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Rubber scion growth is the key step of rubber budding propagation. However, there is still a lack of systematic studies investigating leaf phenology effect on rubber scion growth. In this study, leaf phenology, stem diameter, plant height and the chlorophyll parameters were observed at six periods. The results showed that leaf-unfolding stage was the rapid growth and regulation stage of plant height and stem diameter, and light green leaf stage was the sensitive to environmental temperature. Taken together, leaf phenology affects the growth speed of rubber buddings, and distinguishing the differences in phenological effects helps to regulate the phenological process to raise rubber buddings.

The meandering channel deposit of the upper member of Neogene Guantao Formation in Shengli Chengdao extra-shallow sea oilfield is characterized by rapid change in sedimentary facies. In addition, affected by surface tides and sea water reverberation, the double sensor seismic data processed by conventional methods has low signal-to-noise ratio and low resolution, and thus cannot meet the needs of seismic description and oil-bearing fluid identification of thin reservoirs less than 10 meters thick in this area. The two-step high resolution frequency bandwidth expanding processing technology was used to improve the signal-to-noise ratio and resolution of the seismic data, as a result, the dominant frequency of the seismic data was enhanced from 30 Hz to 50 Hz, and the sand body thickness resolution was enhanced from 10 m to 6 m. On the basis of fine layer control by seismic data, three types of seismic facies models, floodplain, natural levee and point bar, were defined, and the intelligent horizon-facies controlled recognition technology was worked out, which had a prediction error of reservoir thickness of less than 1.5 m. Clearly, the description accuracy of meandering channel sand bodies has been improved. The probability semi-quantitative oiliness identification method of fluid by prestack multi-parameters has been worked out by integrating Poisson's ratio, fluid factor, product of Lame parameter and density, and other prestack elastic parameters, and the method has a coincidence rate of fluid identification of more than 90%, providing solid technical support for the exploration and development of thin reservoirs in Shengli Chengdao extra-shallow sea oilfield, which is expected to provide reference for the exploration and development of similar oilfields in China.

The solid-state lithium-ion battery is proposed as the ultimate form of battery and has rapidly become an updated attentive research field due to its high safety and extreme temperature tolerance. However, current solid-state electrolytes hardly meet the requirement in practical applications due to its low ionic conductivity, weak mechanical properties, and poor interfacial contact between the electrolyte and the electrode. In this work, we developed a double-network-supported poly(ionic liquid)-based ionogel electrolyte (DN-Ionogel) via a one-step method. Due to its compact cross-linking structure, the leakage-free DN-Ionogel electrolyte exhibits outstanding flexibility and favorable mechanical properties. In this ionogel electrolyte, the double network favors dissociation of lithium bis(trifluoromethanesulfony)imide (LiTFSI), further resulting in remarkable ionic conductivity (1.8 × 10-3 S/cm, room temperature), wide electrochemical window (up to 5.0 V), and high lithium-ion transference number (0.33). Furthermore, the cell (LiFePO4||DN-Ionogel||Lithium) delivers a discharge capacity as high as 150.5 mAh/g, stable cyclic performance (over 200 cycles), and superior rate behavior.

A graphene aerogel-based composite has recently been deemed as a prospective electrode material for advanced energy storage devices. Here, carbon quantum dots (CQDs) are simultaneously utilized as ...

This study developed a framework to evaluate, in the context of COVID-19, the performance of an OVRWCHT (online 360° virtual reality world cultural heritage tourism) system created by the authors for the purpose of heritage interpretation and presentation. The research framework was based on the seven main principles of the ICOMOS Charter for the Interpretation and Presentation of Cultural Heritage Sites, and evaluation criteria were established for each. This framework was used to evaluate an OVRWCHT for the Hailongtun Tusi World Heritage Site in Guizhou Province, China. Data were mainly based on 1,062 questionnaires and analyses of the developed system. The findings indicated that, whether in terms of user experience or the interpretation of the UNESCO criterion “outstanding universal value,” Stakeholders agreed that OVRWCHT has played a positive role in heritage interpretation. Yet, more data support is needed to improve both technology and theory – especially the transferability of OVRWCHT to countries other than China. Based on the findings, it is suggested that the International Council on Monuments and Sites should continue to issue charters on how emerging technologies can support heritage site interpretation and presentation.

