基于NOMA的共生反向散射通信的性能分析

非正交多址接入和环境反向散射通信是提高无线通信系统频谱效率的关键技术.针对能量受限问题,提出了一种基于瑞利衰落信道的下行非正交多址接入多路传输的共生反向散射通信系统.该系统由1个源节点S、1个反向散射设备BD和1个目的节点D组成.考虑到实际的非线性能量收集模型,在满足反射设备的能量因果约束的情况下,采用了一种最优动态反射系数以最大化反向散射信号的功率,推导了该系统中断概率的解析表达式,通过仿真验证了理论推导的正确性.仿真结果表明,反射设备电路的自身损耗对系统中断性能有重要影响.此外,通过仿真对比分析了基于非正交多址的共生反向散射通信系统和基于正交多址的共生反向散射通信系统性能,结果表明基于非正交多址的共生反向散射通信系统具有更好的中断性能.

基于多任务学习的同行评审细粒度情感分析模型

学术论文同行评审能够直接反映审稿人对论文的主观评价,对审稿文本进行情感分析有利于挖掘审稿人对论文多维度的评价信息。现有的情感分析模型仅能挖掘专家单一的评审维度和相应的情感倾向,本文提出了一种基于多任务学习的同行评审细粒度情感分析模型。该模型在多任务学习框架下,通过在BERT-LCF模型的基础上增加BiLSTM-CRF模块,使其具备了同时完成属性词抽取和细粒度情感分析任务的能力。与传统的基于Pipeline模式的单任务细粒度情感分析模型相比,本模型在保证精度的情况下可以同时完成评审属性提取和情感分析任务。在这两项任务中,所提出模型的F1分数分别达到了89.01%和90.71%。对比实验证明,在多任务场景下,引入BiLSTM-CRF模块对评审文本属性词提取任务有一定的提升作用。

Analysis of Static Temperature Field of Vehicle's Solid Rubber Tire

Aim To analyse the static temperature field ofthe solid rubber tire(SRT).Methods The mechanical and thermal FE models were developed and analyzed respectively with the FE software ANSYS.Results The maximum temperature becomes higher with the higher with the higher velocity of tire and scales down slightly with the higher convection coefficients.The mixed models are reasonable.Conclusion The study on static temperature field is important and reasonable.It gives the fundament for life analysis of SRT.

Application of combination weighting method in contract risk's evaluation of third party logistics

First,the analytical hierarchy process(AHP),which stands for the subjective weighting method,and the entropy method,which stands for the objective weighting method,are chosen to calculate the index weights of the contract risks of third party logistics(TPL),respectively.Then,they can determine the combination weights using the combination weighting method.Second,using the combination weights,the contract risks of TPL are evaluated through the fuzzy comprehensive evaluation method.According to the combination weights,the most important risk factor of the contract risks of TPL is choosing sub-contractors.The results are basically consistent with the facts and show that the weights determined by the combination weighting method can avoid the man-made deviations of the subjective weighting method on the one hand,and prevent results opposite to the reality brought about by the objective weighting method on the other hand.Meanwhile,the results of the fuzzy comprehensive evaluation are that the contract risks of TPL are at a high risk level.Roughly this matches real situations,and it indicates that the combination weighting method can generate the comprehensive assessment more scientifically and more reasonably as well.

我国大豆生产波动动因分析——基于省际面板模型的实证研究

在我国大豆生产波动频繁的情况下,找出影响大豆单产、种植面积的影响因素是实现“提单产、稳面积”的首要举措。研究采用1999~2020年21个省份面板数据,在分析大豆单产、种植面积的变化趋势基础上,根据大豆单产增减趋势,把大豆产区划分成增产区、减产区和波动区,采用改进的面板数据模型分别对三个产区的大豆单产和种植面积的影响因素进行实证分析。结果表明,机械化收割、产研结合、农药投入、小型拖拉机的投入是影响不同区域大豆单产的显著因素;机械化耕作是提升所有区域种植面积的显著因素,玉米种植面积、化肥投入、农药投入、灌溉条件、科研资金与人员投入、产研结合、机械化收割是影响不同区域大豆种植面积显著因素。根据分析,提出了相应政策建议。

