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From the perspective of high-temperature applications, materials with excellent high-temperature mechanical properties are always desirable. The present work demonstrates that the binder-free nanopolycrystalline WC ceramic with an average grain size of 103 nm obtained by high-pressure and high-temperature sintering exhibits excellent mechanical properties at both room temperature and high temperature up to 1000 °C. Specifically, the binder-free nanopolycrystalline WC ceramic still maintains a considerably high Vicker hardness HV of 23.4 GPa at 1000 °C, which is only 22% lower than the room temperature HV. This outstanding thermo-mechanical stability is superior to that of typical technical ceramics, e.g. SiC, Si3N4, Al2O3, etc. Nanocrystalline grains with many dislocations, numerous low-energy, highly stable Σ2 grain boundaries, and a relatively low thermal expansion coefficient, are responsible for the observed outstanding high-temperature mechanical properties.

Columbite-rich multiphase TiO2 nanoceramics with outstanding mechanical and dielectric properties were successfully prepared through high-pressure sintering by using anatase-type TiO2 as precursor. High-pressure sintering combined with phase transformation assisted consolidation can effectively refine the grain size of the recovered samples. This process is conducive to obtain nanocrystalline columbite-rich TiO2 ceramics with excellent performance. The highest hardness is approximately 12.76 GPa, which is 2.5 times higher than that of ordinary coarse-grained ceramics. The effect of columbite phase on the hardness of multiphase ceramics is discussed. The columbite-rich TiO2 ceramic shows a colossal permittivity (∼8 × 103) and low loss (∼0.2) at 1 kHz and room temperature, which are superior to that of undoped rutile polycrystalline ceramics. This ceramic shows a steadier frequency-dependent dielectric permittivity and loss than rutile TiO2 crystal. These results enrich the fundamental knowledge of columbite-rich TiO2, thereby enabling the exploitation of new applications.

Boron carbide (B4C) is an important structural ceramic material, however, the use of this material is limited by its poor sinterability and low fracture toughness. Nano-sized powders have small particle size, high chemical activity and great sintering ability, which can promote the fabrication of the dense B4C ceramics. Herein, by spark plasma sintering (SPS) homemade high-purity nanopowders, single phase B4C ceramics with density close to the theoretical value were prepared. Results showed that the best SPS condition was holding at temperature of 1850 °C for 4 min. Under this condition the sample exhibited enhanced mechanical properties including Vickers hardness of 33.9 GPa, fracture toughness of 3.81 MPa m1/2 and flexure strength of 554.7 MPa. Transmission electron microscopy (TEM) analysis shows that non-coherent twins exist at the grain boundary instead of amorphous phase or second phase, which further confirms the high purity and high densification of the obtained B4C ceramics.

Low dimensional semiconductors can be used for various electronic and optoelectronic devices because of their unique structure and property. In this work, one-dimensional Sb2S3 nanowires (NWs) with high crystallinity were grown via chemical vapor deposition (CVD) technique on SiO2/Si substrates. The Sb2S3 NWs exhibited needle-like structures with inclined cross-sections. The lengths of Sb2S3 nanowires changed from 7 to 13 μm. The photodetection properties of Sb2S3 nanowires were comprehensively and systematically characterized. The Sb2S3 photodetectors show a broadband photoresponse ranging from ultraviolet (360 nm) to near-infrared (785 nm). An excellent specific detectivity of 2.1 × 1014 Jones, high external quantum efficiency of 1.5 × 104 %, sensitivity of 2.2 × 104 cm2W−1 and short response time of less than 100 ms was achieved for the Sb2S3 NW photodetectors. Moreover, the Sb2S3 NWs showed outstanding switch cycling stability that was beneficial to the practical applications. The high-quality Sb2S3 nanowires fabricated by CVD have great application potential in semiconductor and optoelectronic fields.

Conventional nitrogen (N) fertilizers used in crop production typically have use efficiencies of only 30 to 40%. While reduced efficiency can be a result of multiple factors (rate, placement, source), mismatched timing between N availability and N crop demand is a significant cause of reduced efficiency. This study aims to develop a biochar-based controlled release nitrogenous fertilizer (BCRNF) from relatively low-cost renewable materials to improve N availability when needed by the corn crop thus reducing N losses and improving nitrogen use efficiency. Ammonium sulfate was impregnated in biochar and then pelletized into particles. Three concentrations (3%, 6%, and 10%) of polylactic acid (PLA) solutions were used to coat the particles to produce BCRNF. The effects of different PLA concentrations on N release and physical properties of BCNRFs were investigated in both water and soil conditions. Water absorption and retention, thermal stability, and microstructures of BCRNFs were also analyzed to determine the N release mechanism of BCRNFs. The BCRNF coated by 10% and 6% of PLA both released 70% of N over 12 days in water and 25 days in soil. The biochar held 14% N that was not released into the water. However, coating with PLA, increased N holding to 16% inside BCRNF particles. The thermal properties of BCRNFs were stable under 230 °C. The PLA concentration of the coating layer significantly affected not only the N releasing time and rate but also the morphology and thermal properties of BCRNFs. Higher PLA concentrations resulted in a longer releasing time at lower N release rates. This study demonstrates that a biochar-based controlled-release nitrogen fertilizer (BCRNF) can enhance N release time and rate in both water and soil environments through the integration of biochar absorption and a PLA coating. Further development could yield a BCRNF that can optimally synchronize timing and amount of available N with crop N demand to increase N use efficiency.

This paper solves the robust control problem of robotic manipulator systems with uncertain dynamics by friction compensation approach. A weighting factor is introduced to distinguish the role of friction in control process by comparing the directions of sliding vector and friction. Utilizing the weighting factor, model-based and model-free adaptive friction compensation controllers are designed to achieve asymptotical tracking of the desired joint-space trajectory according to the knowledge of friction. The damping property of friction is fully used to improve the control performance by compensating the friction harmful for the stability, and on the other hand, utilizing the beneficial friction. Numerical simulations are given to demonstrate the control performance of the proposed approach.

We introduce a generalized extrapolation framework as a constrained optimization problem to enhance the resolution in terahertz digital in-line holography. The alternating minimization method is employed to iteratively extrapolate the hologram beyond the actually detecting area and to reconstruct the complex amplitude distribution of the object wavefront. Within this framework, we propose a sparsity-based extrapolation model based on L1-norm, where the object mask is not required and the generalized positive absorption constraint can be utilized. This work can achieve super-resolution reconstruction completely by numerical postprocessing without any modification to the imaging system. Both the simulation and experiments on the terahertz band demonstrate the feasibility of the proposed algorithms, and the limit of resolution can be extended by a factor of 1.67.

