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• Rice cultivation areas continue to expand from tropical and subtropical areas to high altitudes and high latitudes, and the chances of rice suffering from chilling injury gradually increase. • Regional-scale chlorophyll fluorescence data show a close correlation with the monitoring chilling injury losses in rice. • Real-time hazard assessment of the occurrence of chilling injury in rice and its intensity, and estimation of the possible loss of rice yield caused by different disaster-causing intensities. Rice is a warm-temperature crop, and sterile-type chilling injuries may be induced by acute periods of low-temperature weather during the reproductive growth period. This study considered the daily mean and minimum temperatures in Northeast China from 1979 to 2018 as influencing factors to construct a process-based rice accumulated intensity index (PARII) and hazard assessment model based on known crop disaster periods, analyzed the spatiotemporal distribution characteristics of chilling injury during the rice growth period (booting and flowering stages), used solar-induced chlorophyll fluorescence (SIF) and yield fluctuation data to calculate the adaptability of the hazard assessment model, and selected two typical events of disaster processes to verify the proposed real-time hazard assessment model. The change in the cumulative intensity index of rice sterile-type chilling injury indicated an increasing trend in chilling injury in the rice booting stage. Based on the probability density static hazard and cumulative probability dynamics, the results of real-time hazard analysis showed that the chilling injury hazard area was significantly expanded compared with the sterile-type chilling injury during the booting and flowering periods. The hazard value was greater than 0.2 in central and southeastern Heilongjiang, and the static hazard index was significantly negatively correlated with SIF and fluctuating yield, which indicated the chilling injury impacted rice yield and physiology. Regional-scale hazard levels were assessed by daily real-time hazard evaluation to highlight spatial heterogeneity in crop stress and damage. The results of this study provide a scientific basis for real-time risk assessment and management of chilling injury in rice crops and may support future adaptation strategies for addressing risks associated with severe low-temperature events. [Display omitted] [ABSTRACT FROM AUTHOR]

Highlights • We propose the Vernier effect induced by the birefringence in fiber-optic modal interferometers for sensitivity enhancement. • We experimentally demonstrate an ultrahigh RI sensitivity of 35,823.3 nm/RIU at low RI of 1.333 using a fiber coupler with the Vernier effect. • We apply this sensor for human cardiac troponin T detection, and a LOD of 1 ng/mL is achieved. Abstract We report a simple and effective method to improve the sensitivities of fiber-optic modal interferometers with birefringence induced Vernier effect. Taking optical microfiber coupler as an example, we study the sensitivity enhancement of a microfiber coupler for refractive index (RI) sensing both theoretically and experimentally in the RI range of 1.33–1.35 where bioassays are typically carried out. Numerical results show that by tracing the wavelength shifts of dips in the envelope formed by the Vernier effect, RI sensitivities can be improved by almost one order of magnitude compared to the sensors without the Vernier effect. Then we experimentally achieve an ultra-high sensitivity of 35,823.3 nm/RIU using a microfiber coupler with a width of 3.2 μm. More importantly, we apply this ultra-sensitive sensor to detect human cardiac troponin, and a limit of detection of 1 ng/mL is achieved. This sensor is simple in configuration andcan serve as a bio-photonic platform for clinical diagnostics environmental monitoring and food safety. [ABSTRACT FROM AUTHOR]

Polycrystalline ferrites Ni 0.5- x Cu 0.12 Zn 0.4 Co x Fe 1.98 O 4- δ with different cobalt-substituted contents ( x  = 0, 0.003, 0.006, 0.009, 0.012, 0.015) are synthetized via the solid-state reaction method. The magnetocrystalline anisotropy constant is calculated based on the law of approach to saturation. As the amount of cobalt substitution increases, the absolute value of the magnetocrystalline anisotropy constant first decreases and then rises due to the positive compensation by the Co 2+ ions. The value of the magnetocrystalline anisotropy constant tends to be zero for the samples with cobalt substitution contents in the range of 0.003–0.006. Meanwhile, when the cobalt substitution content is 0.003, the NiCuZn ferrite shows minimum ferromagnetic resonance linewidth (9.87 kA/m) and low dielectric loss tangent (tg δ ε , 1.1 × 10 −4 ) at 9.4 GHz as well as a high magnetization ( M s , 406 kA/m) and high squareness ratio ( B r / B s , 0.83). Furthermore, the linewidth contribution is identified by the anisotropy and porosity linewidth broadening model based on the spin-wave approach, and the results show that porosity linewidth broadening is the predominant effect. [ABSTRACT FROM AUTHOR]