大麦条纹花叶病毒新疆株(BSMV-XJ)RNA2 3′端结构分析

本文利用双脱氧序列分析法对我国大麦条纹花叶病毒新疆株(BSMV-XJ)RNA2 cDNA的3′端进行序列分析,证明XJ株RNA2 3′端239个核苷酸与国外典型株3′端相应部位有高度的序列同源性。通过序列分析及使用寡核苷酸定位裂解法和分子杂交确定,在紧邻239个核苷酸的上游有一个Poly(A)结构,3′终端为一个类tRNA结构,亦与国外典型株相同。经分析认为BSMV-XJ3个基因组RNA具有相同的3′端结构。

Poisson's Theory of the Chaplygin's Equations

Puts forward an algebraic structure of the Chaplygin's equations of nonholonomic systems, establish the Poisson's theory of the integration equations and gives an example for illustrating the application of the result.

带后续队列长度通告的呼叫中心性能分析

从排队心理学的角度考虑了队列长度对顾客等待耐心的影响,设计了一个带队列信息通告机制的M/M/N模型。等待的顾客可以像有形排队一样获知目前排队的人数及其所处的队列位置,并以此决定继续等待或者放弃。使用仿真方法对该机制下的呼叫中心性能进行了分析,并与Erlang-A模型和Erlang-C模型进行了比较。

Electronic structure and ultraviolet spectra of p-C_(6)H_(4)-C_(20)

Geometry optimization of p-C_(6)H_(4)-connected cyclo[20]carbon(p-C_(6)H_(4)-C_(20))was carried out at M062X/6-311G(d,p)level,three kinds of bond orders(Mayer,Laplacian,and Wiberg),electron-hole distributions,localized orbital locators(LOL),and infrared(IR)spectrum were also performed at the same level.Based on TD-DFT M062X/6-311G(d,p)method,the first 20 excited states and ultraviolet(UV)spectra of p-C_(6)H_(4)-C_(20) were calculated.Calculation results of π-electron delocalization analyses prove thatπ-electron delocalization of p-C_(6)H_(4)-C_(20) is more likely to occur on shorter C-C bonds rather than longer C-C bonds,and inside/outside of the ring plane rather than above/below the ring plane.Two absorption peaks of p-C_(6)H_(4)-C_(20) locate at about 319 nm and 236 nm,respectively.

The Key Techniques of VHDL Parser's Automatic Generation

VHDL and its supporting environment are active domain in the field of logic design.In the paper the design principle and some key techniques to solve the problems on the implementation of the VHDL parser are introduced. According to the methods discussed in the paper, the VHDL parser based on VHDL IEEE 1076 standard version is implemented and a series of strict tests are done. This VHDL parser is front-end tool of the VHDL high level synthesis and mixed level simulation system developed by the Research Center of ASIC of BIT.

On the Employment Structure and Transfer Characteristics of Rural Laborers in He'nan Province

He’nan is a populous province in China, in which a large number of rural laborers are one of the important factors affecting social and economic development of He’nan Province. However, the employment structure and transfer characteristics of rural laborers have important effect on regional industrial structure. Applying shiftshare method（ SSM） which is often used in analyzing the characteristics of industrial structure to the structure analysis of the labour force can better show the characteristics of labor employment and transfer, thereby providing some reference for the development of regional social economy. The results showed that the transfer of rural laborers in He’nan Province still showed the typical characteristics of traditional agricultural province; the basic advantages of agricultural employment of rural laborers have gradually weakened, while the competitive advantages of the industry, the building industry, and the wholesale ＆ retail trade and catering service industry gradually became obvious, at the same time, there were differences in the deviation of departments among different regions of He’nan Province.