Amphoteric oxides (Al2O3 and B2O3) represent opposite effects on the structure and properties of silicate melts in different conditions, while the understanding about the transition from acidity to basicity is far from complete. Molecular dynamics simulation was adopted in the present study to investigate the performance and acidity-basicity transformation of Al2O3 and B2O3 in the SiO2–CaO–Al2O3–B2O3 system. The results showed that, different from Ca2+ ions, excessive Al3+ or B3+ ions tend to destroy the bridge oxygen structures, showing the function of basic oxide. This is similar to the behavior of Ca2+ ions and other basicity ions. It was found that, on the one hand, B3+ ions tend to form [BO3]3- planar triangular structures with the increase of B3+ ions contents, on the other hand, B3+ ions could reduce the stability of Si–O bonds. Therefore, B3+ ions could make the system structure less stable, which is the reason why the B2O3 is a kind of active agent. In addition, because of the significant differences in lattice energy and atomic structure between Al2O3 and B2O3, the effects of Al2O3 and B2O3 on the thermodynamic properties of silicate melts are quite different.

Recent attention on the lanthanides (Ln) contaminant such as lanthanum (La) and neodymium (Nd) extensively used in industry has aroused the great desire for the effective adsorbent. Biochar, relying on its high selectivity and optional ease, is regarded as a promising adsorbent for lanthanides removal although the evaluation of the efficiency and mechanism of La(III) and Nd(III) adsorption on biochar still lags. Here, we investigated the aqueous adsorption processes through SEM, TEM, EDS, FTIR and Raman spectra, XPS, and batch experiments. The porous structure of biochar and the complex functional groups on its surface contributed to the La(III) and Nd(III) removal processes. The kinetic of La(III) and Nd(III) adsorption agreed well with the pseudo-second-order kinetic model. The adsorption capacity showed a strong positive correlation with pH value. However, it was only slightly altered and robust in La(III) and Nd(III) adsorption respectively. The isotherm results reflected significant fitting to the Sips model as well as Langmuir and Freundlich model. Thermodynamic demonstrated the spontaneity, endothermic nature, and temperature favor of the adsorptions on biochar surface (La: ΔH0=35.39 (kJ/Mol), ΔS0=104.71(J*Mol-1*K-1) and ΔG0

The development of stable and low-cost catalysts with high reactivity to replace Pt-based ones is the central focus but challenging for hydrogen evolution reaction (HER). The incorporation of single atoms into two-dimensional (2D) supports has been demonstrated as an effective strategy because of the highly active single atomic sites and extremely large surface area of two-dimensional materials. However, the doping of single atoms is normally performed on the surface suffering from low stability, especially in acidic media. Moreover, it is experimentally challenging to produce monolayered 2D materials with atomic doping. Here, we propose a strategy to incorporate single foreign Fe atoms to substitute W atoms in sandwiched two-dimensional WS2. Because of the charge transfer between the doped Fe atom and its neighboring S atoms on the surface, the proximate S atoms become active for HER. Our theoretical prediction is later verified experimentally, showing an enhanced catalytic reactivity of Fe-doped WS2 in HER with the Volmer-Heyrovsky mechanism involved. We refer to this strategy as proximity catalysis, which is expected to be extendable to more sandwiched two-dimensional materials as substrates and transition metals as dopants.

Dual-color photodetection can increase detection accuracy due to the specific information from different wavelengths. Traditional dual-color detectors are based on double optical modules or photovoltage devices, which suffer from huge system weight or low gain. In this Letter, a novel dual-color photodetector with Ge/Graphene/CdS sandwich profile is proposed. While visible and infrared light is mainly absorbed by the CdS and Ge layers, respectively, photoelectrical signals from two wavelengths both conducted by graphene are extracted on time-sequence with different sampling frequencies. Based on a tailored interface process and epitaxy InGaAs instead of bulk Ge layer, the difference in response speed more than 3 orders of magnitude (76 kHz/14 Hz) was realized. Due to the photogating effect, the high gain was obtained for both wavelengths, and a photoresponse enhancement originated from the overlapping of local photogating field is observed. The device provided a new solution for high-gain and CMOS-compatible dual-color photodetection.

Numerous field studies have shown that leaf wax n-alkane δD values (δDn-alkane) can be used as a proxy for paleoelevation reconstruction. However, the lack of systematic global analysis of δDn-alkane values with respect to altitude limits the reliability of δDn-alkane values for paleoaltimetry at the global scale. In this study, we analyzed the variation of δDn-alkane values with altitude in terrestrial higher plants based upon our compiled global δDn-alkane database. The general decrease in δDn-alkane values with altitude corresponds to the variation in precipitation δD (δDprec) with altitude, suggesting that the δDn-alkane values effectively reflect δDprec values. When eliminating the effect of latitude at the global scale, the global δDn-alkane-altitude lapse rate for all species was −1.01±0.10‰ (100 m)−1, while these lapse rates were −1.03±0.13‰ and −0.47±0.13‰ (100 m)−1 for dicots and monocots, respectively. Our study reveals that it is reliable to use δDn-alkane values to gain information about paleoelevation at the global scale, and the global δDn-alkane-altitude lapse rates provide an alternative to reconstruct paleoelevation at some δDn-alkane-uninvestigated areas.

Colloidal particles with surface patches can self-assemble with high directionality, but the resulting assemblies cannot reconfigure unless the patch arrangement (number, symmetry, etc.) is altered...

Here a series of sp2-sp3 BxNx+1 (x = 1, 2, 3, 4, 5, 6) structures was constructed. These structures can be viewed as diamond-like BN blocks connected by single N-N bonds. Elastic constants and phonon dispersion curves confirm that all of the proposed structures are mechanically and dynamically stable. These structures all possess metallicity originating from the conductive channels formed by sp2-hybridized N atoms and adjacent sp3-hybridized B and N atoms. These structures exhibit tunable mechanical properties with a regular change in the sp2/sp3 ratio. The theoretical Vickers hardness increases and the ductility decreases as the number of diamond-like BN blocks increases, gradually approaching those of c-BN. Moreover, the convex hull at ambient pressure and 50 GPa indicates that high pressure is beneficial in the synthesis of these B-N phases. The simulated X-ray diffraction patterns of these structures were also calculated to provide more information for further experiments.