Sensitive detection of cardiac biomarkers is critical for clinical diagnostics of myocardial infarction (MI) while such detection is quite challenging due to the ultra-low concentration of cardiac biomarkers. In this work, a label-free immunosensor based on optical microfiber coupler (OMC) has been developed for the ultrasensitive detection of cardiac troponin I (cTnI), a selective and highly sensitive biomarker of acute myocardial infarction (AMI). CTnI monoclonal antibodies were immobilized on the surface of the fiber through polyelectrolyte layer using layer-by-layer deposition technique. For refractive index sensing characterization, an ultra-high sensitivity of 91777.9 nm/RIU was achieved when the OMC works around the dispersion turning point, which is the highest experimental demonstration in the field of fiber-optic evanescent biosensors. For biosensing, the immunosensor with good specificity showed a linear wavelength shift in the range of 2–10 fg/mL and an ultra-low detection limit of 2 fg/mL. Such immunosensors have huge application potential for the detection of cardiac biomarkers of myocardial infarction due to simple detection scheme, quick response time, ease of handling and miniaturation. [ABSTRACT FROM AUTHOR]

In recent years, global warming has led to frequent waterlogging disaster (WLD), hindering the normal growth and development of crops, affecting the sustainable development of the peanut industry and food security in China. Henan Province, the main peanut-producing area with frequent WLD, was selected as the study area. Based on the soil-crop-atmosphere continuum system, this study constructed a comprehensive waterlogging index (CWI) to monitor waterlogging events. To determine the applicability of CWI, the standardized precipitation evapotranspiration index (SPEI) was calculated. A risk assessment model was constructed to evaluate the hazards of WLD during the different stages of development of spring peanut. The water stress at different growth stages of peanut on crucial physiological indices were studied to determine the natural vulnerability curve of WLD. As a consequence, based on the "Four-Factor" theory of disaster formation, this study established a dynamic WLD assessment model for peanut and evaluated the comprehensive risk of WLD in Henan from 1990 to 2020. The results indicated that the CWI is capable of accurately identifying waterlogging events and peanut responded significantly differently to water stress; the longer the duration of stress in the late growth period (LGP), the higher was the rate of yield reduction. The comprehensive risk of WLD to peanut rose from north to south during the three growth periods. During the LGP, high-risk regions constituted approximately 34.3% of the total population. This study provides a scientific basis and technical support for better exploration of peanut growth under waterlogging stress to manage and reduce the risk of WLD. • The comprehensive waterlogging index (CWI) can be used to identify waterlogging events. • Different water stress days in three periods had different effects on the growth of spring peanut. • Water stress in the late growth period had the greatest influence on the yield of spring peanut. • The risk was evaluated through "Four-Factor" theory, while the south of Henan had high-risk levels. [ABSTRACT FROM AUTHOR]

