Energy dissipation mechanism and ballistic characteristic optimization in foam sandwich panels against spherical projectile impact

This study systematically examines the energy dissipation mechanisms and ballistic characteristics of foam sandwich panels(FSP)under high-velocity impact using the explicit non-linear finite element method.Based on the geometric topology of the FSP system,three FSP configurations with the same areal density are derived,namely multi-layer,gradient core and asymmetric face sheet,and three key structural parameters are identified:core thickness(t_(c)),face sheet thickness(t_(f))and overlap face/core number(n_(o)).The ballistic performance of the FSP system is comprehensively evaluated in terms of the ballistic limit velocity(BLV),deformation modes,energy dissipation mechanism,and specific penetration energy(SPE).The results show that the FSP system exhibits a significant configuration dependence,whose ballistic performance ranking is:asymmetric face sheet>gradient core>multi-layer.The mass distribution of the top and bottom face sheets plays a critical role in the ballistic resistance of the FSP system.Both BLV and SPE increase with tf,while the raising tcor noleads to an increase in BLV but a decrease in SPE.Further,a face-core synchronous enhancement mechanism is discovered by the energy dissipation analysis,based on which the ballistic optimization procedure is also conducted and a design chart is established.This study shed light on the anti-penetration mechanism of the FSP system and might provide a theoretical basis for its engineering application.

Expert consensus on irrigation and intracanal medication in root canal therapy

Chemical cleaning and disinfection are crucial steps for eliminating infection in root canal treatment. However, irrigant selection or irrigation procedures are far from clear. The vapor lock effect in the apical region has yet to be solved, impeding irrigation efficacy and resulting in residual infections and compromised treatment outcomes.

Controllably partial removal of thiolate ligands from unsupported Au_(25) nanoclusters by rapid thermal treatments for electrochemical CO_(2)reduction

Colloidal synthesis of metal nanoclusters will inevitably lead to the blockage of catalytically active sites by organic ligands.Here,taking[Au_(25)(PET)_(18)]-(PET=2-phenylethanethiol)nanocluster as a model catalyst,this work reports a feasible procedure to achieve the controllably partial removal of thiolate ligands from unsupported[Au_(25)(PET)_(18)]-nanoclusters with the preservation of the core structure.This procedure shortens the processing duration by rapid heating and cooling on the basis of traditional annealing treatment,avoiding the reconfiguration or agglomeration of Au_(25)nanoclusters,where the degree of dethiolation can be regulated by the control of duration.This work finds that a moderate degree of dethiolation can expose the Au active sites while maintaining the suppression of the competing hydrogen evolution reaction.Consequently,the activity and selectivity towards CO formation in electrochemical CO_(2)reduction reaction of Au_(25)nanoclusters can be promoted.This work provides a new approach for the removal of thiolate ligands from atomically precise gold nanoclusters.

揭示层状晶态CoMoO_(4)的水裂解电催化机制:从晶面选择到活性位点设计的理论研究

电解水制氢具有效率高、操作简单、易于耦合可再生能源等优点,被认为是大规模产氢最有希望的技术之一.通常贵金属基材料Pt和Ir(Ru)O_(2)分别用作阴极析氢反应(HER)和阳极析氧反应(OER)催化剂,进而提高水裂解效率.然而,它们的稀缺性、成本高和稳定性差等缺点严重限制了在电解水中的大规模应用.因此,急需开发廉价且高效的水裂解电催化剂.钼酸钴(CoMoO_(4))由于成本低、储量丰富、氧化还原活性位点多和稳定性高等优点,被认为是替代贵金属基催化剂的理想候选者.但由于CoMoO_(4)复杂的单斜晶体结构,从原子层面揭示其HER和OER电催化机理仍然是一个极大挑战,而在原子水平探索电催化剂不同晶面的催化活性对理解电催化机制和识别活性位点起着推动作用.本文采用密度泛函理论(DFT)从层状晶态CoMoO_(4)的晶面选择到活性位点设计系统研究了其水裂解电催化机制.CoMoO_(4)沿[110]晶格方向呈现层状排列晶体特征,通过表面能计算并基于Wulff原则构造了CoMoO_(4)的热力学稳定晶体结构,结果表明,具有较低表面能的(110)A(62 mJm^(-2))和(001)A(179mJm^(-2)面均为理论热力学稳定晶体结构的主导晶面,分别占据了64.25%和23.53%.因此以(110)A和(001)A晶面为研究对象,重点研究了其碱性水裂解的电催化活性及其深入的催化机制.结果发现,在CoMoO_(4)的(110)A面上的O_(3)位点吸附的H可以与两个氧原子(O_(3)和Oadj)相互作用,理论计算得到的氢吸附吉布斯自由能(ΔGH*)仅为0.22 eV,对应了最高的类似Pt的交换电流密度i0,所以其表现出最优异的HER活性;另外,(110)A面水解离(Volmer反应)能垒约为1.6 eV,远低于(001)A的4.6 eV,说明(110)A面拥有比(001)A面更好的H_(2)O解离能力,更有利于碱性溶液中的HER.过渡态计算结果表明,(110)A上的H*更倾向于与另一个来自吸附水的H结合,Heyrovsky步骤的能垒为1.63 eV,低于两个H*结合形成H_(2)的Tafel步骤能垒(2.04 eV).因此,CoMoO_(4)催化剂上的HER是沿着Volmer-Heyrovsky步骤进行的.此外,根据吉布斯自由能计算,(110)A面上OER过电位仅为0.74 V,优于(001)A面(0.84 V),这是因为(110)A面的Co和O间的结合力更强,中间体*O的吸附状态更稳定,使得决速步(*OH→*O)能垒降低.综上,本文对CoMoO_(4)及其同构物质如Mn(Ni,Fe)MoO4纳米催化剂的选择性合成和电催化机理研究具有借鉴意义.

