Internet of Things Intrusion Detection System Based on Convolutional Neural Network

In recent years, the Internet of Things (IoT) technology has developedby leaps and bounds. However, the large and heterogeneous networkstructure of IoT brings high management costs. In particular, the low costof IoT devices exposes them to more serious security concerns. First, aconvolutional neural network intrusion detection system for IoT devices isproposed. After cleaning and preprocessing the NSL-KDD dataset, this paperuses feature engineering methods to select appropriate features. Then, basedon the combination of DCNN and machine learning, this paper designs acloud-based loss function, which adopts a regularization method to preventoverfitting. The model consists of one input layer, two convolutional layers,two pooling layers and three fully connected layers and one output layer.Finally, a framework that can fully consider the user’s privacy protection isproposed. The framework can only exchange model parameters or intermediateresults without exchanging local individuals or sample data. This paperfurther builds a global model based on virtual fusion data, so as to achievea balance between data privacy protection and data sharing computing. Theperformance indicators such as accuracy, precision, recall, F1 score, and AUCof the model are verified by simulation. The results show that the model ishelpful in solving the problem that the IoT intrusion detection system cannotachieve high precision and low cost at the same time.

An Early Warning Model of Telecommunication Network Fraud Based on User Portrait

With the frequent occurrence of telecommunications and networkfraud crimes in recent years, new frauds have emerged one after another whichhas caused huge losses to the people. However, due to the lack of an effectivepreventive mechanism, the police are often in a passive position. Usingtechnologies such as web crawlers, feature engineering, deep learning, andartificial intelligence, this paper proposes a user portrait fraudwarning schemebased on Weibo public data. First, we perform preliminary screening andcleaning based on the keyword “defrauded” to obtain valid fraudulent userIdentity Documents (IDs). The basic information and account information ofthese users is user-labeled to achieve the purpose of distinguishing the typesof fraud. Secondly, through feature engineering technologies such as avatarrecognition, Artificial Intelligence (AI) sentiment analysis, data screening,and follower blogger type analysis, these pictures and texts will be abstractedinto user preferences and personality characteristics which integrate multidimensionalinformation to build user portraits. Third, deep neural networktraining is performed on the cube. 80% percent of the data is predicted basedon the N-way K-shot problem and used to train the model, and the remaining20% is used for model accuracy evaluation. Experiments have shown thatFew-short learning has higher accuracy compared with Long Short TermMemory (LSTM), Recurrent Neural Networks (RNN) and ConvolutionalNeural Network (CNN). On this basis, this paper develops a WeChat smallprogram for early warning of telecommunications network fraud based onuser portraits. When the user enters some personal information on the frontend, the back-end database can perform correlation analysis by itself, so as tomatch the most likely fraud types and give relevant early warning information.The fraud warning model is highly scaleable. The data of other Applications(APPs) can be extended to further improve the efficiency of anti-fraud whichhas extremely high public welfare value.

孔隙式粘滞阻尼器CFD计算与试验分析

结合具体的孔隙式粘滞阻尼器开发案例,重点探讨了采用CFD数值模拟与试验验证相结合的方法来指导阻尼器开发设计的可行性。结果表明仿真阻尼力和试验阻尼力的活塞运动速度相关性和活塞位移相关性表现均一致,各工况下的计算误差均控制在合理范围以内。所提出的先采用流体介质粘性试验数据拟合出本构模型特征参数,再基于CFD软件平台进行阻尼器力学性能数值模拟的方法能够比较准确的分析出阻尼器的基本力学规律,对控制设计偏差和指导现场试验具有实际意义。

体位与眼压研究进展

青光眼是受多因素影响的不可逆性致盲眼病,眼压升高是已知最重要的危险因素。研究普遍认为眼压越高,眼压波动越大,青光眼性视神经损害越严重。全身和局部因素变化都可能影响到患者的眼压,而体位是其中重要因素之一。青光眼患者眼压受体位变化的影响普遍大于正常人。体位与眼压的关系在青光眼的日常诊疗和管理中起到重要作用,也越来越得到眼科医生的关注,本文主要就体位与眼压的研究进展及可能机制进行综述。