Variations of speech content increase the difficulty of speaker verification. In this paper, to alleviate the negative effect of the variations, phoneme-unit-specific time-delay neural network (PUSTDNN) is proposed and applied to the state-of-the-art x-vector system. It models each phoneme unit with an individual time-delay neural network (TDNN). That is to say, each TDNN mainly deals with a phoneme unit. Compared with handling all phoneme units together, when handling a phoneme unit, a TDNN can extract more discriminative speaker information, thus improving the system performance. Two realizations of the PUSTDNN are proposed. The first one can retain speech temporal information. The second one further combines all the TDNNs in a PUSTDNN into a larger TDNN to reduce computational complexity. To avoid model overfitting, the phoneme units are obtained by clustering phonemes based on the phonetic knowledge and phonetic sparsity degree. The PUSTDNN is also compared with two other techniques, i.e., phonetic vector and multitask. Experiments on the Fisher, NIST SRE10, and VoxCeleb datasets show that the phonetic vector technique is most robust to the phoneme unit recognition accuracy. When the accuracy is high enough, the multitask performs better than the phonetic vector, and the PUSTDNN performs best and can achieve over 10% relative improvement compared with the x-vector baseline.

In this article, a new synthesis method for generalized multi‐band filters has been proposed. Different from the traditional frequency transformation method, which transforms a low‐pass prototype into a multi‐band filter, multiple low‐pass prototypes have been transformed into a multi‐band filter. This study introduces the idea of transforming more than two lowpass prototypes into a filter, called multi‐prototype transformation. It divides the multi‐band filter to be synthesized into different segments each of which corresponds to a low‐pass prototype. After frequency transformation, these segments are combined together to get the final transfer function. The multi‐band filter synthesized by this method can have different orders, bandwidths or return losses in different passbands. Prescribed transmission zeros can also be realized. The return loss adjustment, segment boundary estimation and equal‐ripple realization of this method are further explained in theory. To verify this method, an asymmetric quad‐band filter is synthesized as an example and a symmetric triple‐band filter is synthesized, designed, fabricated and measured. The obtained results show good agreement with the simulation.

Root trainers are increasingly being used to avoid root coiling and distortion and lack of wind tolerance after field transplanting, when compared to the conventional polybag planting system. Root tips grew out of root trainer forming an intact root mass and then could be transplanted to the field with high survival rate. While the influence of spatial position on root tips growing out of budded stump root trainer was still unknown at nursery stage. Therefore, the bottoms of root trainer were placed in aboveground(20cm, current practice), touchdown(0cm) and underground(15cm) for budded stump nursery, respectively. Clone CATAS 7-20-59 budded stump was raised in root trainer and percentage of plants with root tips outgrowing, growth performance, leaf N content, leaf SPAD, leaf temperature and leaf surface humility were recorded, respectively. The results showed that root trainer touchdown of budded stump gave more percentage in root tips growing out of root trainer, more leaf N content(P

The rapid development of modern electrical equipment toward miniaturization and high power puts forward stringent requirements to the mechanical reliability, dielectric property, and heat resistance of electrical insulating materials. Simultaneous integration of all these properties for mica-based materials remains unresolved. Herein, inspired by the three-dimensional (3D) chitin nanofiber framework within the layered architecture of natural nacre, we report a large-area layered mica-based nanopaper containing a 3D aramid nanofiber framework, which is prepared by a sol-gel-film transformation process. The coupling of 3D aramid nanofiber framework and oriented mica nanoplatelets imparts the nanopaper with good mechanical strength, particularly outstanding ductility (close to 80%) and toughness (up to 109 MJ m

It is a great challenge to enhance the specific capacitance while without sacrificing the remarkable rate capability and long-term cycle durability of carbon materials for supercapacitors. Here we present a novel spherical and multi-shell hollow carbon material with tunable shell numbers and N-doping derived from a sequential synthetic route recombining hydrothermal nucleation, carbonization, and etching. The very special features, including uniform in shape and size, hollow structure, core/multi-shell architecture, hierarchical porous structures, and nitrogen doping, facilitated high specific surface area, abundant active sites, fast ion diffusions kinetics and good electrical conductivity. As a result, very superior electrochemical performance with an excellent combination of high specific capacitance (318.5 F g−1), and outstanding rate capability (the capacity retention ratio was more than 80% when the current density was raised from 0.1 to 10 A g−1), and very stable cycling (more than 94% capacity retention after 50000 cycles at 1 A g−1) has been achieved. This hierarchical multi-shell strategy opens a new avenue for design of high performance electrode for next-generation energy storage devices.

