Study on the Photocatalytic Properties of Metal-Organic Framework-Derived C-, N-Co-Doped ZnO.

In this study, C- and N-co-doped ZnO photocatalysts were prepared through pyrolysis using metal-organic frameworks (MOFs) as precursor materials. The crystal structure, morphology, and surface chemical composition of the samples were characterised via X-ray diffraction (XRD), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). Their activities in photocatalytic reactions were also evaluated through photocatalytic experiments. The results show that C-, N-co-doped ZnO has a high specific surface area, which is favourable for a photocatalytic reaction. Meanwhile, C-, N-doping can effectively modulate the energy band structure of ZnO, broaden its light absorption range, and improve the separation efficiency of photogenerated electron-hole pairs. The photocatalytic experiments show that the C/N-ZnO-500 samples, which have the optimal photocatalytic performances, have improved performances of 50% and 35%, respectively, compared with those of the blank control group and the ZIF-8 samples. The preparation of ZnO materials with a morphology change and doping using metal frameworks as precursors provides a new idea for designing efficient photocatalysts.

Dual-coupling effect enables a high-performance self-powered UV photodetector.

Self-powered ultraviolet photodetectors generally operate by utilizing the built-in electric field within heterojunctions or Schottky junctions. However, the effectiveness of self-powered detection is severely limited by the weak built-in electric field. Hence, advances in modulating the built-in electric field within heterojunctions are crucial for performance breakthroughs. Here, we suggest a method to enhance the built-in electric field by taking advantage of the dual-coupling effect between heterojunction and the self-polarization field of ferroelectrics. Under zero bias, the fabricated AgNWs/TiO2/PZT/GaN device achieves a responsivity of 184.31 mA/W and a specific detectivity of 1.7 × 1013 Jones, with an on/off ratio of 8.2 × 106 and rise/decay times reaching 0.16 ms/0.98 ms, respectively. The outstanding properties are primarily attributed to the substantial self-polarization of PZT induced by the p-GaN and the subsequent enhancement of the built-in electric field of the TiO2/PZT heterojunction. Under UV illumination, the dual coupling of the enhanced heterojunction and the self-polarizing field synergistically boost the photo-generated carrier separation and transport, leading to breakthroughs in ferroelectric-based self-powered photodetectors.

Large-scale snake genome analyses provide insights into vertebrate development.

Snakes are a remarkable squamate lineage with unique morphological adaptations, especially those related to the evolution of vertebrate skeletons, organs, and sensory systems. To clarify the genetic underpinnings of snake phenotypes, we assembled and analyzed 14 de novo genomes from 12 snake families. We also investigated the genetic basis of the morphological characteristics of snakes using functional experiments. We identified genes, regulatory elements, and structural variations that have potentially contributed to the evolution of limb loss, an elongated body plan, asymmetrical lungs, sensory systems, and digestive adaptations in snakes. We identified some of the genes and regulatory elements that might have shaped the evolution of vision, the skeletal system and diet in blind snakes, and thermoreception in infrared-sensitive snakes. Our study provides insights into the evolution and development of snakes and vertebrates.

DNA barcoding of Chinese snakes reveals hidden diversity and conservation needs.

DNA barcoding has greatly facilitated studies of taxonomy, biodiversity, biological conservation, and ecology. Here, we establish a reliable DNA barcoding library for Chinese snakes, unveiling hidden diversity with implications for taxonomy, and provide a standardized tool for conservation management. Our comprehensive study includes 1638 cytochrome c oxidase subunit I (COI) sequences from Chinese snakes that correspond to 17 families, 65 genera, 228 named species (80.6% of named species) and 36 candidate species. A barcode gap analysis reveals gaps, where all nearest neighbour distances exceed maximum intraspecific distances, in 217 named species and all candidate species. Three species-delimitation methods (ABGD, sGMYC, and sPTP) recover 320 operational taxonomic units (OTUs), of which 192 OTUs correspond to named and candidate species. Twenty-eight other named species share OTUs, such as Azemiops feae and A. kharini, Gloydius halys, G. shedaoensis, and G. intermedius, and Bungarus multicinctus and B. candidus, representing inconsistencies most probably caused by imperfect taxonomy, recent and rapid speciation, weak taxonomic signal, introgressive hybridization, and/or inadequate phylogenetic signal. In contrast, 43 species and candidate species assign to two or more OTUs due to having large intraspecific distances. If most OTUs detected in this study reflect valid species, including the 36 candidate species, then 30% more species would exist than are currently recognized. Several OTU divergences associate with known biogeographic barriers, such as the Taiwan Strait. In addition to facilitating future studies, this reliable and relatively comprehensive reference database will play an important role in the future monitoring, conservation, and management of Chinese snakes.

