Evaluation of Expansion Process to Improve Corrosion Resistance of Copper Tubes with High Residual Carbon on the Inner Surface

Residual carbon on the inner surface of copper tubes is known to be a cause of pitting corrosion. We showed previously that the rapid filling test was useful to evaluate the pitting corrosion resistance of copper tubes. Immersion tests using the rapid evaluation test solution showed that corrosion occurs on the entire surface of copper tubes with low residual carbon amounts, while those with high residual carbon amounts show pitting corrosion. Therefore, it is necessary to improve the corrosion resistance of copper tubes with high residual carbon amount, which are expected to undergo pitting corrosion. As pitting corrosion occurs when anodes are locally concentrated on part of the metal surface, it has been suggested that anodes be dispersed over the entire surface by the processing of the metal surface. Metal processing methods have various purposes, including changing the shape and properties of metals, and in this case, leading to desirable surface properties (such as expansion and drawing processes). Here, we focused on the expansion process and its effects on corrosion resistance of copper tubes. The results showed that hydraulic expansion has a significant effect on the inner copper surface by improving corrosion resistance as the anode area increases.

Thermal Expansion Coefficients of Thin Crystal Films

The formulas for atomic displacements and Hamiltonian of a thin crystal film in phonon occupation number representation are obtained with the aid of Green's function theory. On the basis of these results, the formulas for thermal expansion coefficients of the thin crystal film are derived with the perturbation theory, and the numerical calculations are carried out. The results show that the thinner films have larger thermal expansion coefficients.

Polyploidy events shaped the expansion of transcription factors in Cucurbitaceae and exploitation of genes for tendril development

Cucurbitaceae is one of the most important plant families distributed worldwide.Transcription factors(TFs)regulate plant growth at the transcription level.Here,we performed a systematic analysis of 42641 TFs from 63 families in 14 Cucurbitaceae and 10 non-cucurbit species.Whole-genome duplication(WGD)was the dominant event type in almost all Cucurbitaceae plants.The TF families were divided into 1210 orthogroups(OGs),of which,112 were unique to Cucurbitaceae.Although the loss of several gene families was detected in Cucurbitaceae,the gene families expanded in five species that experienced a WGD event comparing with grape.Our findings revealed that the recent WGD events that had occurred in Cucurbitaceae played important roles in the expansion of most TF families.The functional enrichment analysis of the genes that significantly expanded or contracted uncovered five gene families,AUX/IAA,NAC,NBS,HB,and NF-YB.Finally,we conducted a comprehensive analysis of the TCP gene family and identified 16 tendril-related(TEN)genes in 11 Cucurbitaceae species.Interestingly,the characteristic sequence changed from CNNFYFP to CNNFYLP in the TEN gene(Bhi06M000087)of Benincasa hispida.Furthermore,we identified a new characteristic sequence,YNN,which could be used for TEN gene exploitation in Cucurbitaceae.In conclusion,this study will serve as a reference for studying the relationship between gene family evolution and genome duplication.Moreover,it will provide rich genetic resources for functional Cucurbitaceae studies in the future.

Coefficient of thermal expansion of stressed thin films

A new technique was proposed to determine the coefficient of thermal expansion (CTE) of thin films at low temperature. Different pre-stress could be applied and the elastic modulus of materials at different temperatures was measured with CTE simultaneously to eliminate the influence of mechanical deformation caused by the pre-stress. By using this technique, the CTEs of polyimide/silica nanocomposite films with different silica doping levels were experimentally studied at temperature from 77 K to 287 K, and some characteristics related to this new technique were discussed.

Land use and land cover change within the Koshi River Basin of the central Himalayas since 1990

Land change is a cause and consequence of global environmental change.Land use and land cover have changed considerably due to increasing human activities and climate change,which has become the core issue of major international research projects.This study interprets land use and land cover status and the changes within the Koshi River Basin(KRB)using Landsat remote sensing(RS)image data,and employs logistic regression model to analyze the influence of natural and socioeconomic driving forces on major land cover changes.The results showed that the areas of built-up land,bare land and forest in KRB increased from 1990 to 2015,including the largest increases in forest and the highest growth rate in construction land.Areas of glacier,grassland,sparse vegetation,shrub land,cropland,and wetland all decreased over the study period.From the perspective of driving analysis,the role of human activities in land use and land cover change is significant than climate factors.Cropland expansion is the reclamation of cropland by farmers,mainly from early deforestation.However,labor force separation,geological disasters and drought are the main factors of cropland shrinkage.The increase of forest area in India and Nepal was attributed to the government’s forest protection policies,such as Nepal’s community forestry has achieved remarkable results.The expansion and contraction of grassland were both dominated by climatic factors.The probability of grassland expansion increases with temperature and precipitation,while the probability of grassland contraction decreases with temperature and precipitation.