Due to the national nutrition crisis and the adjustment of planting structure, millet has once again become a widely planted cash crop in Northern China. However, as the climate warms in recent years, drought has occurred frequently and repeatedly in Northern China, which has seriously threatened millet production safety in this area. Therefore, it is urgent to clarify the hazard of millet drought disaster and provide reference for the formulation of millet disaster prevention and reduction measures. In this paper, combined with the water demand of millet in each growth period, Standardized Precipitation Requirement Index (SPRI) was selected to identify and quantify the drought disaster of millet. Considering the impact of different degrees of drought in different growth periods, a hazard assessment model is constructed to evaluate the hazard of millet drought disaster in Northern China under the background of climate change. The results show that: (1) SPRI can well characterize the drought of millet in Northern China. (2) In the context of climate change, millet drought in Northern China shows a trend of increasing intensity and decreasing frequency, and it is possible that millet drought will be even more severe in the future. (3) Combined with the hazard assessment model, millet drought in Northern China will still be dominated by middle hazard in the future, but the areas with high hazard will gradually increase, mainly distributed in northeast China, central and western Inner Mongolia and northern Gansu. The research results can be of great practical significance for the adjustment of agricultural production structure in the future, especially for the sustainable development of agriculture and the formulation of measures to prevent and resist agricultural disasters. [Display omitted] • We apply SPRI to identify millet drought by considering actual water demand. • Future changes of millet drought evaluated by CMIP6-GCM models. • Hazard assessment model was presented combined with disaster loss coefficient. • The areas with high hazard of millet drought will gradually increase in future. [ABSTRACT FROM AUTHOR]

The recognition of abrin is of great civil and military importance. As an alternative to general detecting techniques, such as enzyme-linked immunosorbent assay (ELISA) and electrochemiluminescence (ECL)-based assay, micro/nano optical fibers (MNFs) for the label-free detection of abrin have been investigated for the first time in this paper. The MNFs fabricated through chemical etching are robust and have excellent mechanical strength for practical applications. This MNF-based biosensors feature fast response, high sensitivity, and low cost. A limit of detection of 10 pg/mL was obtained using a MNF with a waist diameter of circa 1.0 μm, and the typical measurement time was less than 10 min. By taking advantage of the label-free detection, Langmuir kinetics fitting for the dynamic reaction curve suggested a large affinity constant between the antibody and abrin. Regeneration ability of the sensor was also demonstrated by the maintenance of high sensitivity and selectivity after releasing experiments. [ABSTRACT FROM AUTHOR]

Abstract: Sensitive and selective detection for cancer biomarkers is critical in cancer clinical diagnostics. In this work, we report a new optical microfiber (OMF) biosensor using gold nanoparticles (GNPs) as amplification labels for the detection of alpha-fetoprotein (AFP) in serum samples. By combining the unique optical property of OMFs and the strong optical absorption of GNPs, very high sensitivity and selectivity can be achieved. Critical parameters namely fiber diameter and GNP size were optimized for better performance. The limit of detection (LOD) of this sensor for AFP is 0.2ng/mL in PBS and 2ng/mL in bovine serum, which is comparable to conventional assays. The advantages of this biosensor are simple detection scheme, fast response time, and ease of miniaturization, which might make this biosensor a promising platform for clinical cancer diagnosis and prognosis. [Copyright &y& Elsevier]

Highlights: [•] A bent optical fiber taper is proposed for highly sensitive refractive index detection. [•] The peak wavelength is sensitive to external refractive index. [•] The tapered cladding in the downtaper enhances the sensitivity. [•] Higher sensitivity can be obtained from peak at longer wavelength. [•] A high sensitivity of 4000nm/RIU was experimentally obtained. [Copyright &y& Elsevier]

In this paper, we investigate photonic nanojets (PNJs) generated from silicon-based cuboids and grating structures. The cuboid structure consists of a base microcuboid and a nanocuboid sitting on top. By tuning the parameters of cuboids and surrounding medium, we show that ultra-narrow PNJs with spot sizes between 82 nm (~ λ /7.8) and 86 nm (~ λ /7.4) can be achieved under a 638 nm TE-polarized light illumination. These results are comparable to the solid immersion resolution limit of λ /7.8 for silicon lenses, but significantly exceeding the half wavelength limit in air. By arranging an array of hybrid-cuboids structures into a grating structure, we show that the PNJ resolution can be pushed beyond the solid immersion limit, reaching λ /8.3 with spot size ~77 nm. This is one of the highest optical resolutions reported to date for a visible light PNJ array generated by a grating and may find applications in sensing and lithography. [ABSTRACT FROM AUTHOR]

