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During the operation of a permanent magnet synchronous motor, the electrical parameters of the motor will be affected by the temperature and the saturation of the magnetic chain, which will lead to a decrease in the effectiveness of the control algorithm for motor control. In this paper, we address the problem that the traditional MRAS algorithm has under-ranked equations when identifying motor parameters, and the three parameter identification values are coupled with each other and affect each other, which leads to scattered identification results and slow identification speed. In this paper, we propose a segmentation identification algorithm that combines the traditional MRAS algorithm with the recursive least squares method. In this paper, the inductance value is first identified by the recursive least squares method, and then the inductance value is substituted into the MRAS to identify the stator resistance and rotor magnetic chain, which effectively solves the problems of equation under-ranking and slow identification speed in the traditional MRAS, thus improving the stability of the permanent magnet synchronous motor operation.

In micro electro discharge machining (EDM), single pulse energy of pulsed power supply needs to be limited to a micro order of magnitude. One developing direction is to reduce the discharge pulse width for increasing discharging frequency. In order to research on micro EDM with nanometer gaps and nanometer removing units, a novel pulsed power supply with nanosecond pulse width was developed based on triode avalanche principle. The basic electric circuit with a steepening electric circuit was designed for the nanosecond pulse width. The test results show that the discharge pulses with an adjustable peak voltage and a pulse width down to 18 ns can be obtained. The developed pulsed power supply can output a single pulse and continuous pulses under high frequency.

Three novel tripodal bipolar compounds (CNTPA-CZ, CNTPA-PXZ and CNTPA-PTZ) were designed and synthesized, where three functional groups were attached to 1,3,5-positions of the central benzene ring, respectively. In these three compounds, carbazole/phenoxazine/phenothiazine (CZ/PXZ/PTZ) and benzonitrile were applied as electron-donating and electron-withdrawing groups, respectively, to achieve bipolar transport functionality, which was confirmed by the hole-only and electron-only device results. Due to the efficient energy transfer from these compounds to the dopant (Ir(MDQ)2(acac)), the red phosphorescent OLEDs demonstrated high device performance with maximum external quantum efficiency (EQE) over 20%. Particularly, the red OLED hosted by CNTPA-PTZ achieved a maximum efficiency of 42.5 cd/A, 44.3 lm/w and 23.4% with the EQE roll-off ratio of 3.4% from the peak value to that at a brightness of 500 cd/m2.

Exciplex-forming co-hosts have been reported to be a potentially suitable material for organic light-emitting diodes (OLEDs). However, they might not be able to provide optimal low voltage and maximal power efficiency (PE), when used in white organic light-emitting diodes (WOLEDs). Herein, a novel strategy using multi-exciplex-forming co-hosts (MEHs) is introduced to achieve enhanced efficiency and low operating voltage. To realize this strategy, a new tripodal bipolar compound CNTPA-DPA was synthesized and used as a co-host in the devices. As a result, the orange light-emitting component in WOLEDs provides 27% external quantum efficiency (EQE), 2.1 V turn-on voltage, and 115.5 lm W−1 PE, which are among the best values of orange color emission in OLEDs. And then this orange light emitting component was adopted in the MEH strategy to construct WOLEDs, achieving 19.5% EQE and 73 lm W−1 PE at the maximum, which are 45.7% and 19.6% higher than those using a single exciplex as the host, respectively. Moreover, the well-matched energy alignment endows the device with a very low operating voltage of 3.8 V at 1000 cd m−2. These results indicate that the performance of the exciplex-based WOLEDs can be remarkably enhanced by using the MEH strategy.

