comparison experiments of two degrees of freedom motion errors of an indexing table were performed by our measuring device and a standard instrument. The results show that the repeatability values of the angular positioning error e z and tilt motion error around the Y axis e y are 1.2'' and 4.4'', and the comparison deviations of the two motion errors are 4.0'' and 4.4'', respectively. The repeatability values of the radial and axial motion errors, δ y and δ z , are 1.3 and 0.6 µm, respectively. The repeatability value of the tilt motion error around the X axis e x is 3.8''.

In this paper, we discuss the problem on the construction of asymmetric quantum codes [[n, k, dz/dx]]4 from primitive narrow sense BCH codes. Take advantage of dual containing BCH codes of length n = 4m -- 1 where m = 2l and m = 2l + 1, we construct two families of new asymmetric quantum codes with dz ≥ δmax + 1, where δmax is the maximal designed distance of dual containing narrow sense BCH code. Our asymmetric quantum codes are new ones, and are not included in the known literature.

The tunicamycins constitute a delicate mimic of the bisubstrate intermediates of N-acetyl-D-hexosamine-1-phosphate translocases and thus inhibit bacterial cell-wall synthesis and the N glycosylation of eukaryotic proteins. An efficient approach to the synthesis of this unique type of nucleoside antibiotics is now reported and features the assembly of five modules in a highly stereoselective and robust manner. A Mukaiyama aldol reaction, intramolecular acetal formation, gold(I)-catalyzed O and N glycosylation, and final N acylation were used as the key steps.

The leakage of toxic or hazardous gases not only pollutes the environment, but also threatens people's lives and property safety. Many countries attach great importance to the rapid and effective gas leak detection technology and instrument development. However, the gas leak imaging detection systems currently existing are generally limited to a narrow-band in Medium Wavelength Infrared (MWIR) or Long Wavelength Infrared (LWIR) cooled focal plane imaging, which is difficult to detect the common kinds of the leaking gases. Besides the costly cooled focal plane array is utilized, the application promotion is severely limited. To address this issue, a wide-band gas leak IR imaging detection system using Uncooled Focal Plane Array (UFPA) detector is proposed, which is composed of wide-band IR optical lens, sub-band filters and switching device, wide-band UFPA detector, video processing and system control circuit. A wide-band (3µm~12µm) UFPA detector is obtained by replacing the protection window and optimizing the structural parameters of the detector. A large relative aperture (F#=0.75) wide-band (3μm~12μm) multispectral IR lens is developed by using the focus compensation method, which combining the thickness of the narrow-band filters. The gas leak IR image quality and the detection sensitivity are improved by using the IR image Non-Uniformity Correction (NUC) technology and Digital Detail Enhancement (DDE) technology. The wide-band gas leak IR imaging detection system using UFPA detector takes full advantage of the wide-band (MWIR&LWIR) response characteristic of the UFPA detector and the digital image processing technology to provide the resulting gas leak video easy to be observed for the human eyes. Many kinds of gases, which are not visible to the naked eyes, can be sensitively detected and visualized. The designed system has many commendable advantages, such as scanning a wide range simultaneously, locating the leaking source quickly, visualizing the gas plume intuitively and so on. The simulation experiment shows that the gas IR imaging detection has great advantages and widely promotion space compared with the traditional techniques, such as point-contact or line-contactless detection.

Simplexides constitute a unique group of immunosuppressive glycolipids that demonstrate antiproliferative activities against activated T-cell lymphocytes via a unique non-cytotoxic inhibition. To investigate the structure–activity relationship of the varied long-chain secondary alcohols on simplexides, we developed an efficient and divergent route to the synthesis of simplexides and congeners, taking advantage of a late-stage olefin cross-metathesis reaction.