Genomic evidence reveals intraspecific divergence of the hot-spring snake (Thermophis baileyi), an endangered reptile endemic to the Qinghai-Tibet plateau.

Understanding how and why species evolve requires knowledge on intraspecific divergence. In this study, we examined intraspecific divergence in the endangered hot-spring snake (Thermophis baileyi), an endemic species on the Qinghai-Tibet Plateau (QTP). Whole-genome resequencing of 58 sampled individuals from 15 populations was performed to identify the drivers of intraspecific divergence and explore the potential roles of genes under selection. Our analyses resolved three groups, with major intergroup admixture occurring in regions of group contact. Divergence probably occurred during the Pleistocene as a result of glacial climatic oscillations, Yadong-Gulu rift, and geothermal fields differentiation, while complex gene flow between group pairs reflected a unique intraspecific divergence pattern on the QTP. Intergroup fixed loci involved selected genes functionally related to divergence and local adaptation, especially adaptation to hot spring microenvironments in different geothermal fields. Analysis of structural variants, genetic diversity, inbreeding, and genetic load indicated that the hot-spring snake population has declined to a low level with decreased diversity, which is important for the conservation management of this endangered species. Our study demonstrated that the integration of demographic history, gene flow, genomic divergence genes, and other information is necessary to distinguish the evolutionary processes involved in speciation.

Field test study on the evaluation of the microvibration controlling capacity of a mass concrete layer.

Microvibration induced by natural disturbance and human activities has an adverse effect on the operation of the large-scale and ultraprecise facilities in the world. Under such circumstances, a passive vibration control method is generally deployed for such vibration-sensitive facilities, taking the High Energy Photo Source (HEPS) in Beijing as an example, a 3 m-thick mass concrete layer forming a ring foundation was cast at the facility, where a 1 m-thick reinforced concrete slab (RC slab) lies. Since microvibration control plays a crucial role in the operation of such large-scale scientific and ultraprecise facilities and few studies have been reported for large-scale concrete layer as antimicrovibration devices, this paper presents four field tests in Beijing, China, to evaluate the vibration control capacity of a mass concrete layer. Based on a large number of field tests, the effect of applying the concrete layer is discussed, and a reference is provided for the construction of similar facilities. The vibration signals, generated by shock excitation and ambient excitation, are measured through a highly sensitive and high-accuracy vibration acquisition system. It is concluded that the existence of the 1 m-thick RC slab has little influence on the microvibration signal frequency distribution in the vertical direction and that the signals from the concrete layer and subsoil differ by approximately 10 Hz in the vertical direction while differing by approximately 5 Hz in the horizontal direction. The microvibration control ability of the concrete layer is favorable in a higher frequency band over 20 ~ 30 Hz and more than 50% attenuation can be gained through the concrete layer; however, the microvibration control ability is not significant below 20 ~ 30 Hz. The vibration levels across different heights of the concrete layer section are the same. To prevent adverse vibration disturbance below 20 ~ 30 Hz, it is suggested that the traffic and road surface conditions should be taken into consideration when choosing the construction location. In addition, a long-term monitoring shows that 75% vibration energy at the site is firmly related to the construction activities which are approximately 1.4 km from the site.

New snakeflies of the genus Mongoloraphidia H. Aspck amp; U. Aspck, 1968 (Raphidioptera: Raphidiidae) from Xinjiang, China.

The raphidiopteran fauna of Xinjiang in northwestern China is poorly known, although it is near Central Asia where the diversity of this group is high. Herein we report a new species and a new Chinese record of the raphidiid genus Mongoloraphidia H. Aspck U. Aspck, 1968 from Xinjiang, namely Mongoloraphidia xinjiangana sp. nov. and Mongoloraphidia (Mongoloraphidia) kaszabi (H. Aspck U. Aspck, 1967), respectively. A key to the identification of the Mongoloraphidia species from China is provided.

