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Podocarpium (Fabaceae), characterized by single seeded pods and paripinnate compound leaves, is well known as an extinct legume genus having extensive fossil occurrences from the Miocene of Central Europe and eastern Asia. However, the Palaeogene unambiguous megafossils are quite scarce, especially the Oligocene record from eastern Asia, which heavily impedes our understanding of early dispersal patterns and infrageneric relationships of this enigmatic genus. Here, we described dozens of legume specimens from the Oligocene Ningming Formation of Guangxi in South China, the Early Miocene Guide Group of Qinghai in Northwest China and the Middle–Late Miocene Shengxian Formation of Zhejiang in Southeast China as Podocarpium podocarpum (A. Braun) Herendeen based on extremely similar fruit characters. Meanwhile, we reexamined variation in fruit morphology among the previously reported fruits of Eurasia and present legumes as a basis for interpreting the infrageneric relationship and subfamily affinity of Podocarpium. The high similarities presented by these fossil fruits support the previous recognition of the specimens from the Oligocene–Miocene of Central Europe and the Miocene– Pliocene of eastern Asia as P. podocarpum, but such a low species diversity of Podocarpium appears to indicate a bradytelic morphological evolution for this whole ancient lineage through geologic time. Moreover, judging from seed orientation as well as seed and fruit comparative sizes, the oblong seed is parallel to the long axis of the fruit and its placentation is near the apex of the seed chamber, which favor the previous assignment of Podocarpium to the subfamily Caesalpinioideae. Additionally, we speculated that this extinct genus may prefer a warm and humid (or mildly arid) environment by plotting the megafossil localities on the overall Eocene, Oligocene and Miocene palaeoclimate maps based on continental drift. The Oligocene occurrence from the Ningming Formation in Guangxi, South China sheds new light on the historical biogeographical pattern between Central Europe and eastern Asia, i.e. after the probable origin in low latitude tropic coastal regions of southernmost South China (i.e. Hainan) by the Middle Eocene, Podocarpium may subsequently disperse into Guangxi and then Europe via a probable low-latitude land connection located among the Tethys and Paratethys seas to the southwest of Eurasia in the Early Oligocene, independent of the gradual closure of the Turgai Strait in the middle-high latitudes during the Oligocene.

The fossil records of Burretiodendron Rehder are reviewed based on diagnostic winged fruits from the Oligocene Ningming Formation, Guangxi, South China. Today, this genus is endemic to Southeast Asia with six extant species that are well distributed in limestone mountain forests under a monsoonal climate. The fossil records of this genus were represented only in Yunnan of southwestern China. The fossil fruits are assigned to a new species, Burretiodendron guangxiensis J.L. Dong et B.N. Sun sp. nov., are smaller than those of living species. Burretiodendron is a good indicator of paleoclimate and karstification due to its restricted distribution which is determined by specific temperature, precipitation and the topographic condition. We investigated the climate requirements of Burretiodendron. It is possible to accurately infer that the Ningming paleoflora represented a warm and humid climate with seasonal precipitation during the Oligocene. Edaphic preferences of the nearest living relative identified for the fossil species may point to the existence of a karstic system in the Ningming Region during the Oligocene.

The Oligocene marked the beginning of the present ‘icehouse’ epoch and witnessed the development and evolution of the Asian monsoon system (AMS). In this paper, the early Oligocene Ningming flora of Guangxi, southern China, is analysed to investigate the AMS based on climate proxies derived from Climate Leaf Analysis Multivariate Program (CLAMP). CLAMP results suggest that the prevailing climate experienced by the Ningming flora was humid subtropical with hot summers and warm winters. Although the record of precipitation seasonality is muted, it is about half as strong as that seen today in monsoon climates of South China, indicating a very weak monsoonal signal. Despite suggesting weak rainfall seasonality, the position of the Ningming flora in physiognomic space indicates that leaves exhibit monsoon-adapted morphologies, comparable to today's vegetation exposed to the Indonesia–Australia monsoon (I-AM) and the transitional monsoon area (influenced by the East Asia monsoon, South Asia monsoon and I-AM). Leaf architectural signatures reveal that the Ningming flora grew under a humid subtropical climate with subtle monsoon signatures. Although it is difficult to distinguish the different domains of the Asian monsoon under such a subtle monsoon influence, based on leaf signatures from southern Asia, it can be inferred that the Ningming Basin during the early Oligocene was exposed to a climate regime similar to that today influenced by the I-AM. In addition, the moist enthalpy method was applied to quantitatively reconstruct the paleoelevation of the Ningming Basin. This approach suggests a paleoelevation estimate of ~1.24–1.35 ± 0.52 km for the early Oligocene, suggesting that a drop in paleoelevation of the Ningming Basin took place after the early Oligocene (Rupelian). The CLAMP results suggest that the early Oligocene Ningming area was at a mid-altitude and experienced a humid subtropical climate with subtle monsoon signatures.

