Preliminary Identification of a Prime Number Other Than 2 and 3, the Origin of Twin Prime Numbers, the Structure of the Chain of Prime Numbers and the Set of Prime Numbers Less Than a Given Integer

The application of the Euclidean division theorem for the positive integers allowed us to establish a set which contains all the prime numbers and this set we called it set of supposedly prime numbers and we noted it Esp. We subsequently established from the previous set the set of non-prime numbers (the set of numbers belonging to this set and which are not prime) denoted Enp. We then extracted from the set of supposedly prime numbers the numbers which are not prime and the set of remaining number constitutes the set of prime numbers denoted Ep. We have deduced from the previous set, the set of prime numbers between two natural numbers. We have explained during our demonstrations the origin of the twin prime numbers and the structure of the chain of prime numbers.

刺参germ cell-less基因表达分析及转录因子预测

不同性别的刺参(Apostichopus japonicus)在生长速度、免疫能力等方面具有显著差异,解析其性别决定和性别分化机制具有重要的理论和经济价值。目前,刺参的性腺发育机制尚不清晰,挖掘性腺发育相关基因是解析其发育机制的重要途径。研究表明,germ cell-less基因在哺乳动物性腺发生中起重要作用,但无脊椎动物中关于germ cell-less基因的研究较少。本研究从刺参基因组中鉴定了germ cell-less (Ajgcl)基因片段,随后通过c DNA末端快速扩增技术(rapid amplification of c DNA ends,RACE)获得其全长c DNA序列。通过荧光定量PCR (real-time quantitative PCR,RT-q PCR)揭示了Ajgcl在成体组织中呈现泛表达状态,性腺中表达量最高,且雌性性腺中的表达量是雄性性腺中表达量的2.25倍。随着卵子的发生,Ajgcl的表达量呈现先上升后下降的动态表达变化,而在精子发生的过程中其表达量变化不大,意味着其可能在卵子发生过程中发挥重要作用。在整个胚胎发育过程中均能检测到Ajgcl转录本,意味着Ajgcl作为母源因子可能与原始生殖细胞的形成有关。此外,Ajgcl基因启动子中具有Oct-1、FOXD3、PAX-6、CRP、c-Myb和NF-1等转录因子的结合位点。本研究为深入解析germ cell-less基因在刺参等无脊椎动物性腺发育中发挥的功能奠定了基础。

Study of Radio over Fiber Transmission with a Single Line in Ring Topology for Deployment of MIMO Antenna Access Points in a Cell-less Network

The massive growth of wireless traffic goes hand in hand with the deployment of advanced radio interfaces as well as network densification. This growth has a direct impact on the radio access architecture, which today is moving from centralized to distributed deployments through the use of a large number of access points (APs). This paper verifies the feasibility of deploying multiple APs in series on a single line in a ring topology in a cell-less network. On the one hand, this technique will further improve the communication capacity and flexibility of a Radio-over-Fiber (RoF) based mobile communication system and will reduce its construction cost. And on the other hand, this deployment topology is a solution to achieve a massive cell-free Multiple-Input Multiple-Output (MIMO) architecture and a cost-effective fronthaul solution. First, a passive optical add/drop multiplexer (OADM) is used to extract and add downlink and uplink signals from the remote access points of one kilometer. Then, a deployment model is developed with version 17 Optisystem software. The results obtained showed that the quadrature amplitude modulation (QAM) does not adapt to this multi-carrier transmission to deploy several AP in series on a single line. Thus, the performance degradation increases when the number of APs integrated on the line increases.

基于序列和结构特征分析植物TATA和TATA-less启动子

分析启动子区域内调控元件是阐明基因转录起始机制的重要前提.利用从PlanPromDB数据库下载的植物Pol-ⅡTATA和TATA-less启动子数据,深入分析了两类启动子GC偏好、位点结构保守性、序列碱基组分、保守模体分布、TATAbox位点分布及关联位点保守性等特点,统计出两类植物启动子许多特有的序列组分和结构规律,这些规律对进一步揭示植物Pol-Ⅱ启动子的转录调控机制有一定的帮助.通过构建能够同时考虑位点保守性和关联性的位点关联性权重矩阵扫描模型(PCWM),利用相应打分函数(Score)对两类启动子进行区分,得到了较好结果,说明PCWM的预测性能要优于单碱基的位点权重矩阵(PWM).