Color fusion technology, one of the typical technologies, has been emphasized all over the world. Multiband images are fused into a color image. Some effective visible and thermal infrared color fusion algorithms have been proposed now. We have successfully run a real-time natural sense of visible/infrared color fusion algorithm in DSP and FPGA hardware processing platforms. However, according to different needs, gray image fusion technology has its own unique applications. Based on the natural sense of color image fusion algorithm of the visible and infrared, we have proposed a visible / infrared gray image fusion algorithm. Firstly we do a YUV color fusion. Then we output the brightness of the fusion as gray fusion images. This algorithm for image fusion is compared with typical fusion algorithms: the weighted average, the Laplace Pyramid and the Haar basis wavelet. Several objective evaluation indicators are selected. The results of objective and subjective comparison show that the algorithm has most advantages. It shows that multiband gray image fusion in the color space is available. The algorithm is implemented on a DSP hardware image processing platform real-time with the TI's chip as the kernel processor. It makes natural sense of color fusion and gray fusion for visible light (low level light) and thermal imaging integrated. Users are convenient to choose model of the natural sense of color fusion or gray fusion for real-time video imaging output

Passive infrared gas imaging systems have been utilized in the equipment leak detection and repair in chemical manufacturers and petroleum refineries. The detection performance mainly relates to the sensitivity of infrared detector, optical depth of gas, atmospheric transmission, wind speed, and so on. Based on our knowledge, the spatial concentration distribution of continuously leaking gas plays an important part in leak detection. Several computational model of gas diffusion were proposed by researchers, such as Gaussian model, BM model, Sutton model and FEM3 model. But these models focus on calculating a large scale gas concentration distribution for a great amount of gas leaks above over 100- meter height, and not applicable to assess detection limit of a gas imaging system in short range. In this paper, a wind tunnel experiment is designed. Under different leaking rate and wind speed, concentration in different spatial positions is measured by portable gas detectors. Through analyzing the experimental data, the two parameters σ y (x) and σ z (x) that determine the plume dispersion in Gaussian model are adjusted to produce the best curve fit to the gas concentration data. Then a concentration distribution model for small mount gas leakage in short range is established. Various gases, ethylene and methane are used to testify this model.

As to visualize the leaking gas cloud which is not visible to the naked eyes, three categories of techniques have emerged, Backscatter Absorption Gas Imaging, Passive Thermal Imaging, and Imaging Spectrometer. Among these systems, Signal to Noise Ratio (SNR) is generally used to deduce gas leakage detection limit and leads to several performance evaluation parameters, such as Noise-Equivalent Spectral Radiance and Noise-Equivalent Concentration-Path Length. However, in most cases, measuring the SNR accurately is not accessible and usually needs auxiliary instruments. Therefore, we focus on researching a gas leakage detection model according to the general parameter of a thermal imager, Noise Equivalent Temperature Difference (NETD). Firstly, the Gas Equivalent Blackbody Temperature Difference (GEBTD) is obtained by calculating the attenuated radiation of the On-plume path and that of the Off-plume path respectively. A simplified form of GEBTD was derived by our previous paper, assuming that the work range was short and the affection of atmospheric transmission was omitted. But in this paper, more factors are considered to establish a more realistic and accurate detectivity model. The radiation of the gas cloud and the attenuation of the atmosphere are taken into account as well as the size of the leakage spot which inevitably affects the concentration path length. Secondly, the NETD and the GEBTD are compared to determine the detection capability. At last, an experiment is designed to verify the accuracy and reliability of this model on the basis of the gas cloud concentration cone distribution model.

In order to improve the performance of grayscale image colorization based on color transfer, this paper proposes a novel method by which pixels are matched accurately between images through region texture analysis using Gray Level Co-occurrence Matrix (GLCM). This method consists of six steps: reference image selection, color space transformation, grayscale linear transformation and compression, texture analysis using GLCM, pixel matching through texture value comparison, and color value transfer between pixels. We applied this method to kinds of grayscale images, and they gained natural color appearance like the reference images. Experimental results proved that this method is more effective than conventional method in accurately transferring color to grayscale images.