New legume fossils can provide a historical perspective of their early evolution and biogeographic history. Three legume species, Albizia ningmingensis sp. nov., Leguminocarpum sp. 1 and Leguminocarpum sp. 2, from the Oligocene Ningming Formation of Guangxi, South China, are described on the basis of morphological and/or anatomical characteristics. Albizia ningmingensis sp. nov. bears a close resemblance to the extant species Albizia kalkora in morphology and anatomy and represents a reliable occurrence of Albizia in the Oligocene deposits of China. An incomplete fruit fossil is described as Leguminocarpum sp. 1, predominantly on the basis of anatomical characteristics. Fruits of Leguminocarpum sp. 2 are straight and strongly asymmetrical, with one straight suture and the other strongly constricted. The occurrence of Albizia fruits indicate that Albizia elements existed in the South China during the Oligocene. Our legume fossils, together with earlier records of three Bauhinia species, indicate that a flora with the unusual abundance of legumes was present in South China in the Oligocene. The legumes from the Ningming Formation, having a relatively high diversity, can contribute to the palaeoclimatic interpretation and indicate that the Oligocene Ningming flora most likely lived in a tropical-to-warm subtropical climate.

Recently, several leaf fossils with good cuticles were discovered from the Oligocene deposits in Guangxi, China. The high fossilization potential of these leaves and easily identifiable stomata and epidermal cells make them an excellent source for CO2 reconstruction. In this study, atmospheric CO2 of the Oligocene is reconstructed using the mechanistic-theoretical model based on stomatal data, photosynthesis and gas exchange control and using an alternative method based only on stomatal ratio. Fossil leaves of Buxus ningmingensis, Chuniophoenix slenderifolius and Cephalotaxus ningmingensis, two angiosperms and one gymnosperm, were considered. It was found that some differences were present between the results obtained by the two methods. The SR-based method yields a somewhat narrower CO2 range (from 355 to 578 ppmv) than the model approach (from 255 to 972 ppmv) which encloses the former range. The CO2 results derived from the three species using the two approaches are overlapped to a high degree with CO2 data from other terrestrial plants and phytoplankton material. More data provided by different proxies are desirable to unravel the interactions between atmospheric CO2 and climate change for the Oligocene.

New palm leaves from the Oligocene Ningming Formation are placed into the morphogenus Sabalites because of their costapalmate leaf shape. Four taxa are described on the basis of leaf compressions w...

A new fossil species of Zelkova is described from the Oligocene Ningming Formation of Guangxi, South China. Zelkova ningmingensis sp. nov. is characterized by leaves with craspedodromous venation pattern and drupaceous fruit type. The new species possesses elliptical to ovate leaves, bearing 7–12 pairs of secondary and simple toothed margin, as well as epidermal cells with straight or rounded anticlinal walls. The species is compared with extant and other fossil species hitherto reported of the genus. It is most similar to the living Zelkova schneideriana in the leaf gross morphology and epidermal characters, which may be suggested to be the ancestral type of Zelkova schneideriana. The discovery of Zelkova ningmingensis sp. nov. in Guangxi indicates that Zelkova has already existed in southern China as early as the Oligocene. In combination with Zelkova material from the Oligocene of Europe, it can be inferred that Eurasian Zelkova had begun to diversify by at least the Oligocene. Because China is the bio...

A new fossiliferous horizon from the Middle Triassic Dingjiayao Formation, Pingchuan District, Gansu Province, China is described. The plant assemblage preserves a diverse community of horsetails, ferns and seeds of unknown systematic affinity. Ferns are the most diverse elements of the assemblage and are also ecologically dominant, while horsetails contribute a smaller component to floristic diversity and have a lower abundance. Here, five fern taxa are assigned to Marantoidea, Symopteris, Neuropteridium, Cladophlebis and Sphenopteris. Also, six species belonging to three horsetail taxa are described from this assemblage, which are assigned to Equisetites, Echinostachys and Neocalamites. Additionally, remains of doubtful botanical attribution comprise Carpolithus seeds. Some of these groups are recorded from the Middle Triassic of China for the first time. The preservation of these fossils suggests that the assemblage was buried autochthonously or para-autochthonously by volcanic ash fall. Fossilization of these specimens occurred rapidly after the specimens embedded in the volcaniclastic sediments. Also the plant assemblage indicates a local riparian environment in a warm, humid climate.