Recently, tunable photonic nanojets (PNJs) utilizing a mask have been investigated to produce narrow PNJs and curved PNJs (photonic hooks, PHs). Herein, a dielectric nano-layer is employed to tune the PNJs from a micro-cylinder. Symmetric and asymmetric illumination caused by the nano-layer are studied separately with finite element method. The results show that, for the symmetric illumination, narrow PNJs and twin PNJs (t-PNJs) can be generated through controlling the width of the layer. For the asymmetric illumination, it has the ability to produce PHs and asymmetric t-PNJs by changing the thickness of the nano-layer. Based on these results, an optical switch for light-route selection depending on the incident light wavelength is presented. This work may have great potential in the fields of optomechanical manipulation, super-resolution imaging and optical nanolithography. [ABSTRACT FROM AUTHOR]

• A quantitative assessment framework for ecosystem drought risk was established. • Nearly 45.4% of ecosystem vegetation in NEC has a moderate or high risk of drought. • Quantitative assessment of vulnerability is the key point to drought risk assessment. • The drought risk patterns driven by climate variability and human activities are different in farmland and natural vegetation. Given the significant increasing trend of droughts in Northeast China (NEC) under climate change, it is of particularly urgency to quantify the drought risk to vegetation in different ecosystems. Based on the theory of risk formation, we developed a quantitative framework for the assessment of ecosystem drought risk that integrates both drought hazard and vulnerability (sensitivity and adaptability). To quantitatively assess the drought risk to different vegetation types in NEC, we used long-term (1982–2015) normalized difference vegetation index (NDVI) data and standardized precipitation evapotranspiration index (SPEI) data. The effects of climate change and non-climatic factors (mainly human activities) on the NDVI dynamics and drought risk were analyzed using the partial least squares regression method to explore key drivers of risk formation. Our findings indicate that almost 45.4% of ecosystem vegetation in NEC is at a moderate or high risk of drought. Our findings indicate that vulnerability is key to NEC drought risk assessment, and adaptability plays an important role in regulating sensitivity. Land cover is the main driving factor for the spatial pattern of drought vulnerability in NEC, and forests have the lowest vulnerability. The impact of climate change on vegetation dynamics in dry years (R2 dry = 0.35) is significantly higher than over the entire study period (R2 all = 0.20). Cropland drought risk is dominated by human activities, whilst woodland and grassland drought risk is controlled by temperature and precipitation variability, respectively. The driving force analysis of vegetation dynamics and drought risk improves our understanding of the mechanisms behind the formation of risk patterns in NEC. Our study provides a basis for land use management and the formulation of drought adaptation options for vegetation types at different growth stages. [ABSTRACT FROM AUTHOR]

Electroadhesion devices render shape perception on the flat surface by reconstructing friction based on the finger position. The positioning sensor with a low sampling rate limits rendering because of the discontinuous friction caused by fast finger sliding. The positioning sensor with a higher sampling rate needs to be designed to meet the high-fidelity rendering at fast movement. However, a sensor with a high sampling rate that exceeds the range of human perception is also unnecessary because this will increase the burden of the hardware and software. Thus, it is importance to determine the upper limit of the sampling rate required for electroadhesion devices. The minimum perceived width and sliding velocity together determine the maximum sampling rate. This paper uses the line with varying widths to study the minimum perceived linewidth. The minimum perceived linewidths and influencing factors were studied by psychophysical experiments under 16 conditions of four driving voltages and four sliding velocities. The results showed that minimum perceived linewidths were in the micron scale, and the averages were 5.00–53.75 μ m. The minimum perceived linewidths were significantly affected by voltages and velocities, especially at low voltages and fast velocities. The minimum perceived width and influencing factors guide the future electroadhesion application. • We proposed a design to maintain finger moving velocity constant and obtain 10 μ m smallest linewidth with four different velocities. • We measured minimum perceived linewidths by electroadhesion for the first time and determined dual effects of driving voltage and moving velocity. • We found that the averages of minimum perceived linewidths increased with increasing velocities at low voltages. [ABSTRACT FROM AUTHOR]