A previous study reported an observed unidentified graphite/hexagonal boron nitride (hBN) superlattice structure in special multilayer heterojunction devices via cross-sectional transmission electron microscopy [Haigh S. J. et al., Nat. Mater. 2012, 11, 764-767]. In this letter, we designed and confirmed two possible graphite/hBN superlattice structures (AA and Ab), which were probably the structures observed by the aforementioned experiment. The formation enthalpies of both structures were negative, indicating that they could be successfully synthesized as the previous experiment reported. The results also showed that both structures possessed dynamic stability and elastic stability. Importantly, the theoretical interlayer distances of AA and Ab were 3.34 and 3.30 A, respectively, which were consistent with the experimental value of 3.32 A. The X-ray diffraction patterns and Raman spectra of both structures were simulated to aid in distinguishing them. This study on the atomic structure of the graphite/hBN superlattice lays a foundation for further research and application of this material.

Understanding the microbial linkages among the soils, plants, and animals is crucial for maintaining the balance of the grazed grassland ecosystem. However, previous studies always focused on the biotopes of soil, phyllosphere, and feces separately and little has been known about microbial distributions and migrations among these biotopes. In this study, systematic surveys about the overlap and differentiation among various microbiotas of biotopes and how the environmental filter on microorganisms served for the ecosystem were conducted. Soil, phyllosphere, and feces samples were collected from grazed and ungrazed grassland in Inner Mongolia, China. High-throughput sequencing and qPCR were employed to obtain the genome data. The results were analyzed by various statistical tools such as genomic analysis and machine learning classification to describe the disparities and linkages among the microbiotas of three biotopes. Our findings revealed that the biotopes drove the distinct microbial community assemblages with various richness, β-diversity and composition. The substantial overlaps between soil and phyllosphere in fungi, bacteria and archaea indicated that soil played the role of the microbial source for the phyllosphere. Communal OTUs could be found between phyllosphere and feces. Nevertheless, Ascomycota were the only microorganisms migrating among all the biotopes massively. After the long-term impact of feces via grazing, the soil and phyllosphere microbiota also altered significantly. Biotopes drive the discrepancy of microbiota distribution among the soil, phyllosphere, and feces. Soil could potentially perform as the microbial reservoir for the phyllosphere. The phyllosphere plays the role of bridge to link soil and feces biotope through its fluctuated condition. However, there was only fungal migration running through the ecosystem to link all the biotopes. These findings promoted our understanding of the biotope contribution to microbial migration and improved the knowledge of microbial linkages in the grazed grassland ecosystem.

We consider the spread of an infectious disease in a heterogeneous environment modeled as a network of patches. We focus on the invasibility of the disease, as quantified by the corresponding value...

p-Type BiSbTe alloys possess the highest ZT near room temperature, but inferior mechanical properties due to the atomically layered structure with weak van der Waals interactions. Here we report the successful preparation of porous BiSbTe alloys by sequential high-pressure synthesis, ball milling, and spark plasma sintering. Porosity usually has a negative effect on the material's mechanical properties. However, both thermoelectric and mechanical properties of our porous bulks are greatly enhanced, which benefit from the unique microstructure featuring closely bonded equiaxed grains and uniformly distributed pores (with a porosity of ca. 0.15). The optimal Bi0.42Sb1.58Te3 shows a maximum ZT of 1.27 around 350 K and an average ZT of 1.15 in the measured temperature range of 298–463 K. Furthermore, excellent mechanical properties including hardness, bending and compressive strengths are achieved in these porous samples, which are competitive with (or even better than) those of dense samples. The current structural architecture strategy can promote the development of porous thermoelectric materials, especially materials with similar anisotropic crystal structures.

A co-contaminated environment with metals and antibiotics ultimately provides exposing of bacteria to metals and antibiotics at the same time and prevails co-contamination in the environment. This study objective, to explore the efficacy of sublethal concentrations of copper ions contaminated with tetracycline to antibiotic resistance in sensitive strain E. coli K12. We proved that copper ions and tetracycline co-contaminated environments could considerably enhance the mutation frequencies of chloramphenicol and polymyxin B resistance in antibiotic susceptible E. coli; however, the corresponding copper ions and tetracycline alone showed weaker effects. Results also demonstrated that the relatively high sublethal concentrations of copper ion and tetracycline co-contaminated environment could induce much higher antibiotic resistance compared to the low sublethal and the control groups. Whole-genome characterization results indicated the variability of genotype and phenotype involved in antibiotic resistance. In addition, the evolved resistant strains displayed hereditary resistance after 5 round culture cycles in LB broth over 5 days. Results implied that co-contamination with metals and antibiotics environment could fortify the resistance, and might further contribute to the induction and dissemination of antibiotic resistance in metal and antibiotic co-contaminated environment.

Context Re-yan-ning mixture (RYNM) is a new national drug approved by China's State Food and Drug Administration for the treatment of colds, simple pneumonia and acute bronchitis. Objective To determine the mechanism of action of RYNM in the treatment of bacterial pneumonia. Materials and methods Using the network pharmacology approach, the multiple components, component candidate targets and multiple therapeutic targets of RYNM were screened and functionally enriched. Also, we established a rat Streptococcus pneumonia model to verify the results of network pharmacology enrichment analysis. Forty male SPF Sprague Dawley rats were divided into four groups of 10 rats: control (normal saline), model (normal saline), levofloxacin-intervened and RYNM-intervened groups. IL-10, NOS2, COX-1, IL-6, TNF-α and NF-κB in serum and BALF were detected by ELISA. Western blot detected IL-17, IL-6, TNF-α, COX-2 and Bcl-2. Results The network pharmacology approach successfully identified 48 bioactive components in RYNM, and 65 potential targets and 138 signal pathways involved in the treatment of Streptococcus pneumonia with RYNM. The in vivo experiments indicated that model group has visible inflammation and lesions while RYNM and levofloxacin groups have not. The RYNM exhibited its therapeutic effects on Streptococcus pneumonia mainly via the regulation of cell proliferation and survival through the IL-6/IL-10/IL-17, Bax/Bcl-2, COX-1/COX-2, NF-κB and TNF-α signalling pathways. Discussion and conclusions The present study demonstrated the protective effects of RYNM on Streptococcus pneumonia, providing a potential mechanism for the treatment of bacterial pneumonia with RYNM.