Three species of Palaeocarya were found from the Oligocene Ningming Formation of Guangxi, South China. Two species have been identified, Palaeocarya guangxiensis and Palaeocarya ningmingensis, and a new species is described, Palaeocarya longipedicelata J.L. Dong et B.N. Sun sp. nov. The new species is diagnosed primarily by a distinct long pedicel of 8.0–10.0 mm in length, lobe base tri-veined, upper pinnate venation with retuse apex, small prophyllum, and nutlet without hair. The epidermal cells show obscure polygons with undulated cell walls from the tri-lobed bract and show clear polygons with straight cell walls from the pedicel. The peltate scales and circular peltate trichomes are also observed. The occurrence of these winged fruit fossils from the Oligocene suggests that Palaeocarya began to diversify no later than the Oligocene in Guangxi, South China. From the correlation between present fossils with previously published fossils from the Oligocene Jilin, Northeast China, it can be inferred that Palaeocarya had a wide distribution during the Oligocene in China, ranging from the south to the northeast. Based on the analysis of the ecological requirements of the extant relative species, Engelhardia, Alfaropsis and accompanying plant and fungi fossils, we can infer that the palaeoclimate of the Ningming region should be considered a warm and humid tropical–subtropical climate. Finally, we speculate that the Ningming Basin during the Oligocene was close to the low-latitude mountains. Drei Arten von Palaeocarya wurden in der oligozanen Ningming-Formation in Guangxi (S-China) gefunden. Zwei Arten wurden identifiziert, Palaeocarya guangxiensis und Palaeocarya ningmingensis, wie auch eine neue Art (Palaeocarya longipedicelata J.L. Dong et B.N. Sun sp. nov.) beschrieben wird. Die neue Art wurde primar anhand des langen, ausgepragten Pedicellus mit einer Lange von 8.0–10.0 mm, der dreiaderigen Basis der Loben, der oben gefiederten Aderung mit gestutztem Apex, dem kleinem Vorblatt und der kleinen, haarfreien Nuss festgelegt. Die Epidermalzellen weisen ein undeutliches Polygon mit undulierenden Zellwanden des dreiaderigen Deckblatts und deutliche Polygone mit geraden Zellwanden des Pedicellus auf. Peltate Schuppen und runde, peltate Trichome wurden ebenfalls festgestellt. Dieses Fossilvorkommen geflugelter Fruchte aus dem Oligozan belegt den Beginn der Diversifizierung von Palaeocarya spatestens im Oligozan des sudchinesischen Guangxi. Ein Vergleich zwischen den vorliegenden Fossilien mit fruher publizierten Funden aus dem Oligozan von Jilin (NE-China) ermoglicht den Ruckschluss, dass Palaeocarya eine weite Verbreitung wahrend des Oligozans in China aufwies, vom Suden bis zum Nordosten. Aus der okologischen Analyse heutiger verwandter Arten wie Engelhardia und Alfaropsis nebst begleitenden Pflanzen- und Pilzfossilien konnen wir schliesen, dass das Palaoklima der Ningming-Region ein warmes, humides, tropisch–subtropisches Klima war. Wir vermuten, dass das Ningming-Becken wahrend des Oligozans an aquatornahe Berge grenzte.

The study of plant–insect interactions can provide valuable information about terrestrial ecosystems. A plant assemblage from the Toupi Formation of Jiangxi, China, provides indirect evidence of the plant–insect interactions that occurred in a Miocene forest community. A total of 123 dicot leaf specimens were examined and 25 of them showed traces of insect herbivory. Twenty-four damage types were identified and categorized into eight functional feeding groups. These traces indicate that insects interacted with these plants for various purposes, including feeding, sheltering and egg laying. To survey the responses of plant–insect interactions to climate conditions, the data on insect damage frequency and temperature variables from the Toupi assemblage and four other assemblages (from the middle Miocene to the early Pleistocene) from China were analyzed based on a linear stepwise regression analysis. The analysis suggests that there is a significant positive correlation between the damage frequency and the coldest month (mean) temperature (CMT) (R2 = 0.709 and P = .047). The present result provides additional support for the hypothesis that the CMT, rather than the mean annual temperature, could be one of the factors influencing the frequency of damage in paleoflora communities. When compared to the four other assemblages, the Toupi assemblage has the lowest damage frequency which could be due to the lowest CMT. It is possible that a low CMT could result in a low insect metabolic rate per unit area and unit time, leading to a low frequency of insect attack and a low herbivory rate.