The quantified analysis of China's GM cotton yield capacity by C-D function and stochastic frontier model

Using a modified C D function and stochastic frontier model, the paper analyzed China's cotton yield capacity and found that the yield and technical efficiency of China's cotton planting system can be increased by the use of genetically modified (GM) varieties.

PCR-RFLP and Sequence Analysis of Mx Gene 3'Sequence in Langya Chicken Breeds

Objective The aim was to provide basis for molecular marker assisted selection and resistance breeding of Langya chicken. Method The genetic polymorphism of Hae III site of Mx gene 3＇ sequence in Langya chicken was analyzed by PCR-RFLP. Result The results showed that Hae III site controlled by allele A and B were polymorphic in Langya chicken breeds and the allele frequencies of A and B were 0.562 and 0.438 respectively. The genotype distribution of Hae III site was significantly not in Hardy-Weinberg equilibrium （ P 〈0.01 ）. The polymorphic fragments were cloned and sequenced, and the results revealed that the fragment size was 357 bp and a deletion of 31 bp occurred in variation sequences. Conclusion It was found that Hae III-RFLP exists in Mx gene 3＇ sequence in Langya chicken breeds of Shandong Province.

高职专业教师岗位胜任力的政策文本分析

高等职业教育具有鲜明的实用性和实践性,1995年国家在正式文件中首次提出建设"双师型"教师,作为其胜任高职专业教育教学的基本条件。文章从政策文本分析的视角解读了"双师型"教师内涵,以明确高职专业教师胜任其岗位,必须具备高校教师资格,具有讲师以上职称或硕士以上学历和3～5年本专业实践工作经验。

工程造价与进度的偏差分析

工程造价与进度的偏差分析是近年来国际工程管理的重要方法之一,它通过对工程造价的执行状况进行分析,获得有关造价和进度的偏差,以评价项目管理的绩效和对未来的管理提供决策的依据。对工程造价进度的偏差分析步骤、分析方法进行了介绍。最后用实际资料对一个具体工程造价与进度进行了偏差分析,说明了该方法的应用。根据分析结果对该工程执行状况进行了评判。

医院处方用药点评分析中遇到几个问题的探讨

通过对医院门诊处方点评过程中具体遇到的用药不适宜,主要如诊断与处方用药、处方用药交待的书面表达、注意药物使用方法、中西药合用的合理性这四个方面进行阐述。提出医师处方要有清晰的文字书写表达;药师要在实际工作中发现问题,提高知识水平;处方点评工作的实施要避免片面性和盲目性,应该注重处方点评的针对性和全面性。不断提高处方分析水平,最终促进临床合理用药,保障患者的用药权益。

国内隐喻能力研究热点话题和发展路径耙梳——基于CNKI核心期刊文献(1997-2017)的共词可视化分析

依据文献计量法及数据可视化分析方法,运用可视化数据分析软件,对我国隐喻能力研究现状进行量化分析。以中国学术网络出版总库CNKI中CSSCI和核心期刊文献为数据来源,以“隐喻能力”为主题检索词,从发表时间、发文期刊、第一作者、高频关键词等维度出发,探究我国隐喻能力研究路径和热点话题,归纳总结研究成果,并尝试指出未来隐喻能力研究的发展方向。

Correlations between endoscopic and clinical disease activity indices in intestinal Behcet's disease

