First record of Lower Triassic <Emphasis Type="Italic">Undichna</Emphasis> spp. fish swimming traces from Emei,Sichuan Province,China

We discuss traces from the ichnospecies Undichna unisulca recorded from the Triassic that are reported for the first time in this paper. These fossils are also some of the oldest vertebrate ichnites discovered in China to date. The fish swimming traces (Undichna unisulca) described originate from the Lower Triassic. These traces were found in the Jialingjiang Formation and are located at a gorge ~7.5 km from Emei, Sichuan Province, China. The ichnospecies Undichna unisulca consists of a regular sinusoidal wave. The wavelengths and amplitudes are quite constant between each specimen ranging between 28-32 mm and 9-12 mm, respectively. The fish swimming traces and distribution within the same bed are preserved as hypichnial ridges at the undersurface.     

Neutrino physics from precision cosmology

Cosmology provides an excellent laboratory for testing various aspects of neutrino physics. Here, I review the current status of cosmological searches for neutrino mass, as well as other properties of neutrinos. Future cosmological probes of neutrino properties are also discussed in detail.     

Cultivating a research imperative: Mentoring mathematics at Stockholms Högskola, 1882–1887

Though the central role of Gösta Mittag-Leffler in the promotion of specialized, research-oriented mathematics at Stockholms Högskola is widely acknowledged, the specific social and technical means by which he sought to cultivate a fledgling research community there during the early- to mid-1880s have received little attention. In particular, a detailed study of the relationship of his own research activity to that of his first Swedish students is absent from the existing literature.Through the juxtaposition of their research activities and unpublished correspondence, this paper explores Mittag-Leffler's active and deliberate efforts to engage his students Ivar Bendixson and Edvard Phragmén in open problems within his own research agenda, support them through his institutional connections, and instill within them norms concerning research ideologies, practices of communication and criticism, and frameworks for shared knowledge. It also illuminates the extent to which his teachings took root in at least one student to emerge from his program, who would perpetuate the mathematical practices set in place by his teacher and set forth on the international stage to promote his newly-acquired system of values.     

Investigating young students’ multiplicative thinking: The 12 little ducks problem

Children’s multiplicative thinking as the visualization of equal group structures and the enumeration the composite units was the subject of this study. The results were obtained from a small sample of Australian children (n = 18) in their first year of school (mean age 5 years 6 months) who participated in a lesson taught by their classroom teacher. The 12 Little Ducks problem stimulated children to visualize and to draw different ways of making equal groups. Fifteen children (83 %) could identify and create equal groups; eight of these children (44 %) could also quantify the number of groups they formed. These findings show that some young children understand early multiplicative ideas and can visualize equal group situations and communicate about these through their drawings and talk. The study emphasises the value of encouraging mathematical visualization from an early age; using open thought-provoking problems to reveal children’s thinking; and promoting drawing as a form of mathematical communication.     

钒硼双原子阳离子活化甲烷研究

Methane activation by transition metal species has been extensively investigated over the past few decades. It is observed that ground-state monocations of bare 3d transition metals are inert toward CH₄ at room temperature because of unfavorable thermodynamics. In contrast, many mono-ligated 3d transition metal cations, such as MO⁺ (M = Mn, Fe, Co, Cu, Zn), MH⁺ (M = Fe, Co), and NiX⁺ (X = H, CH₃, F), as well as several bis-ligated 3d transition metal cations including OCrO⁺, Ni(H)(OH)⁺, and Fe(O)(OH)⁺ activate the C―H bond of methane under thermal collision conditions because of the pronounced ligand effects. In most of the above-mentioned examples, the 3d metal atoms are observed to cooperate with the attached ligands to activate the C―H bond. Compared to the extensive studies on active species comprising of middle and late 3d transition metals, the knowledge about the reactivity of early 3d transition metal species toward methane and the related C―H activation mechanisms are still very limited. Only two early 3d transition metal species HMO⁺ (M = Ti and V) are discovered so far to activate the C―H bond of methane via participation of their metal atoms. In this study, by performing mass spectrometric experiments and density functional theory calculations, we have identified that the diatomic vanadium boride cation (VB⁺) can activate methane to produce a dihydrogen molecule and carbon-boron species under thermal collision conditions. The strong electrostatic interaction makes the reaction preferentially proceed the V side. To generate experimentally observed product ions, a two-state reactivity scenario involving spin conversion from high-spin sextet to low-spin quartet is necessary at the entrance of the reaction. This result is consistent with the reported reactions of 3d transition metal species with CH₄, in which the C―H bond cleavage generally occurs in the low-spin states, even if the ground states of the related active species are in the high-spin states. For VB⁺ + CH₄, the insertion of the synergetic V―B unit (rather than a single V or B atom) into the H₃C―H bond causes the initial C―H bond activation driven by the strong bond strengths of V―CH₃ and B―H. The mechanisms of methane activation by VB⁺ discussed in this study may provide useful guidance to the future studies on methane activation by early transition metal systems.     

