A new method of mesh simplification for 3-Dimension terrain using Laplace operator

This paper proposes a new method to simplify mesh in 3D terrain. The 3D terrain is presented by digital elevation model. First, Laplace operator is introduced to calculate sharp degree of mesh point, which indicates the variation trend of the terrain. Through setting a critical value of sharp degree, feature points are selected. Second, critical mesh points are extracted by an recursive process, and constitute the simplified mesh. Third, the algorithm of linear-square interpolation is employed to restore the characteris- tics of the terrain. Last, the terrain is rendered with color and texture. The experimental results demonstrate that this method can compress data by 16% and the error is lower than 10%.

双师化学课堂“1+3”规范化教学模式的实践研究

“互联网+”在教育领域正以前所未有的力度推动着教学模式的革新,其中,云校双师课堂是一种新兴的教学模式。本文采用问卷调查、学生访谈等方法,发现双师课堂中出现新的伴生性问题,同时,通过对问题的分析、归纳与实践,提出了有针对性、实效性的课堂教学策略,建构双师课堂“1+3”规范化教学管理模式,以期为提升云校双师课堂教育教学质量贡献力量。

Universe and Matter Conjectured as a 3-Dimensional Lattice with Topological Singularities

One fundamental problem of modern physics is the search for a theory of everything able to explain the nature of space-time, what matter is and how matter interacts. There are various propositions, as Grand Unified Theory, Quantum Gravity, Supersymmetry, String and Superstring Theories, and M-Theory. However, none of them is able to consistently explain at the present and same time electromagnetism, relativity, gravitation, quantum physics and observed elementary particles. In this paper, one summarizes the content of a new book, published in English [2] and in French [3], in which it is suggested that Universe could be a massive elastic 3D-lattice, and that fundamental building blocks of Ordinary Matter could consist of topological singularities of this lattice, namely diverse dislocation loops and disclination loops. For an isotropic elastic lattice obeying Newton’s law, with specific assumptions on its elastic properties, one obtains the result that the behaviours of this lattice and of its topological defects display “all” known physics, unifying electromagnetism, relativity, gravitation and quantum physics, and resolving some longstanding questions of modern cosmology. Moreover, studying lattices with axial symmetries, represented by “colored” cubic 3D-lattices, one has identified a lattice structure whose topological defect loops coincide with the complex zoology of elementary particles, which could open a very promising field of research. Here, only main steps and principal results of the new theory are presented and discussed, without showing the mathematical concepts and developments contained in the book.

3D打印实物模型在颈椎疾患住院医师规范化培训教学中的应用和探讨

目的探讨3 D打印实物模型在提高颈椎疾患住院医师规范化培训(简称住培)教学效果中的作用。方法选取参加骨科住培的颈椎疾患学习的住院医师80名为研究对象,随机分为两组,观察组(40人)以幻灯讲解加3 D打印实物模型教学,对照组(40人)采用幻灯讲解教学。课后即时和课后1月分别对住院医师的知识掌握情况和诊疗技术进行现场测试,利用问卷的形式对住院医师的满意度和参与兴趣(10分法)进行调查。结果课后即时观察组的知识掌握情况和对照组相当(P>0.05),但是观察组的诊疗技术测试成绩显著高于对照组(P<0.05),观察组的满意度和参与兴趣评分均显著高于对照组,两者对比差异有统计学意义(均P<0.05);课后1月时,观察组的知识掌握情况和诊疗技术测试成绩均显著高于对照组(均P<0.05)。结论3 D打印实物模型应用于颈椎疾患住培的带教中,可显著提高教学效果,提升住院医师的满意度和参与兴趣,值得在住培教学中推广。

NUMERICAL MODELLING OF THREE-DIMENSION CHARACTERISTICS OF WIND-DRIVEN CURRENT IN THE BOHAI SEA

Three- dimension (3-D) wind-driven currents in the Bohai Sea in both winter and summer are calculated by using a 3- D barotropic steady model, and the results are consistent with observed flow char -acteristics. Based on the results, 3- D characteristics of flow, currents at different depths, compensated flow in the lower layer , long and narrow alongshore current, the area of upwelling and downwelling, main circulation in vertical profile, and the current in Bohai Strait are discussed.

Balancing the customization and standardization:exploration and layout surrounding the regulation of the growing field of 3D-printed medical devices in China

Medical devices are instruments and other tools that act on the human body to aid clinical diagnosis and disease treatment,playing an indispensable role in modern medicine.Nowadays,the increasing demand for personalized medical devices poses a significant challenge to traditional manufacturing methods.The emerging manufacturing technology of three-dimensional(3D)printing as an alternative has shown exciting applications in the medical field and is an ideal method for manufacturing such personalized medical devices with complex structures.However,the application of this new technology has also brought new risks to medical devices,making 3D-printed devices face severe challenges due to insufficient regulation and the lack of standards to provide guidance to the industry.This review aims to summarize the current regulatory landscape and existing research on the standardization of 3D-printed medical devices in China,and provide ideas to address these challenges.We focus on the aspects concerned by the regulatory authorities in 3D-printed medical devices,highlighting the quality system of such devices,and discuss the guidelines that manufacturers should follow,as well as the current limitations and the feasible path of regulation and standardization work based on this perspective.The key points of the whole process quality control,performance evaluation methods and the concept of whole life cycle management of 3D-printed medical devices are emphasized.Furthermore,the significance of regulation and standardization is pointed out.Finally,aspects worthy of attention and future perspectives in this field are discussed.

