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The “signatures” of rare earth elements (REEs) in fossil bones are used as proxies for provenance, taphonomy, and palaeoenvironment evaluations. However, measuring the content of REEs requires several steps, which is highly time-consuming. An online detection approach involving sequential leaching with mass spectrometry was developed to quantify REEs in dinosaur (Yimenosaurus species) bone. Five fractions of REEs (water-soluble, exchangeable, reducible, oxidizable, and crystalline) could be detected sequentially within 1 h and consume only 1 mg of sample. Most importantly, compared with traditional methods, our method was more accurate, faster (1 h), consumed less sample (1 mg), and could provide more information regarding the spatial distribution of REEs. Our method allowed rapid analyses of REEs in different phases and had good sensitivity and accuracy.

Remote sensing satellites are playing very important roles in diverse earth observation fields. However, long revisit period, high cost and dense cloud cover have been the main limitations of satel...

Despite growing work on the positive outcomes resulting from ambidextrous leadership, limited research has examined whether ambidextrous leadership always has desirable consequences on followers. In order to achieve explorative and exploitative innovation, ambidextrous leaders are required to perform two styles of leadership behaviors, namely opening and closing leadership behaviors. The present study argues that as followers are reliant on their leaders to provide them with information and clarification about the tasks, by engaging in ambidextrous leadership behaviors to try and foster innovative behaviors amongst their followers, the leader may unintendedly increase the follower’s job stress and role ambiguity. Drawing on a sample of 416 leader–follower dyads, we established that while ambidextrous leadership contributes to the innovative behaviors of followers, it also increases followers’ job stress and role ambiguity, which subsequently reduces innovative behaviors. The results suggest that ambidextrous leadership has two faces, enabling and burdening, which can both enhance and stifle innovative behaviors.

Inverted top-emitting organic light-emitting devices (TEOLEDs) have great potential in flat-panel displays and lighting, yet poor electron injection is a key issue limiting its use in active-matrix OLED. Here, a high-performance green phosphorescent inverted TEOLEDs with ZnO and ZnS double electron injection layers (EILs) were demonstrated. The double EILs which provide a work function gradient can greatly enhance the electron-injection efficiency. For the green phosphorescent TEOLED device based on this double EILs, a high current efficiency of 33.1 cd A−1 is achieved with low turn-on voltage of 4.0 V. Results indicate that a novel pathway of electron transport to accelerate electron injection is created by applying this double EILs.

The development of white organic light-emitting diodes (WOLEDs) holds great promise for the production of high-color-quality lighting sources. High quantum efficiencies for the conversion of electrical energy to light have been realized. The color stability and color-rendering index (CRI) become bottleneck for the commercial application of WOLEDs. Here, we employed a metal-free dimerization of 1‑phenyl‑3,5‑diamine‑triazine (DPDT) as a single non-doped emitter in WOLEDs, that exhibits mild efficiency roll-off while maintaining CRI of 92. This high CRI is attributable to the DPDT with efficient monomer and excimer emission, which together emit a relatively wide spectrum that nearly covers the entire range of visible light. The formation of the excimer can make the emission color of single-emitter based WOLEDs tunable with the applied bias over a wide range from blue to pure white.

More than 200 toxic substances (including narcotic drugs, psychotropic drugs, organic phosphorus compounds, carbamates, pyrethroids and other pesticides, veterinary drugs, rodenticides, natural toxins, and other drugs) were identified and quantified using an ion-trap mass spectrometer. The advantages of this technique-its selectivity, accuracy, precision, utilization of only small amounts of the sample, and short analysis time for a single sample (less than 30s)-render it a rapid and accurate methodology for toxin screening. Subsequently, an extractive electrospray ionization (EESI) mass spectrometry database was established by combining the Xcalibur data processing system with NIST database software. This allowed unknown toxicants in urine and blood samples, stomach contents, and liver samples, as provided by the Jiangxi Provincial Public Security Department, to be analyzed and identified. This EESI methodology and databank has the potential for widespread application to the large-scale analysis of practical samples. Graphical abstract ᅟ.