Magnetic biochar adsorbents often suffer from the uneven distribution and shedding problems of nanoparticles. In this study, a one-pot sol-gel pyrolysis method was proposed to synthesize a MnFe 2 O 4 functionalized magnetic sawdust-based biochar (MnFe 2 O 4 @SBC) for efficient removal of diclofenac sodium (DCF). The MnFe 2 O 4 @SBC was characterized by XRD, Raman, VSM, TG-DSC, SEM, TEM, BET, FTIR and XPS. The results demonstrated that the combination of sol-gel and sawdust effectively led to a homogeneous distribution of MnFe 2 O 4 on biochar and the MnFe 2 O 4 @SBC possessed a much richer pore structure and functional groups than the original biochar. A systematic comparison of MnFe 2 O 4 @SBC with commercial activated carbon (CAC) was conducted by analyzing the effects of initial pH, adsorbent dosage, coexisting ions, contact time and temperature on their adsorption performance. Based on the adsorption isotherm study, the maximum adsorption capacity of MnFe 2 O 4 @SBC was predicted to be 352.17 mg/g, which was almost 3.5 times that of CAC. Selectivity adsorption study and real water-based removal experiment further demonstrated the satisfactory adsorption selectivity and applicability of MnFe 2 O 4 @SBC for DCF. This study reveals that the one-pot sol-gel pyrolysis is a promising method for synthesizing excellent magnetic biochar adsorbents. [Display omitted] • The sawdust-based biochar was prepared by one-pot sol-gel pyrolysis method. • The sol-gel procedure favored the homogeneous distribution of MnFe 2 O 4 in biochar. • MnFe 2 O 4 @SBC had abundant functional groups along with graded pore structure. • The adsorption prformance of MnFe 2 O 4 @SBC overtook commercial activated carbon. • The MnFe 2 O 4 @SBC had good selectivily and real sample applicability for DCF removal. [ABSTRACT FROM AUTHOR]

[Display omitted] To improve the measurement resolution and accuracy of the grating displacement sensor, this paper proposes an image signal denoising method of grating linear displacement sensors based on NLM. Firstly, the optical system is designed to load the displacement information into the fringe image based on the grating pitch; Then, the principle of NLM image denoising is studied, and the inverse ratio kernel NLM denoising algorithm is designed; Thirdly, the effect of denoising algorithm is compared with the typical kernel function; Finally, the optimized image is used for displacement demodulation. The experimental results show that the SNR of the image is 30.1370db after denoising by this algorithm, and the high-precision displacement stage is set at 20 nm, 40 nm, and, 60 nm. Using the method in this paper, the positioning can be calculated to 22.7 nm, 38.2 nm, and 63.3 nm, and the sub-pixel positioning of the image and the nanopositioning measurement of the displacement are completed. [ABSTRACT FROM AUTHOR]