Homotopy analysis solutions for the asymmetric laminar flow in a porous channel with expanding or contracting walls

In this paper, the asymmetric laminar flow in a porous channel with expanding or contracting walls is investigated. The governing equations are reduced to ordinary ones by using suitable similar transformations. Homotopy analysis method （HAM） is employed to obtain the expres- sions for velocity fields. Graphs are sketched for values of parameters and associated dynamic characteristics, especially the expansion ratio, are analyzed in detail.

Mean-field and high temperature series expansion calculations of some magnetic properties of Ising and XY antiferromagnetic thin-films

In this work, the magnetic properties of Ising and XY antiferromagnetic thin-films are investigated each as a function of Neel temperature and thickness for layers （n = 2, 3, 4, 5, 6, and bulk （∞） by means of a mean-field and high temperature series expansion （HTSE） combined with Pade approximant calculations. The scaling law of magnetic susceptibility and magnetization is used to determine the critical exponent γ, veff （mean）, ratio of the critical exponents γ/v, and magnetic properties of Ising and XY antiferromagnetic thin-films for different thickness layers n = 2, 3, 4, 5, 6, and bulk （∞）.

Thermal and Mechanical Properties of a Complex Nonlinear Optical Material:Cadmium Mercury Thiocyanate Crystal

Institute of Crystal Materials and State Key Laboratory of Crystal Materials,Shandong University,Ji'nan 250100(Received 18 March 2000)The data of the thermal expansion and specific heat of cadmium mercury thiocyanate crystal have been obtained.The specific heat is 0.7588J/g℃at room temperature.The thermal expansion occurs in the direction parallel to the c-axis,and the thermal contraction occurs in the direction parallel to the a-axis.The thermal expansion is the same as the thermal contraction at 353 K.The relationship between thermal properties and crystal structure is discussed.

Investigation of Thermodynamic Properties of Zirconia Thin Films by Statistical Moment Method

The moment method in statistical (SMM) dynamics is used to study the thermodynamic quantities of ZrO2 thin films taking into account the anharmonicity effects of the lattice vibrations. The average lattice constant, thermal expansion coefficient and specific heats at the constant volume of ZrO2 thin films are calculated as a function of temperature, pressure and thickness of thin film. SMM calculations are performed using the Buckingham potential for the ZrO2 thin films. In the present study, the influence of temperature, pressure and the size on the thermodynamic quantities of ZrO2 thin film have been studied using three different interatomic potentials. We discuss temperature and thickness dependences of some thermodynamic quantities of ZrO2 thin films and we compare our calculated results with those of the experimental results.

Flow patterns and their transition characteristics of the air-water two-phase flow in a horizontal pipe with a sudden-changed cross-section area

Flow patterns in upstream and downstream straight tubes of sudden-changed areas in a horizontal straight pipe were experimentally examined. Both sudden-expansion cross-section (SECS) and sudden-contraction cross-section (SCCS) were investigated. The flow pattern maps upstream and downstream were delineated and compared with those in straight tubes with uniform cross-sections. The effects of the SECS and SCCS on flow patterns were discussed and analyzed. Furthermore, flow pattern transition mechanisms resulting in occurrences of different flow patterns were simply discussed and some transition criteria for the flow pattern transitions were deduced by using the non-dimensionlized analysis method.

An exploratory study of the growth of the Accountable Care Organization and its impact on physician groups’ profit: a complex adaptive system approach

The emergence of Accountable Care Organizations(ACOs)in the landscape of the U.S.healthcare system marks a paradigm shift in healthcare operations.The potential impact of ACOs has been a topic of intense debate.Traditional analytical approaches do not lend themselves to examining the complex phenomenon of the emergence and growth of ACOs in the healthcare network.We adopt a complex adaptive system lens to examine the growth of ACOs among physician groups and explore factors that influence this growth.We also discuss the impact of ACOs on the profit of physician groups.An agent-based model was built to simulate physician groups'ACO entrance and exit based on a set of simple rules and their complex interactions with other agents.Based on the simulation results,we derive patterns of ACO expansion and contraction,following four stages of wait-and-see,rollercoaster,fast growth,and stabilizing.Findings suggest that the growth of ACOs is sensitive to the initial state of ACO membership.When the initial size of ACO membership increases,it helps to eliminate the rollercoaster stage.In addition,the growth of the ACO varies depending on the cost–quality tradeoff.When both cost and quality objectives can be met simultaneously,the growth of ACO membership follows wait-and-see and fast growth stages followed by a different stage that we term sticky state.The impact of ACOs on physician groups’cumulative profit varies by the service quality level of the physician group.Physician groups affiliated with insurance companies charging the lowest or the highest level of health insurance premiums are worse off with the ACO option.However,the ACO benefits physician groups affiliated with an insurance company charging a moderate level of premiums.

