Volume, Side-Area, and Force Direction of Berkovich and Cubecorner Indenters, Novel Important Insights

The iteration-free physical description of pyramidal indentations with closed mathematical equations is comprehensively described and extended for creating new insights in this important field of research and applications. All calculations are easily repeatable and should be programmed by instrument builders for even easier general use. Formulas for the volumes and side-areas of Berkovich and cubecorner as a function of depth are deduced and provided, as are the resulting forces and force directions. All of these allow for the detailed comparison of the different indenters on the mathematical reality. The pyramidal values differ remarkably from the ones of so-called “equivalent cones”. The worldwide use of such pseudo-cones is in severe error. The earlier claimed and used 3 times higher displaced volume with cube corner than with Berkovich is disproved. Both displace the same amount at the same applied force. The unprecedented mathematical results are experimentally confirmed for the physical indentation hardness and for the sharp-onset phase-transi- tions with calculated transition energy. The comparison of both indenters provides novel basic insights. Isotropic materials exhibit the same phase transition onset force, but the transition energy is larger with the cube corner, due to higher force and flatter force direction. This qualifies the cube corner for fracture toughness studies. Pile-up is not from the claimed “friction with the indenter”. Anisotropic materials with cleavage planes and channels undergo sliding along these under pressure, both to the surface and internally. Their volumes add to the depression volume. These volumes are essential for the exemplified pile-up management. Phase-transitions produce polymorph interfaces that are nucleation sites for cracks. Technical materials must be developed with onset forces higher than the highest thinkable stresses (at airliners, bridges, etc.). This requires urgent revision of ISO 14577-ASTM standards.

Performance of Different Cultivars in Direct Seeded Rice (<i>Oryza sativa</i>L.) with Various Seeding Densities

Optimum seeding density is necessary to achieve the production potential of a cultivar in all crops. To investigate the performance of different cultivars in direct seeded rice in response to various seeding densities, a field experiment was conducted at Agronomic Research Area, University of Agriculture, Faisalabad during the kharif 2012. Super basmati (fine rice) and KSK-133 (coarse rice) were sown using seeding densities of 30, 45, 60 and 75 kg&middotha-1. Results indicated that leaf area index and crop growth rate varied among rice cultivars as well as various seeding densities. The growth of rice at seeding density of 75 kg&middotha-1 was higher than rest of treatments. The response of rice yield and its components like number of productive tillers, number of kernels per panicle and 1000-kernal weight differed significantly under the influence of cultivars and various seeding densities. Seeding density of 75 kg&middotha-1 remained superior for both rice cultivars regarding final yield. This treatment furnished kernel yields of 3.83 and 5.49 t&middotha-1 in fine and coarse rice, respectively which were significantly higher than other treatments. However, Kernel quality was improved in terms of lower number of sterile and chalky kernels at lower seeding densities (30 kg&middotha-1). Based on these findings, it is concluded that using seeding density of 75 kg&middotha-1 for direct seeded fine and coarse rice cultivars is beneficial in terms of better growth and higher yield but kernel quality is reduced by increasing the seeding density.

Environmental Conditions of Barchan Dune and Barchan Chain-A Case Study from the Hexi Desert Area of Gansu

[Objective] The paper was to discuss why the top of tall barchan dunes and barchan chains widespread in single prevailing wind area had not been leveled by wind erosion. [Method] Based on the preliminary survey of distribution status,the morphological characteristics and environmental conditions of barchan dunes and barchan chains in Hexi desert area of Gansu were investigated in details. The significance of difference between samples and significance of correlation between indicators were examined via variance test. [Result] Barchan dunes and barchan chains in Hexi desert area of Gansu distributed at the leeward direction of desert fringe,generally in patch distribution. The distribution area was gravelly beach or cohesive gravel beach,with broader dune slack; winds in distribution area of barchan dunes and barchan chains blew obviously from one direction,while winds at other directions were light or occasionally strong but with low frequency;the barchan dune in the desert fringe of Hexi desert area of Gansu was relatively tall,while barchan chain was even more taller and larger. Coincidence or separation of the dune peak and the sand ridge might be related to distribution frequency of dominant prevailing wind or wind at opposite direction and the observation seasons.[Conclusion]Studying top stability of barchan dune has an important academic value in revealing blowing sand movement rule at desert fringe,invasion of sand flow,and expansion of desert.