Azafluorenone was discovered decades ago and its derivatives have received widespread attention in various research fields. However, the application of azafluorenone and its derivatives in organic light-emitting diode (OLED) materials is rarely reported and the related device performance is still not satisfactory. In this work, 1,4-diazafluorenone and its two analogues were prepared as precursors and three novel spiro compounds, SAIP, SAIQ, and SABIQ, were synthesized. The basic physical and chemical properties of SAIP, SAIQ, and SABIQ were studied in detail. From SAIP to SAIQ and SABIQ, the triplet energies (ETs) and optical band gaps (Egs) decrease gradually with the extension of the intramolecular conjugation length. In addition, blue/green/red and green/red phosphorescent OLEDs (PHOLEDs) were fabricated with SAIP and SAIQ as host materials, respectively. It is worth noting that all green and red devices based on SAIP or SAIQ showed a relatively high device performance with maximum external quantum efficiencies (EQEs) of 17.8% and 21.4%, respectively. These results further show the high potential of azafluorenone and its analogues in the building of efficient host materials.

Deciphering the role of climatic oscillations in species divergence helps us understand the mechanisms that shape global biodiversity. The cold-adapted species may have expanded their distribution with the development of glaciers during glacial period. With the retreat of glaciers, these species were discontinuously distributed in the high-altitude mountains and isolated by geographical barriers. However, the study that focuses on the speciation process of cold-adapted species is scant. To fill this gap, we combined population genetic data and ecological niche models (ENMs) to explore divergence process of snow partridge (Lerwa lerwa). Lerwa lerwa is a cold-adapted bird that is distributed from 4,000 to 5,500 m. We found 2 genetic populations within L. lerwa, and they diverged from each other at about 0.40–0.44 million years ago (inter-glacial period after Zhongliangan glaciation). The ENMs suggested that L. lerwa expanded to the low elevations of the Himalayas and Hengduan mountains during glacial period, whereas it contracted to the high elevations, southern of Himalayas, and Hengduan mountains during inter-glacial periods. Effective population size trajectory also suggested that L. lerwa expanded its population size during the glacial period. Consistent with our expectation, the results support that inter-glacial isolation contributed to the divergence of cold-adapted L. lerwa on Qinghai-Tibetan Plateau. This study deepens our understanding of how climatic oscillations have driven divergence process of cold-adapted Phasianidae species distributed on mountains.

For the first time, we illuminate the complete mitochondrial genome (mitogenome) sequence of the Paradiplospinus antarcticus, which is 16,988 bp in size and contains 13 protein-coding (PCGs), 2 rRNA genes, 22 tRNA genes, and one control region.The base composition of the mitogenome is 26.08% A, 26.77% T, 28.46% C and 18.69% G. Here, we selected 11 genera of species from the mostly monotypic snake mackerel family, including representative Antarctic Paradiplospinus antarcticus that have been identified, and constructed phylogenetic trees to better study the snake mackerel family.

Although a number of inter-sensor comparisons have been conducted, no comparison between the SJ-9A, SPOT5, and THEOS sensors has been conducted. This study provides such a comparison, with the aim of evaluating the SJ-9A image quality. A synchronized satellite network technical system was proposed, and a comparison of SJ-9A, SPOT5, and THEOS based on synchronous data was successfully completed. Compared with previous methods, proposed method is an active mode for quality assessment and shown to be practical and operable. The study had two outcomes; first, a new comparison method for new sensor quality assessment was proposed and verified, and second, the new SJ-9A sensor was evaluated.

Four novel bipolar host materials, namely 9,9'-(4-(pyridin-2-yl)-1,3-phenylene)bis(9H-carbazole) ( 2CzPy ), 9,9'-(4-(pyridin-2-yl)-1,3-phenylene)bis(3,6-di- tert -butyl-9H-carbazole) ( 2TCzPy ), 5,5'-(4-(pyridin-2-yl)-1,3-phenylene)bis(5H-benzofuro[3,2- c ]carbazole) ( 2BFCzPy ) and 9′,9‴-(4-(pyridin-2-yl)-1,3-phenylene)bis(9-phenyl-9H,9′H-3,3′-bicarbazole) ( 2PBCzPy ) were designed and synthesized. Within each host material, one pyridine group serving as electron-transporting unit and two identical electron-donating groups serving as hole-transporting motifs were attached to the central benzene ring. These two donor units are located ortho and para to pyridine group, respectively. The four compounds showed excellent thermal stability with the glass-transition temperature up to 192 °C and decomposed temperature up to 571 °C. These hosts possessed triplet energies over 2.80 eV, indicating that they could be used as suitable hosts for blue phosphorescent organic light-emitting diodes (PHOLEDs). The bis[2-(4,6-difluorophenyl)-pyridinato-C2,N](picolinato)iridium(III) (FIrpic) based PHOLEDs hosted by 2CzPy and 2BFCzPy exhibited high device performance with maximum external quantum efficiencies (EQEs) of 17.8% and 17.4%, respectively. More importantly, 2CzPy exhibited a low efficiency roll-off at a brightness of 1000 cd m −2 with an external quantum efficiency of 17.1% (3.9% roll-off). The results demonstrate that 2CzPy could be a promising host for blue PHOLEDs.