Glassy carbon (GC) is a type of non-graphitizing disordered carbon material at ambient pressure and high temperatures, which has been widely used due to its excellent mechanical properties. Here we report the changes in the microstructure and mechanical properties of GC treated at high pressures (up to 5 GPa) and high temperatures. The formation of intermediate sp2–sp3 phases is identified at moderate treatment temperatures before the complete graphitization of GC, by analyzing synchrotron X-ray diffraction, Raman spectra, and transmission electron microscopy images. The intermediate metastable carbon materials exhibit superior mechanical properties with hardness reaching up to 10 GPa and compressive strength reaching as high as 2.5 GPa, nearly doubling those of raw GC, and improving elasticity and thermal stability. The synthesis pressure used in this study can be achieved in the industry on a commercial scale, enabling the scalable synthesis of this type of strong, hard, and elastic carbon materials.

A novel, thermally resistant, dual-phase Mg alloy was prepared, and the microstructural evolution and tensile properties were investigated. The results showed that the Mg alloy matrix mainly consis...

The Q-factor is an important physical parameter for characterizing the absorption and attenuation of seismic waves propagating in underground media, which is of great significance for improving the resolution of seismic data, oil and gas detection, and reservoir description. In this paper, the local centroid frequency is defined using shaping regularization and used to estimate the Q values of the formation. We propose a continuous time-varying Q-estimation method in the time-frequency domain according to the local centroid frequency, namely, the local centroid frequency shift (LCFS) method. This method can reasonably reduce the calculation error caused by the low accuracy of the time picking of the target formation in the traditional methods. The theoretical and real seismic data processing results show that the time-varying Q values can be accurately estimated using the LCFS method. Compared with the traditional Q-estimation methods, this method does not need to extract the top and bottom interfaces of the target formation; it can also obtain relatively reasonable Q values when there is no effective frequency spectrum information. Simultaneously, a reasonable inverse Q filtering result can be obtained using the continuous time-varying Q values.

Based on the purpose of solving the “secondary absorption” of adjacent nanowires and the lateral emission in the GaN nanowire arrays (NWAs) cathode, an exponential-doping and graded Al compositional GaN NWAs photocathode is proposed, which could generate internal electric field to increase the quantum efficiency (QE) of top surface, and the introduction of an external electric field promote the side-emission electrons to shift toward the collecting side. The QE and collection efficiency (CE) of exponential-doping and graded compositional GaN NWAs under different array structure parameters, incident angles and external electric field intensities are analyzed. The results show that although the collection ratio of emitted electrons in the exponential-doping GaN NWAs is higher, the graded Al compositional photocathode with a stronger built-in electric field can obtain better CE under the application of an external electric field, and the peak value can reach 33.2% in a specific structure. External electric field has a more significant effect on the CE of uniform-doping GaN NWAs. The solutions provided in this study can make the GaN NWAs photocathode more suitable for the strict requirements of vacuum electron sources

Increasing levels of atmospheric CO2 are expected to enhance crop yields and alter soil greenhouse gas fluxes from rice paddies. While elevated CO2 ( E CO 2 ) effects on CH4 emissions from rice paddies have been studied in some detail, little is known how E CO 2 might affect N2 O fluxes or yield-scaled emissions. Here, we report on a multi-site, multi-year in-situ FACE (free-air CO2 enrichment) study, aiming to determine N2 O fluxes and crop yields from Chinese subtropical rice systems as affected by E CO 2 . In this study, we tested various N fertilization and residue addition treatments, with rice being grown under either E CO 2 (+200 μmol/mol) or ambient control. Across the six site-years, rice straw and grain yields under E CO 2 were increased by 9%-40% for treatments fertilized with ≥150 kg N/ha, while seasonal N2 O emissions were decreased by 23%-73%. Consequently, yield-scaled N2 O emissions were significantly lower under E CO 2 . For treatments receiving insufficient fertilization (≤125 kg N/ha), however, no significant E CO 2 effects on N2 O emissions were observed. The mitigating effect of E CO 2 upon N2 O emissions is closely associated with plant N uptake and a reduction of soil N availability. Nevertheless, increases in yield-scaled N2 O emissions with increasing N surplus suggests that N surplus is a useful indicator for assessing N2 O emissions from rice paddies. Our findings indicate that with rising atmospheric CO2 soil N2 O emissions from rice paddies will decrease, given that the farmers' N fertilization is usually sufficient for crop growth. The expected decrease in N2 O emissions was calculated to compensate 24% of the simultaneously observed increase in CH4 emissions under E CO 2 . This shows that for an agronomic and environmental assessment of E CO 2 effects on rice systems, not only CH4 emissions, but also N2 O fluxes and yield-scaled emissions need to be considered for identifying most climate-friendly and economically viable options for future rice production.

The design and synthesis of superhard carbon nitrides have always been a focus of attention. Recently, an experiment has revealed the existence of the previously predicted three-dimensional strongl...

There have been reports of ignition of high-pressure hydrogen during its sudden release for unexplained reasons and ignition mechanism still need to be further investigated. In this paper, mechanism of spontaneous ignition of high-pressure hydrogen during its sudden release into the L-shaped tube is investigated. LES, EDC model, 10-step like opening process of burst disk and 18-step detailed hydrogen combustion mechanism are employed. Three cases with burst pressures of 2.16, 6.21, and 9.10 MPa are simulated. It is found that shock wave is strongly reflected after it hits the tube corner wall, forming a reflected-shock-affected region and an energy conversion region with higher temperature, greater pressure and lower velocity. Afterwards, the reflected shock wave moving forward is reflected several times by the tube wall until it disappears and oblique shock is generated. After the hydrogen/air mixture enters the corner, it extends downstream along inner wall and separated from the main hydrogen/air mixture. The reflected shock wave moving backward interacts with the expansion waves and increases the temperature and pressure again, but spontaneous ignition cannot be initiated. Three mechanisms of spontaneous ignition of high-pressure hydrogen in the L-shaped tube are proposed eventually. The results reproduce the experimental spontaneous ignition conditions and positions, indicating that the numerical models can be applied as a tool for hydrogen safety engineering.

This brief focuses on the controllability of star-shaped networks, where the nodes are identical multi-input/multi-output (MIMO) linear time-invariant (LTI) systems. Some necessary and sufficient conditions on the controllability of undirected and directed star networks are established, respectively. These conditions are more easily-verified, which show the effect of the node-system dynamics, inner interactions and external control inputs on the network controllability explicitly. Moreover, some necessary conditions are further derived, which are more straightforward and intuitive. The effectiveness of the new conditions is illustrated by some examples.