Epstein-Barr virus infection and persistence in nasopharyngeal epithelial cells

Epstein-Barr virus(EBV) infection is closely associated with undifferentiated nasopharyngeal carcinoma(NPC), strongly implicating a role for EBV in NPC pathogenesis; conversely, EBV infection is rarely detected in normal nasopharyngeal epithelial tissues. In general, EBV does not show a strong tropism for infecting human epithelial cells, and EBV infection in oropharyngeal epithelial cells is believed to be lytic in nature. To establish life-long infection in humans, EBV has evolved efficient strategies to infect B cells and hijack their cellular machinery for latent infection. Lytic EBV infection in oropharyngeal epithelial cells, though an infrequent event, is believed to be a major source of infectious EBV particles for salivary transmission. The biological events associated with nasopharyngeal epithelial cells are only beginning to be understood with the advancement of EBV infection methods and the availability of nasopharyngeal epithelial cell models for EBV infection studies. EBV infection in human epithelial cells is a highly inefficient process compared to that in B cells, which express the complement receptor type 2(CR2) to mediate EBV infection. Although receptor(s) on the epithelial cell surface for EBV infection remain(s) to be identified, EBV infection in epithelial cells could be achieved via the interaction of glycoproteins on the viral envelope with surface integrins on epithelial cells, which might trigger membrane fusion to internalize EBV in cells. Normal nasopharyngeal epithelial cells are not permissive for latent EBV infection, and EBV infection in normal nasopharyngeal epithelial cells usually results in growth arrest. However, genetic alterations in premalignant nasopharyngeal epithelial cells, including p16 deletion and cyclin D1 overexpression, could override the growth inhibitory effect of EBV infection to support stable and latent EBV infection in nasopharyngeal epithelial cells. The EBV episome in NPC is clonal in nature, suggesting that NPC develops from a single EBV-infected nasopharyngeal epithelial cell, and the establishment of persistent and latent EBV infection in premalignant nasopharyngeal epithelium may represent an early and critical event for NPC development.

Neuroprotective effect of pretreatment with ganoderma lucidum in cerebral ischemia/reperfusion injury in rat hippocampus

Ganoderma lucidum is a traditional Chinese medicine, which has been shown to have both an-tioxidative and anti-inflammatory effects, and noticeably decreases both the infarct area and neuronal apoptosis of the ischemic cortex. This study aimed to investigate the protective effects and mechanisms of pretreatment with ganoderma lucidum （by intragastric administration） in cerebral ischemia/reperfusion injury in rats. Our results showed that pretreatment with ganoderma lucidum for 3 and 7 days reduced neuronal loss in the hippocampus, diminished the content of malondialdehyde in the hippocampus and serum, decreased the levels of tumor necrosis factor-a and interleukin-8 in the hippocampus, and increased the activity of superoxide dismutase in the hippocampus and serum. These results suggest that pretreatment with ganoderma lucidum was protective against cerebral ischemia/reperfusion injury through its anti-oxidative and an-tiinflammatory actions.

Establishment and characterization of a new cell line derived from human colorectal laterally spreading tumor

AIM:To study the molecular mechanism of laterally spreading tumor (LST), a cell line [Laterally Spreading Tumor-Rectum 1 (LST-R1)] was derived and the characteristics of this cell line were investigated. METHODS:A new cell line (LST-R1) originated from laterally spreading tumor was established. Properties of the cell line were characterized using scanning and transmission electron microscopy, immunohistochemistry method, cytogenetic analysis and nude mice xenograft experiments. In vitro invasion assay, cDNA microarray and Western blotting were used to compare the difference between the LST-R1 and other colorectal cancer cell lines derived from prudent colon cancer. RESULTS:Our study demonstrated that both epithelial special antigen (ESA) and cytokeratin-20 (CK20) were expressed in LST-R1. The cells presented microvilli and tight junction with large nuclei. The karyotypic analysis showed hyperdiploid features with structural chromosome aberrations. The in vivo tumorigenicity was also demonstrated in nude mice xenograft experiments. The invasion assay suggested this cell line has a higher invasive ability. cDNA microarray and Western blotting show the loss of the expression of E-cadherin in LST-R1 cells.CONCLUSION:We established and characterized a colorectal cancer cell line, LST-R1 and LST-R1 has an obvious malignant tendency, which maybe partially attributed to the changes of the expression of some adhesion molecules, such as E-cadherin. It is also a versatile tool for exploring the original and progressive mechanisms of laterally spreading tumor and the early colon cancer genesis.