Synergistic effects of elevated homocysteine level and abnormal blood lipids on the onset of stroke

Hyperhomocysteinemia and abnormal blood lipids are independent risk factors for stroke. However, whether both factors exert a synergistic effect in the onset of stroke remains unclear. The present study is a retrospective analysJs of 2 089 cases of stroke and 2 089 control cases of simple in- tervertebral disk protrusion using a paired multivariate logistic regression method. Adjusting for known confounding variables including the patients＇ age, gender, smoking status, alcohol con- sumption status, patient and family medical history, and clinical biochemical indices, elevated ho- mocysteine level was related to the onset of stroke. Patients with elevated homocysteJne levels and abnormal blood lipids showed a 40.9 % increase in the risk for stroke compared to patients with normal homocysteine levels and blood lipids （odds ratio 1.409; 95% confidence interval 1.127-1.761）. These results indicate that elevated homocysteine and abnormal blood lipids exert synergistic effects in the onset of stroke. Patients with elevated homocysteine levels and abnormal blood lipids are predisposed to stroke.

Security and privacy issues of physical objects in the IoT:Challenges and opportunities

In the Internet of Things(IoT),security and privacy issues of physical objects are crucial to the related applications.In order to clarify the complicated security and privacy issues,the life cycle of a physical object is divided into three stages of pre-working,in-working,and post-working.On this basis,a physical object-based security architecture for the IoT is put forward.According to the security architecture,security and privacy requirements and related protecting technologies for physical objects in different working stages are analyzed in detail.Considering the development of IoT technologies,potential security and privacy challenges that IoT objects may face in the pervasive computing environment are summarized.At the same time,possible directions for dealing with these challenges are also pointed out.

Chaperone-mediated autophagy targeting chimeras (CMATAC) forthe degradation of ERα in breast cancer

Estrogen receptor alpha(ERα/ESR1)is overexpressed in over half of all breast cancers and is considered a valuable therapeutic target in ERαpositive breast cancer.Here,we designed a membrane-permeant Chaperonemediated Autophagy Targeting Chimeras(CMATAC)peptide to knockdown endogenous ERαprotein through chaperone-mediated autophagy.The peptide contains a cell membrane-penetrating peptide(TAT)that allows the peptide to by-pass the plasma membrane,anαI peptide as a protein-binding peptide(PBD)that binds specifically to ERα,and CMA-targeting peptide(CTM)that targeting chaperone-mediated autophagy.We validated that ERαtargeting peptide was able to target and degrade ERαto reduce the viability of ERαpositive breast cancer cells.Taken together,our studies provided a new method to reduce the level of intracellular ERαprotein via CMATAC,and thus may provide a new strategy for the treatment of ERαpositive breast cancer.

CNN-Based Fast HEVC Quantization Parameter Mode Decision

With the development of multimedia presentation technology,image acquisition technology and the Internet industry,long-distance communication methods have changed from the previous letter,the audio to the current audio/video.And the proportion of video in work,study and entertainment keeps increasing,high-definition video is getting more and more attention.Due to the limits of the network environment and storage capacity,the original video must be encoded to be efficiently transmitted and stored.High Efficient Video Coding(HEVC)requires a large amount of time to recursively traverse all possible quantization parameter values of the coding unit in the adaptive quantization process.The optimal quantization parameter is calculated by comparing the rate distortion cost.In this paper,we propose a fast decision method for HEVC quantization parameters selection based on convolutional neural network,which saves video’s encoding time.