The electron-injecting layer (EIL) is one of the key factors in inverted organic light-emitting diodes (OLEDs) to realize high electroluminescence efficiency. Here, we proposed a novel cathode-modified EIL based on ZnS quantum dots (QDs) in inverted OLEDs, and demonstrated that the device performance was dramatically improved compared to traditional ZnO EIL. The EIL of ZnS QDs may greatly promote the electron injection ability and consequently increase the charge carrier recombination efficiency for the device. We also investigated the effects of different pH values (ZnS-A, pH = 10; ZnS-B, pH = 12) on the properties of ZnS QDs. The best inverted phosphorescent OLED device employing mCP:Ir(ppy)3 as the emission layer showed a low turn-on voltage of 2.9 V and maximum current efficiency of 61.5 cd A−1. Also, the ZnS-A based device exhibits very-low efficiency roll-off of 0.9% and 4.3% at 1000 cd m−2 and 5000 cd m−2, respectively. Our results indicate that use of ZnS QDs is a promising strategy to increase the performance in inverted OLEDs.

A novel host material featuring the characteristics of bipolarity and thermally activated delayed fluorescence, 10-(4-(5,5-dimethylbenzofuro[3,2-c]acridin-13(5H)-yl)phenyl)-10-phenylanthracen-9(10H)-one (DphAn-5BzAc), has been designed and synthesized. By employing this material as the host of green emitter Ir(ppy)2acac, we have fabricated phosphorescent organic light-emitting diodes (PhOLEDs) with two hosting schemes, which are the single host system consisting of DhAn-5BzAc and the co-host system with 1,3-bis(carbazolyl)benzene (mCP). We found that the co-host based PhOLED achieved very low energy consumption values at high brightnesses, which were only 0.5, 5.9 and 94.0 mW m−2 at 100, 1000 and 10 000 cd m−2, respectively. The extremely low energy consumption for DhAn-based PhOLEDs were attributed to the excellent bipolar transport properties and thermally activated delayed fluorescence characteristics.

In this work, we investigated the light-soaking effect in inverted polymer solar cells (PSCs) employing ZnO as an electron extraction layer (EEL) and demonstrated highly efficient light-soaking-free PSCs with a LiF modified ZnO (ZnO:LiF) EEL. A blend of poly(3-hexylthiophene-2,5-diyl) (P3HT):[6,6]-phenyl-C61-butyric acid methyl ester (PC61BM) was applied as the active layer. The PSCs fabricated with the LiF doped ZnO EEL showed a 21.2% increase in power conversion efficiency (PCE) from 3.35% to 4.06% as compared with the pristine ZnO-based devices. In contrast to the devices with a lithium chloride (LiCl) or lithium bromide (LiBr) modified ZnO EEL, the ZnO:LiF-based PSC devices show excellent light-soaking-free characteristics with high fill factor (FF) and short circuit current density (Jsc). More importantly, the photovoltaic devices employing a poly[4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)-benzo[1,2-b:4,5-b′]dithiophene-alt-3-fluorothieno[3,4-b]thiophene-2-carboxylate] (PTB7-Th) and [6,6]-phenyl C71-butyric acid methyl ester (PC71BM) blend system as the active layer have been also fabricated, which achieved a high PCE of 8.85%. Our results indicate that the inclusion of additional LiF made for reduced oxygen vacancy defects at the metal-oxide/organic interface, which were confirmed by X-ray photoelectron spectroscopy and charge extraction analysis. It is shown that LiF modified ZnO as an efficient and cost-effective EEL material has the potential to open a new avenue for high performance optoelectronic devices.