Evaluation of Structural Patterns and Related Alteration and Mineralization Zones by Using ASAR-ASTER Imagery in Siyahrood Area (East Azarbaijan—NW Iran)

The NW part of Iran belongs to the Iranian plateau that is a tectonically active region within the Alpine-Himalayan orogenic belt. The intrusion of Oligocene parts in various faces caused the alteration and mineralization such as copper, molybdenum, gold and iron in the Siyahrood area. Granitoidic rocks with component of Granodiorite to alkali have been influenced by hydrothermal fluids. Alteration zones are important features for the exploration of deposits and the ASTER sensor is able to identify the type of alteration and its alteration zoning. This method can be a useful tool for detecting potential mineralization area in East Azarbaijan—Northwest of Iran. The purpose of this study is to evaluate ASTER data for mapping altered minerals in Siyahrood area in order to detect the potential mineralized areas. In this study, false color composite, and band ratio techniques were applied on ASTER data and argillic, phyllic, Iron oxide and propylitic alteration zones were separated. ASAR image processing has been used for lineaments and faults identified by the aid of directional filter. The structural study focused on fracture zones and their characteristics including strike, length, and relationship with alteration zones. The results of this study demonstrate the usefulness of remote sensing methods and ASTER multi-spectral data for alteration, and ASAR data are useful for lineament mapping.

胶东金矿与中生代区域性花岗岩关系及成矿预测和找矿方向

胶东地区是世界著名的金矿资源基地,截至2023年6月已累计探明金矿资源量已达5757余吨。与金矿成矿密切的中生代花岗岩分布广泛,岩石类型多样,也是山东省最发育、最典型的地区。本文对胶东地区金矿与中生代区域性花岗岩空间展布、形成时代和形成环境等关系进行了分析研究。区域性广泛分布的中生代花岗岩为晚侏罗世玲珑期(166~146 Ma)、早白垩世早期郭家岭期(135~123 Ma)、早白垩世晚期伟德山期(123~110 Ma)和崂山期(118~108 Ma),研究认为区域性岩浆事件一般持续10 Ma左右,而重熔型花岗岩一般持续20 Ma,反映了由基底岩石熔融到侵入结晶的2个阶段,它有一个由基底固体岩石熔融的过程,大致也需要10 Ma,既固体岩石熔融10 Ma,熔浆活动上侵结晶10 Ma。玲珑期重熔型花岗岩是扬子板块和华北板块碰撞的期后产物,郭家岭期岩浆事件代表了中国东部中生代构造体制转换的开始,伟德山期岩浆事件代表了构造体制转换的高峰期,崂山期岩浆事件代表了构造体制转换的结束期。86.8%的金矿赋存在玲珑期花岗岩中,6.9%的金矿赋存于郭家岭期花岗岩中,玲珑期花岗岩和郭家岭期花岗岩Au元素背景值明显高于伟德山期花岗岩和崂山期花岗岩。矿石硫与玲珑期花岗岩、郭家岭期花岗岩范围相近,特别是与玲珑期花岗岩大范围重叠,具有岩浆热液硫同位素变化小的特点,说明矿石硫主要源为玲珑期花岗岩、郭家岭期花岗岩。矿石铅主要为再活化的下地壳铅,即前寒武纪结晶基底铅,有幔源铅加入。金矿成矿年龄有162~146 Ma、133~120 Ma、120~115 Ma、112~105 Ma共4个区间范围,与胶东地区四期区域性花岗岩形成时间对应,成矿年龄一般晚于成岩年龄3~5 Ma。根据胶东金矿及多金属矿与岩浆热液事件对应关系,划分为玲珑金成矿期、郭家岭金成矿期、伟德山金及多金属成矿期和崂山多金属成矿期。胶东地区金矿主要是新太古代变质地层和古元古代底部片岩层位经过重熔作用金元素活化、迁移、富集和郭家岭期岩浆作用成矿。基于以上成矿作用认识,根据地球化学块体理论,对胶东金矿潜力进行了估算,胶东地区3000 m以浅金矿潜力约为1.8万t,同时对胶西北深部金矿进行了系统预测,预测3000 m以浅金资源量3997 t,5000 m以浅7497 t。通过地质综合研究,栖霞地区中新太古代变质岩下部有隐伏玲珑期花岗岩,根据金矿主要赋存在玲珑期花岗岩中的空间展布,S、Pb等同位素以及玲珑期花岗岩是金矿成矿直接围岩或母岩的认识,该地区变质岩中发育众多的石英脉型中小型金矿和矿(化)点,可能是浅部或顶部矿体的表现,认为该地区具有良好的成矿背景和潜力,是胶东地区今后金矿找矿的重要地区和方向。并建议在该地区部署地震和大功率激电剖面及地质科研钻探,查清一系列NE向断裂和地质结构,为金矿找矿提供科学依据。