Plastid phylogenomic insights into the evolution of subfamily Dialioideae (Leguminosae)

The subfamily Dialioideae(Leguminosae)consists of 17 genera and about 85 species.Previous studies have detected significant plastid genome(plastome)structure variations in legumes,particularly in subfamilies Papilionoideae and Caesalpinioideae.Hence it is important to investigate plastomes from the newly recognized Dialioideae to better understand the plastome variation across the whole family.Here,we used nine plastomes representing nine genera of Dialioideae to explore plastome structural variation and intergeneric relationships in this subfamily.All plastomes of Dialioideae exhibited a typical quadripartite structure,and had relatively conserved structure compared with other legume subfamilies.However,the genome size ranged from 154,124 bp to 165,973 bp and gene numbers ranged from 129 to132,mainly due to the expansion and contraction of the inverted repeat(IR)regions.The IR of Distemonanthus benthamianus has experienced two separate expansions into the large single copy(LSC)region and the small single copy(SSC)region,and one contraction from SSC.Poeppigia procera has experienced two separate IR expansions into LSC,while Dicorynia paraensis has experienced an IR contraction from LSC.Highly divergent regions or genes(ndhC-trnV^(UAC),psbK-trnQ^(UUG),rps19-rps3,rpl33-rps18,accD-psaI,trnG^(UCC)-trnS^(GCU),psbI-trnS^(GCU),5'rps16-trnQ^(UUG)and ycf1)were identified as potential molecular markers for further species delimitation and population genetics analysis in legumes.Phylogenetic analysis based on 77 protein-coding sequences fully resolved the intergeneric relationships among nine genera except a moderately supported sister relationship between Petalostylis labicheoides and Labichea lanceolata.Our study reveals new insights into the structural variations of plastomes in subfamily Dialioideae and advances our understanding of the evolutionary trajectories of legume plastomes.

“It's Time to Turn the Page”话语介入资源分析

介入系统是评价理论一个子系统,也是衡量话语人际意义重要评估指标。文章通过对"It’s Time to Turn the Page"话语介入资源分析发现,对话性缩约与对话性扩展策略的使用帮助了演讲话语人际意义的有效实现。同时,对话性缩约策略使用频率更高,突出演讲者的主动承担话语责任的特点。

Expansion and contraction of Chinese deserts during the Quaternary

Episodic dune formations during the Quaternary are found in many deserts of China.The causes of desert expansions on different time scales are not the same. Desert extension atabout 1.1 and 0.9 Ma ago were the response to the active tectonic movements, whereas the de-sert evolutions on the ten-thousand years time scale were the response to the orbital scale climaticchanges. Spatial scale studies on desert evolution indicate that desert margins shifted greatly dur-ing the last glacial maximum (LGM) and the Holocene optimum, its changing from 125°E of theLGM to 105°E of the climatic optimum. Historical desertification in the semiarid China is not a re-sponse to climate drought but largely associated with the human impacts (mainly over-cultivation)since about 2300 years ago, which leads to the reworking of the underlying LGM sands.

作物茎秆膨胀收缩监测柔性可穿戴传感器研制与试验

作物茎秆膨胀和收缩变化与其水分状态密切相关,实时监测茎秆的膨胀和收缩变化能够及时掌握作物水分状态,对指导灌溉、提高农业水资源利用率具有重要意义。目前,对于作物茎秆膨胀和收缩变化的监测主要采用基于线性微位移测量原理的传感器,通过测量茎秆的膨胀和收缩引起的位移变化来反映水分状态,存在体积大、价格高、安装不便等问题。为此,该研究提出了一种基于压阻效应的柔性可穿戴传感器,采用柔性压力电极作为传感元件,贴附在作物茎秆表面,通过监测茎秆膨胀和收缩引起的压力变化来反映作物的水分状态,压力检测电路和数据采集电路将作物茎秆的压力信号转换成电信号进行输出和存储。首先在实验室环境下对传感器性能进行测试和标定,然后在温室环境下将传感器安装在番茄茎秆上观测番茄茎秆的压力变化,并与线性微位移传感器观测结果进行比较,最后在充分灌溉和水分亏缺2种条件下观测番茄茎秆的膨胀和收缩变化。结果表明,柔性压力传感器稳定性测试的平均相对变化率为0.109%;弯折前后引起的输出变化非常小,可以忽略不计;标定结果的决定系数大于0.99,最合适的工作压力范围为2~100 kPa;实验室环境下,柔性压力传感器与线性微位移传感器输出值之间的决定系数为0.9551;温室环境下,充分灌溉组中柔性压力传感器与线性微位移传感器输出值变化趋势一致,两者之间的决定系数为0.7672,亏缺灌溉组中两类传感器输出值均因水分亏缺而呈现下降趋势,输出值之间的决定系数为0.8519。本文所设计的柔性可穿戴压力传感器不仅能够实时监测番茄茎秆的膨胀和收缩变化,还可以对番茄亏水胁迫进行诊断,为实现高效节水灌溉提供重要的技术支撑。