Leakage of dangerous gases will not only pollute the environment, but also seriously threat public safety. Thermal infrared imaging has been proved to be an efficient method to qualitatively detect the gas leakage. But some problems are remained, especially when monitoring the leakage in a passive way. For example, the signal is weak and the edge of gas cloud in the infrared image is not obvious enough. However, we notice some important characteristics of the gas plume and therefore propose a gas cloud infrared image enhancement method based on anisotropic diffusion. As the gas plume presents a large gas cloud in the image and the gray value is even inside the cloud, strong forward diffusion will be used to reduce the noise and to expand the range of the gas cloud. Frames subtraction and K-means cluttering pop out the gas cloud area. Forward-and-Backward diffusion is to protect background details. Additionally, the best iteration times and the time step parameters are researched. Results show that the gas cloud can be marked correctly and enhanced by black or false color, and so potentially increase the possibility of gas leakage detection.

The fingerprint region of most gases is within 3 to 14μm. A mid-wave or long-wave infrared thermal imager is therefore commonly applied in gas detection. With further influence of low gas concentration and heterogeneity of infrared focal plane arrays, the image has numerous drawbacks. These include loud noise, weak gas signal, gridding, and dead points, all of which are particularly evident in sequential images. In order to solve these problems, we take into account the characteristics of the leaking gas image and propose an enhancement method based on adaptive time-domain filtering with morphology. The adaptive time-domain filtering which operates on time sequence images is a hybrid method combining the recursive filtering and mean filtering. It segments gas and background according to a selected threshold; removes speckle noise according to the median; and removes background domain using weighted difference image. The morphology method can not only dilate the gas region along the direction of gas diffusion to greatly enhance the visibility of the leakage area, but also effectively remove the noise, and smooth the contour. Finally, the false color is added to the gas domain. Results show that the gas infrared region is effectively enhanced.

Standoff detection of gas leakage is a fundamental need in petrochemical and power industries. The passive gas imaging system using thermal imager has been proven to be efficient to visualize leaking gas which is not visible to the naked eye. The detection probability of gas leakage is the basis for designing a gas imaging system. Supposing the performance parameters of the thermal imager are known, the detectivity based on electromagnetic radiation transfer model to image gas leakage is analyzed. This model takes into consideration a physical analysis of the gas plume spread in the atmosphere-the interaction processes between the gas and its surrounding environment, the temperature of the gas and the background, the background surface emissivity, and also gas concentration, etc. Under a certain environmental conditions, through calculating the radiation reaching to the detector from the camera's optical field of view, we obtain an entity "Gas Equivalent Blackbody Temperature Difference (GEBTD)" which is the radiation difference between the on-plume and off-plume regions. Comparing the GEBTD with the Noise Equivalent Temperature Difference (NETD) of the thermal imager, we can know whether the system can image the gas leakage. At last, an example of detecting CO 2 gas by JADE MWIR thermal imager with a narrow band-pass filter is presented.

In order to detect the moisture content of fabric quickly and accurately, an on-line measurement system based on microwave transmission principle was designed for measuring moisture content of fabric,which achieve the moisture content of the fabric on-line non-destructive testing. Focused on the measurement principle and method, using least square method fitting a straight line to obtain calibration curve. Experimental results show that the system is effective for measuring moisture content of 30% to 70% of the fabric; The measurement accuracy is higher than ± 1%.

With the development of the wireless technology, ZigBee is paid more attention to in many aspects of industry automation, social communication, smart home and so on. The purpose of this article is to analyze some definitive descriptions of NWK layer of the ZigBee protocol stack, and to realize some basic applications. Through descriptions and some applications, the article analyzed and verified ZigBee is a reliable and ideal proposal used in low rate, low cost and low consumption wireless communication.

In view of the deficiency of most of programming tool in connecting a professional database and manipulating data difficultly, a method is applied to realize the exchange visits between LabVIEW and database, and actualized the exchange visits. Tested by experimentation, the method can provide both students and administrators with an easy to learn, easy to use system that, through automation and web technologies, allows the laboratory to be run with out the need for notebooks, printouts, or other types of paper administration. Students in these classes will have the opportunity to analyze real-world data from a facility that they have worked in or may easily visit and observe. It has been applied in our laboratory successfully and proved operating easy and responding quick. The general, flexibility and security of the laboratory management information system are very well.