Clamshell (CS) bio-filler derived from clam shells was produced and then applied as a synergist in waterborne intumescent fire-retardant coatings. Fire protection and smoke density tests show that the combination of CS bio-filler and intumescent flame retardant (IFR) exhibits excellent synergistic effect on reducing the flame spread index (FSR), char index, weight loss, equilibrium backside temperature and smoke density rating (SDR) of the intumescent coatings. Especially, the FC-3 sample containing 52 wt% IFR and 3 wt% CS bio-filler exhibits the lowest FSR and SDR values, which are 68.3% and 37.3%, respectively, lower than those of FC-0 sample with 55 wt% IFR. The results from the accelerated ageing test show that the combination of IFR and CS imparts super durability of smoke suppression and flame-retardant properties to the intumescent coatings, exhibiting excellent anti-ageing properties. Char residue analysis demonstrates that the FC-3 sample containing 3 wt% CS bio-filler shows higher mass ratios of O/C, N/C and P/C than those of FC-0 without CS bio-filler, indicating more P, N and O-containing cross-linking structures remained in the FC-3 char, thus imparting high char-forming ability and thermal stability to the coatings, as supported by the results of thermogravimetric (TG) analysis and Fourier transform infrared spectroscopy (FTIR) analysis.

Significance We recovered the world’s thickest continuous loess record from the southern margin of the Taklimakan desert, a global-scale dust source area. The continuous high-resolution grain size and flux records of dust emission, reflecting histories of aridity and westerlies climate, indicate an extant dry climate, desert area, and stable land surface supporting continuous loess deposition at least since ∼3.6 Ma, and that global cooling, rather than Tibet uplift, modulated the histories of aridity and westerlies climate changes in inland Asia since ∼3.6 Ma. Moreover, our study may suggest potential positive linkages and feedback among dust emission, marine biogeochemical activity, atmospheric CO2, and global cooling, which might provide insights into dynamics of Earth’s climate system and improve predictions for the future., Midlatitude Asia (MLA), strongly influenced by westerlies-controlled climate, is a key source of global atmospheric dust, and plays a significant role in Earth’s climate system . However, it remains unclear how the westerlies, MLA aridity, and dust flux from this region evolved over time. Here, we report a unique high-resolution eolian dust record covering the past 3.6 Ma, retrieved from the thickest loess borehole sequence (671 m) recovered to date, at the southern margin of the Taklimakan desert in the MLA interior. The results show that eolian dust accumulation, which is closely related to aridity and the westerlies, indicates existence of a dry climate, desert area, and stable land surface, promoting continuous loess deposition since at least ∼3.6 Ma. This region experienced long-term stepwise drying at ∼2.7, 1.1, and 0.5 Ma, coeval with a dominant periodicity shift from 41-ka cyclicity to 100-ka cyclicity between 1.1 Ma and 0.5 Ma. These features match well with global ice volume variability both in the time and frequency domains (including the Mid-Pleistocene Transition), highlighting global cooling-forced aridity and westerlies climate changes on these timescales. Numerical modeling demonstrates that global cooling can dry MLA and intensify the westerlies, which facilitates dust emission and transport, providing an interpretive framework. Increased dust may have promoted positive feedbacks (e.g., decreasing atmospheric CO2 concentrations and modulating radiation budgets), contributing to further cooling. Unraveling the long-term evolution of MLA aridity and westerlies climate is an indispensable component of the unfolding mystery of global climate change.

Breakthroughs have been made for the natural gas exploration of the Middle Devonian and the Middle Permian formations in the Sichuan Basin in recent years. Nevertheless, its natural gas source is still not clear, which then affects the next exploration deployment decision. A comprehensive study is conducted on the geochemical characteristics of the Middle Devonian and the Middle Permian natural gas, the biomarkers of reservoir bitumen, and the source rocks. The results show that these natural gases are secondary cracking dry gas that includes more than 86% of methane content, a small amount of ethane, propane, and a non-hydrocarbon gas (e.g., nitrogen, carbon dioxide, and hydrogen sulfide). The natural gas maturity varies slightly in different regions. The carbon and hydrogen isotope values of natural gas are as follows: δ13C1 ranges from −35.7‰ to −27.3‰, δ13C2 ranges from −38.7‰ to −26.6‰, δ13C3 ranges from −37‰ to −26.5‰, δ2HCH4 ranges from −141‰ to −138‰, and δ2HC2H6 ranges from −164‰ to −112‰. The isotope values indicate that the genetic type of natural gas is the sapropelic type and the mixture type is dominated by sapropelic type. The difference between natural gas values of δ13C1, δ13C2, and δ2HCH4 in different regions is related to the contribution ratio of source rocks from different ages. The gases of the Middle Devonian and the Middle Permian of the Shuangyushi structure in Northwestern Sichuan, the Middle Permian of Southwestern Sichuan, and the Middle Permian of Paleo-uplift in Central Sichuan are mainly derived from the Cambrian Qiongzhusi Formation and the Middle-Lower Permian source rocks. The Middle-Upper Permian natural gases of the volcanic reservoir in Southwestern Sichuan is mainly from the Qiongzhusi source rock. The Middle Permian natural gases of the Hewanchang structure in Northwestern Sichuan, Eastern Sichuan, and Southern Sichuan are mainly derived from the Silurian Longmaxi source rock. The research results have important guiding significance for developing exploration and deployment solutions for natural gas of the Middle Devonian and the Middle Permian formation in the Sichuan Basin.

传统陶瓷材料的刚性结构变形能力非常有限, 通常在很小的应变下就发生断裂. 具有层状原子结构的陶瓷, 原子层间存在较弱的相互作用, 因而具有大的变形潜力. 我们以氮化硼(BN)为例, 研究了该类陶瓷的室温压缩行为. 分别以洋葱结构BN纳米颗粒和石墨状六方BN纳米片为原料, 采用放电等离子烧结(SPS)技术分别制备了BN-I和BN-II陶瓷材料. 在BN-I中, 随机取向的BN纳米薄片构成三维互锁的结构, 而在BN-II中, BN纳米薄片表现出垂直于SPS压缩方向的择优取向. BN-I的压缩强度为 343 MPa, 断裂应变为4.2%. 相比之下, BN-II的强度和应变分别为 112 MPa 和2.2%. 不同的微观组织结构导致了BN-I和BN-II压缩性能的差异. 此外, 这两种陶瓷材料均表现出1.1%的塑性变形. 该研究表明, 对于具有层状原子结构的陶瓷, 其纳米片作为结构基元构筑成无(或低)择优取向的三维互锁结构, 有望同时提高其强度和变形能力.