Two novel heterofluorene motifs consisting of the group 14 elements Si and Ge were developed as robust molecular platforms for the construction of organic light-emitting diode (OLED) materials. These two compounds exhibited similar photophysical properties, thermal stabilities and electrochemical behaviors except for the charge transport abilities. The red OLED hosted by a 9-silafluorene derivative (DPS) with Ir(MDQ)2(acac) as the emitter exhibited state-of-the-art current efficiency, power efficiency, and external quantum efficiency (EQE) with maxima of 50.7 cd A−1, 44.7 lm W−1, and 28.3%, respectively. In addition, the maximum EQE of a 9-germafluorene derivative (DPG)-based red device could reach 20%. These results indicated the great potential of group 14 element derivatives in the construction of highly efficient OLED materials.

For the first time, we illuminate the complete mitochondrial genome (mitogenome) sequence of the Paradiplospinus antarcticus, which is 16,988 bp in size and contains 13 protein-coding (PCGs), 2 rRN...

Researchers have spared no effort to design new thermally activated delayed fluorescence (TADF) emitters for high-efficiency organic light-emitting diodes (OLEDs). However, efficient long-wavelength TADF emitters are rarely reported. Herein, a red TADF emitter, TPA-PZCN, is reported, which possesses a high photoluminescence quantum yield (ΦPL ) of 97% and a small singlet-triplet splitting (ΔEST ) of 0.13 eV. Based on the superior properties of TPA-PZCN, red, deep-red, and near-infrared (NIR) OLEDs are fabricated by utilizing different device structure strategies. The red devices obtain a remarkable maximum external quantum efficiency (EQE) of 27.4% and an electroluminescence (EL) peak at 628 nm with Commission Internationale de L'Eclairage (CIE) coordinates of (0.65, 0.35), which represents the best result with a peak wavelength longer than 600 nm among those of the reported red TADF devices. Furthermore, an exciplex-forming cohost strategy is adopted. The devices achieve a record EQE of 28.1% and a deep-red EL peak at 648 nm with the CIE coordinates of (0.66, 0.34). Last, nondoped devices exhibit 5.3% EQE and an NIR EL peak at 680 nm with the CIE coordinates of (0.69, 0.30).

The DC distribution network can integrate the photovoltaic power generation system with high efficiency, but the random fluctuation of the photovoltaic output power is strong and there is a problem of PV consumption, which has a certain degree of impact on the economic optimization operation of the system. Therefore, the source-network-load-storage optimization interaction concept is introduced in the DC distribution network. Based on the in-depth analysis of the interactive load characteristics, the interaction load and energy storage technology can be fully utilized to the system to consumpt the photovoltaic. Combined with the features of DC distribution network structure, comprehensively consider the impact of the interactive load and energy storage system collaborative optimization on the system operating cost and power flow distribution, so that both the power generation side and the power side can participate in the resource optimization configuration of the grid operation. A multiobjective optimal scheduling model for photovoltaic DC distribution networks with operational cost, network loss and voltage deviation is established. The simulation example shows that: Collaborative optimization using interactive load and energy storage system can greatly reduce system operating cost, network loss and voltage deviation, effectively improve the level of PV consumption, and realize safe and reliable operation of DC distribution network.