AIM:To develop a novel endoscopic severity model of intestinal Behcet's disease(BD) and to evaluate its feasibility by comparing it with the actual disease activity index for intestinal Behcet's disease(DAIBD).METHODS:We reviewed the medical records of 167 intestinal BD patients between March 1986 and April 2011.We also investigated the endoscopic parameters including ulcer locations,distribution,number,depth,shape,size and margin to identify independent factors associated with DAIBD.An endoscopic severity model was developed using significant colonoscopic variables identified by multivariate regression analysis and its correlation with the DAIBD was evaluated.To determine factors related to the discrepancy between endoscopic severity and clinical activity,clinical characteristics and laboratory markers of the patients were analyzed.RESULTS:A multivariate regression analysis revealed that the number of intestinal ulcers(≥ 2,P = 0.031) and volcanoshaped ulcers(P = 0.001) were predictive factors for the DAIBD.An endoscopic severity model(Y) was developed based on selected endoscopic variables as follows:Y = 47.44 + 9.04 × non-Ileocecal area + 11.85 ×≥ 2 of intestinal ulcers + 5.03 × shallow ulcers + 12.76 × deep ulcers + 4.47 × geographicshaped ulcers + 26.93 × volcano-shaped ulcers + 8.65 ×≥ 20 mm of intestinal ulcers.However,endoscopic parameters used in the multivariate analysis explained only 18.9% of the DAIBD variance.Patients with severe DAIBD scores but with moderately predicted disease activity by the endoscopic severity model had more symptoms of irritable bowel syndrome(21.4% vs 4.9%,P = 0.026) and a lower rate of corticosteroid use(50.0% vs 75.6%,P = 0.016) than those with severe DAIBD scores and accurately predicted disease by the model.CONCLUSION:Our study showed that the number of intestinal ulcers and volcano-shaped ulcers were predictive factors for severe DAIBD scores.However,the correlation between endoscopic severity and DAIBD(r = 0.434) was weak.

miR-200 family expression is downregulated upon neoplastic progression of Barrett's esophagus

AIM: To investigate miR-200 family expression in Barrett's epithelium, gastric and duodenal epithelia, and esophageal adenocarcinoma. METHODS: Real-time reverse transcriptase-polymerase chain reaction was used to measure miR-200, ZEB1 and ZEB2 expression. Ingenuity Pathway Analysis of miR-200 targets was used to predict biological outcomes. RESULTS: Barrett's epithelium expressed lower levels of miR-141 and miR-200c than did gastric and duodenal epithelia (P < 0.001). In silico analysis indicated roles for the miR-200 family in molecular pathways that distinguish Barrett's epithelium from gastric and duodenalepithelia, and which control apoptosis and proliferation. All miR-200 members were downregulated in adenocarcinoma (P < 0.02), and miR-200c expression was also downregulated in non-invasive epithelium adjacent to adenocarcinoma (P < 0.02). The expression of all miR-200 members was lower in Barrett's epithelium derived high-grade dysplastic cell lines than in a cell line derived from benign Barrett's epithelium. We observed signif icant inverse correlations between miR-200 family expression and ZEB1 and ZEB2 expression in Barrett's epithelium and esophageal adenocarcinoma (P < 0.05). CONCLUSION: miR-200 expression might contribute to the anti-apoptotic and proliferative phenotype of Barrett's epithelium and regulate key neoplastic processes in this epithelium.

Immunogenicity Analysis of Prokaryotic Expression Products of Kaposi's Sarcoma Associated Herpesvirus orf65

To purify the protein encoding the small capsid protein （SCP） of KSHV and analyze its immunogenicity, the carboxyl terminus of orf65 of Kaposi＇s sarcoma associated-herpesvirus （KSHV） was expressed in a prokaryotic expression system. The expression of recombinant E.coli containing pQE-80L-orf65 was induced by isopropyl-13-D-thiogalactopyranoside （IPTG） and the fusion protein was purified by chromatography. The expressed protein and its purified product were identified by sodium dodecyl sulfate- polyacrylamide gel electrophoresis （SDS-PAGE） and showed that 9 kDa was the expected size of the purified orf65 protein. The antiserum was produced in rabbit which was immunized by purified orf65 protein. An ELISA assay was established to analyze the immunogenicity of the purified orf65 protein. The ELISA analysis demonstrated that orf65 protein has strong immune activity, and the immune activity of polyclonal antibody against orf65 was more than 4 fold higher than that in the serum of the non-immunized rabbit. These results demonstrate that purified orf65 protein has very strong immunogenicity and can be used in screening KSHV infection in the general population using ELISA.