Tailored Zwitterionic Hemicyanine Reporters for Early Diagnosis and Prognostic Assessment of Acute Renal Failure

Drug-induced renal failure (DIRF) poses a serious medical complication with high mortality risk. However, early diagnosis or prognosis of DIRF remain challenging, as current methods rely on detecting late-stage biomarkers. Herein we present a library of zwitterionic unimolecular hemicyanines (ZCs) available for constructing activatable reporters to detect DIRF since its initial stage. Zwitterionic properties of these probes are achieved through interspersedly integrating alkyl sulfonates and quaternary ammonium cations onto hemicyanine skeleton, which result in record low plasma protein binding (<5 %) and remarkable renal clearance efficiencies (≈96 %). An activatable reporter ZCRR is further developed by masking the optimal candidate ZC6 with a tetrapeptide specifically cleavable by caspase-8, an initiating indicator of apoptosis. In living mice with cisplatin-induced DIRF, systematically administered ZCRR efficiently accumulates in kidneys and responds to elevated caspase-8 for near-infrared fluorescence signals ‘turn-on’, enabling sensitive detection of intrarenal apoptosis 60 h earlier than clinical methods, and precise evaluation of apoptosis remediation effects by different medications on DIRF mice. As it's urinary excretable, ZCRR also allows for remote detection of DIRF and predicting renoprotective efficacy through in vitro optical urinalysis. This study thus presents unimolecular renal clearable scaffolds that are applicable to developing versatile activatable reporters for renal diseases management.     

Starch grain evidence reveals early pottery function cooking plant foods in North China

Early pottery sherds excavated in northern China date back to more than 11,000 cal a BP, and are presumed to have been used as cooking vessels. There has been, however, no direct evidence to demonstrate this function. Here we report ancient starch grains recovered from carbonized residues adhering to the bases of flat- bottomed vessels excavated from the Zhuannian site dating more than 10,000 cal a BP in the North China Plain. This evidence demonstrates that early pottery was being used to cook cereal grains, particularly millets, and acorns. Because millets were in the process of domestication at thistime, we propose that pottery invention in northern China may have been related to early farming activities.     

川西拗陷上三叠统断层封闭性研究

本文用裂缝充填物、碳氧同位素、声发射、包体均一温度测定等方法确定川西拗陷上三叠统断层形成期次,研究其与油气演化的匹配关系;用钻井、流体性质、地层压力、断层面剖面图、断裂带地面调查等多种方法和资料,综合研究该区内断层的纵向、横向及有效封闭性。并进行区域评价,指出了封闭条件差、中等、好、极好的地区,为提高勘探效益提供了直接铱据。     

鄂中地区下三叠统碳酸盐岩储层成岩作用与孔隙演化

鄂中沉湖—土地堂地区早三叠世以局限—半局限台地环境为主,有过短暂的台内浅滩环境,东部曾发展为蒸发台地环境.下三叠统主要有微晶灰岩、微晶白云岩,夹少量亮晶鲕粒灰岩,局部硬石膏岩. 经历了海底环境的白云化,胶结、硬石膏化,大气环境的溶蚀,埋藏环境的胶结、溶蚀、白云化、表生环境的溶性等成岩作用过程.大气及浅埋藏环境产生的孔、缝隙多为后来的方解石等充填,对储层贡献甚微. 深理藏环境的扩溶孔的形成及后期构造缝的产生与油气演化大致配套,具有一定的意义,表生环境的溶蚀,保存较好,对储层有较大贡献. 区内下三叠统主要发育裂缝型及裂缝孔洞型两类储层,前者孔隙度低,仅为2%~3%,后者孔隙度可达26%左右,至今仍受大气淡水影响,保存条件差,不利于成截.     

甘肃金塔及其附近早白垩世介形类

报道了首次发现于花海－金塔盆地花海凹陷花探９井、湖西新村、阿拉善左旗早白垩世介形类化石。根据它们的组合面貌及其在国内外分布的主要层位,认为：湖西新村原划归为上侏罗统并含有丰富介形化石的这套地层应属下白垩统;花探９井和阿拉善左旗塔塔水沟含化石地层的时代应为早白垩世。这些新的研究成果为建立该地区中生代地层层序奠定了基础,特别是对认识花海－金塔盆地的形成与演化,及进一步的油气勘探提供了新的资料