East palearctic treefrog past and present habitat suitability using ecological niche models.

Ecological niche modeling is a tool used to determine current potential species' distribution or habitat suitability models which can then be used to project suitable areas in time. Projections of suitability into past climates can identify locations of climate refugia, or areas with high climatic stability likely to contain the highest levels of genetic diversity and stable populations when climatic conditions are less suitable in other parts of the range. Modeling habitat suitability for closely related species in recent past can also reveal potential periods and regions of contact and possible admixture. In the east palearctic, there are five Dryophytes (Hylid treefrog) clades belonging to two groups: Dryophytes japonicus group: Clades A and B; and Dryophytes immaculatus group: Dryophytes immaculatus, Dryophytes flaviventris, and Dryophytes suweonensis. We used maximum entropy modeling to determine the suitable ranges of these five clades during the present and projected to the Last Glacial Maximum (LGM) and Last Interglacial (LIG) periods. We also calculated climatic stability for each clade to identify possible areas of climate refugia. Our models indicated suitable range expansion during the LGM for four clades with the exclusion of D. immaculatus. High climatic stability in our models corresponded to areas with the highest numbers of recorded occurrences in the present. The models produced here can additionally serve as baselines for models of suitability under climate change scenarios and indicate species ecological requirements.

Genomic adaptations for arboreal locomotion in Asian flying treefrogs.

SignificanceTo adapt to arboreal lifestyles, treefrogs have evolved a suite of complex traits that support vertical movement and gliding, thus presenting a unique case for studying the genetic basis for traits causally linked to vertical niche expansion. Here, based on two de novo-assembled Asian treefrog genomes, we determined that genes involved in limb development and keratin cytoskeleton likely played a role in the evolution of their climbing systems. Behavioral and morphological evaluation and time-ordered gene coexpression network analysis revealed the developmental patterns and regulatory pathways of the webbed feet used for gliding in Rhacophorus kio.

Transcriptome Analysis Reveals Olfactory System Expression Characteristics of Aquatic Snakes.

Animal olfactory systems evolved with changes in habitat to detect odor cues from the environment. The aquatic environment, as a unique habitat, poses a formidable challenge for olfactory perception in animals, since the higher density and viscosity of water. The olfactory system in snakes is highly specialized, thus providing the opportunity to explore the adaptive evolution of such systems to unique habitats. To date, however, few studies have explored the changes in gene expression features in the olfactory systems of aquatic snakes. In this study, we carried out RNA sequencing of 26 olfactory tissue samples (vomeronasal organ and olfactory bulb) from two aquatic and two non-aquatic snake species to explore gene expression changes under the aquatic environment. Weighted gene co-expression network analysis showed significant differences in gene expression profiles between aquatic and non-aquatic habitats. The main olfactory systems of the aquatic and non-aquatic snakes were regulated by different genes. Among these genes, RELN may contribute to exploring gene expression changes under the aquatic environment by regulating the formation of inhibitory neurons in the granular cell layer and increasing the separation of neuronal patterns to correctly identify complex chemical information. The high expression of TRPC2 and V2R family genes in the accessory olfactory systems of aquatic snakes should enhance their ability to bind water-soluble odor molecules, and thus obtain more information in hydrophytic habitats. This work provides an important foundation for exploring the olfactory adaptation of snakes in special habitats.

A new species of the Achalinus rufescens complex (Xenodermidae: Achalinus) from Fujian Province, China.

A new species of the xenodermid snake genus Achalinus Peters, 1869 is described from Fujian Province, China, based on six specimens. Bayesian inference and maximum likelihood analyses based on a mitochondrial DNA fragment (CO1) indicated the new taxon is different from its congeners (pdistance ≥ 18.5%). Morphologically, the new species can be diagnosed from the other species by a combination of following characters: (1) dorsal scales 23 rows throughout, strongly keeled, the most outer rows on both sides also keeled and slightly enlarged; (2) tail relatively longer, TaL/TL ratio 0.260.29 in males, 0.210.22 in females; (3) maxillary teeth 3033; (4) length of suture between internasals significantly longer than that between prefrontals; (5) nasal divided into two sections by nasal cleft; (6) a single loreal; (7) SPO 1, seldom 2; (8) SPL 6, the fourth and fifth contacting eye; (9) IFL5, rarely 6, the first three touching the first pair of chin shields; (10) TMP 79, arranged in three rows; (11) VS 142149 in males, VS 152154 in females; (12) SC 7481 in males, SC 6365 in females, arranged in a single row; (13) cloacal entire; (14) greyish brown above, pale yellow beneath; (15) dorsum with an indistinct longitudinal vertebral stripe. The description of the new species brings the total species of Achalinus to 19.