Authentication and Access Control in RFID Based Logistics-customs Clearance Service Platform

The content security requirements of a radio frequency identification （RFID） based logistics-customs clearance service platform （LCCSP） are analysed in this paper. Then, both the unified identity authentication and the access control modules are designed according to those analyses. Finally, the unified identity authentication and the access control on the business level are implemented separately. In the unified identity authentication module, based on an improved Kerberos-based authentication approach, a new control transfer method is proposed to solve the sharing problem of tickets among different servers of different departments. In the access control module, the functions of access controls are divided into different granularities to make the access control management more flexible. Moreover, the access control module has significant reference value for user management in similar systems.

Crystal growth, spectroscopic characteristics, and Judd–Ofelt analysis of Dy:Lu_2O_3 for yellow laser

Dy：Lu2O3 was grown by the float-zone （Fz） method. According to the absorption spectrum, the Judd-Ofelt （JO） parameters Ω2, Ω4, and Ω6 were calculated to be 4.86 × 10-20 cm2, 2.02 × 10-20 cm2, and 1.76 ×10-20 cm2, respectively. The emission cross-section at 574 nm corresponding to the 4F9/2 →6H13/2 transition was calculated to be 0.53 ×10 20 cm2. The yellow （4F9/2 →6H13/2 transition） to blue （4F9/2 →6H15/2 transition） intensity ratio ranges up to 12.9. The fluorescence lifetime of the 4F9/2 energy level was measured to be 112.1 μs. These results reveal that Dy：Lu2O3 is a promising material for use in yellow lasers.

Strength enhancement of nanocrystalline tungsten under high pressure

Three tungsten powder samples—one coarse grained(c-W;grain size:1μm–3μm)and two nanocrystalline(n-W;average grain sizes:10nm and 50 nm)—are investigated under nonhydrostatic compression in a diamond anvil cell in separate experiments,and their in situ X-ray diffraction patterns are recorded.The maximum microscopic deviatoric stress in each tungsten sample,a measure of the yield strength,is determined by analyzing the diffraction line width.Over the entire pressure range,the strength of tungsten increases noticeably as the grain size is decreased from 1μm–3μmto 10 nm.The results show that the yield strength of tungsten with an average crystal size of 10nmis around 3.5 times that of the sample with a grain size of 1μm–3μm.

The propensity for tumorigenesis in human induced pluripotent stem cells is related with genomic instability

The discovery of induced pluripotent stem cells (iPSCs) is a promising advancement in the field of regenerative medicine. Previous studies have indicated that the teratoma-forming propensity of iPSCs is variable; however, the relationship between tumorigenic potential and genomic instability in human iPSCs (HiPSCs) remains to be fully elucidated. Here, we evaluated the malignant potential of HiPSCs by using both colony formation assays and tumorigenicity tests. We demonstrated that HiPSCs formed tumorigenic colonies when grown in cancer cell culture medium and produced malignancies in immunodeficient mice. Furthermore, we analyzed genomic instability in HiPSCs using whole-genome copy number variation analysis and determined that the extent of genomic instability was related with both the cells′ propensity to form colonies and their potential for tumorigenesis. These findings indicate a risk for potential malignancy of HiPSCs derived from genomic instability and suggest that quality control tests, including comprehensive tumorigenicity assays and genomic integrity validation, should be rigorously executed before the clinical application of HiPSCs. In addition, HiPSCs should be generated through the use of combined factors or other approaches that decrease the likelihood of genomic instability.

Crystal growth,structure and optical properties of Pr^(3+)-doped yttria-stabilized zirconia single crystals

The development of blue semiconductor light-emitting diodes(LEDs)has produced potential applications for Prdoped materials that can absorb blue light,especially crystals,and we now report structure and optical properties for high-quality Pr-doped single crystals of yttria-stabilized zirconia(YSZ)grown by the optical floating zone(FZ)method.X-ray diffraction(XRD)and Raman spectroscopy showed that all of the single crystal samples were in the cubic phase,whereas the corresponding ceramic samples contained a mixture of monoclinic and cubic phases.X-ray photoelectron spectroscopy(XPS)and electron paramagnetic resonance(EPR)spectroscopy showed that Pr was present as the Pr^(3+)ion in ceramic rods and single crystals after heating to high temperatures.The absorption and photoluminescence excitation(PLE)spectra of the Pr-doped YSZ crystals measured at room temperature showed strong absorption of blue light,while their photoluminescence(PL)spectra showed five emission peaks at 565 nm,588 nm,614 nm,638 nm,and 716 nm under450 nm excitation.The optimum luminescence properties were obtained with the crystal prepared using 0.15 mol%Pr_(6)O_(11),and those with higher concentrations showed evidence of quenching of the luminescence properties.In addition,the color purity of Pr-doped YSZ single crystal reached 98.9%in the orange–red region.