[Display omitted] • Fitting drought intensity and yield loss rate to construct sensitivity curves. • Considering millet planting climatic suitability as a potential exposure index. • A perfect index system suitable for millet drought risk assessment was built. • Distribution and dynamic migration characteristics of millet drought risk were analyzed. Due to the improvement of living standards and the adjustment of dietary structure, the cereal industry shows excellent growth prospects. Clarifying millet drought risk distribution and determining its dynamic evolution characteristics are therefore of great importance for guiding millet production, preventing drought risks, and ensuring food security. In this study, SPRI was used to identify millet drought, and drought intensity-yield loss rate curves were constructed to characterize millet drought sensitivity. The potential exposure of millet was explored by considering millet climatic suitability and farmland proportion. In light of this, a comprehensive assessment of millet drought risk in different growth periods was made using natural disaster risk theory. The results showed that: (1) The sensitivity model for each growth period had passed the F-test of α = 0.05 (R2 were 0.544, 0.408 and 0.347 respectively), reaching a significant level, which proved that the model can be used to assess millet drought sensitivity. (2) More than 70 % of Liaoning Province had a suitable climatic environment for millet production. Combined with the farmland proportion, the area with high potential exposure was distributed in the central region of Liaoning. (3) The millet drought risk in different growth periods showed a characteristic distribution of high in the northwest and low in the southeast. Among them, Chaoyang had the largest high and extremely high drought risk area in the three growth periods, accounting for 92.11 %, 99.34 % and 98.86 % respectively. At the same time, the center-of-gravity model shows that the barycenter of millet drought risk has a trend of spreading from the west of Liaoning to the northeast and southwest. To sum up, the millet drought risk area in Liaoning may increase in the future, measures should be taken to prevent and mitigate millet drought from three aspects: before, during and after the disaster. [ABSTRACT FROM AUTHOR]

In this paper, we report the realization of Mie resonances in air using eccentric hollow metallic cylinders. Our numerical results show that electric resonances/magnetic resonances can be selectively generated in a properly-designed eccentric hollow metallic cylinder under TE-/TM-polarization plane wave illuminations, respectively. We find that the critical dimension for Mie resonance generation is the radius of the hollow hole. Finally, two resonant modes supported by a dual-hole cylinder are presented. This study can be highly favorable to various applications, including optical sensing and nonlinear optics. [ABSTRACT FROM AUTHOR]

In situ and highly sensitive monitoring of tumor cells provides a fundamental understanding of the valuation of cancer diagnosis. However, existing techniques are largely unable to rapidly capture and precisely quantify the tumor cells. To address this, we propose a novel approach based on a nanotube-functionalized & microfluidic-controlling multiresonance optical fiber sensor. The sensor consists of a tilted fiber Bragg grating (TFBG) inscribed in the fiber core and specially designed halloysite nanotubes (HNTs) coated over the fiber surface. In particular, the HNTs are arranged in an orderly manner along the fiber surface to form slit-like patterned layers for enhanced the interaction with tumor cells, resulting in more effective capture of tumor cells. Such a sensor provides a powerful light scattering sensing ability. Based on the spectral area interrogation method, normal cells and tumor cells can be unambiguously discriminated within a few minutes, providing high sensitivity (limit of detection of 10 cells/mL), and a linear response for a large cell concentration range (10 ∼ 105 cells/mL). Meanwhile, by integrating the fiber sensor with a well-designed microfluidic chip, rapid and precise measurement of different tumor cell samples with low consumption (sub-microliter volumes) can be achieved, which provides a potential tool for cancer diagnosis and treatment. • A novel fiber sensor for tumor cells at very low concentrations is proposed. • A new demodulation method based on the light scattering effect is proposed. • The sensor could rapidly capture of tumor cells through HNTs. • The sensor is promising for the in situ initial screening of tumor cells. [ABSTRACT FROM AUTHOR]

Highlights • An eco-friendly one-step synthesis of β-CD-capped AuNPs is demonstrated. β-CD acts as both reducing and stabilizing agent. • The systematic characterization and study on the formation mechanism, size control and quality of the β-CD-capped AuNPs. • Integration of β-CD-capped AuNPs and microfiber to realize a biosensor with high-performance LSPR behavior, flexibility and small footprint. • Ultralow LOD of cholesterol of 5 aM is achieved, providing extremely low consumption of clinical samples. • Selective detection of cholesterol molecules in human serum is demonstrated, taking a step towards the practical applications. Abstract Plasmonics in conjunction with supramolecular chemistry brings new opportunities for biosensing. Modified with macrocyclic supramolecules, noble metal nanoparticles possess improved biocompatibility and highly efficient biomolecule immobilization and recognition via host-guest interaction. In this work, we synthesize high-quality and monodisperse β-cyclodextrin-capped gold nanoparticles (β-CD-capped AuNPs) in one-step facile and eco-friendly process, where β-CD functions as both reducing and capping agent. Integrated with a microfiber, the β-CD-capped AuNPs deliver promising localized surface plasmon resonance properties and ultralow detection limit of cholesterol molecules of 5 aM. The selective recognition of our proposed biosensor to cholesterol is further verified by interference study and analysis of real human serum samples. This study shows the bright prospects of supramolecular chemistry assisted plasmonics in achieving highly integrated and highly sensitive biosensing with extremely low consumption of clinical samples and small footprint. [ABSTRACT FROM AUTHOR]