Large-Area Freestanding Weyl Semimetal WTe_(2) Membranes

We report a universal transfer methodology for producing artificial heterostructures of large-area freestanding single-crystalline WTe_(2) membranes on diverse target substrates.The transferred WTe_(2) membranes exhibit a nondestructive structure with a carrier mobility comparable to that of as-grown films(∼179–1055 cm^(2)·V^(−1)·s^(−1)).Furthermore,the transferred membranes show distinct Shubnikov–de Haas quantum oscillations as well as weak localization/weak anti-localization.These results provide a new approach to the development of atom manufacturing and devices based on atomic-level,large-area topological quantum films.

Clinical application of traditional herbal medicine in five countries and regions: Japan;South Korea;China's Mainland;Hong Kong, China;Taiwan, China

Objective:To study the characteristics of the clinical application of traditional herbal medicine in five countries and regions where traditional medicine(TM)is widely used:Japan;South Korea;China's Mainland;Hong Kong,China;Taiwan,China.And to analyze,from multiple angles,the variations in the methods of TM used in each countries and regions.Methods:Fifty commonly used traditional herbs(TOP50)from classical formulae were selected,and descriptive statistics,correlation analyses,and Friedman test were used to compare methods of clinical application and dosages in the countries and regions of interest based on a retrospective review of randomly-selected medical records.Results:There were significant differences in sequencing TOP50 among the five countries and regions(P<.01).The adherence to the classical formulae,from strong to weak was Japan;China's Mainland;Taiwan,China;Hong Kong,China;South Korea.There were also significant differences in TOP50 dosing regimens(P<.01).Overall dosages of TOP50 from high to low were:China's Mainland;Hong Kong,China;Taiwan,China;South Korea;Japan.Finally,there were significant differences in the dosage intervals(P<.01),with dosage intervals from maximum to minimum as follows:China's Mainland;Taiwan,China;Hong Kong,China;South Korea;Japan.Conclusions:The clinical dosages of traditional herbal medicine used in the China's Mainland are relatively large compared with those prescribed in the other four countries and regions,and the range of dosages in China's Mainland is more flexible.On the other hand,clinical dosages of TOP50 are the lowest in Japan,where the dosage range is also the narrowest,supporting the idea that Doctors of Kampo medicine are highly cautious and are likely to adhere strictly to classical formulae,while Hong Kong,China and Taiwan,China are in the middle.The dosage of TOP50 in South Korea is significantly lower than that used in the China's Mainland;Hong Kong,China and Taiwan,China where the adherence to the classical formulae was the lowest,albeit slightly higher than that in Japan.The methods of clinical application of traditional herbal medicine in the five countries and regions were affected by multiple factors,including history,geography,climate,and culture.

Collimated gamma rays from laser wakefield accelerated electrons

Betatron radiation from laser wakefield accelerated electrons and X-rays scattered off a counter-propagating relativistic electron bunch arecollimated and hold the potential to extend the energy range to hard X-ray or gamma ray band. The peak brightness of these incoherent radiations could reach the level of the brightest synchrotron light sources in the world due to their femtosecond pulse duration and source sizedown to a few micrometers. In this article, the principle and properties of these radiation sources are briefly reviewed and compared. Then wepresent our recent progress in betatron radiation enhancement in the perspective of both photon energy and photon number. The enhancement istriggered by using a clustering gas target, arousing a second injection of a fiercely oscillating electron bunch with large charge or stimulating aresonantly enhanced oscillation of the ionization injected electrons. By adopting these methods, bright photon source with energy over 100 keVis generated which would greatly impact applications such as nuclear physics, diagnostic radiology, laboratory astrophysics and high-energydensity science.

Observation of Shubnikov-de Haas Oscillations in Large-Scale Weyl Semimetai WTe2 Films

Topological Weyl semimetal WTe2 with large-scale Him form has a promising prospect for new-generation spintronic devices.However,it remains a hard task to suppress the defect states in large-scale WTe2 films due to the chemical nature.Here we significantly improve the crystalline quality and remove the Te vacancies in WTe2 films by post annealing.We observe the distinct Shubnikov-de Haas quantum oscillations in WTe2 films.The nontrivial Berry phase can be revealed by Landau fan diagram analysis.The Hall mobility of WTe2 films can reach 1245cm^2V^-1s^-1 and 1423cm^2V^-1s^-1 for holes and electrons with the carrier density of 5× 10^19 cm^-3 and 2 × 10^19 cm^-3,respectively.Our work provides a feasible route to obtain high-quality Weyl semimetal films for the future topological quantum device applications.