There is broad consensus that many bones of extinct vertebrates contain Rare Earth Elements (REE) and other trace minerals that have been incorporated and enriched into the fossil during diagenesis. During fossilization, apatite minerals in vertebrate bones recrystallize from metastable biogenic forms to thermodynamically more stable inorganic apatite minerals while incorporating REEs from their environment. More than ∼95% of the REE in fossil bones are diagenetically incorporated post-mortem, and bones in different environments have different and distinct REE signatures, generally viewed to be controlled by sedimentological and taphonomic processes. The REE pattern in fossils is generally stable, and the normalized concentration patterns provide unique “fingerprints” or signatures that have been used for various geological and paleontological investigations. The discovery of embryos and their adults at the same site, a previously unrecorded occurrence in the fossil record, allowed us to compare for the first time the relationship between REE concentrations in the same taxon at widely differing ontogenetic stages. Here we compare REE patterns in bones from two distinct sites in Yunnan, China, both preserving embryonic and adult bones of Early Jurassic Sauropodomorpha dinosaurs. These dinosaurs are closely related to each other and close in geological age, and their bones show very similar REE patterns. However, the embryonic bones have significantly lower levels of total REEs when compared to their adult counterparts. We attribute the 10-fold La_REE difference and U concentration 5/1 ratio to the level of ossification of the bones and the dramatically lower concentration of apatites in the embryonic than in the adult bones. We conclude that the ontogenetic stage of fossil materials can have a significant impact on REE concentrations, and discuss the impact of these results on future work.

Summary The design of blue fluorescent materials combining both deep-blue emission (CIEy, Graphical Abstract, Highlights • Highly efficient deep-blue luminogens BBPA and DMPA are synthesized • Low-efficiency roll-off deep-blue OLEDs with CIE coordinate Y < 0.06 • Record-high external quantum efficiency of 10.27% for deep-blue fluorescent OLEDs • Host matrix of twisted structure showing steric effect reduces intermolecular aggregation, Materials Science; Polymers; Optical Materials

We develop a novel two-photon ratiometric fluorescent probe based on the conjugation of the specific recognition moiety of the γ-glutamyl group to 6-acetyl-2-aminonaphthalene, which enables highly sensitive, selective monitoring of γ-glutamyltransferase activities in human serum and imaging in living cells and cancer tissues down to a depth of 120 μm.

Three novel host materials, IpCm-PhBzAc (1,3-(4-(12,12-dimethylbenzofuro[3,2-b]acridin-7(12H)-yl)phenyl)-6-isopropyl-4H-chromen-4-one), DpAn-BzAc (2,10-(4-(12,12-dimethylbenzofuro[3,2-b]acridin-7(12H)-yl)phenyl)-10-phenylanthracen-9(10H)-one) and DpTrz-BphBzAc (3,7-(4′-(4,6-diphenyl-1,3,5-triazin-2-yl)-[1,1′-biphenyl]-4-yl)-12,12-dimethyl-7,12-dihydrobenzofuro[3,2-b]acridine) have been designed and synthesized, and their utilization as host materials for phosphorescent organic light-emitting diodes (PhOLEDs) has been investigated. We have fabricated PhOLEDs using green bis(2-phenylpyridine)iridium(III) acetylacetonate as doped emitters and two hosting schemes, which are the single host system consisting of BzAc derivatives and the co-host system with 1,3-bis(carbazolyl)benzene. We found that the PhOLEDs with the co-host system of DpAn-BzAc and DpTrz-BphBzAc achieved CEs of 57.1 cd A−1 and 53.0 cd A−1, with corresponding efficiency roll-off of only 7.6% and 0.9%, respectively, from the maximum to the practical brightness of 5000 cd m−2. Extremely reduced efficiency roll-off values for BzAc-based PhOLEDs were attributed to their superior thermal stability and excellent bipolar transport properties, and a small singlet–triplet energy gap also afforded efficient reverse intersystem crossing, thus reducing the triplet density of the host for PhOLEDs.

Botrytis cinerea is the causative agent of a common and serious disease, gray mold of tomato, which can infect the flower, fruit, leaf, and stem tissues. The occurrence of gray mold account for dramatic decrease of tomato yield, threatening the food security, with rarely effective biocontrol approach. In this study, we isolated 56 bacterial strains from tomato rhizosphere, with 7 strains among which had great control effect against B. cinerea. Among the 7 identified strains, Pantoea jilinensis D25 which had the strongest inhibitory effect, was a new strain. Further we found that P. jilinensis D25 can inhibit the mycelial growth and spore production of B. cinerea, with alterations of the mycelial morphology of B. cinerea. The highest growth inhibition (83.1%) of B. cinerea occurred upon the exposure to a concentration of 5.0×105 cfu/mL of P. jilinensis D25, at pH 6 and 25 °C. The inhibitory effect against B. cinerea by P. jilinensis D25 was further validated with inoculation assay on tomato leaf tissues and tomato seedlings. The results demonstrated that P. jilinensis D25 strain from soils of tomato growing areas is a new and effective biocontrol agent against notorious tomato gray mold disease.

