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Isolating Soil Drought-Induced Genes from Maize Seedling Leaves Through Suppression Subtractive Hybridization

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Agricultural Sciences in China 2007年第6期6卷 647-651页

作者： LI Hui-yong HUANG Su-hua SHI Yun-su SONG Yan-chun ZHAO Jiu-ran WANG Feng-ge WANG tian-yu LI Yu Institute of Food Crops Henan Academy of Agricultural Sciences Zhengzhou 450002 P.R.China Institute of Crop Sciences Chinese Academy of Agricultural Sciences Beijing 100081 P.R.China Maize Research Institute Beijing Academy of Agricultural and Forestry Sciences Beijing 100081 P.R.China

In this study, a forward cDNA library was constructed by suppression subtractive hybridization using seedling leaves of CN165, a drought-tolerant maize inbred line. In the suppression subtractive hybridization （SSH） library, 672 positive clones were picked up randomly. After polymerase chain reaction （PCR） of each clone, all the single clones were sequenced. Totally 598 available sequences were obtained. After cluster analysis of the EST sequences, 80 uniESTs were obtained, among which 57 uniESTs were contigs and 23 uniESTs were singlets. The results of BLASTN showed that all the uniESTs had homologous sequences in the nr database. The BLASTX results indicated that 68 uniESTs had significant protein homology, 8 uniESTs with homology of unknown proteins and putative proteins, and 4 uniESTs without protein homology. Those drought stress-induced genes were involved in many metabolism pathways to regulate plant growth and development under drought stress.

关键词： maize drought stress suppression subtractive hybridization (SSH) uniESTs

Estimation of reproduction numbers of COVID-19 in typical countries and epidemic trends under different prevention and control scenarios

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Frontiers of Medicine 2020年第5期14卷 613-622页

作者： Chen Xu Yinqiao Dong Xiaoyue Yu Huwen Wang Lhakpa Tsamlag Shuxian Zhang Ruijie Chang Zezhou Wang Yuelin Yu Rusi Long Ying Wang Gang Xu tian Shen Suping Wang Xinxin Zhang Hui Wang yong Cai School of Public Health Shanghai Jiao Tong University School of MedicineShanghai 200025China Department of Environmental and Occupational Health School of Public HealthChina Medical UniversityShenyang 110122China Department of Cancer Prevention Shanghai Cancer CenterFudan UniversityDepartment of OncologyShanghai Medical CollegeFudan UniversityShanghai 200025China Research Laboratory of Clinical Virology National Research Center for Translational Medicine(Shanghai)Ruijin Hospital and Ruijin Hospital North Affiliated to Shanghai Jiao Tong University School of MedicineShanghai 200025China

The coronavirus disease 2019(COVID-19)has become a life-threatening *** epidemic trends in different countries vary considerably due to different policy-making and resources *** calculated basic reproduction number(R0)and the time-varying estimate of the effective reproductive number(Rt)of COVID-19 by using the maximum likelihood method and the sequential Bayesian method,*** and North American countries possessed higher (R0)and unsteady Rt fluctuations,whereas some heavily affected Asian countries showed relatively low (R0)and declining Rt *** numbers of patients in Africa and Latin America are still low,but the potential risk of huge outbreaks cannot be *** scenarios were then simulated,generating distinct outcomes by using SEIR(susceptible,exposed,infectious,and removed)***,evidence-based prompt responses yield lower transmission rate followed by decreasing ***,implementation of effective control policies at a relatively late stage,in spite of huge casualties at early phase,can still achieve containment and ***,wisely taking advantage of the time-window for developing countries in Africa and Latin America to adopt adequate measures can save more people’s *** mathematical modeling provides evidence for international communities to develop sound design of containment and mitigation policies for COVID-19.

关键词： reproduction number SEIR model COVID-19 estimate

Source-Free Unsupervised Domain Adaptation with Sample Transport Learning

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Journal of Computer Science & Technology 2021年第3期36卷 606-616页

作者： Qing tian Chuang Ma Feng-Yuan Zhang Shun Peng Hui Xue School of Computer and Software Nanjing University of Information Science and TechnologyNanjing 210044China Engineering Research Center of Digital Forensics Ministry of EducationNanjing University of Information Science and TechnologyNanjing 210044China School of Computer Science and Engineering Southeast UniversityNanjing 211189China