Nano electro discharge machining (nano EDM), as a frontier processing method in the research stage of exploration, has an important application prospect in the machining of metal and alloy materials for achieving nanoscale removal resolution. A pulsed power supply used in nano EDM is expected to limit a single pulse energy to nJ order of magnitude for improving the removal resolution of single pulsed discharge even to nanoscale. One developing direction is to decrease pulsewidth of the pulsed power supply. Conventional pulsed power supplies hardly output a single pulse and continuous pulses with nanosecond (ns) pulsewidth, resulting in too large single pulsed energy of μJ order of magnitude usually. In this research, a novel pulsed power supply is designed for realizing the ns-pulsewidth with controllable pulsewidth and peak voltage. The key novelty lies in a cascaded circuit with two triodes working in the state of ultra-fast avalanche conduction, where pF capacitors are applied to adjust the pulsewidth and pulsed energy precisely. Performance tests verified that a single pulse of 5 ns pulsewidth or continuous pulses up to 9 MHz can be outputted. Furthermore, nano EDM experiments of single pulsed discharge are carried out under the conditions of nanometer (nm) discharge gap and nm-tip tool electrode based on an atomic force microscope (AFM) system. The special results are achieved: a single pulsed energy can reach down to 1.75 nJ by outputting a pulsewidth of 10 ns, and a nano-EDM crater is only about 182 nm in diameter with regular shape and little recasting. Those results verify the possibility of AFM-tip-based nano EDM for machining nanostructures.

Associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) could induce extensive and rapid future liver remnant hypertrophy. However, the morbidity for ALPPS is very high. This paper reports a modified ALPPS (associating microwave ablation and portal vein ligation for staged hepatectomy, AMAPS), which was successfully applied in the treatment of huge hepatocellular carcinoma with cirrhosis, and the procedure of operation was greatly simplified. Hence, AMAPS is feasible and safe in selected patients with primary hepatocellular carcinoma and cirrhosis.

Up to date, several kinds of thermally activated delayed fluorescence (TADF) host molecules have been rapidly developed to fulfill the increasing demand of high-efficiency phosphorescent organic light-emitting diodes (PHOLEDs). Herein, three wide-bandgap TADF materials BPCN-Cz2Ph, BPCN-2Cz, and BPCN-3Cz are newly designed and synthesized as host materials for sky-blue PHOLEDs. By modulation of carbazole-units in the molecular skeleton, we find that the optimized molecules can realize both high triplet energies and balanced carrier transport properties with obvious TADF properties. The sky-blue PHOLEDs with ultralow phosphor doping ratio employing BPCN-Cz2Ph, BPCN-2Cz, and BPCN-3Cz as host materials demonstrate really high performance with alleviated roll-offs and achieve impressive current efficiencies (CEs) of 46.5 cd A−1, 50.0 cd A−1, and 34.5 cd A−1, power efficiencies (PEs) of 40.6 lm W−1, 46.8 lm W−1, and 34.8 lm W−1, and external quantum efficiencies (EQEs) of 22.2%, 24%, and 15.8%, respectively. More encouragingly, even at an applied luminance of 1000 cd m−2, the EQEs could maintain high levels of 21.0%, 21.5% and 12.8%, respectively, which represents the potential utility value of the new family of these molecules in blue PHOLEDs. Our molecular design strategy provides a practical way to construct promising wide-bandgap TADF host materials with an excellent combination of TADF property, high triplet energy, and balanced carrier-transporting ability for high-performance devices.

Background & objective The results of epidemiologic studies on the relationship between the coffee consumption and pancreatic cancer risk were inconsistent. Thus, we performed an update meta-analysis of cohort studies to quantitatively summarize the association between coffee consumption and pancreatic cancer risk. Methods We searched CBM (China Biology Medicine disc) and MEDLINE for studies of coffee consumption and pancreatic cancer risk up to June 2015. A total of 20 cohort studies were identified in this meta-analysis, and we analyzed these studies using random effects model. The dose-response analysis was conducted too. Results The overall relative risk (RR) for highest coffee consumption versus lowest coffee consumption was 0.75 (95% Confidence Interval (CI), 0.63-0.86). Statistic significant heterogeneity was found among these studies (I (2) =37.8%, P for heterogeneity =0.045). The pooled RR for increment of 1 cup/day of coffee consumption was 0.99 (95%CI, 0.96-1.03) for the nine studies, without statistically significant. Conclusions High coffee consumption is associated with a reduced pancreatic cancer risk. However, the result should be accepted with caution, due to the potential confounder and bias could not be excluded. Further well designed studies are needed to confirm the finding.