Ultra-fast x-ray-dynamic experimental subsystem

Ultra-fast x-ray-dynamic experimental subsystem is a facility which can provide femtosecond hard x-ray sources using a femtosecond laser interacting with plasmas. By utilizing these ultra-fast x-rays as a probe, combined with a naturally synchronized driver laser as a pump, we can perform dynamic studies on samples with a femtosecond time resolution. This subsystem with a four-dimensional ultra-high spatiotemporal resolution is a powerful tool for studies of the process of photosynthesis, Auger electron effects, lattice vibrations, etc. Compared with conventional x-ray sources based on accelerators, this table-top laser-driven x-ray source has significant advantages in terms of the source size, pulse duration, brightness, flexibility, and economy. It is an effective supplement to the synchrotron light source in the ultrafast detection regime.

Effects of Different Irrigation Management on the Textural Properties of Double-Cropping Late Indica Rice in South China

In order to investigate the effects of different irrigation management on the textural properties of two different double-cropping late indica rice,the effects of three irrigation management including conventional irrigation(CK),constant irrigation(CI)and alternate wetting and drying(AWD)on textural properties has been researched under field conditions of two years.The results indicated that the firmness,cohesiveness and chewiness were decreased under AWD treatment,and the stickiness was increased compared with CK,while the textural properties under CI treatment showed the opposite trend with AWD treatment.Additionally,AWD treatment signifi-cantly improved the springiness of TY871 compared with CK and CI treatment,but had no significant effect in RYHZ,suggesting improvement of the cooking and eating quality of TY871 under AWD treatment.Correlation analysis showed that the chewiness was positively correlated with the firmness and cohesiveness,and the cohesiveness was positively correlated with the firmness.AWD could promote the textural properties of high-quality late indica rice in South China whereas CI treatment has shown the disadvantage of the textural properties,which will provide useful information for the improvement of cooking and eating quality of rice.

Construction and Biological Function Analysis of a dldh Deletion Mutant Strain of Vibrio alginolyticus

[ Objeetlve] This study aimed to investigate the role of dihydrolipoamide dehydrogenase （DLDH） in the pathopoiesis of Vibrio alginolyticua. [ Method] Using suicide plasmid pRE112 as the vector, d/dh deletion mutant strain ZJO3Adldh was constructed with insertion inactivation mutation method by Overlap PCR and homologous recombination technology to compare and analyze the differences in the growth, swimming ability, enzyme activity, biofilm formation and pathogenicity between wild-type strain ZJ03 and deletion mutant strain ZJO3△dldh. [ Result] dldh deletion mutant strain ZJ03 △d/dh exhibited prolonged lag phase, significantly reduced swimming ability （P 〈 0.05 ）, significantly reduced enzyme activity （P 〈 0.05 ）, significantly reduced biofilm formation ability （P 〈 0.05 ） and remarkably reduced pathogenicity to Epinephelus coioides （P 〈0.05） compared to wild-type strain ZJ03. [ Conclusion] This study provided theoretical basis for revealing the pathogenic mechanisms of Vibrio from the perspective of bacterial energy metabolism.

Guest editorial:Special issue on data intelligence for IoT

The Internet of Things(IoT)is increasingly deployed to enable smart applications.Various types of data are accumulated continuously during the running of these applications.Managing and using these IoT data to derive intelligence for making the smart world reality is attracting both industrial and academic efforts.Though quite some progress has been made in this area,there is still a need for high data intelligence in IoT applications.

Strategic Path for the Development of Live Pig Healthy Breeding Industry in China

The objective of study in the paper was to analyze advantages, disadvantages, opportunities and threats of development of pig healthy agriculture in China, using systematic analysis and SWOT strategic analysis, as well as to show severe diseases, abnormal fluctuation, misplaced way and versatile environment confronted by pig breeding in China. The paper establishes ＂double-hug mode＂, from which pig breeding industry transforms and upgrades to modern breeding industry. Combing with the designed multi-party cooperation mechanism of advantageous regions, urban sale areas and group corporations, it sets up three paths for development of pig healthy agriculture in China, i.e., strategic paths of advantageous regions, urban sale areas and group corporations oriented, with an attempt to provide strategic path reference for transformation and upgrading of pig breeding in China and mode reference for breakthrough of development strategy for pig healthy industry.