一种ROM-Less的流水线型DDS设计

本文介绍一种ROM-Less直接数字频率合成器设计。利用正弦多项式近似直接产生数字正弦波,而无需限制相幅转化速度的ROM.。其数字部分采用流水线结构,可以实现高速,小芯片面积,并且可以得到约为-85dBc的无杂散动态范围,提高了整个DDS系统的性能。关键字:直接数字频率合成器;ROM-Less;多项式近似;

谈more和less与than结构搭配的形式、意义及译法

英语中more和less与than结构的搭配形式是多种多样的,而且也比较复杂,本文针对这些不同的搭配形式进行研究并从中阐明这些不同搭配的意义以及翻译这些搭配时应注意的技巧。

More/Less的语法、修辞功能

More与Less是英语中非常常用的词。使用它们不仅是构成比较语义结构的重要方式，也是提高委婉、强调、对照、比拟、夸张等修辞效果不可或缺的手段，因而有必要对它们进行深入研究。

Development of Battery-Less Wireless Current Sensor Node Utilizing Charging Time of Capacitors with Wide Measurement Range

We report a novel battery-less wireless current sensor node without an analog to digital converter (ADC). If a capacitor is charged using a current transformer (CT) and a rectifying circuit, the charging time depends on the current flowing through a power line. In the case that the node transmits data every time when voltage of the capacitor exceeds a threshold voltage, we can indirectly measure the current by measuring the transmission intervals. In this method, the circuit of the node can be simplified and power consumption for the wireless transmission can be decreased because the measured current data does not need to be included in the transmitted packet. However, the measurable range is about single digit because the transmission interval decreases suddenly as the current increases. In this work, we have ex- panded the range using one CT, one wireless transmission module, and two charging circuits that include different load resistors connected in series. The results indicated that the measurable range was from 0.5 A to 50 A.

Theoretical Analysis and Experimental Verification on Valve-less Piezoelectric Pump with Hemisphere-segment Bluff-body

Existing researches on no-moving part valves in valve-less piezoelectric pumps mainly concentrate on pipeline valves and chamber bottom valves, which leads to the complex structure and manufacturing process of pump channel and chamber bottom. Furthermore, position fixed valves with respect to the inlet and outlet also makes the adjustability and controllability of flow rate worse. In order to overcome these shortcomings, this paper puts forward a novel implantable structure of valve-less piezoelectric pump with hemisphere-segments in the pump chamber. Based on the theory of flow around bluff-body, the flow resistance on the spherical and round surface of hemisphere-segment is different when fluid flows through, and the macroscopic flow resistance differences thus formed are also different. A novel valve-less piezoelectric pump with hemisphere-segment bluff-body （HSBB） is presented and designed. HSBB is the no-moving part valve. By the method of volume and momentum comparison, the stress on the bluff-body in the pump chamber is analyzed. The essential reason of unidirectional fluid pumping is expounded, and the flow rate formula is obtained. To verify the theory, a prototype is produced. By using the prototype, experimental research on the relationship between flow rate, pressure difference, voltage, and frequency has been carried out, which proves the correctness of the above theory. This prototype has six hemisphere-segments in the chamber filled with water, and the effective diameter of the piezoelectric bimorph is 30mm. The experiment result shows that the flow rate can reach 0.50 mL/s at the frequency of 6 Hz and the voltage of 110 V. Besides, the pressure difference can reach 26.2 mm H20 at the frequency of 6 Hz and the voltage of 160 V. This research proposes a valve-less piezoelectric pump with hemisphere-segment bluff-body, and its validity and feasibility is verified through theoretical analysis and experiment.

Breaking and Repairing the Certificateless Key Agreement Protocol from ASIAN 2006

The certificateless authenticated key agreement protocol proposed by Mandt et al does not haVE the property of key-compromise impersonation （K-CI） resilience. An improved protocol with a simple modification of their protocol is proposed in this paper. In particular, our improved protocol is proved to be immune to the K-CI attack and at the same time possess other security properties.