We report an electrically controlled micro-flow of liquid on Au-patterned glass surfaces with a driving voltage lower than 10 volts. The Joule heating produced by electrical current passing through the Au layer activates the selective wetting of liquids, performing complicated micro-flow control over pre-designed circuits. Transportation and serial dilution of the dye molecules in the liquid are further demonstrated.

We have developed a novel organic–inorganic hybrid color conversion electrode composed of Ag NWs/poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV) via a solution process, which is the first report on a color conversion electrode for applications in flexible optoelectronics. Using the Ag NWs/MEH-PPV composite film as the anode on polyethylene terephthalate substrate and combined with a blue organic light emitting devices (OLEDs) unit employing bis(3,5-difluoro-2-(2-pyridyl)phenyl-(2-carboxypyridyl)iridium(III)) (Flrpic) in 1,3-bis(carbazol-9-yl)benzene (mCP) as the emitting layer, a highly efficient and chromaticity-stable color-conversion flexible white OLEDs (WOLEDs) is achieved with a maximum current efficiency of 20.5 cd A−1. To the best of our knowledge, this is the highest efficiency reported for color-conversion based flexible WOLEDs. Our work provides an approach to achieving high-performance flexible WOLEDs devices and demonstrates great potential for lighting and display applications.

A novel one-step synthesis of PMDA–ODA polyimide at ambient temperature was reported for the first time, in which a polyimidization reaction was rapidly accomplished in 99% yield in an imidazolium-based ionic liquid containing a non-nucleophilic base. The base–ionic liquid medium showed good reusability. The high molecular weight product could be isolated by direct filtration.

International audience; Flexible conductive electrodes are essential components for organic optoelectronic devices (OODs). One of the main challenges in the development of flexible OODs is to achieve an optimal combination of photoelectrical properties, enhanced flexibility and stability in transparent conductive electrodes (TCEs). In this work, high-performance flexible nonfullerene organic solar cells (OSCs) and polymer light-emitting diodes (PLEDs) based on TCEs of silver nanowires (AgNWs) encapsulated with an ultra-thin atomic layer deposited aluminum oxide (Al 2 O 3) have been demonstrated. The hybrid AgNWs/Al 2 O 3 composite electrodes with enhanced thermal, ambient and mechanical stabilities enable an efficient flexible transparent electrode with high transmittance and conductivity, which can synergistically optimize the device performance of nonfullerene OSCs and PLEDs. The maximum power conversion efficiency value of 7.03%, as well as a current efficiency of 7.26 cd A À 1 for flexible OSCs and PLEDs are achieved, respectively. Notably, excellent flexibility, long-term atmospheric and thermal stabilities have been systematically investigated and demonstrated. These results provide a new design platform for the fabrication of high-performance, flexible transparent electrodes, which can be further explored in a wide range of organic optoelectronics field.

Correction for ‘Cryptand-imidazolium supported total synthesis of the lasso peptide BI-32169 and its d-enantiomer’ by Ming Chen et al., Chem. Commun., 2019, 55, 3323–3326, DOI: 10.1039/C8CC10301A.

Blue organic light-emitting diodes (OLEDs) play an important role in OLED display and lighting applications, but short lifetime and low efficiency are still their two key issues in the commercialization. Here, we manage to address the two issues at the same time by simply inserting an ultrathin aluminum (Al) interlayer between the indium tin oxide (ITO) cathode and the electron injection layer of an inverted pure blue OLED. Current efficiency (CE) and external quantum efficiency were improved by optimizing the thickness of the Al interlayer. It has been approved from current-voltage characteristics, impedance spectra and an ultraviolet photoelectron spectrum that 1 nm thick Al interlayer is an effective work function modifier for the ITO cathode and can help to enhance electron injection from the ITO cathode to the electron transporting layer. The Al interlayer contributed also to extend dramatically the lifetime of the inverted pure blue OLED. A long operation lifetime (T80 > 83 h) with the maximum CE of 7.9 cd A−1 was achieved after adding 1 nm Al interlayer.