Taxonomic revision of Amolops chunganensis (Pope, 1929) (Amphibia: Anura) and description of a new species from southwestern China, with discussion on Amolops monticola group and assignment of species groups of the genus Amolops.

Amolops chunganensis is a species complex and reported widely from eastern, southern, and southwestern China. Based on molecular data of 19 populations of A. chunganensis sensu lato from China, including the population from Mt. Wuyi (type locality), we recognize A. chunganensis sensu stricto and provide an expanded description based on the topotypic specimens. Combining morphological and molecular data, we describe a new species, Amolops chaochin sp. nov., from southwestern China, which was previously identified as A. chunganensis. The new species is distinguished from all other species in the A. monticola group by: (1) moderate body size, SVL 35.3-39.2 mm in males (n=7), and 50.5-54.4 mm in females (n=7); (2) distinct tympanum, larger than half of eye diameter; (3) small tooth-like projection on anteromedial edge of mandible; (4) circummarginal groove on all fingers; (5) white tubercles on dorsal side of posterior body in both sexes; (6) distinct tubercles on dorsal thigh and white spinose tubercles on dorsal tibia in both sexes; (7) white tubercles on posterior region of tympanum in males; (8) toe webbing reaching disk by dermal fringe on inner side of toe II; (9) vomerine teeth present; (10) transverse bands on dorsal limbs; (11) external vocal sacs present in males. We further reviewed the assignment of Amolops groups, with an overall revision of membership and diagnosis of all species groups.

Review of the emGekko/em (emJaponigekko/em) emsubpalmatus/em complex (Squamata, Sauria, Gekkonidae), with description of a new species from China.

The gecko species Gekko (Japonigekko) subpalmatus was previously recorded with a relatively wide distribution from eastern, southern, and southeastern China. However, the populations in southern China are currently recognized as another valid species G. (J.) melli. In this study, we conduct a detailed morphological examination and phylogenetic analysis of the populations currently treated as G. (J.) subpalmatus or G. (J.) melli, which are collectively designated as the G. (J.) subpalmatus complex. Our results reveal that the G. (J.) subpalmatus complex comprises three evolutionarily independent taxa. The populations from Zhejiang, eastern China are G. (J.) subpalmatus, those from southern China are G. (J.) melli, while those from the Sichuan Basin, southwestern China represent a cryptic species, Gekko (Japonigekko) cib sp. nov.. Gekko (Japonigekko) cib sp. nov. can be distinguished from all congeners, by its divergence from other complex members in the CYTB and 16S genes, and a combination of morphological characteristics, especially in hemipenial morphology. Historic records of G. (J.) subpalmatus complex are also reviewed.

Two new species of Tipula (Vestiplex) Bezzi (Diptera, Tipulidae) from Northwest China.

Fourteen species/subspecies of the subgenus Tipula (Vestiplex) Bezzi (1924) were previously known to occur in the Northwest China. Here, four species are added to the fauna of this region. Among them T. (V.) quadricorna sp. nov. and T. (V.) shaanxiana sp. nov. are described and illustrated as new; T. (V.) coquillettiana Alexander, 1924 and T. (V.) scripta Meigen, 1830 are reported from China for the first time. Furthermore, we re-described and illustrated the T. (V.) kuwayamai Alexander, 1921 based on additional morphological characters. A key to the species of Tipula (Vestiplex) from Northwest China is presented.

Flexoelectricity Driven Fano Resonance in Slotted Carbon Nanotubes for Decoupled Multifunctional Sensing.