高效液相色谱法测定间苯二甲酸中微量3-CBA的研究

间苯二甲酸(PIA)中间羧基苯甲醛(3-CBA)的含量,是直接判断产品品质等级的重要指标之一。主要探索了选用合适的色谱柱、检测器波长、流动相配比,确定了典型色谱操作条件,建立了高效液相色谱法测定PIA中3-CBA的方法。结果表明,3-CBA含量在0~100mg/kg时,外标法测定3-CBA含量的线性相关系数大于0.999,线性良好,标准溶液的重复性测定结果小于5%,加标回收率在96.0%~103.8%之间。分别采用液相色谱法和极谱法对标准样品进行测定,检测结果相似,没有明显差异,表明该方法的准确度和精密度良好。

Measurement Method of Compressibility and Thermal Expansion Coefficients for Density Standard Liquid at 2329 kg/m^3 based on Hydrostatic Suspension Principle

The accurate measurement on the compressibility and thermal expansion coefficients of density standard liquid at 2329kg/m3（DSL-2329） plays an important role in the quality control for silicon single crystal manufacturing. A new method is developed based on hydrostatic suspension principle in order to determine the two coefficients with high measurement accuracy. Two silicon single crystal samples with known density are immersed into a sealed vessel full of DSL-2329. The density of liquid is adjusted with varying liquid temperature and static pressure, so that the hydrostatic suspension of two silicon single crystal samples is achieved. The compression and thermal expansion coefficients are then calculated by using the data of temperature and static pressure at the suspension state. One silicon single crystal sample can be suspended at different state, as long as the liquid temperature and static pressure function linearly according to a certain mathematical relationship. A hydrostatic suspension experimental system is devised with the maximal temperature control error ±50 μK; Silicon single crystal samples can be suspended by adapting the pressure following the PID method. By using the method based on hydrostatic suspension principle, the two key coefficients can be measured at the same time, and measurement precision can be improved due to avoiding the influence of liquid surface tension. This method was further validated experimentally, where the mixture of 1, 2, 3-tribromopropane and 1,2-dibromoethane is used as DSL-2329. The compressibility and thermal expansion coefficients were measured, as 8.5′10–4 K–1 and 5.4′10–10 Pa–1, respectively.

Standard energies of combustion and standard enthalpies of formation for the complexes RE (Et_2dtc)_3(phen) (RE = Ho,Er,Tm,Yb,Lu)

The treatment of RECl3.xH2O （RE = Ho, Er, Tm, Yb, Lu; x = 3-4） with sodium diethyldithiocarbamate （NaEtEdtc-3H2O） and 1,10-phenanthroline hydrate （o-phen.H2O） in absolute ethanol yielded five ternary solid complexes RE（EtEdtC）a（phen）. IR spectra of the complexes showed that RE^3＋ coordinated to two sulfur atoms in NaEt2dtc and two nitrogen atoms in o-phen. The constant-volume energies of combustion of the complexes have been determined by a precise rotating-bomb calorimeter at 298.15 K. The standard enthalpies of combustion and standard enthalpies of formation were calculated.

The application of 3D printing in the development of RECIST standard for evaluating tumor efficacy

Three-dimensional(3D)printing technology,as a novel technical method,can convert conventional computed tomography(CT)or magnetic resonance imaging(MRI)scans to computer-aided design files and develop a 2D spatial structure into a 3D imaging structure.In recent years,the technology has been widely used in numerous areas,including head and neck surgery,orthopedics,and bio-medicinal research.This article uses examples of 3D printed tumor models to develop Response Evaluation Criteria In Solid Tumors(RECIST)standards to evaluate the changes in tumors.RECIST standard is currently recognized as the standard for assessment of chemotherapy.Under the RECIST standard,changes occurring in tumors before and after the surgery,are evaluated.The assessment depends upon a CT evaluation of the changes in the lesions with the largest diameters.In addition,the disease progression and stability of remission is also assessed.Three-dimensional printing technology is more intuitive in the evaluation of changes to human tumors following chemotherapy and targeted therapy.However,a few reports are available.