Unsupervised domain adaptation(UDA)has achieved great success in handling cross-domain machine learning *** typically benefits the model training of unlabeled target domain by leveraging knowledge from labeled source *** this purpose,the minimization of the marginal distribution divergence and conditional distribution divergence between the source and the target domain is widely adopted in existing ***,for the sake of privacy preservation,the source domain is usually not provided with training data but trained predictor(e.g.,classifier).This incurs the above studies infeasible because the marginal and conditional distributions of the source domain are *** this end,this article proposes a source-free UDA which jointly models domain adaptation and sample transport learning,namely Sample Transport Domain Adaptation(STDA).Specifically,STDA constructs the pseudo source domain according to the aggregated decision boundaries of multiple source classifiers made on the target ***,it refines the pseudo source domain by augmenting it through transporting those target samples with high confidence,and consequently generates labels for the target *** train the STDA model by performing domain adaptation with sample transport between the above steps in alternating manner,and eventually achieve knowledge adaptation to the target domain and attain confident labels for ***,evaluation results have validated effectiveness and superiority of the proposed method.

关键词： unsupervised domain adaptation domain shift sample transport pseudo source domain

Channel Measurement and Path Loss Modeling from 220 GHz to 330 GHz for 6G Wireless Communications

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China Communications 2021年第5期18卷 19-32页

作者： Pan Tang Jianhua Zhang Haoyu tian Zhaowei Chang Jun Men Yuxiang Zhang Lei tian Liang Xia Qixing Wang Jingsuo He State Key Lab of Networking and Switching Technology Beijing University of Posts and TelecommunicationsBeijing 100876China China Mobile Research Institute Beijing 100053China Capital Normal University Beijing 100048China

Terahertz(THz)communication has been envisioned as a key enabling technology for sixthgeneration(6G).In this paper,we present an extensive THz channel measurement campaign for 6G wireless communications from 220 GHz to 330 ***,the path loss is analyzed and modeled by using two single-frequency path loss models and a multiplefrequencies path loss *** is found that at most frequency points,the measured path loss is larger than that in the free *** at around 310 GHz,the propagation attenuation is relatively weaker compared to that in the free ***,the frequency dependence of path loss is observed and the frequency exponent of the multiple-frequencies path loss model is ***,the cellular performance of THz communication systems is investigated by using the obtained path loss *** results indicate that the current inter-site distance(ISD)for the indoor scenario is too small for THz ***,the tremendous capacity gain can be obtained by using THz bands compared to using microwave bands and millimeter wave ***,this work can give an insight into the design and optimization of THz communication systems for 6G.

关键词： terahertz channel measurement channel modeling path loss

Construction of full length cDNA expression library of hepatopancreas of Penaeus monodon

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Acta Oceanologica Sinica 2002年第3期21卷 437-443页

作者： Luo tian(罗田) Xu Xun(徐洵) School of Life Science Xiamen University Xiamen 361005 China Third Institute of Oceanography State Oceanic Administration Xiamen 361005 China

mRNA was isolated from the hepatopancrease of shrimp Penaeus monodon with a PolyAT-tract System 1000 Kit. By using mRNA as template, double - strand cDNA with EcoR I/Xho I ends was synthesized by using a ZAP Express cDNA Synthesis Kit. The cDNA was inserted into the lambda ZAP Express vector predigested with EcoR l/Xho Ⅰ, and the recombinant DNA was in vitro packaged into lambda phage with GigapackⅢ Gold packaging extracts. These recombinant phages were then used to transfect E. coli XL1 - Blue MRF', and finally a cDNA expression library was constructed. The library is 7.2 × 10~5pfu in capacity and its recombination ratio is higher than 99 % . The size of the inserted cDNAs was determined by EcoR l/Xho I digestion of 9 phagemids prepared by in vivo excision of plaques selected randomly from amplified cDNA library . The longest inserted cDNA is about 1.6 kb in length. The complete sequence (about 1.2 kb) of actin cDNA was amplified from the library by PCR reveals that this library contains full-length cDNAs of Penaeus monodon hepatopancreas and is available for screening and expression of shrimp genes.

关键词： Penaeus monodon cDNA expression library hepatopancreas

Influence of friction-lubrication characteristics varying with rolling speed on instability of chatter and slip in cold tandem rolling process

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Journal of Iron and Steel Research International 2024年第4期31卷 894-908页

作者： Yan-li Xin Zhi-ying Gao Bo tian Qing-dong Zhang School of Mechanical Engineering University of Science and Technology BeijingBeijing 100083China