A disposable blood sampler, which is consisted of a sub-microliter whole blood collector and a graphene filter, loading graphene sheet to selectively capture hemoglobin from sub-microliter whole blood, was developed for both qualitative and quantitative characterization hemoglobin by internal extractive electrospray ionization mass spectrometry (iEESI-MS). The blood collector was elegantly fabricated in syringe-like fashion for precisely sampling tiny amounts (1.0 μL - 2%) of whole blood, which was immediately diluted by water inside the syringe and was then pressed through the graphene filter placed between the waste outlet and the syringe reservoir to capture the hemoglobin in the blood sample. Then the graphene with hemoglobin was directly eluted by a charged (+2.5 kV) solution (mathanol/water/formic acid, 48/48/4, v/v/v) to produce the hemoglobin ions for mass spectrometric analysis. Low detection-of-limit (19.3 mg L−1 (89.5 picomol)), acceptable linear response range (300–1500 mg L−1, R2 = 0.998), relative standard deviation (0.5–6.5%, n = 3), low sample consumption (≤1.0 μL) and a relatively high speed (≤4 min per sample, including the sample loading) were achieved, demonstrating that the graphene based iEESI-MS was an alternative choice for direct detection of hemoglobin in whole blood with minimal sample consumption.

The electron extraction layer (EEL) plays a pivotal role in realizing high performance organic photovoltaics (OPVs). In this work, we report the effort to develop high-efficiency inverted OPVs with solution-processed ZnO/MoS2 quantum dots (QDs) EEL. The employ of MoS2 QDs helps to suppress the exciton quenching by passivating the ZnO surface defects. It is shown that ZnO/MoS2 EEL enables promoted electron extraction and suppressed charge recombination properties. A blend of poly(3-hexylthiophene-2,5-diyl) (P3HT):[6,6]-phenyl-C61-butyric acid methyl ester (PC61BM) was applied as the active layer. The ZnO/MoS2-based OPVs demonstrate superior photovoltaic performance with a champion power conversion efficiency (PCE) of 3.83%, which is >17.5% higher than that of the pristine ZnO-based device (~3.26%). It is shown that the use of a blend ZnO/MoS2 QDs EEL offers an effective approach to obtain high performance optoelectronic devices.

In this work, an atomic layer deposited (ALD) Al

Nano-silica was introduced to enhance the mechanical strength of polymer hydrogels obtained via the crosslinking of polyacrylamide (PAM) and chromium acetate. Rheological properties, compression strength and compressive stress–strain of both nanocomposite and normal hydrogels without nano-silica were investigated by HAKKE rheometer, compression strength test device and electronic universal material testing machine. Moreover, environmental scanning electronic microscopic (ESEM) was adopted to observe the three-dimension network structure of nanocomposite and normal hydrogel, as well as the distribution of nano-silica. The results demonstrated that elastic moduli (G′) and viscous moduli (G″) of nanocomposite hydrogel were both improved with increasing nano-silica concentration. Especially when silica content reached 10 wt%, G′ and G″ of nanocomposite hydrogel increased over one hundred times higher than those of normal hydrogel. The original compression strength of hydrogel was 70.8 kPa m−1, while the resulting strength of nanocomposite was enhanced to be 196.64 kPa m−1. When the hydrogel were sheared, the normal hydrogel was fractured under low strain, whereas nanocomposite hydrogel was not broken under high strain, and it quickly recovered its original shape after the release of load. In addition, the ESEM images indicated that a large quantity of silica particles aggregated and attached around the polymer chains, and others aggregated to fill into the three-dimension network of hydrogel, which induced the compaction of the space between the network layers and reduced the flowing of free water wrapped in the network, therefore the mechanical strength of hydrogel was enhanced.

Urchin-shaped Nb 2 O 5 microspheres have been synthesized through the facile hydrothermal method. Nb 2 O 5 microspheres, wrapped tightly by filaments about 10 nm in diameter and 1.5 μm in length, are about 0.8 μm in diameter. The initial discharge and charge capacities for Nb 2 O 5 microspheres are 480.43 mA h g −1 and 406.80 mA h g −1 at 50 mA g −1 , meanwhile it exhibits the capacity retention of 390.0 mA h g −1 after 200 cycles. The urchin-shaped Nb 2 O 5 microspheres are a potential anode material for lithium ion batteries.