• Realizing excellent fusion of optical fiber and lithium-ion battery. • Implementation of internal temperature monitor by implanting FBG. • FBG sensor displays better signal-to-noise ratio than thermocouple. • The internal temperature is 3.83 °C higher than the external temperature at 2C. • Revealing relationship between charge/discharge rates and temperature gradient. Current cell performance monitoring, which relies on measurements of sporadic surface temperature through the battery management system (BMS), does not provide a reliable information on the true internal battery state. Here we proposed and demonstrated in-operation temperature monitoring of lithium-ion batteries using an implanted femtosecond-laser-inscribed fiber Bragg grating (FBG) sensor. For comparison, both FBG and thermocouple are simultaneously implanted in an 18650 cell. Over repeat cycles with different conditions (0.5C, 1C and 2C), we experimentally demonstrated that implanted FBG and thermocouple sensors show very similar temperature response curves but the FBG sensor provide a much better signal-to-noise ratio. The monitored internal temperature by FBG is 3.71 °C higher than the external temperature during 2C cycling, demonstrating the necessity to record internal temperature especially at long cycles and higher rates within BMS. This operando FBG sensor is a powerful tool in current battery monitoring and its state-of-health evolutions. [ABSTRACT FROM AUTHOR]

A side-channel photonic crystal fiber (SC-PCF) is proposed and fabricated to serve as a high sensitivity surface enhanced Raman scattering (SERS) sensing platform. The SC-PCF has a solid core with triangular lattice cladding structure, and one third of the cladding is removed intentionally to enable fast liquid infiltration and enlarge effective interaction area between liquid samples and the fiber core guided lightwave. The geometry of the SC-PCF is designed to obtain high evanescent field power in cladding side-channel, high free space coupling efficiency and low transmission loss at the excitation wavelength of 632.8 nm. Rhodamine 6G (R6G) solutions mixed with gold nanoparticles (AuNPs) are used to test the SERS performance of the proposed platform. A low detection limit of 50 fM R6G solution is achieved. Moreover, an accumulative effect of SERS signal along the SERS-active fiber length is demonstrated experimentally, and a numerical–analytical model for backward scattering scheme is developed to investigate the dependence of Raman intensity on fiber length. [ABSTRACT FROM AUTHOR]

Due to global warming, it is necessary to study the influence of extreme climate and concurrent events on crop growth. The study area was the Songliao Plain, where drought events frequently occur. First, the daily meteorological data of 14 meteorological stations from 1981 to 2016 were collected to analyze the temporal and spatial changes in the crop water surplus and deficit index, extreme growing degree-days, and heat stress intensity during different growth stages of maize. Second, the cloud model was used to describe the fuzziness of concurrent events (simultaneous drought and heat), and mutual mapping between qualitative and quantitative data was undertaken. The fuzzy certainty degree of the influence of different degrees of concurrent events on maize was calculated. Third, the copula function was used to describe the randomness of concurrent extreme events and calculate the joint probability distribution and return period. An assessment method was proposed for concurrent events from the perspective of system uncertainty. Finally, we analyzed the relationship between concurrent events and maize yield, which showed different degrees of water deficit and warming trends during each growth period. Crops were most affected by extreme weather during the reproductive growth period (RGP). During the vegetative growth period (VGP), the temperature increase was higher than in other periods, especially in the high-latitude region. The frequency of mild concurrent events was higher during the VGP and RGP. During the vegetative and reproductive period, the average occurrence probability of mild, moderate, and severe concurrent events was 21.9%, 1.7%, and 0.35%, respectively, whereas during the RGP, it was 23.1%, 8.2%, and 0.12%, respectively. The present study provides a meaningful reference for a better understanding of the occurrence laws of drought, heat, and concurrent events during crop growth periods and how to optimize the agricultural management of maize. • Cloud model qualitative and quantitative mapping of drought and heat events. • Copula function was used to describe the randomness of concurrent extreme events. • Vegetative growth periods (VGP) and reproductive growth periods (RGP) were modelled. [ABSTRACT FROM AUTHOR]