“青年向”:文化自信视域下国产动画电影的自觉拓展

中国动画电影正处在从“文化自觉”迈向“文化自信”的关键性转型时期,由此也正在以往的“低幼向”与“合家欢”方向之外积极区分目标观众,自觉拓展并巩固分层市场,瞄准数量庞大的青年受众,探索一套与“青年向”契合的生产营销机制。“青年向”国产动画电影以过去引进美、日动画所培养起来的庞大观众群体为基础,在叙事上摆脱了“低幼”标签,开始通过动画体裁探讨成人世界的现实问题,在审美上自觉形成了一种融汇着古今中西元素的新的美学风格。票房数据和观众口碑都可以佐证,“青年向”有望以其巨大的发展潜力,给国产动画电影产业链补充一个重要环节,并与“低幼向”“合家欢”作品一起朝着“国漫崛起”迈进。

合同视野下的影视表演者权行使和实现

影视表演者权利通过合同行使和实现由来已久,合同保护有其独特价值。互联网环境下影视表演者权利合同行使存在双方地位实质性不平等、演艺经纪合同纠纷多、集体合同无法有效发挥作用等问题。结合中国集体合同主体缺陷,借鉴英美法系影视表演者集体合同先进经验,在《视听表演北京条约》和新《著作权法》生效的背景下,建议积极筹建影视表演者的行业性工会组织,对相关演艺合同进行细致立法,在未来《著作权法实施条例》修订时,进一步区分电影电视剧作品和其他视听作品,为不同作品中影视表演者和制片者的不同合同约定提供可预期的前提。

Effect of Aggregation Structure on Thermal Expansion Behavior of Polyimide Films with Different Thickness

Polyimide films derived from representative PMDA/ODA were prepared with thickness ranging from 5 μm to 25 μm,and the effect of aggregation structure on thermal expansion behavior along different directions was studied.Both in-plane and out-of-plane linear thermal expansion(CTEand CTE) were respectively characterized by thermal mechanical analysis and FT-near-IR interference method.Volumetric and anisotropic behavior of thermal expan sion were also investigated.With increasing film thickness,CTEgradually increased from 32.2 ppm/℃ to46.1 ppm/℃ while CTEdecreased from 149.7 ppm/℃ to 128.2 ppm/℃.Volumetric thermal expansion of polyimide films was less sensitive to the va ried thickness,but anisotropy of thermal expansion was reduced.Polyimide film of 5 μm thickness showed large birefringence,indicating more considerable in-plane chain orientation anisotropy.Besides,molecular chains were more densely packed along in-plane direction when film thickness increased,while became loosely stacked in the out-of-plane direction.In contrast to the enhanced lateral chain packing for thicker film s,higher vertical chain packing order was found in thinner films.The variation of aggregation structure during thermal expansion procedure was analyzed by temperature-dependent WAXD.It is proved that thermal expansion behavior of thinner films could be largely attributed to molecular chain packing,whereas that may be influenced by many factors for thicker films in addition to the effect of chain packing.The results revealed that thermal expansion of films with thickness variation is closely related to molecular chain orientation and packing,which is associated with both chemistry and morphological structure of polyimide.

中国古代对行星盈缩历起点黄经及其进动值的测算

唐代天文学家一行在《大衍历》中,首次用行星变差来刻画行星盈缩历起点每年相对于冬至点的进动,此后的历法或者沿袭《大衍历》的做法直接给出行星变差,或者将行星变差隐含在相关算法中。本文全面考察了《大衍历》类历法中的行星变差常数及其含义,对于未直接给出行星变差的历法,则根据历法中的相关术文,重新构建了这些历法中行星盈缩历起点平均每年进动数值的表达式,并总结了行星盈缩历起点的进动规律。本文的研究结果表明,行星盈缩历起点并非行星近日点,但是由于外行星盈缩历起点黄经与其近日点黄经相差较小,因此可以将外行星盈缩历起点视为近日点。与此相应,行星变差或盈缩历起点进动并非行星近日点进动,由于各部历法中的行星变差或盈缩历起点进动值没有明显的规律可循,因此历法家很有可能已经具备了通过实测确定行星盈缩历起点的能力,而行星变差或盈缩历起点进动值应该是历法家确定行星盈缩历起点之后,配合上元积年而调整出来的数值。