Application of digital pattern-less molding technology to produce art casting

Compared with the conventional casting process, digital pattern-less casting technology has many advantages such as good machining accuracy, a short processing cycle, and low production cost. It is a new rapid manufacturing technology for castings, integrated with CAD/CAM, casting, CNC machining and many other advanced technologies. With this digital casting technology, no pattern is needed for making molds; it is precise, f lexible, and green. Usually, art castings have complex structures and are made in small batches or even made in a single-piece, especially for large-sized art castings. So it has the shortcomings of high cost, low eff iciency and long time for making a pattern to produce art castings with the conventional casting processes. However, the digital pattern-less casting technology can be applied to fabricate art castings, since it can greatly shorten the manufacturing cycle and lower the production cost, thus having a very good prospect. In this study, based on the digital pattern-less casting technology, a plaque casting with artistic Chinese characters(a Chinese poem) was designed and manufactured, and the production process was demonstrated in detail.

Miniature magnetically anchored and controlled camera system for trocar-less laparoscopy

AIM To design a miniature magnetically anchored and controlled camera system to reduce the number of trocars which are required for laparoscopy.METHODS The system consists of a miniature magnetically anchored camera with a 30° downward angle, an external magnetically anchored unit, and a vision output device. The camera weighs 12 g, measures Φ10.5 mm × 55 mm and has two magnets, a vision model, a light source, and a metal hexagonal nut. To test the prototype, the camera was inserted through a 12-mm conventional trocar in an ex vivo real liver laparoscopic training system. A trocar-less laparoscopic cholecystectomy was performed 6 times using a 12-mm and a 5-mm conventional trocar. In addition, the same procedure was performed in four canine models.RESULTS Both procedures were successfully performed using only two conventional laparoscopic trocars. The cholecystectomy was completed without any major complication in 42 min(38-45 min) in vitro and in 50 min(45-53 min) using an animal model. This camera was anchored and controlled by an external unit magnetically anchored on the abdominal wall. The camera could generate excellent image. with no instrument collisions.CONCLUSION The camera system we designed provides excellent optics and can be easily maneuvered. The number of conventional trocars is reduced without adding technical difficulties.

Burden Distribution for Bell-Less Top With Two Parallel Hoppers

The circumferential burden distribution of bell-less top with two parallel hoppers was analyzed to obtain the expressions of burden flux and uneven ratio. The four-batch feeding spirally with two parallel hoppers was proposed to realize even burden distribution by uneven flux, ensuring reasonable distribution of BF gas and effective usage of heat energy and chemical energy of gas as well as stable BF production with higher quality and lower consumption.

Research progress in lead-less or lead-free three-dimensional perovskite absorber materials for solar cells

The trend toward lead-free or lead-less perovskite solar cells(PSCs) has attracted increasing attention over the past few years because the toxicity of lead(Pb) is one of the substantial restrictions for large-scale applications. Researchers have investigated the viability of substituting Pb with other elements(group 14 elements, group 2 elements, transition-metal elements, and group 13 and 15 elements) in the three-dimensional(3 D) perovskites by theoretical calculations and experimental explorations. In this paper, recent research progress in Pb-less and Pb-free PSCs on the perovskite compositions, deposition methods, and device structures are summarized and the main problems that hinder the enhancement of device efficiency and stability are discussed in detail. To date, the fully Sn-based PSCs have shown a power conversion efficiency(PCE) of 8.12% and poor device stability. However, lead-less PSCs have shown higher PCE and a better stability. In addition, the introduction of double-perovskite materials also draws researchers' attention. We believe that the engineering of elemental composition, perovskite deposition methods, and interfacial modification are critical for the future development of Pb-less and Pb-free PSCs.

小儿经脐单孔腹腔镜手术(LESS)2338例病例报告

目的:探讨小儿经脐单孔腹腔镜手术(LESS)的可行性、局限性及技术难点。方法:回顾性收集分析我院2 338例小儿外科经脐单孔腹腔镜手术的临床资料,手术种类有:经脐单孔腹腔镜疝囊高位结扎术、嵌顿疝松解复位后疝囊高位结扎术、经脐单部位肾积水肾盂输尿管离断成形术等。结果:本组2 338例经脐单孔手术全部顺利完成,无1例中转开放或转多孔法。手术时间:腹股沟疝单双侧5～15 min,平均10 min左右,术后6 h恢复正常饮食;术后第1天出院。嵌顿疝单侧25～45 min,平均30 min,3例因可疑肠穿孔放置腹腔引流,2～3 d无发热引流液体清亮拔管。腹腔镜阑尾切除手术时间17～50 min,平均30 min,术中出血5～10 m L,术后当日或次日下地活动,8 h后可进饮,24 h后可进流质,术后3～5 d出院,无不良并发症发生。肾盂输尿管离断成形术手术120～200 min,平均160 min。所有患儿的腹壁切口隐蔽,无切口出血感染等并发症,均达到良好的美容效果。结论:开展经脐单孔腹腔镜手术必须有三孔、多孔法腹腔镜手术的经验基础,初期有一定难度、手术操作局限性及手术风险,随着病例的增多,利用适当器械不断总结经验,提高手术技巧,可达到更加微创与更好的腹部美容效果。