Fossil palm leaves from the Oligocene deposits in Ningming County, Guangxi, China, have been reported for the first time. The palmate leaf shape along with a definite costa support the placement of the fossils in the Coryphoideae. Three new species are described: Chuniophoenix slenderifolia sp. nov., Livistona roundifolia sp. nov. and Trachycarpus formosa sp. nov. The palm fossils belong to three taxa and indicate that palms in southern China began to diversify no later than the Oligocene and that a diversified palm flora was already present at that time in Guangxi. This report provides new information about the biogeographical history of Chinese palms over geological time.

A new species of Meliolinites (fossil Meliolaceae), M. buxi sp. nov., is reported from the Oligocene Ningming Formation of Guangxi, South China. The fungus has hyphopodia characteristics of extant Meliolaceae, such as thick-walled, branching hyphae with appressoria and phialides. However, these fossils entirely lack mycelial or perithecial setae and have only a few phialides, thereby distinguishing the new species from most known species. The fungus was discovered on the adaxial and abaxial cuticles of several fossilized Buxus leaves. Thickening and twisting of cell walls in the Buxus leaf cuticle, along with the parasitic feeding strategy of the extant Meliolaceae, suggest that a parasitic interaction between Buxus and M. buxi seems feasible. The distribution of modern Meliolaceae suggests that they live in warm, humid subtropical-tropical climates. It is possible that the presence of M. buxi indicates a similar climatic condition. The co-occurrence of large-leaf Buxus and floristic comparisons of the Ningming assemblage also corroborate this conclusion.

Several three-dimensionally preserved Pious female cones from the upper Miocene Shengxian Formation of Zhejiang Province, eastern China, were identified as two fossil species, Pinus preyunnanensis X.H. Xu and B.N. Sun sp. nov. and Pinus prekesiya Xing, Liu and Zhou. Morphologically, comparisons of P. preyunnanensis sp. nov. with previously published Cenozoic cones and related extant pine cones reveal that the present specimens differ from all of them. The new species has the closest affinity with the extant Pious yunnanensis. The occurrence of P. preyunnanensis sp. nov. and P. prekesiya from the upper Miocene in Zhejiang, eastern China, indicates that 1) P. yunnanensis and Pinus kesiya (or their ancestral taxa) had a wider distribution during the late Miocene compared to the present; 2) P. yunnanensis and P. kesiya (or their ancestral taxa) disappeared from eastern China probably because of the prominent declining cold month mean temperature from the Miocene to the present; and 3) the differentiation of P. yunnanensis and P. kesiya can be traced back in eastern China to at least the late Miocene. (C) 2015 Elsevier B.V. All rights reserved.

Two new species, Castanopsis praefissa R.Y. Li et B.N. Sun sp. nov. and Castanopsis praeouonbiensis R.Y. Li et B.N. Sun sp. nov., are described from fossil specimens collected from the upper Miocene Shengxian Formation, Zhejiang Province, Southeast China. The fossil leaves are obovate to elliptical with serration mostly confined to the upper 1/3 of the lamina, pinnate venation, straight anticlinal walls and cyclocytic stomata. The fossil cupule is globose with fasciculate and branched spines, and a broadly ovate nut scar. The fossil leaves and cupule have been compared with those extant and other fossil species hitherto described in this genus. Castanopsis praefissa shows the closest affinity to C. fissa, and C. praeouonbiensis closely resembles C. ouonbiensis. Castanopsis fissa has toothed leaves and scaly cupules, whereas C. ouonbiensis has untoothed leaves and spiny cupules. Furthermore, they were not collected from the same site. So it is reasonable to assign them to two different species, rather than to one. Castanopsis praeouonbiensis and C. praefissa became extinct in this area because of the cooling climate from the late Miocene to the present day in Zhejiang Province.