世界规划教育30年的演变概览——以代表期刊为例1991-2020年的动态分析

文章基于代表期刊《规划教育与研究》(Journal of PlanningEducation and Research)30年跨度的1670篇文献及18093次引用数据,使用“引文关系”替代测度规划教育研究的发展演变概况。研究发现,规划教育群落在扩大,社会关注度随城镇化进程稳步增加,前景广阔。证实其在演变过程中与内外部学科互动日益密切,体现了跨学科、多元的特性。总结规划教育关注领域的演变,将规划教育的核心思想和关注领域归纳为4个主要群落,展示30年间规划教育64个研究方向、热点的演变。按时间维度分类,总结其研究方向的演变规律。规划教育的研究方向和热点虽潮起潮落,此起彼伏,但均与社会保持高度互动,证明规划教育从未脱离物质空间规划这一核心,协同多学科解决城市社会问题,实用性的学科本质未变,促进城市社会可持续发展的初心未变。

Is transcranial direct current stimulation a potential method for improving response inhibition?

Inhibitory control of movement in motor learning requires the ability to suppress an inappropriate action, a skill needed to stop a planned or ongoing motor response in response to changes in a variety of environments. This study used a stop-signal task to determine whether transcranial direct-current stimulation over the pre-supplementary motor area alters the reaction time in motor inhibition. Forty healthy subjects were recruited for this study and were randomly assigned to either the transcranial direct-current stimulation condition or a sham-transcranial direct-current stimulation condition. All subjects consecutively performed the stop-signal task before, during, and after the delivery of anodal transcranial direct-current stimulation over the pre-supplementary motor area （pre-transcranial direct-current stimulation phase, transcranial direct-current stimulation phase, and post-transcranial direct-current stimulation phase）. Compared to the sham condition, there were significant reductions in the stop-signal processing times during and after transcranial direct-current stimulation, and change times were significantly greater in the transcranial direct-current stimulation condition. There was no significant change in go processing-times during or after transcranial direct-current stimulation in either condition. Anodal transcranial direct-current stimulation was feasibly coupled to an interactive improvement in inhibitory control. This coupling led to a decrease in the stop-signal process time required for the appropriate responses between motor execution and inhibition. However, there was no transcranial direct-current stimulation effect on the no-signal reaction time during the stop-signal task. Transcranial direct-current stimulation can adjust certain behaviors, and it could be a useful clinical intervention for patients who have difficulties with response inhibition.