Progress of 3GPP LTE Standardization

The 3rd Generation Partnership Project (3GPP) initiated its Long Term Evolution (LTE) standardization work to retain its technology and standard advantages in the field of mobile communications. A series of advanced technologies and novel concepts related to the physical layer (Layer 1),air interface protocol structure layer (Layer 2) and network architecture are adopted. Solutions to Voice over IP (VoIP) and Multimedia Broadcast/Multicast Service (MBMS) are in the optimization process. 3GPP LTE has achieved the design goals of high data rate,low latency and an all-packet basis.

Progress of 3G Evolution Technology Standardization

The challenges brought by broadband wireless access technologies to cellular mobile communication technologies speed up the study and standardization of 3G evolution technologies that support higher data rates. Both the 3GPP and the 3GPP2 have launched research programs on the study and standardization of the emerging 3G evolution technologies. The Long Term Evolution (LTE) program of 3GPP has made progress in key technical indexes of air interface, wireless network architecture and high-level protocols. At the same time, the Air Interface Evolution (AIE) program of 3GPP2 has made study achievements in the formulation of air interface standards for Layer 2 and upper layers, as well as for the physical layer.

Harvest from our investments in all 3G standards.

Only ZTE can deliver end-to-end equipment for all 3G standards-WCDMA, CDMA2000, TD-SCDMA and WiMAX. Our WCDMA solutions are used in 30 countries and regions,

Harvest from our investments in all 3G standards.

Only ZTE can deliver end-to-end equipment for all 3G standards-WCDMA, CDMA2000, TD-SCDMA and WiMAX. Our WCDMA solutions are used in 30 countries and regions, and our CDMA systems are used by 120 operators in more than 70 countries.

Announcement of Newly Approved National Standards of P.R.China 2010 No.3(total No.158)

General Administration of Quality Supervision,Inspection and Quarantine of P.R.China and Standardization Administration of China have approved the following 163 national standards and 81 national reference materials.

The Decision-making Study of 3G Standard in China

From the discussion above, the 3G choice of China is difficult to makerapidly because of multiple complicated factors. Either delay or impulsion will be costly. So theChinese government regulators need intensive and careful study on key factors before making a rightdecision. But the following policy trends can be inferred: (1)The regulator will not use the auctionlike Europe to issue 3G licenses; (2)Three 3G standards will co-exist in China mobile market withmultiple 3G services competition; (3)The 3G licenses schedule of China will inevitably be associatedwith the market demand and standard mature.

Quality Standard of Tibetan Medicine Nardostachys jatamansi Herba Based on"An Integrated Plant but Multi-purpose"

[Objectives]To establish the quality standard of Nardostachys jatamansi Herba.[Methods]The characters and microscopical identification of N.jatamansi Herba were carried out.The contents of moisture,total ash,acid-insoluble ash and extract were determined according to the relevant methods of the Chinese Pharmacopoeia(2020 edition).Using chlorogenic acid and 3,5-O-dicaffeoylquinic acid as quality control indexes,TLC and HPLC methods were established for qualitative and quantitative determination,and HPLC fingerprints were established.[Results]The characteristics of character identification,microscopic identification and thin layer identification were obvious.The moisture content ranged from 2.7%to 7.8%,with an average value of 5.4%.The total ash content ranged from 6.7%to 16.2%,with an average of 11.0%.The acid-insoluble ash content ranged from 0.7%to 8.5%,with an average of 3.6%.Extractives content ranged from 20.9%to 34.4%,with an average of 29.7%.Chlorogenic acid content was between 0.45%and 1.30%,with an average value of 0.77%.The content of 3,5-O-dicaffeoylquinic acid ranged from 0.18%to 0.58%,with an average of 0.31%.The similarity of each batch was between 0.930 and 0.994,indicating that the quality of medicinal materials from different producing areas was stable.[Conclusions]The quality standard of N.jatamansi Herba was established,which could provide quality control basis for rational,comprehensive and efficient utilization of N.jatamansi DC.resources and clinical use.

3D打印模型在脊柱外科住院医师规范化培训中的创新应用

目的探讨3 D打印模型在脊柱外科住院医师规范化培训(简称住培)中的应用效果。方法选取2023年1月—2023年12月在广东省人民医院脊柱外科轮转的46名二年级外科学专业住院医师作为研究对象,通过抽签方式随机分为观察组和对照组,每组各23名。观察组采用3 D打印模型辅助教学,对照组则采用传统教学。经过1个月的教学培训,通过出科考试、综合考核、教学满意度及自我鉴定问卷调查等方式多维度评估教学效果。采用独立样本t检验进行数据分析。结果观察组的出科考试成绩、综合考核评分及教学满意度均显著优于对照组(均P<0.0001)。此外,观察组自我鉴定部分的学习兴趣、自学能力、团队合作能力及综合分析能力也均显著高于对照组(P<0.001)。结论3 D打印模型辅助教学模式能有效提升脊柱外科住培的教学质量,并显著提高住院医师的教学满意度、综合能力及自我评价,为脊柱外科住培教学提供了新的有效路径。