Inhibiting PARP-1/2 offered an important arsenal for cancer treatments via interfering with DNA repair of cancer cells. Novel PARP-1/2 inhibitors were designed by capitalizing on methyl- or ethyl-substituted piperizine ring to capture the characteristics of adenine-ribose binding site (AD site), and their unique binding features were revealed by the cocrystal structures of compounds

Carbon quantum dots (CQDs) as novel types of emerging materials have aroused tremendous attention in recent years. Herein, we report for the first time a new application of 3D CQD-based composite aerogels as excellent electrode materials for alkaline aqueous batteries. The scalable graphitic CQDs are prepared with high yields (>40%) and further utilized to fabricate the novel nitrogen-doped CQDs/reduced graphene oxide/porous Fe2O3 (N-CQDs/rGO/Fe2O3) composite aerogels with different contents of Fe2O3. Benefiting from the unique 3D network composite aerogel structure with a high surface area and hierarchical porous structure as well as the synergistic effect of high-capacity Fe2O3 and highly conductive and stable N-CQDs/rGO, the composite aerogels achieve enhanced electrochemical properties with ultrahigh specific capacity, admirable rate property, and superior cycling performance. Furthermore, the N-CQDs/rGO/Fe2O3-1 electrode (Fe2O3, 34.9 wt %) exhibits the best rate capability (72.1, 58.9, and 46.2% capacity retention at 5, 50, and 100 A g-1, respectively) and cycle performance (80.4% capacity retention at 3 A g-1 over 5000 cycles), while the N-CQDs/rGO/Fe2O3-3 electrode (Fe2O3, 62.3 wt %) displays the highest specific capacity (274.1 mA h g-1 at 1 A g-1). The current research provides a valuable guidance for developing high-performance 3D CQD-based composite aerogels for application in energy storage systems.

In this study, a new type of polyimide (PI) composite material was synthesized by a two-step method using 2,3,5,6-tetramethyl-1,4-phenylenediamine (TMPDA), 4,4′-methylenedianiline (MDA), and 3,3′,4,4′-benzophenonetetracarboxylic dianhydride (BTDA). The PI material was then used to prepare an ultrafiltration (UF) membrane by phase inversion method. The membrane showed a dense surface layer, a porous sublayer, and fully developed finger-like macrovoids at the bottom, which had excellent hydrophilicity and antifouling property. In the recovery experiments with a protein solution, the PI membrane displayed a satisfactory water flux recovery ratio of 90.03%. The PI membrane can operate stably in 1 mol L−1 hydrochloric acid solution, and the retention rate of BSA remains at 93%. In addition, the flux of the membrane is 325.60 L m−2 h−1 and the BSA retention rate the retention rate is still higher than 95% after soaking in various solvents for 7 days.

This work focused on a fabrication of lotus root-like Li3V2(PO4)3/C composites via a repeated immersion process using the dandelion as a bio-template. The Li3V2(PO4)3/C composites were characterized using X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The Li3V2(PO4)3/C composites exhibited various structures that were dependent on the various processing techniques. By increasing immersion of the product to three repetitions, a bundle of dandelion carbon fibers was found to be covered by Li3V2(PO4)3 and formed a perfect lotus root-like structure (D-3). The Li3V2(PO4)3/C composite (D-V) prepared using the vacuum method displayed a dense scrub board-like structure. However, sample D-3 that was prepared using the novel method, exhibited a capacity of 126.8 mAh g−1 at the 1 C rate, a prominent capacity retention of 96.8% after 2000 cycles at the 15 C rate. The experimental results showed that this unique lotus root-like structure is beneficial for improving the capability and cycling stability.

A novel spherical tremella-like Sb2O3 was prepared by using metal-organic frameworks (MOFs) method under a mild liquid-phase reaction condition, and was further employed as an anode material for lithium-ion batteries (LIBs). The effect of reaction temperature and time on morphologies of Sb2O3 was studied. The results from SEM and TEM demonstrate that the tremella-like Sb2O3 architecture are composed of numerous nanosheets with high specific surface area. When the tremella-like Sb2O3 was used as LIBs anode, the discharge and charge capacities can achieve 724 and 446 mA.h/g in the first cycle, respectively. Moreover, the electrode retains an impressive high capacity of 275 mA-h/g even after 50 cycles at 20 mA/g, indicating that the material is extremely promising for application in LIBs.

To confine the intermediate polysulfides to obstruct their dissolution from the electrolyte and increase the utilization of sulfur, a novel sulfur host for decorated nitrogen-doped carbon nanotube ...