We consider a risk sharing problem in which agents pool their random costs together and seek an allocation rule to redistribute the risk back to each agent. The problem is put into a cooperative game framework and we focus on two salient properties of an allocation rule: stability and monotonicity employing concepts of core and population monotonicity from cooperative game theory. When the risks of the agents are measured by coherent risk measures, we construct a risk allocation rule based on duality theory and establish its stability. When restricting the risk measures to the class of distortion risk measures, the duality-based risk allocation rule is population monotonic if the random costs are independent and log-concave. For the case with dependent normally distributed random costs, a simple condition on the dependence structure is identified to ensure the monotonicity property.

To solve the trajectory control problem of vehicular missile virtual mark ,we design a kind of stepping motor control system based on single chip microcomputer, according to the generation principle of missile control instruction, single chip microcomputer generates longitudinal direction and horizontal direction control signal, realizes simulation of missile flight trajectory on the graphic. This design adopts to 8051 single chip microcomputer, study and explore missile trajectory operation rule, and combine with control theory, establish stepper motor control system based on single-chip, design hardware and software structure, simulate actual missile trajectory, finally realizes a vehicle-mounted striker anti-tank missile training simulation system of trajectory control.

Congenital heart disease (CHD) seriously threatens fetal health. Therefore, prenatal examination to detect deformity is extremely important. The present study aimed to investigate the clinical application value of prenatal ultrasonography combined with molecular biology methods in the diagnosis of fetal CHD. A total of 1,000 pregnant women who had received fetal ultrasonography to examine fetal CHD were enrolled. Ultrasounds were performed for fetal heart examination and diagnosis, mainly on fetal heart position, size, structure and function, and heart valve morphology and function. These indexes were tested again 2 weeks after birth. Blood samples were collected from pregnant women with fetal CHD. Polymerase chain reaction (PCR) and western blotting were performed to detect the association between heart development and T‑box transcription factor 1 (TBX1) expression. The results revealed that 10 fetuses had CHD (1%), of which ultrasound detected 9 cases. The specificity and sensitivity of ultrasounds were 100 and 90%, respectively. Of the 9 cases were identified by prenatal ultrasound screening, including 2 cases had endocardial cushion defect, 1 case had pulmonary stenosis combined with right ventricular dysplasia, 1 case had tetralogy of Fallot combined with a cleft lip and palate, 2 cases had ventricular septal defect, 1 case had a single ventricle defect, 1 case had Ebstein and 1 case had a triatrial heart. One case of ventricular septal defect was missed prior to delivery. PCR and western blotting demonstrated that TBX1 expression may be associated with CHD. Therefore, ultrasonography combined with laboratory examinations represent efficient, economic and safe methods for fetal CHD detection. These methods may be significant to improve the rate of CHD diagnosis, and require further investigation.

We have systematically investigated hole/electron distribution and exciton dynamics in blue fluorescent and yellow phosphorescent organic light-emitting diodes (OLEDs). We demonstrate that the importance of appropriate charge carrier confinement and exciton management for the realization of highly efficient and stable OLEDs. For yellow phosphorescent device based on Ir(MePQ)2(acac), we have studied the behavior of various intrinsic emission zones on the characteristics of OLEDs with the hole/electron-transporting matrix. The current efficiency increases from 15.7 to 31.7 cd A−1 with the rise in electron-transporting matrix from 20 to 80 nm. We attributed the improved performance to the strong hole-transfer capabilities and relatively weak electron-donating abilities of Ir-complex doped transporting matrix. In contrast, the efficiencies of blue devices decreased with increasing emitting layer (EML), suggesting that the rate of hole-electron pair recombination continuously decrease with the increasing EML thickness due to blue fluorescent dopant hindering hole transfer. In addition, the complementary-color white OLEDs (WOLEDs) with various EML thickness were also demonstrated. Based on their performance, we have found that the use of thin EML in WOLEDs can significantly improve optoelectronic conversion efficiency, whereas deteriorated device properties reversely.