川东南綦江地区中侏罗统凉高山组陆相页岩油气勘探潜力分析

随着评价和开发技术的不断进步,陆相页岩油气已成为我国未来重要的接替能源。近期,川东南綦江地区部署的多口过路井在中侏罗统凉高山组页岩段钻遇了良好的油气显示。为明确该区页岩油气基本地质特征,以川东南綦江地区凉高山组富有机质页岩为研究对象,在岩心观察和化验分析的基础上,开展了綦江地区凉高山组二段页岩油气基础地质条件评价,并结合优质页岩地震预测、构造保存条件评价,落实了勘探潜力,指明了下一步勘探方向。以綦江典型井为例,综合有机地化特征、热演化程度、储层物性特征及含油气性特征等,对该区页岩油气进行了资源潜力分析。结果表明,綦江地区凉高山组二段下亚段优质页岩分布面积大,达4569 km2,厚度20~39 m,受半深湖相控制,有机碳含量平均为1.3%~1.6%,有机质类型以Ⅱ1—Ⅱ2为主,镜质体反射率为1.00%~1.29%,生烃潜力大,实测含油气性好;优质页岩具有明显的高GR、高声波、低密度特征,结合地震波形分类和波阻抗反演技术,明确平面上丁山—东溪—关圣场地区最厚;发育宽缓稳定向斜,钻井普遍见良好油气显示,保存条件整体较好,主体埋深1000~3500 m,构造应力单一,可压性好。综合分析认为,綦江地区凉高山组陆相页岩具备良好的物质基础,保存条件好,页岩油总资源量超5亿吨,勘探潜力大。评价过程为持续扩大四川盆地陆相页岩油气勘探场面提供了研究思路。

柴达木盆地三湖地区第四系七个泉组物源研究

为了深入评价柴达木盆地东部三湖地区第四系七个泉组天然气勘探潜力以及预测有利岩性气藏勘探区带和目标,文中通过重矿物组合、ZTR指数、重矿物稳定系数以及砂岩碎屑组分等参数,系统分析了该地区七个泉组的物源组成,确定物源方向并恢复母岩类型。研究表明:(1)七个泉组沉积时期,三湖地区重矿物稳定系数和ZTR指数均由柴达木盆地边缘向盆地中央方向增大,大致呈环带状展布,不同物源区主要重矿物组合差异显著,不稳定重矿物含量变化明显。(2)格尔木物源主要流动方向为北偏西方向,向北影响涩北地区的南部;乌图美仁物源规模小于格尔木物源,主要流动方向为北东方向,向北东影响台南地区的西南部和涩南3井区。(3)锡铁山—埃姆尼克山物源和绿梁山物源规模均较小,其中前者影响范围向南达察尔汗地区,而后者向南影响伊克雅乌汝北部和驼峰山地区。(4)台南—涩北地区主要为乌图美仁物源和格尔木物源的共同影响区。该研究首次明确了柴达木盆地三湖地区物源由乌图美仁物源和格尔木物源组成的昆仑山缓坡物源体系、由锡铁山—埃姆尼克山物源和绿梁山物源组成的祁连山陡坡物源体系以及盆地内部台南—涩北地区混合物源体系组成,可为该地区天然气勘探开发提供指导作用。

基于三维空间面积划分的轨迹相似性度量算法

针对大部分轨迹相似性度量算法无法区分方向相反轨迹的问题,提出了一种基于三维空间面积划分的三维三角分割(3TD)算法。首先,按照3TD算法的时间转换规则将轨迹集的绝对时间序列转变为相对时间序列;然后,在由经度、纬度以及时间三要素构成的三维空间坐标系中,通过划分规则将轨迹间面积分割成若干互不重叠的三角形,累加三角形面积并计算轨迹相似度;最后,在从船舶自动识别系统(AIS)收集的随机采样轨迹数据集上,与最长公共子序列(LCSS)算法和三角分割(TD)算法等进行了对比实验。实验结果表明:3TD算法对实验数据集中异向轨迹识别精确度达到100%;同时该算法面对海量数据集以及轨迹点部分缺失的数据集时,也能维持准确的度量结果以及较高的运算效率,能更好地适应异向轨迹相似度量工作。

吉林省洮南金蟾一带控矿因素及找矿方向研究

笔者通过近年来在吉林省洮南金蟾一带的地质勘查工作,大致查明了本区的地层、构造、岩浆岩分布特征,分别圈定综合异常10处、圈定5条北东向视极化率异常带、高磁异常8处、断裂构造5条,并且新发现矿(化)体16条。结合成果实际材料,综合研究发现本区的矿(化)体与物化探异常形态相吻合,物化探异常形态与本区北东向断裂构造、北西向次级构造方向大致吻合,进一步验证了该地区找矿远景及潜力。通过成果实际材料研究比对,初步认为矿(化)体的存在与区域内发育的火山岩、断裂构造有着密切的因果关系。