Morphological Characteristics of the Dorsal Skin of Two Hynobiids and Their Adaptive Role in Aquatic and Terrestrial Habitats

The morphological characteristics of the dorsal skin of trunk in two species of hynobiid salamanders, Batrachuperus pinchonii and Hynobius chinensis were examined by light microscopy. The basic structures of the skin in the two species are similar and consist of two layers： epidermis and dermis. The epidermis consists of stratum corneum, stratum intermedium and stratum germinativum, while the dermis is composed of a stratum spongiosum and stratum compactum. However, some species-specific variation has been identified （e.g., the distribution of capillary vessels and gland cells, and the thickness of skin）. H. chinensis is a terrestrial species and only lives in water during breeding period, but B. pinchonii is aquatic and remains aquatic throughout its lifetime. The differences in the distribution of capillary vessels and gland cells are related to their different habitats, and show a morphological adaptation.

High-sensitive phototransistor based on vertical HfSe_(2)/MoS_(2) heterostructure with broad-spectral response

Van der Waals heterostructures based on the two-dimensional(2D)semiconductor materials have attracted increasing attention due to their attractive properties.In this work,we demonstrate a high-sensitive back-gated phototransistor based on the vertical HfSe_(2)/MoS_(2)heterostructure with a broad-spectral response from near-ultraviolet to near-infrared and an efficient gate tunability for photoresponse.Under bias,the phototransistor exhibits high responsivity of up to 1.42×103A/W,and ultrahigh specific detectivity of up to 1.39×1015cm·Hz^(1/2)·W^(-1).Moreover,it can also operate under zero bias with remarkable responsivity of 10.2 A/W,relatively high specific detectivity of 1.43×1014cm·Hz^(1/2)·W^(-1),ultralow dark current of 1.22 f A,and high on/off ratio of above 105.These results should be attributed to the fact that the vertical HfSe_(2)/MoS_(2)heterostructure not only improves the broadband photoresponse of the phototransistor but also greatly enhances its sensitivity.Therefore,the heterostructure provides a promising candidate for next generation high performance phototransistors.

Crystal growth and spectral properties of Tb：Lu2O3

The crystal growth,x-ray diffraction pattern,absorption spectrum,emission spectrum,and fluorescence lifetime of a Tb：Lu2O3 single crystal were studied.Excited at 483 nm,the peak absorption cross-section was calculated to be 3.5×10（-22）cm2,and the full width at half maximum was found to be 2.85 nm.The Judd-Ofelt（J-O）intensity parameters 2,4,and 6 were computed to be 3.79×10（-20）cm2,1.30×10（-20）cm2,and 1.08×10（-20）cm2,with a spectroscopic quality factor 4/6 being 1.20.The emission cross-sections of green emission around 543 nm and yellow emission around 584 nm were calculated to be 9.43×10（-22）cm2 and 1.32×10（-22）cm2,respectively.The fluorescence lifetimeτexp of -5D4 was fitted to be 1.13 ms.The data suggest that the Tb：Lu2O3 crystal could be a potential candidate for green and yellow laser operation.

关于企业自愿采用团体标准的思考

团体标准的有效实施是标准化深化改革取得成效的关键,企业作为市场主体和标准主要用户,自愿采用团体标准是衡量团体标准有效实施的重要指标之一。本文简要介绍了国外标准体系发展概况,分析了我国企业自愿采用团体标准的现状,以企业的视角,分析了自愿采用团体标准存在的问题和原因,并提出了建议和措施。

Optically-controlled resistive switching effects of CdS nanowire memtransistor

Since it was proposed,memtransistors have been a leading candidate with powerful capabilities in the field of neural morphological networks.A memtransistor is an emerging structure combining the concepts of a memristor and a field-effect transistor with low-dimensional materials,so that both optical excitation and electrical stimuli can be used to modulate the memristive characteristics,which make it a promising multi-terminal hybrid device for synaptic structures.In this paper,a single CdS nanowire memtransistor has been constructed by the micromechanical exfoliation and alignment lithography methods.It is found that the CdS memtransistor has good non-volatile bipolar memristive characteristics,and the corresponding switching ratio is as high as 10^(6) in the dark.While under illumination,the behavior of the CdS memtransistor is similar to that of a transistor or a memristor depending on the incident wavelengths,and the memristive switching ratio varies in the range of 10 to 10^(5) with the increase of the incident wavelength in the visible light range.In addition,the optical power is also found to affect the memristive characteristics of the device.All of these can be attributed to the modulation of the potential barrier by abundant surface states of nanowires and the illumination influences on the carrier concentrations in nanowires.