Carbon materials as host matrix of lithium (Li) anode attract more and more attention in order to inhibit uncontrollable dendritic growth of Li. Powdery carbon materials are usually synthesized and loaded on current collector by binder. The pore structure and active site of powdery materials will be easily destroyed during cycling. Herein, a self-supporting carbon film consisting of nitrogen (N)-doped carbon rod array (NCRA) with high N content and large surface area skeleton is developed as Li host matrix to regulate Li metal nucleation and suppress dendrites growth. The NCRA matrix exhibits low lithium loss mass and good long-term cycling stability during Li plating/stripping. The loss mass of Li in each cycle on NCRA is less than 0.01 mg cm−2 at 1.0 mA cm−2 and the value is much smaller than that (0.063 mg cm−2) on Cu foil. The Li|NCRA@Li symmetric cell has ultralong lifespan beyond 620 h and small voltage hysteresis of less than 40 mV at 2.0 mA cm−2. The good electrochemical performance is ascribed to the stable self-supporting array structure for the storage of Li and abundant lithiophilic active sites for uniform Li electrodeposition in NCRA host matrix. Therefore, the dendritic growth of Li is effectively inhibited. This study provides a promising self-supporting lithiophilic NCRA as host material of Li anode to promote practical application in next-generation lithium-metal based batteries.

This is the first report of the use of an original precursor obtained from an abundant, green and economical bio-mass waste: cattail fibers. Nitrogen-doped Li3V2(PO4)3/carbon composites with copious conductive networks have been successfully synthesized using cattail fibers as a bio-template employing facile, repeated solution immersions. The morphologies and microstructure of the nitrogen-doped Li3V2(PO4)3/carbon composites were characterized using an X-ray diffractometer and scanning electron microscopy. A nitrogen-doped Li3V2(PO4)3/carbon composite (sample C-3) was obtained through three times solution immersion, which completely covered the carbon fibers with thin, porous layers of Li3V2(PO4)3. These orderly nitrogen-doped Li3V2(PO4)3/carbon (C-3) were orderly interconnected porous Li3V2(PO4)3 nanoconnections. This novel structure was found to have interlaced conductive networks that were formed between the N-doped carbon fibers and porous Li3V2(PO4)3 nanoconnections. However, the Li3V2(PO4)3/carbon composites, termed sample (C-V), obtained using the immersion process in a vacuum, displayed a random accumulation of rod-like Li3V2(PO4)3/carbon composites. Sample C-3 exhibited the highest reversible capacity of 113.2 mAh g−1 after 500 cycles at 15 C between 3.0 and 4.3 V, but at under these same conditions, the remaining reversible capacity of sample C-V was only 82.3 mAh g−1.

This work focused on the design and fabrication of porous, nitrogen-doped Li3V2(PO4)3/C cathode materials using a repeated impregnation synthesis process employing oroxylum as a template. The resulting Li3V2(PO4)3/C cathode materials were comprehensively analyzed using Fourier transform infrared spectroscopy, X-ray diffraction analysis, selected area electron diffraction, scanning electron microscopy and galvanostatic experiments. The Li3V2(PO4)3/C cathode materials of varying structure were prepared by various processing techniques using select precursors. The resulting porous, nitrogen-doped Li3V2(PO4)3/C cathode materials (IM-15) obtained using repeated impregnation exhibited a novel, overlapping hollow slab structure, which was covered by thin layers of porous, foamed Li3V2(PO4)3 on the surface of IM-15. It was found that the porous, foamed Li3V2(PO4)3 material was sandwiched between thin layers of adjacent Li3V2(PO4)3/C layers. IM-15 product exhibited an outstanding rate capability of 87.4 mAh g−1 at the 10 C rate, and an excellent capacity retention of 96.9% after 1000 cycles at 5 C in the range of 3–4.3 V. These results were attributed to the porous, nitrogen-doped structure of the material, which provided a high diffusion coefficient and superior structural stability. The unique porous, nitrogen-doped structure was responsible for improving the rate capability and cycling stability of LIBs containing the subject experimental material.