In recent years, Spin-Transfer-Torque Magnetic Random Access Memory (STT-MRAM) has been considered as one of the most promising non-volatile memory candidates for in-memory computing. However, system-level performance gains using STT-MRAM for in-memory computing at deeply scaled nodes have not been assessed with respect to more mature memory technologies. In this letter, we present perpendicular magnetic tunnel junction (pMTJ) STT-MRAM devices at 28nm and 7nm. We evaluate the system-level performance of convolutional neural network (CNN) inference with STT-MRAM arrays in comparison to Static Random Access Memory (SRAM). We benchmark STT-MRAM and SRAM in terms of area, leakage power, energy, and latency from 65nm to 7nm technology nodes. Our results show that STT-MRAM keeps providing $\sim 5\times $ smaller synaptic core area, $\sim 20\times $ less leakage power, and $\sim 7\times $ less energy than SRAM when both devices are scaled from 65nm to 7nm. With the emerging need for low power computation for a broad range of applications such as internet-of-things (IoT) and neural network (NN), STT-MRAM can offer energy-efficient and high-density in-memory computing.

Printed circuit board (PCB) defect detection is one of the primary problems in quality control of the most electronic products. Usually, the industrial PCB imagery has high resolution, but defects take up a small proportion (often only ∼10 pixels in size), which makes it difficult to use traditional machine vision methods. To this end, a novel single shot object detector (SSDT) is proposed for tiny defect detection in PCBs in this study. Specifically, a semantic ascending module, which propagates the semantic property of deep layers to shallow layers, is presented by fusing features of different levels. An attention mechanism is utilised to learn the relationship of the features to be fused across channels and a shuffle module is used to eliminate the aliasing effect after fusion. Moreover, the improved non-maximum suppression is proposed to extenuate the overlap effect for testing the whole PCB image. The proposed detector can rapidly detect tiny defects and the results of SSD and SSDT are further compared not only in PCB defect dataset but also the object detection public dataset PASCAL VOC2007 where SSDT achieves 81.3% mAP, better than SSD (79.5%). In final, the proposed detector is validated to be robust to rotation and blur.

The process of catalytic ozonation shows promise for the degradation of refractory contaminants. A doped MnO2/Al2O3 catalyst was prepared and utilized to achieve catalytic microbubbles ozonation fo...

To meet increasing demands, tea plantations are rapidly expanding in China. Although the emissions of nitrous oxide ( N2O ) and nitric oxide (NO) from tea plantations may be substantially influenced by soil pH reduction and intensive nitrogen fertilization, process model-based studies on this issue are still rare. In this study, the process-oriented biogeochemical model, Catchment Nutrient Management Model – DeNitrification-DeComposition (CNMM-DNDC), was modified by adding tea-growth-related processes that may induce a soil pH reduction. Using a dataset for intensively managed tea plantations at a subtropical site, the performances of the original and modified models for simulating the emissions of both gases subject to different fertilization alternatives and stand ages were evaluated. Compared with the observations in the early stage of a tea plantation, the original and modified models showed comparable performances for simulating the daily gas fluxes (with a Nash–Sutcliffe index (NSI) of 0.10 versus 0.18 for N2O and 0.32 versus 0.33 for NO), annual emissions (with an NSI of 0.81 versus 0.94 for N2O and 0.92 versus 0.94 for NO) and annual direct emission factors (EF d s). For the modified model, the observations and simulations demonstrated that the short-term replacement of urea with oil cake stimulated N2O emissions by ∼62 % and ∼36 % and mitigated NO emissions by ∼25 % and ∼14 %, respectively. The model simulations resulted in a positive dependence of EF d s of either gas on nitrogen doses, implicating the importance of model-based quantification of this key parameter for inventory purposes. In addition, the modified model with pH-related scientific processes showed overall inhibitory effects on the gases' emissions in the middle to late stages during a full tea plant lifetime. In conclusion, the modified CNMM-DNDC exhibits the potential for quantifying N2O and NO emissions from tea plantations under various conditions. Nevertheless, wider validation is still required for simulation of long-term soil pH variations and emissions of both gases from tea plantations.

Wildfires play an important role in earth climate systems, with influences on the atmosphere, vegetation distributions, and human survival. Considerable debate persists with regard to the relationship between wildfire occurrence and climate. Some records indicate relatively fewer wildfires during glacial times as compared to the Holocene, while others support the opposite view. These contradictory views need to be resolved to fully understand the relationship and controlling mechanisms that relate biomass burning to climate. In this study, black carbon (BC), including both char and soot, is used to reconstruct wildfire history over the past 32 ka from Qinghai Lake. BC, especially as micrometer-size soot, is mainly transported via the atmosphere, and can carry evidence of wildfires over long distances. Qinghai Lake's position on the northeastern edge of the Tibet Plateau is especially well-suited to such long-distance transport, with a potentially global climatic impact. We observed a significantly positive relationship between char and soot fluxes that suggest that the Qinghai Lake BC record is dominated by material transported through the atmosphere in large-scale wildfires. We find that relatively more wildfires occurred during cold-dry late glacial time (32.8–11.7 ka), and fewer wildfires during the warm-humid Holocene. Our study demonstrates that drought is the key factor that determines wildfire occurrences on an orbital time-scale. These fundamental and persistent patterns can assist in our understanding of climate-wildfire interactions and in the assessment of feedbacks on the global climate system, for example, through the well-known relationship between soluble iron and atmospheric CO2.

The initial occurrence of desert landscape or eolian sand dunes is thought to have occurred long before the Pleistocene, and desertification was subsequently enhanced under cold, dusty glacial conditions. However, when and how the desert landscape persisted during both glacial and interglacial periods, defined as “permanent” desert here, remain elusive. Here, we present carbonate carbon isotope and grain-size records from the Tarim Basin, western China, revealing a detailed desertification history for the Taklimakan Desert. Our records demonstrate that after desiccation of episodic lakes at ca. 4.9 Ma, alternations of eolian sand dunes and fluvial and playa-like conditions persisted for a long period until 0.7 Ma in the Tarim Basin. The onset of permanent desert landscape around 0.7–0.5 Ma occurred concurrently with the climatic reorganization across the mid-Pleistocene transition. The occurrence of mountain glaciers on the Tibetan Plateau and atmospheric circulation changes may have controlled the formation and extreme aridification of the permanent desert in inland Asia since the mid-Pleistocene transition.