地下水型饮用水水源补给区划分——以辽宁省沈阳市北部某地区饮用水水源为例

选择辽宁省沈阳市北部某地区集中式地下水型饮用水水源作为研究区,收集其地形地貌、水源所属地下水含水系统的地质和水文地质概况等相关信息进行分析。选择公式法,根据含水层岩性,采取经验值参数,以水源开采井保护区外为基准,以15 a(5475 d)为地下水质点迁移时间,计算得出补给区面积为40.18 km^(2)。鉴于补给区边界部分横跨村庄,在补给区定界过程中,将横跨村庄纳入补给区范围内,切实加强补给区安全防护。并从补给区环境管理方面提出对策和建议。

柴达木盆地南八仙地区渐新世浅水三角洲物源及沉积演化

以古近系渐新统下干柴沟组上段(E23)为研究对象,在精细岩芯观察和钻(测)井资料综合分析的基础上,结合重矿物组合、ZTR指数、砂岩碎屑组分、粒度累积概率图和砂地比等参数综合分析结果,对柴达木盆地南八仙地区E23湖盆扩张期弱退积型浅水三角洲物源方向、砂体展布规律和沉积微相发育演化进行了深入研究。结果表明:①南八仙地区E23沉积时期物源主要来自南祁连山中酸性岩浆岩和中高级变质岩发育区,物源方向为近北东—南西向,稳定重矿物(磁铁矿、石榴子石、白钛矿和锆石)含量高(质量分数介于81.0%~99.9%)、不稳定重矿物(绿帘石和角闪石)含量低。②南八仙地区E23沉积时期为浅水三角洲—滨浅湖沉积环境,主要发育水下分流河道砂体,岩性主要为岩屑长石砂岩,其次为长石岩屑砂岩,砂体的成分成熟度一般中等—较差、分选磨圆度中等—较差,粒度概率图以反映河流作用的一跳跃一悬浮式为主;沉积构造类型多样,主要发育块状层理、正粒序层理、平行层理和槽状交错层理。③E23沉积时期,南八仙地区继承性发育3条北东—南西向呈条带状展布的砂体富集带(砂地比值介于35%~65%之间),早期到中期砂体发育程度增强,呈进积式;中期到晚期砂体发育程度有所减弱,呈弱退积式。④E23沉积时期,南八仙地区处于浅水三角洲前缘亚相沉积环境,持续发育3个呈北东—南西向展布的沉积朵叶体,主要发育水下分流河道微相,其次为水下分流间湾微相,早期到中期浅水三角洲前缘发育规模增大,中期到晚期发育规模减小。

家蚕驯化起源研究概述

家蚕(Bombyx mori)的驯化是农业史上的重大事件之一,由之形成的养蚕业对中华文明和世界农业历史产生了深远的影响。关于家蚕的驯化起源,除了远古的神话传说外,研究人员从历史学、考古学和生物学角度进行了溯源,尤其是近20年获得了大量的分子生物学证据。本文对家蚕驯化起源的2个核心科学问题——野生祖先来源和起源地(驯化事件发生地)的相关生物学研究进展进行概述。分子生物学和基因组学证据表明,家蚕的野生祖先是中国野桑蚕(Chinese Bombyx mandarina),而不是日本野桑蚕(Japanese B.mandarina),所有的家蚕品种都来自于一个起源中心。最新的泛基因组分析结果表明,家蚕的驯化起源于黄河中下游地区。

播种量对滨海稻区水稻机械旱直播产量、米质及经济效益的影响

为了完善滨海稻区水稻机械旱直播稻高产栽培技术体系,保证产量米质同时尽量降低农业成本、降低劳动强度,提高农业生产效率、经济效益,为直播稻未来在滨海稻区发展提供理论依据。采用田间对比试验方法,研究了不同播种量对滨海稻区水稻机械旱直播产量、米质及经济效益的影响,探索滨海稻区水稻机械旱直播最佳播种量。结果表明,播种量为97.5 kg/hm^(2)机械旱直播产量最高,加工品质较好,但稻米营养品质及食味值略低于播种量为120 kg/hm^(2);水稻机械旱直播比机插秧分别减产2.13 t/hm^(2)、1.76 t/hm^(2)、2.05 t/hm^(2),但效益比机插秧分别增加了0.144万元/hm^(2)、0.218万元/hm^(2)、0.118万元/hm^(2),处理2比处理1、3分别增加0.074万元/hm^(2)、0.100万元/hm^(2)。