Countermeasures and Investigation of Land Circulation in Less Developed Agricultural Area of Henan Province,China

Some places in Henan Province are investigated by using sample surveys and interviews. Result shows that land circulation in less developed agricultural area of Henan Province has the characteristics of small scale,single form,short period,and circulation land in economic core region. Problems in land circulation are as follows:slow transfer of rural surplus labor force,hard implementation of fundamental land circulation,complicated mentality towards rural land circulation,many misgivings about land circulation,the unformed social service system of land circulation,and imperfect agricultural risk prevention mechanism for circulated land use. Based on the characteristics of land circulation,suggestions for promoting the land circulation of less developed agricultural areas are put forward in order to solve the problems in land circulation and to lay the foundation for effective implementation of land circulation,such as speeding up the development of urbanization,developing the circulation of collective land,effectively implementing the laws and regulations of rural collective land circulation,transferring land according to law,establishing market mechanism of agricultural land circulation,promoting the agricultural industrialization,establishing market mechanism of agricultural land circulation,promoting the agricultural industrialization,energetically readjusting rural industrial structure,and developing economy with local characteristics.

Combined Use of Percutaneous Canulated Screws and External or Internal Fixation for Less Invasive Treatment of Tibial Plateaux Fractures

The classic way of treatment of tibial plateau fractures with an extensive approach, opening of the knee and compressive internal fixation can lead to major complications such as infection, skin necrosis and knee stiffness. Here we present a less invasive and thus safer surgical technique, and its indications and results. Twenty patients with various types of fractures according to Schatzker’s classification (mainly V and VI) were treated during a time period of seven years. Surgical treatment usually consisted of a combination of percutaneous canulated screws with a hybrid external fixator. In three cases canulated screws were combined with a laterally applied anatomic locking plate. Patients were followed up for six months to three years postoperatively. Indications as well as intra and postoperative parameters such as surgical time, stability of fixation, blood loss, wound healing, infection, fracture healing and final result were studied. No major complications were recorded either early or later. The use of external οr less invasive internal fixation in combination with percutaneous canulated screws appears to be an adequate method for the treatment of most types of these fractures.

对“less is more”的再思考——纪念密斯·凡·德·罗逝世40周年

"Iess is more"是20世纪20年代密斯·凡·德·罗提出的一项经典建筑设计法则。该法则对同时代乃至随后的几代建筑师都产生了深刻的影响。在西方近现代建筑发展史上该法则曾倍受推崇,也饱受诟病。在密斯本人逝世40周年之际,本文简要回顾了该法则产生的时代背景,并对其在不同时代所产生的影响进行了分析和阐述,最终致力于提出在可持续发展的社会大背景下,该法则对现代建筑设计仍然具有极其深刻的借鉴意义和推广价值。

A Lacan's Three Orders Approach to Winter in July by Doris Lessing

As a famous English contemporary women writer, Doris Lessing always puts her attention on the female characters that live in South Africa. Their lives are pathetic and sad. This thesis tries to analyze one of Lessing's short stories— Winter in July from Lacan's three Orders approach. Lessing is a feminist, but the deeper description of the desire and struggle in men's inner world in her works is also remarkable.

A Thematic Analysis of Doris Lessing’ How I Finally Lost My Heart from Feminist Approach

As a prolific writer of British literature in 20th century,Doris Lessing creates literary works which challenge in both theme and writing style.In her works,the style is distinctive and various,the thought s are deep,ideas are sharp and new.This pa per studies women's subject consciousness and their awakenings,and at the same time,intends to explore her transcendence to western feminist criticism.