Ultrahard nanotwinned diamond (nt-D) is an ideal material for next-generation high-precision, high-efficiency cutting tools, due to its high hardness, enhanced fracture toughness, and increased oxidation resistance temperature, when compared with natural diamond. However, a critical problem that limits the application of such material is the grinding and polishing of nt-D material into suitable shapes. In this study, we confirmed the feasibility of classical mechanical polishing for nt-D through amorphization transition. The effect of mechanical loading and the catalysis of Fe nano-particles work together, promoting the transformation of nt-D into a hard sp2-sp3 amorphous carbon. The surface of the amorphous carbon layer and the interface between amorphous carbon and nt-D were both smooth after polishing. The results are valuable for the mechanical processing and further applications of ultrahard nanotwinned diamond.

Significance Reconstructing past extreme weather events, such as tropical cyclones and cold surges, using natural paleoclimate archives can lengthen the instrumental data and help us have a broader understanding of the range of weather variability not evident in instrumental record. However, the time resolution of current paleoarchives, from millennial to monthly at best, is usually too low to explore past weather events. Here we found that the Tridacna shells from South China Sea, western Pacific, have continuous daily growth bands, and several daily to hourly resolution biogeochemical proxy records were developed. Our results demonstrate that these records can record nearby tropical cyclones and cold surges, indicating that Tridacna shells have the potential to be an unprecedented ultra-high-resolution archive for paleoweather reconstructions., Paleoclimate research has built a framework for Earth’s climate changes over the past 65 million years or even longer. However, our knowledge of weather-timescale extreme events (WEEs, also named paleoweather), which usually occur over several days or hours, under different climate regimes is almost blank because current paleoclimatic records rarely provide information with temporal resolution shorter than monthly scale. Here we show that giant clam shells (Tridacna spp.) from the tropical western Pacific have clear daily growth bands, and several 2-y-long (from January 29, 2012 to December 9, 2013) daily to hourly resolution biological and geochemical records, including daily growth rate, hourly elements/Ca ratios, and fluorescence intensity, were obtained. We found that the pulsed changes of these ultra-high-resolution proxy records clearly matched with the typical instrumental WEEs, for example, tropical cyclones during the summer−autumn and cold surges during the winter. When a tropical cyclone passes through or approaches the sampling site, the growth rate of Tridacna shell decreases abruptly due to the bad weather. Meanwhile, enhanced vertical mixing brings nutrient-enriched subsurface water to the surface, resulting in a high Fe/Ca ratio and strong fluorescence intensity (induced by phytoplankton bloom) in the shell. Our results demonstrate that Tridacna shell has the potential to be used as an ultra-high-resolution archive for paleoweather reconstructions. The fossil shells living in different geological times can be built as a Geological Weather Station network to lengthen the modern instrumental data and investigate the WEEs under various climate conditions.

Materials with superhard and conductive properties are valuable and have great potential applications in multifunctional devices under extreme conditions. Here we propose two carbon polymorphs with superior superhard and conductive properties via first-principle calculations. These two carbon phases, called Orth-C10 and Orth-C10’, contain 10 carbon atoms buckled through sp2-sp3 hybridized bonds in an orthorhombic unit cell with Pmmm and Pmm2 symmetry, which are energetically more stable than fullerene C60 at 0 GPa, and more favorable than graphite at the pressure above 34.4 and 45.4 GPa, respectively. More importantly, their Vickers hardness are as high as 62.2 and 59.9 GPa, respectively, close to the hardness of cubic boron nitride, the second-hardest material. Specially, Orth-C10’ owns ultra-high axial incompressibility even beyond that of diamond at a pressure above 40 GPa. Furthermore, both Orth-C10 and Orth-C10’ are metallic, which is rare in superhard carbon polymorphs. These outstanding natures make Orth-C10 and Orth-C10’ potential materials for electronic devices and mechanical tools.

This experiment was conducted to investigate the effects of live yeast and yeast cell wall polysaccharides on growth performance, rumen function and plasma lipopolysaccharides (LPS) content and immunity parameters of beef cattle. Forty Qinchuan cattle were randomly assigned to one of four treatments with 10 replicates in each treatment. The dietary treatments were: control diet (CTR), CTR supplemented with 1 g live yeast (2×1010 live cell g−1 per cattle per day (YST1), CTR supplemented with 2 g live yeast per cattle per day (YST2) and CTR supplemented with 20 g of yeast cell wall polysaccharides (30.0%≤β-glucan≤35.0%, and 28.0%≤mannanoligosaccharide≤32.0%) per cattle per day (YCW). The average daily gain was higher (P=0.023) and feed conversion ratio was lower (P=0.042) for the YST2 than the CTR. The digestibility of neutral detergent fiber (P=0.039) and acid detergent fiber (P=0.016) were higher in yeast supplemented groups. The acetic acid:propionic acid of the YST2 was lower compared with the CTR (P=0.033). Plasma LPS (P=0.032), acute phase protein haptoglobin (P=0.033), plasma amyloid A (P=0.015) and histamine (P=0.038) were lower in the YST2 compared with the CTR. The copies of fibrolytic microbial populations such as Fibrobacter succinogenes S85, Ruminococcus albus 7 and Ruminococcus flavefaciens FD-1 of the YST2 were higher (P

Near infrared spectra (NIR) technology is a widespread detection method with high signal to noise ratio (SNR) while has poor modeling interpretation due to the overlapped features. Alternatively, mid-infrared spectra (MIR) technology demonstrates more chemical features and gives a better explanation of the model. Yet, it has the defects of low SNR. With the purpose of developing a model with plenty of characteristics as well as with higher SNR, NIR and MIR technologies are combined to perform high-level fusion strategy for quantitative analysis. A novel chemometrical method named as Mahalanobis distance weighted (MDW) is proposed to integrate NIR and MIR techniques comprehensively. Mahalanobis distance (MD) based on the principle of spectral similarity is obtained to calculate the weight of each sample. Specifically, the weight is assigned to the inverse ratio of the corresponding MD. Besides, the proposed MDW method is applied to NIR and MIR spectra of active ingredients in deltamethrin and emamectin benzoate formulations for quantitative analysis. As a consequence, the overall results show that the MDW method is promising with noticeable improvement of predictive performance than individual methods when executing high-level fusion for quantitative analysis.