Digital management of PetroChina Changqing Oilfield Company (PCOC) was a modern management mode for "three-low" oil and gas reservoir economic development. Based on the establishment of digital management "three terminals and five systems", supported by digital technology, we set up one unified platform for production operation management, production operation scheduling, and emergency response and rescue, which provided an efficient collaborative work environment for management decision-making and scientific research. Combined digital technology with management, we promoted a shift in terms of labor organization structure, production organization and production operation mode.

The equilibrium solubility of one CsCl-YCl3-H2O ternary section Of CsCl-YCl3-9.5%HCl-H2O quaternary system at T=298.15 K was investigated by the physico-chemical analysis method and the corresponding phase diagram was plotted. The crystallization of two new double salts Cs4YCl7.10H(2)O (4 : 1 type) and Cs3Y2Cl9.14H(2)O (3 : 2 type) was successful and they were obtained from the complicated system directly. Both were identified and characterized by X-ray, thermal analysis method of TG-DTG, DSC. The fluorescence experiments show that up-conversion phenomenon does not exist in compounds CS4YCl7.10H(2)O and Cs3Y2Cl9.14H(2)O. The equilibrium solubility of one CsCl-YCl3-H2O ternary section Of CsCl-YCl3-9.5%HCl-H2O quaternary system at T=298.15 K was investigated by the physico-chemical analysis method and the corresponding phase diagram was plotted. The crystallization of two new double salts Cs4YCl7.10H(2)O (4 : 1 type) and Cs3Y2Cl9.14H(2)O (3 : 2 type) was successful and they were obtained from the complicated system directly. Both were identified and characterized by X-ray, thermal analysis method of TG-DTG, DSC. The fluorescence experiments show that up-conversion phenomenon does not exist in compounds CS4YCl7.10H(2)O and Cs3Y2Cl9.14H(2)O.

The equilibrium solubility of CsCl-CeCl3-HCl (11%)-H2O quaternary system at 25 °C has been determined by the physic-chemical analysis method, and the phase diagram was plotted. Two new double salts 3CsCl · CeCl3 · 3H2O and CsCl · CeCl3 · 4H2O obtained from the complicated system were identified and characterized by XRD, TG-DTA, DSC, UV and fluorescence spectroscopy. Studies on the fluorescence excitation and emission show that 3CsCl · CeCl3 · 3H2O and CsCl · CeCl3 · 4H2O have upconversion luminescence of infrared-visible range, and the upconversion emission intensity increases with the increase of ratio of CeCl3 in CsCl.

Equilibrium phase relations and the solubility data for the rare earth trichloride RECl3·nH2O (RE = La, n = 7; RE = Nd, Sm, Eu, n = 6) and cadmium chloride CdCl2·2.5H2O in the aqueous system were investigated. The corresponding equilibrium phase diagrams in the ternary system CdCl2−RECl3−H2O at 303 K were constructed. The results showed that these systems were complicated and consisted of four stable equilibrium solid phases [CdCl2·H2O, CdCl2·2.5H2O, Cd4RECl11·nH2O (n = 12, 14, 4:1 type), RECl3·7H2O] and a metastable phase [Cd8RECl19·16H2O (8:1 type)]. The new compounds Cd4RECl11·nH2O and Cd8RECl19·16H2O were found to be incongruently soluble in the systems. The 4:1 type compounds obtained were identified and characterized by the method of X-ray diffraction, thermogravimetry, and differential thermogravimetry (TG, DTG).