• Overall, climate warming is beneficial to sugarcane distribution. • There is a risk of drought in the main sugarcane producing areas. • The cropland fragmentation is significant in sugarcane climate suitable area. • The sugar industry has faced challenges seriously in recent years under global warming and human factors. Guangxi is the primary producer of sugarcane in China and provides a highly suitable habitat for sugarcane growth. However, its distribution range has changed significantly in recent years due to climate change as well as human factors. Without extensive knowledge of the changing trends in suitable sugarcane planting areas, efforts to improve its productivity in Guangxi may be insufficient. In this study, the interdecadal change in sugarcane distribution in Guangxi in response to climate change from 1960 to 2019 was estimated using the MaxEnt model and the landscape pattern of land use in the suitable sugarcane area was analyzed. In addition, we discuss the effects of global warming on sugarcane production in the sustainable development of the sugar industry in Guangxi. Our results indicate: (1) from 1960 to 2019, approximately 65% of Guangxi Province could grow sugarcane. Chongzuo City, Nanning City and Parts of Baise City, are highly suitable areas, and unsuitable areas are mainly concentrated in the north. In general, sugarcane climate suitability extended further in low-altitude areas, and then extended to high- altitude areas. However, from the 2000s to the 2010s, climate suitability showed a decreasing trend, decreasing from 16.036 × 106 ha to 15.4985 × 106 ha (2) The order of land use area in the suitable sugarcane climate range was as follows: woodland > cropland > grassland > construction land > water. With the increase in climate suitability, the distribution of cultivated land expanded. From 1980 to 2005, cropland in suitable areas showed a fragmentation trend. By 2010, the cropland patches disappeared after fragmentation. (3) Due to landscape constraints, infertile soil, and labor costs, the sugar industry faces various challenges. The evaluation of climate suitability could provide a theoretical reference for a planting layout of sugarcane, and landscape pattern analysis of suitable sugarcane climate areas is conducive to the integration of small pieces of land into large ones, making mechanization possible. Overall, strict layout and management measures are required in sugarcane planting areas. [ABSTRACT FROM AUTHOR]

• HfO 2 additive could improve microstructure and enhance DC resistivity ρ. • P h is reflected by the area of hysteresis loops (B - H). • P e is affected by the combined action of microstructure and DC resistivity ρ. Core losses in manganese-zinc (MnZn) ferrites is an important factor governing the performances of power conversion devices such as power converters and switching mode power supplies. With the development trend of miniaturization, lightweight, and high frequency for power supply, it is worth emphasizing that the temperature characteristics of ferrite cores are closely related to energy transfer efficiency and reliability of power conversion devices and components. Herein, the effect of high valence ion additive HfO 2 on the microstructure and electromagnetic performances of MnZn ferrites was systematically discussed, as well as physical mechanism of temperature dependence of core losses. The variation of hysteresis loss has been correlated with the hysteresis loop area (B-H), and the effect of the ratio of square of average grain size to resistivity D 2/ ρ on eddy current loss has been taken into consideration. Remarkably, eddy current loss does not monotonically decrease with the increase of HfO 2 content via enhancing resistivity ρ , as well with the variation of average grain size D. The state-of-the-art MnZn ferrites with excellent temperature characteristics of core losses exhibits great potential in power conversion devices operating in a wide temperature range. [ABSTRACT FROM AUTHOR]