雨养农业区黄芩轻简化膜间直播种植技术规程

为进一步推进甘肃省雨养农业区黄芩种植机械化、精量化和轻简化生产,结合多年的试验示范和生产实践,从范围、规范性引用文件、术语和定义、生产环境、栽培技术、田间管理、采收与产地加工等方面总结出了雨养农业区黄芩轻简化膜间直播种植技术规程。

推进乡村共同富裕的理论逻辑与实践路向:基于空间正义的分析

空间正义是一种城乡空间发展及社会正义问题在空间上的投射,是对社会空间公平与正义的追求,也是实现共同富裕征程中维护公平正义的基本遵循,可以通过相应的顶层设计与价值引领实现城乡发展成果共享。立足于新时代发展背景,从空间正义内涵及特性出发,正视乡村空间非正义现实,并基于乡村共同富裕目标实现对客观规律的充分尊重、空间权益的有效保障和空间资源的合理配置等空间正义需要,从宏观层面的空间制度的顶层设计、中观层面的空间分配的公平正义和微观层面的空间生产的均衡配置等三个层次,构建推进共同富裕的空间分析维度,并阐述其在中国语境下的逻辑理路及其与中国特色社会主义共同富裕的同构性,为我国乡村地区实现共同富裕提供理论参考。在空间正义视域下,实现乡村共同富裕的总体思路与实践路向在于:坚持群众需求的价值导向,树立空间生产为人民的正义观;构建完善的空间分配格局,发挥促进公平正义的最大效用;加快制度创新与改革,保障乡村地区居民的空间权益;尊重乡村差异性文化,打造正义性的多元空间文化。

基于三维扫描的织物多方向可视化弯曲性测试方法

目前常用弯曲性测试方法每次只能测试织物一个方向的弯曲性能,不能直接观察到织物不同方向的弯曲形态,且需要多次裁样、重复测试,耗时费力;针对这种情况,提出了一种多方向可视化织物弯曲性测试方法。以20种织物为测试对象,利用三维扫描技术获取织物弯曲形态的点云图像;基于所得图像提取投影周长、投影面积和截面积3个新指标;最后分析新指标与抗弯长度的关系。结果发现:新指标与斜面法中的抗弯长度有较好的相关性;织物底端的截面积能较好地体现织物整体的弯曲性能,这表明提出的方法具有良好的可行性。该方法一次测量可得到织物经纬向、斜向的弯曲指标,且每个方向分别有5个样条,有效提升了测试效率;同时利用三维扫描技术可以更加直观精确地描述织物弯曲形态。

Is effect of transcranial direct current stimulation on visuomotor coordination dependent on task difficulty?

Transcranial direct current stimulation （tDCS）, an emerging technique for non-invasive brain stimulation, is increasingly used to induce changes in cortical excitability and modulate motor behavior, especially for upper limbs. The purpose of this study was to investigate the effects of tDCS of the primary motor cortex on visuomotor coordination based on three levels of task difficulty in healthy subjects. Thirty-eight healthy participants underwent real tDCS or sham tDCS. Using a single-blind, sham-controlled crossover design, tDCS was applied to the primary motor cortex. For real tDCS conditions, tDCS intensity was 1 mA while stimulation was applied for 15 minutes. For the sham tDCS, electrodes were placed in the same position, but the stimu- lator was turned off after 5 seconds. Visuomotor tracking task, consisting of three levels （levels 1, 2, 3） of difficulty with higher level indicating greater difficulty, was performed before and after tDCS application. At level 2, real tDCS of the primary motor cortex improved the accurate index compared to the sham tDCS. However, at levels 1 and 3, the accurate index was not significantly increased after real tDCS compared to the sham tDCS. These findings suggest that tasks of mod- erate difficulty may improve visuomotor coordination in healthy subjects when tDCS is applied compared with easier or more difficult tasks.