The safety of petrol stations is critical because it stores flammable and explosive gasoline and diesel. Therefore, appropriate fire apparatuses should be deployed to petrol stations in case of a fire emergency. In this work, we proposed a regional evaluation model to predict the fire apparatus requirements of petrol stations based on travel times extracted from online maps. The travel time of the minimum fire apparatus requirements (1 water truck and 1 foam truck) are determined to be within 4 min. To validate the model, 37 fire stations and 458 petrol stations in Changsha, China were considered as case studies leading to 144 evaluation scenarios. The results showed the fire apparatus requirement scores of 144 scenarios were ranged from 47.69 to 56.69 (less than 60) out of 100, which were in bad levels. Furthermore, results from visualization showed that the worst part of scores were petrol stations in rural areas. Therefore, these petrol stations in rural areas should be equipped with more fire extinguishers and foam extinguishing systems.

Rational design of hollow micro- and/or nano-structured cathodes as sulfur hosts has potential for high-performance lithium-sulfur batteries. However, their further commercial application is hindered because infusing sulfur into hollow hosts is hard to control and the interactions between high loading sulfur and electrolyte are poor. Herein, we designed hierarchical porous hollow carbon nanospheres with radially inwardly aligned supporting ribs to mitigate these problems. Such a structure could aid the sulfur infusion and maximize sulfur utilization owing to the well-ordered pore channels. This highly organized internal carbon skeleton can also enhance the electronic conductivity. The hollow carbon nanospheres with further nitrogen-doping as the sulfur host material exhibit good capacity and excellent cycling performance (0.044 % capacity degradation per each cycle for 1000 cycles).

n-Fatty acids (n-FAs) are widely investigated in lake sediments, yet less attention has been given to soil sedimentary n-FAs primarily derived from terrestrial plants. In this study, we performed an analysis of n-FA distributions in modern plants on the Loess Plateau, China. It showed that n-FAs were generally dominated by n-C16, and that short-chain (C16–C20), medium-chain (C22–C26) and long-chain (C28–C32) n-FAs accounted for 49.7%, 33.7% and 16.6%, respectively. The LTR (long-chain/total ratio), and medium-chain EOP (even/odd predominance) are likely to differentiate between dicots and monocots in modern plants. It is believed that this study will promote the paleo-application of soil sedimentary n-FAs on the Loess Plateau.

Introduction The on-line analysis of active pharmaceutical ingredients (APIs) during the extraction process in herbal medicine is a challenge. Establishing a reliable and robust model is a critical procedure for the industrial application of on-line near-infrared (NIR) technology. Objective To evaluate the advantages of on-line NIR model development using system optimisation strategy, Glycyrrhiza uralensis Fisch was used as a case. The content of liquiritin and glycyrrhizic acid was monitored during pilot scale extraction process of Glycyrrhiza uralensis Fisch in three batches. Methods High-performance liquid chromatography (HPLC) was used as reference method for content determination of liquiritin and glycyrrhizic acid. The quantitative models of on-line NIR were developed by system optimisation of processing trajectory. For comparison, the models were simultaneously developed by stepwise optimisation. Moreover, the modelling parameters obtained through system optimisation and stepwise optimisation were reused in three batches. Root mean square error of prediction (RMSEP) and residual predictive deviation (RPD) were used to assess the model quality. Results The average values of RMSEP and RPD of systematic model for liquiritin in three batches were 0.0361, 4.1525 (first batch), 0.0348, 4.7286 (second batch) and 0.0311, 4.9686 (third batch), respectively. In addition, the modelling parameters of systematic model for glycyrrhizic acid in three batches were same, and the average values of RMSEP and RPD were 0.0665 and 5.2751, respectively. The predictive performance and robustness of systematic models for the three batches were better than the comparison models. Conclusion The work demonstrated that system optimisation quantitative model of on-line NIR could be used to determine the contents of liquiritin and glycyrrhizic acid during Glycyrrhiza uralensis Fisch extraction process.

Ternary boron-carbon-nitrogen (B-C-N) compounds are considered to possess hardness comparable to diamond and thermal stability comparable to c-BN. Explorations for desirable B-C-N phases have been continuous. However, the nonconductive properties of most B-C-N compounds narrow the applications of these compounds. Herein, we propose a sp2-sp3 hybridized phase of t-B2C3N2, which consists of diamond-like BC blocks connected with single N-N bonds. Elastic constants and phonon dispersion curves confirm that t-B2C3N2 is mechanically and dynamically stable. The structure processes 2D metallicity in a strong 3D network. Furthermore, hardness and electron-phonon calculations reveal that t-B2C3N2 is superhard and superconductive with a superconducting critical temperature reaching 2.3 K.

Reported herein is the investigation of a unique cathode candidate for Li–S batteries, i.e. Ni3S2/(N, S)-RGO-type hybrid materials, which are expected to optimize battery performance by elevating the utilization of sulfur and chemically confining the adsorption/diffusion of polysulfide. Versatile structural and compositional characterizations confirmed the uniform growth and strong chemical coupling of nanostructured Ni3S2 on the N/S co-doped RGO matrix. Rich physical and chemical properties were revealed, namely, the large specific surface area and pore volume, which are beneficial for polysulfide capture, and the 3D conductive network supporting rapid charge transfer to the Ni3S2-polysulfide interface to improve the intrinsic equilibrium of the polysulfide. Specifically, the integration of ∼28.2 wt% of Ni3S2 produced a highly pleated composite with the largest BET specific surface area (618 m2 g−1) and pore volume (1.73 cm3 g−1) among the hybrids studied. This typical material also performed the best in the battery test, recording ultra-high cycling stability over 1000 cycles at the current density of 3C with the capacity decay of 0.023% per cycle. As the sulfur loading per unit area became as dense as 5.8 mg cm−2, the specific capacities were measured as 6.72 mA h cm−2 (at 0.05C), while the capacity retention for the 200-cycle test (at 1C) was still preserved above 72.5%.

Shipping containers are tokens of multimodal international transportation and rapid logistics. Container deliveries are scheduled to satisfy rapidly changing requirements. Unpredictable increases in costs and unforeseeable events such as pandemics compel ship owners and managers to adopt risk minimization measures. This study addresses one issue: how to determine an alternative port of call from massive data to offer a realistic destination change recommendation for a container vessel. Recommendation algorithms have become ubiquitous and are used effectively in other fields, but there is no such model for the port of call selection or recommendation. Large scale automatic identification system (AIS) data are readily available. We developed a computational framework based on a novel natural language programming algorithm that was tailored to support port recommendation rather than use a conventional adjacency matrix method. We mined large scale AIS data to construct sequential berth records for container vessels and mapped each port onto a vector in an embedded space. The natural language neural programming algorithm can suggest ports similar to the scheduled ports of call that were unable to offer service. The recommendations were validated with geo-analysis of sailing distance and could offer viable alternative ports to shipping managers.