Multifunctionality, interference-free signal readout, and quantum effect are important considerations for flexible sensors equipped within a single unit towards further miniaturization. To address these criteria, we present the slotted carbon nanotube (CNT) junction features tunable Fano resonance driven by flexoelectricity, which could serve as an ideal multimodal sensory receptor. Based on extensive ab initio calculations, we find that the effective Fano factor can be used as a temperature-insensitive extrinsic variable for sensing the bending strain, and the Seebeck coefficient can be used as a strain-insensitive intrinsic variable for detecting temperature. Thus, this dual-parameter permits simultaneous sensing of temperature and strain without signal interference. We further demonstrate the applicability of this slotted junction to ultrasensitive chemical sensing which enables precise determination of donor-type, acceptor-type, and inert molecules. This is due to the enhancement or counterbalance between flexoelectric and chemical gating. Flexoelectric gating would preserve the electron-hole symmetry of the slotted junction whereas chemical gating would break it. As a proof-of-concept demonstration, the slotted CNT junction provides an excellent quantum platform for the development of multistimuli sensation in artificial intelligence at the molecular scale.

New insights on the systematics and reproductive behaviour in tree frogs of the genus Feihyla, with description of a new related genus from Asia (Anura, Rhacophoridae).

The taxonomy of the Asian tree frog genus Feihyla has been in a state of flux ever since its proposal in 2006. Allocation of species to Feihyla remains confusing, particularly with respect to the closely related genus Chirixalus (formerly Chiromantis sensu lato). At the same time, several Chirixalus species are known only from cursory descriptions and remain poorly studied. In this study, we review the systematics of the genus Feihyla and clarify the generic placement of its members along with all other species currently assigned to Chirixalus. Based on integrative evidence gathered from new collections, examination of types and original descriptions, morphological comparisons, phylogenetic relationships inferred from a multi-gene (three mitochondrial + two nuclear) 1,937 bp dataset, as well as reproductive modes including egg-laying, nesting behaviour, and clutch morphology, our results show that the six species formerly attributed to Feihyla represent three morphologically and phylogenetically distinct groups: (1) the type species of the genus, F. palpebralis, along with F. fuhua constitute the Feihyla palpebralis group or Feihyla sensu stricto; (2) F. inexpectata and F. kajau represent the Feihyla vittiger group and are closely related to the Feihyla palpebralis group; (3) 'F. hansenae' and 'F. vittata' constitute another distinct and reciprocally monophyletic lineage, more closely related to Chirixalus + Chiromantis. In light of long-standing taxonomic confusions and unresolved phylogenetic relationships, we propose recognition of a new genus to accommodate 'F. hansenae' and 'F. vittata' in order to stabilise the classification of several Asian rhacophorid species that have been frequently confused and transferred within the Chirixalus-Chiromantis-Feihyla complex. Based on integrative evidence, eight species previously attributed to the genus Chirixalus or Feihyla are formally transferred to Rohanixalus gen. nov., two Chirixalus members are allocated to Feihyla, and one synonymised with Rhacophorus bipunctatus. In addition, we report the first member of the tree frog family Rhacophoridae from the Andaman Islands of India-Rohanixalus vittatus, along with description of its male advertisement call, reproductive behaviour including parental care by the female, and larval morphology. Extended distributions are also provided for Rohanixalus species across Northeast India. The study further reveals the presence of potentially undescribed diversity in the new genus. Altogether, the revised classification and novel insights presented herein will facilitate a better working taxonomy for four phylogenetically distinct but morphologically related groups of Old World tree frogs.

New and little-known species of Tipula Linnaeus (Diptera, Tipulidae) from Laos, with a new synonym.

Only seven species of the genus Tipula Linnaeus were previously known to occur in Laos. Here one new species is added to the fauna of Laos, Tipula (Nippotipula) champasakensissp. nov. Tipula (unplaced) cladomera Alexander, 1936 is designated as a synonym of T. (unplaced) reposita Walker, 1848, syn. nov. A key to species of the genus Tipula from Laos is presented.

Two new species of Limonia Meigen, 1803 from Northwest China (Diptera, Limoniidae).

Two new species of Limonia Meigen, 1803, Limonia medexocha sp. nov. and Limonia subcosta sp. nov. are described and illustrated from Northwest China. The following five species are re-described and reported from China for the first time: L. macrostigma (Schummel, 1829), L. phragmitidis (Schrank, 1781), L. stigma (Meigen, 1818), L. sylvicola (Schummel, 1829) and L. taurica (Strobl, 1895). A key to adult males of Limonia from Northwest China is presented.