In the high-speed cold tandem rolling process of thin plate,chatter or slip instability gives rise to the deterioration of equipment and product *** instability behavior is closely related to interfacial friction-lubrication con-dition which is generally characterized by the friction ***,with higher and higher speed requirements,the commonly used model of friction coefficient is no longer applicable and accurate.A novel approach is suggested to calculate the speed-dependent friction coefficient,in which the viscosity-pressure-temperature effects of the lubricant,surface roughness states of work rolls and rolled piece are comprehensively involved and the mixed flm lubrication theory is ***,the influences of friction coefficient on the instability of slip and chatter are investigated for a five-stand cold tandem rolling *** one side,the critical friction coefficient for each stand is determined by calculating the corresponding slip factor;on the other hand,the friction coefficient varying with rolling speed is combined with the model of theoretical critical rolling speed presented under constant friction coefficient,so that the speed threshold is ***,the stable and unstable regions corresponding to the rear three stands are individually discussed,and the technical strategies are proposed to suppress both slip and chatter frequently occurring in the actual rolling process.

关键词： Cold tandem rolling:Oil film thickness Speed-dependent friction coefficient-Slip:Chatter

双模SU(1,1)猫态与级联三能级原子的粒子布居相干俘获

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物理学报 2000年第4期49卷 696-701页

作者：韩立波田永红李高翔彭金生湖北省荆州师范学院物理系荆州434100 华中师范大学物理系武汉430070

研究了双模相干光场与级联三能级原子的相互作用 ,结果表明 ,在简并双光子过程中 ,使原子发生布居相干俘获的俘获光场为双模SU( 1,1)薛定谔猫态。

关键词：双模相干光场级联三能级原子相干俘获

Entrepreneurial Team's Prior Experience, Commitment and New Technology Venture's Initial Performance——An Interaction Effect Model and Its Implication

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研究与发展管理 2009年第4期21卷 118-118页

作者： tian Li,XUE hong-zhi

New technology ventures contribute a lot to local economic development and technologyinnovation,but their mortality rate is very high,which drives researchers to focus on the determinantsof its initial *** view of organization imprinting puts forward that the entrepreneurialconditions are important for the survival and growth of new *** knowledge economycoming。

关键词：创业团队科技开发项目科学研究工作企业管理

广西大厂矿田大福楼锡多金属矿床地质与地球化学特征

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中国有色金属学报 2012年第3期22卷 751-760页

作者：成永生胡瑞忠伍永田中南大学有色金属成矿预测教育部重点实验室长沙410083 中南大学地球科学与信息物理学院长沙410083 中国科学院地球化学研究所矿床地球化学国家重点实验室贵阳550002 广西堂汉锌铟股份有限公司南丹547200

位于大厂矿田东带的大福楼锡矿床是一个以产锡和锌为主、研究程度相对较低且规模较大的锡石硫化物型矿床。针对该矿床特征典型、研究薄弱、成矿条件优越及找矿前景可观等因素,对流体包裹体和硫同位素特征进行了研究。结果表明:大福楼矿... 详细信息

位于大厂矿田东带的大福楼锡矿床是一个以产锡和锌为主、研究程度相对较低且规模较大的锡石硫化物型矿床。针对该矿床特征典型、研究薄弱、成矿条件优越及找矿前景可观等因素,对流体包裹体和硫同位素特征进行了研究。结果表明:大福楼矿床主要发育6种类型的流体包裹体(单相气相包裹体、单相盐水溶液包裹体、两相富蒸汽包裹体、两相富液体包裹体、含CO2相包裹体和含NaCl子矿物包裹体),包裹体大小一般为5～25μm,少数为30μm,主要呈多边形、米粒状、椭圆形、长方形以及不规则状,少数呈三角形以及半自形的负晶形。包裹体主要含Ca2+、Mg2+、K+、Na+、SO42-、Cl-和NO3-等液相成分以及CO2、CO、CH4和N2等气相成分。成矿流体属于Na(K)-Ca(Mg)-Cl型卤水溶液,呈弱酸性,包裹体中不含O2,表明成矿过程中没有游离氧的存在,而CO2、CH4和H2的含量相对较高,表明成矿流体具有较强的还原性。矿物中含NaCl子矿物包裹体的大量存在,显示成矿流体具有岩浆热液特征。包裹体中的氟对锡的迁移和沉淀起着非常重要的作用,而硫盐矿物的存在可能对锡的富集沉淀造成不利影响。硫同位素研究结果显示,矿石的δ(34S)值为-1.54×10-3～2.18×10-3,极差为3.72×10-3,均值为1.141×10-3,以正值为主,矿石δ(34S)值稍微偏离基性岩类硫的范围,而与陨石硫的同位素组成非常接近,具有重硫富集和典型岩浆来源的特征。锡矿硫元素可能部分来源于龙箱盖隐伏复式花岗岩体。

关键词：大厂矿田大福楼锡多金属矿床流体包裹体硫同位素地质地球化学