Bridging buried interface enable 24.67%-efficiency doctor-bladed perovskite solar cells in ambient condition

Scalable deposition of high-efficiency perovskite solar cells(PSCs)is critical to accelerating their commercial applications.However,a significant number of defects are distributed at the buried interface of perovskite film fabricated by scalable deposition,exhibiting much negative influence on the efficiency and stability of PSCs.Herein,2-(N-morpholino)ethanesulfonic acid potassium salt(MESK)is incorporated as the bridging layer between the tin oxide(SnO_(2))electron transport layer(ETL)and the perovskite film deposited via scalable two-step doctor blading.Both experiment and simulation results demonstrate that MESK can passivate the trap states of Sn suspension bonds,thereby enhancing the charge extraction and transport of the SnO_(2)ETL.Meanwhile,the strong interaction with uncoordinated Pb ions can modulate the crystal growth and crystallographic orientation of perovskite film and passivate buried defects.With employing MESK interface bridging,PSCs fabricated via scalable doctor blading in ambient condition achieve a power conversion efficiency(PCE)of 24.67%,which is one of the highest PCEs for doctor-bladed PSCs,and PSC modules with an active area of 11.35 cm^(2)achieve a PCE of 19.45%.Furthermore,PSCs exhibit excellent long-term stability,and the unpackaged target device with a storage of 1680 h in ambient condition(25℃and humidity of 30%relative humidity(RH))can maintain more than 90%of the initial PCE.The research provides a strategy for constructing a high-performance interface bridge between SnO_(2)ETL and perovskite film,and achieving efficient and stable large-area PSCs and modules fabricated via scalable doctor-blading process in ambient condition.

Impact of ursodeoxycholic acid therapy in autoimmune liver disease patients with COVID-19 and its clinical prognosis

To explore the impact of ursodeoxycholic acid(UDCA)on severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)infection and clinical outcomes in patients with autoimmune liver disease(AILD).Patients diagnosed with AILD were enrolled and divided into a UDCA group and a non-UDCA group based on whether they received UDCA treatment.Relevant data were collected regarding AILD diagnosis,treatment,biochemical indicators,and imaging examination.The incidence of SARS-CoV-2 infection and the prognosis of AILD patients were observed.A total of 1,138 patients completed follow-up.The usage rate of hormone(P=0.003)and immunosuppressant(P=0.001)used for treating AILD in the non-UDCA group was markedly lower than in the UDCA group.The UDCA usage rate was markedly lower in SARS-CoV-2 infected patients than in uninfected patients(P=0.003).The rate of SARS-CoV-2 infection in the non-UDCA group was significantly higher than in the UDCA group(P=0.018).Logistic regression analysis showed that UDCA use(P=0.003)was correlated to a lower incidence of SARS-CoV-2,while immunosuppressant use(P=0.017)increased the incidence.Recovery time from SARS-CoV-2 infection was markedly longer for those receiving UDCA treatment than those in the non-UDCA group(P=0.018).UDCA is associated with low SARS-CoV-2 incidence in AILD patients,while immunosuppressant increases its incidence instead.Patients receiving UDCA treatment have a longer recovery time after being infected.

White light luminescence in Dy/Tm co-doped yttria stabilized zirconia single crystals

A series of high quality Dy_(2)O_(3) and Tm_(2)O_(3)co-doped yttria stabilized zirconia(YSZ) single crystals was synthesized.These crystals have a single cubic structure,and exhibit the characteristic of Dy^(3+)(blue and yellow emissions) and Tm^(3+)(blue emission) under excitation with NUV light.Impo rtantly,the hue can be varied between blue and white by modifying the Tm^(3+)/Dy^(3+)ratio.The photoluminescence and decay curves are consistent with the existence of resonance-type energy transfer from Tm^(3+)to Dy^(3+)ions via an electric multipole interaction mechanism.Maximum luminescence intensity is observed in YSZ doped with 0.50 mol% Tm_(2)O_(3) and 0.75 mol% Dy_(2)O_(3),and this sample has CIE coordinates(x = 0.33,y = 0.33) in accordance with those for white chromaticity.Thus,the outstanding luminescence properties of these single crystals suggest potential applications in white light emission devices.