Clinical significance of heat shock protein 10 in large bowel carcinoma

Objective： To investigate the expression of heat shock protein 10 （HSPIO） during genesis and development of large bowel carcinoma and discuss the clinical significance about its expression. Methods： The expression of HSPIO was observed in specimens from normal colonic mucosa （NC）, colorectal adenomas （CA） and colorectal adenocarcinomas （CAC） by immunohistochemistry EnVisionTM. Its correlations to clinicopathologic features, as well as to postoperative survival time of large bowel carcinoma patients were analyzed. Results： The expression of HSPIO was common in normal colonic mucosa, colorectal adenomas and adenocarcinomas and more intensive in colorectal adenomas and adenocarcinomas than that in normal colonic mucosa （P 〈 0.001）. The positive expression of HSPIO had no correlation to clinicopathologic features, including age, gender, primary tumor, infiltrating of regional lymph node, metastasis, clinical stage and histopathology of large bowel carcinoma patients, as well as to their postoperative survival time. Conclusion： HSPIO was overexpressed in the early stage of colorectal adenocarcinoma suggesting that it could serve as an index for early diagnosis of large bowl carcinoma. The positive expression of HSPIO had no correlation to clinicopathologic features or postoperative survival time of large bowel carcinoma patients.

Expressions and clinicopathologic significance of five heat shock proteins in esophageal squamous cell carcinoma

Objective： To investigate the expressions of heat shock protein （hsp） 10, hsp27, hsp60, hsp70 and hsp90a in esophageal squarnous cell carcinoma （ESCC） and normal tissues along the incisal margin （TIM）, and discuss the clinicopathologic features about their expressions. Methods： 120 specimens from ESCC and 36 specimens from TIM were made into tissue chips. The presence and the levels of expression of hspl0, hsp27, hsp60, hsp70 and hsp90a were observed on tissue chips by immunohistochemistry EnVision^TM. Their correlations to clinicopathologic features were analyzed. Results： The positive staining rates of hsp10, hsp27, hsp60, hsp70 and hsp90a in ESCC and TIM were 53.8% and 37.5%, 62.0% and 42.1%, 92.7% and 63.2%, 57.9% and 22.2%, 33.7% and 18.5% respectively. There were no statistical significances between the differential expressions of hsp10, hsp27 and hsp90a in ESCC and TIM （P 〉 0.05）, but there were great statistical significances about hsp60 and hsp70 （P 〈 0.01）. The level of hsp27 declined with the lower grade of differentiation of ESCC （P 〈 0.05）. Except for hsp27, the positive expressions of the other four HSPs had no correlation to the clinicopathologic features of ESCC. Conclusion： The expressions of hsp10, hsp27, hsp60, hsp70 and hsp90a in ESCC and TIM were a common event. The levels of hsp60 and hsp70 in ESCC were higher than those in TIM. The level of hsp27 declined with the lower grade of differentiation of ESCC showed that it may be play a role in the differentiation of ESCC.

Experimental Study of Ultrasound on MDR in a Human Tumor in Vivo

OBJECTIVE To evaluate the potential efficacy of low-intensity ultrasound （US） in combination with anticancer drugs to reverse multidrug resistance （MDR）in nude mice. METHODS A total of 40 male and female athymic nude mice were inoculated subcutaneously with 5×10^6 HepG2/ADM and HepG2 cells. Ultrasound with pulsed irradiation at an average intensity of 0.5 W/cm^2 was given to the tumor area 10 rain after administration of adriamycin （ADM）. The tumor 3 dimensional diameters were measured by calipers before and after treatment, and the tumor growth indexes （TGI） calculated. RT-PCR was used to detect the gene levels of the HepG2/ADM cells. Immunohistochemical analyses for MDR proteins were conducted on the tumor tissues. RESULTS The ultrasonic treatment resulted in an average reduction in the tumor volume of 62% one month later. The relative mRNA levels of MDR1 and MRP were significantly different among the following 4 groups： untreated group as control, ADM treated; US treated; and ADM plus US treated. The mRNA levels of mdrl and mrp were down-regulated in the US groups compared to those of the non-ultrasound groups by multiple comparisons. The relative mRNA levels of Irp expression were not significantly changed. The results of immunohistochemistry indicated that tumor tissue from animals treated with US had remarkably low mdrl and mrp expression. CONCLUSION The results showed that low-intensity US can effectively reduce the size of adriamycin-resistant human hepotacarcinoma in a nude mouse model, and support the efficacy of US to overcome multiple mechanisms of drug resistance.