In this study, 39 leaf samples of three angiosperms (Betula albo-sinensis, tree species; and Caragana jubata and Berberis diaphana, shrub species) were collected in the middle-east parts at 2300-3640 m asl of the Qilian Mountains to study the variations of leaf characteristics of angiosperms with altitude change in inland high-altitude regions of China. Five leaf indexes, viz. epidermal cell density (ED), stomatal density (SD), stomatal index (SI), leaf vein density (VD) and carbon isotopic ratio (delta C-13), were analyzed in laboratory. The results show that there are significant or even very significant linear correlations between the five indexes and altitude, of which SD, SI and VD exhibit a negative correlation with altitude, while ED and delta C-13 exhibit a positive correlation with altitude. Such a correlation assemblage is quite different from the situation in the low-altitude humid environment. Generally, only an assemblage of positive correlations can be observed between the indexes (viz. SD, SI and delta C-13, etc.) and the altitude in the low-altitude humid environment, which were caused mainly by the plants' responses to the change of atmospheric CO2 concentration (C (a) ). However, an assemblage of the negative and positive correlations found here may be attributed mainly to the plants' responses to the change of physiological drought caused by change of low temperature, and here it is preliminarily called the inland high-altitude pattern of plant leaf variations.

There is a quite difference between optical devices displayed color and printed color. The visual relationship of color gray is an important factor of the visual interface impact. Based on LED optical display screen, this paper selects typical web interface as experimental subjects; after Matlab experimental data analysis, study gray value of interface design color to explore the influence of gray value of interface design on interface visual effects, offers design rules of the color gray from area relationship, shape relationship, and collocation relationship of color gray, which provides a useful reference for interface designers.

This paper presents a negative sequence compensation system based on a novel two-phase three-wire converter to eliminate a negative sequence current for the high-speed railway traction power system with a three-phase V/V traction transformer. In this compensation system, the proposed two-phase three-wire converter is fed by two single-phase power sources formed with two step-down transformers connecting to the two feeder sections. The proposed converter contains three switch legs, one of which is connected to the common ground wire of two single-phase voltages. Hence, a switch leg is saved compared with two conventional single-phase converters, and the ratings of the power switches are not increased. In order to enhance the dynamic and steady-state performances of the compensation system, a compound control method composed of hysteresis control and dividing frequency control is presented. Simulation and experimental results are presented to demonstrate that the proposed compensator and its control strategy are very effective.

With the development of science and technology, mobile computers have become indispensable information tools of people’s daily life. Starting with design experience, this paper discusses the innovation of design concept and emotional design of laptops modeling design by using geometrical method, human engineering, etc, which provides design ideas for designers.

Paliurus favonii Unger is recognized and described based on fruits from the Oligocene Ningming flora of Guangxi, South China. Characteristics of the present specimens include circular winged fruits that are 10.0–11.5 mm in diameter with a central endocarp at 3.0 to 4.0 mm in diameter. The specimens fall into the morphological range of the fossil species P. favonii, which has been observed in other Cenozoic sites in the Northern Hemisphere. The present discovery represents the lowest latitude distribution of P. favonii in the world, and we are presenting the first P. favonii fossil described with detailed cuticular characteristics from China. Further, this finding demonstrates that the genus existed in the Oligocene Ningming region, South China, and provides new information for understanding the fossil history. The dispersal mode for winged fossils demonstrates that wind dispersal is well-represented in the Oligocene Ningming flora.

Mussels have been proposed as appropriate biomonitors of marine pollution, especially for monitoring metallic pollution based on variations of metallothionein as biomarkers. Under 2 exposure levels (12.7 microg/L, 63.5 microg/L), Cu accumulation and metallothionein-like protein (MTLP) induction by mussel (Perna viridis) digestive glands were investigated and simulated into dynamic models in the present work, and the soluble and total Cu burden of digestive glands were also determined. Calculated mean Cu uptake rates by mussel target organ were 2.045 and 7.028 microg x (g x d)(-1) respectively, and the theoretical equilibrium kinetic BCFs of Cu were 2074 and 1619 correspondingly. And within the exposure duration, different changing trends of ratio of soluble Cu to total Cu in digestive glands were observed in the two groups. The MTLP level of control samples was (0.551 +/- 0.037) mg/g, and the counterparts are 0.407 - 0.699 mg/g, 0.826 - 0.942 mg/g respectively when mussels were exposed to 12.7 microg/L and 63.5 microg/L Cu solutions. Statistically significant MTLP induction (p0.001) was observed under higher exposure level. MTLP contents in digestive glands increased with the exposure Cu concentration and body accumulation of metal. There is a significantly negative exponential rise relationship (p0.000 1) between MTLP and Cu concentrations accumulated in the digestive glands of mussels.