In most existing metric learning methods, the data pairs are equally treated without considering their diversity. In fact, for pairs with different distances, the main purpose of the metric acted on them has some differences. If the pairs have smaller distance, metric should focus more on expanding the negative pairs, which are more easily misjudged. While if the pairs have larger distance, metric should focus more on shrinking the positive pairs. However, most metric learning methods neglect these differences. In this letter, we propose a distance-dependent metric learning (D $^2$ ML) method. It partitions data pairs into different clusters according to the $\ell _2$ distance between them. Each cluster is associated with a Mahalanobis metric that learns the pairs’ distance. This not only allows us to make each metric more targeted and adapt to the data diversity flexibly, but also avoids the problem of computing the distance between points assigned to different clusters, which happens in some local metric learning methods. D $^2$ ML is further extended to D $^3$ ML to embrace the nonlinear capacity of neural network. Experiments on UCI datasets and speaker recognition i-vector machine learning challenge show that the proposed methods are superior to other metric learning methods.

Folded-hand silicon/carbon (Si/C) three-dimensional (3D) networks were fabricated by chemical vapor deposition coupled with ultrasonic atomization and successfully applied for a binder-free anode in lithium-ion batteries. The microstructure, morphology and electrochemical performance for Si/C 3D networks were investigated by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and galvanostatic charge-discharge tests. The repeated folded-hand units for Si/C composites are assembled into interconnected 3D networks. The folded-hand Si/C 3D networks show an outstanding charge capacity of 2277 mAh g−1 at 0.1 C, and still remain 2167 mAh g−1 after 100 cycles. They reveal an excellent rate capacity of 1848 mAh g−1 and capacity retention of 99% after 100 cycles at 2 C, the charge capacities of 862 mAh g−1 and capacity retention of 93% after 500 cycles at 5 C. The LiFePO4//Si-C full cell can maintain high capacity of 137 mAh g−1 and capacity retention of 92% after 500 cycles at 1 C rate. The superior electrochemical performance is attributed to the formation of three-dimensional folded-hand interconnected networks.

This study has formulated an evaluation framework for the interpretation and presentation performance of Online virtual reality 360°world cultural heritage tourism (OVRWCHT) approach during the covid-2019 break. The research framework is based on seven main principles of the Charter of the World Cultural Heritage Interpretation and Presentation theory, and establishes evaluation criteria for each principle. The World Cultural Heritage Site Hailongtun Tusi was selected as the case study, the Online virtual reality 360° system was for this site was established and evaluated accordingly. A collection of 1062 effective online questionnaires were support the evaluation. The results show that the OVRWCHT made by the research team which has received relatively wide recognition from stakeholders during the COVID-2019 outbreak period. However, it still needs more data support to improve technology and theory, especially transferability of OVRWCHT in other countries besides China. Finally, this study suggests that the ICOMOS should continue to issue relevant charters (documents) on how emerging technologies which may activate cultural heritage interpretation and presentation.

Shanghai is the gathering place of the Red Cultural Heritage. Based on a questionnaire analysis of 1,047 respondents on the interpretation of the value of red cultural heritage in Shanghai, this study shows that people lack the impression of Shanghai’s “red cultural heritage agglomeration” and the lack of red heritage value display and interpretation, which is mainly due to the lack of representative red IP in Shanghai. Based on the practice of a major virtual reality display project, fully relying on scientific and technological means to achieve three-dimensional visual value interpretation of red heritage is conducive to the transformation and upgrading of red tourism resources to red tourism bases, the development of red tourism products that are popular in the market, and ultimately promote the protection and utilization of red heritage sites. At the same time, talent training and mobilizing community participation enthusiasm are equally important for the display and interpretation of red cultural heritage.

In this paper, double-layered mesopore-rich hollow carbon microspheres (DHCM) were prepared by a Stober method using tetraethyl orthosilicate, resorcinol and formaldehyde as precursor materials, and further utilized as carbon sources to prepare the boron and nitrogen co-doped double-layered mesopore-rich hollow carbon microspheres (B, N-DHCM) by hydrothermal approach utilizing ammonium tetraborate tetrahydrate (NH4B5O8·4H2O) as boron and nitrogen sources. Compared with the undoped DHCM, the as-obtained B, N-DHCM displays improved capacitive properties with a high specific capacitance (221.5 F g−1 at 1 A g−1), good rate performance (104.1 F g−1 at 20 A g−1) and superior cycle life (91% of capacitance retention at 3 A g−1 after 10,000 cycles). The outstanding capacitive performances result from the synergistic effect of the unique double-layered mesopore-rich hollow structure contributing to the rate property and cycle stability and the modification of B and N co-doping providing pseudocapacitance for the enhancement of specific capacitance. Therefore, the excellent capacitive behaviors render the B, N-DHCM promising electrode materials for application in supercapacitors and other energy storage systems.