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We conducted a comprehensive analysis on the causes of prolonged maintenance and widespread precipitation after the landfall of Typhoon Chaba， using the best track data from the Shanghai Typhoon Research Institute of the China Meteorological Administration， the FNL 0.25°×0.25° reanalysis data and the NOAA 0.5°×0.5° global daily precipitation data.The results show that the main moisture source of the remnant of Chaba in the first phase （3-4 July） was the southerly low-level jet， and the second phase （5-6 July） it was mainly the combination of the southerly low-level jet and the boundary layer easterly jet， which resulted in a rare entire atmosphere precipitable water of 75 mm.The vertical wind shear and water vapor convergence formed by the coupling of the double low-level jets provided favorable dynamic conditions for the occurrence and maintenance of heavy rainfall.A cold pool was formed near the surface to the west of the vortex with the intrusion of cold air， which caused the Chaba remnant to gradually degenerate into an extratropical cyclone with a significant increase in baroclinic kinetic energy.In the view of potential divergence diagnosis， we found that as the Chaba remnant kept moving northward to approach the subtropical westerly jet， the vertical wind shear at high and low levels increased.The cold air carried by the high-altitude cold vortex turns the Chaba residual vortex to baroclinic system.The easterly wind jet in the boundary layer increased the instability of the layer below 850 hPa， which provided unstable energy conditions for the occurrence and maintenance of heavy rainfall.

A comparative analysis of the rapid intensification (RI) of super cyclonic storms Chapala (2015) and Kyarr (2019) in the Arabian Sea is conducted using the North Indian Ocean tropical cyclone data, microwave sounding images, the NOAA OISST data and the ERA5 reanalysis data. Results show that the subtropical westerly jet stream and the Southern Hemisphere anticyclonic circulation led to the formation of an obvious double-channel outflow from the northern and southern sides of the two storm centers, and the substantial inflow appeared at the eastern boundary layer of both storms. These promoted the vertical ascent motion and release of the latent heat of condensation. A warm sea surface is a necessary but not dominant factor for the RI of cyclonic storms in the Arabian Sea. During the RI of Chapala and Kyarr, the deep vertical wind shear was less than 10 m s−1; moreover, the mid-level humidity conditions favored the RI of the two cyclonic storms. Chapala had a single warm core, whereas Kyarr had double warm cores in the vertical direction. The impacts of the latent heat of fusion is more obvious for Chapala, and the potential vorticity in its inner core increases from 4.4 PVU to 8.8 PVU, whereas the potential vorticity and vorticity in the inner core of Kyarr do not change significantly. Microwave detection images show that both Chapala and Kyarr were accompanied by the formation of eyewalls during the RI phase, and the radius of maximum wind decreased and the maximum wind speed increased during the eyewall-thinning process. Both Chapala and Kyarr passed through a positive anomaly region of maximum potential intensity during the RI phase, which increases the possibility to develop to higher intensity after genesis.

OsNRAMP5 is a pivotal gene involved in the uptake and transport of cadmium and manganese in rice plants. While the knockout of OsNRAMP5 has significantly decreased cadmium accumulation in rice grains, its impact on the adaptability of indica hybrid rice and its paternal parent still needs to be more adequately explored. This study conducted a three-year field experiment with two of the OsNRAMP5 knockout lines (indica hybrid rice LYDG-1 and its paternal parent DG-1) and their wild-type at four distinct locations in the middle reaches of the Yangtze River. Their adaptability was evaluated by cadmium and manganese accumulation, yield traits, and grain quality. The findings reveal that OsNRAMP5 knockout lines, when grown in mildly and moderately Cd-contaminated paddies, exhibit significantly and stably lower cadmium and manganese accumulation compared with the wild-type. However, there were no significant differences in cadmium and manganese content between LYDG-1 and DG-1. Regarding yield traits, OsNRAMP5 knockout lines did not show a significant reduction compared with the wild-type, except for DG-1 in soil with lower manganese content. For grain quality, the quality of the appearance of OsNRAMP5 knockout lines significantly improved compared with the wild-type. However, the milling quality of DG-1 significantly reduced compared with the wild-type, while this negative impact for LYDG-1 was only observed in soils with lower manganese content. Overall, the indica hybrid rice with an OsNRAMP5 knockout exhibits better adaptability than its paternal parent in the middle reaches of the Yangtze River. These findings offer valuable insights into the potential application and promotion of OsNRAMP5 mutant rice varieties in the middle reaches of the Yangtze River.

A convenient method for producing three-dimensional photonic lattice microstructures was experimentally demonstrated by using a cutting-combination lens. Three-dimensional photonic lattices are optically induced by (4 + 1) plane waves interference in an iron-doped lithium niobate photorefractive crystal. Induced three-dimensional lattice microstructures are observed and verified by planar guided wave intensity imaging and far-field diffraction pattern. This method is inexpensive and does not require complex adjustment devices. In addition, it also has flexibility and scalability. This method can be used to fabricate other more complex three-dimensional photonic lattice microstructures by designing the cutting-combination lens appropriately.

Hill number per unit area and seedling number per hill are foundational agrotechnical factors shaping the growth and development of rice plants. This study aimed to determine the effects of decreasing the hill number per unit area combined with increasing the seedling number per hill on grain quality in hybrid rice. Field experiments were performed in Hengyang, Hunan Province, China, in 2022 and 2023 using the hybrid rice variety Huazheyou 261, as well as in Liuyang, Hunan Province, China, in 2023 using the hybrid rice varieties Yueyou 2646 and Zhenliangyouyuzhan. Treatments (combining hill number per unit area and seedling number per hill) encompassed a combination of 24 hills per m2 and one seedling per hill (H24S1) and a combination of 14 hills per m2 and three seedlings per hill (H14S3) in Hengyang, as well as a combination of 28 hills per m2 and two seedlings per hill (H28S2) and a combination of 14 hills per m2 and four seedlings per hill (H14S4) in Liuyang. There were no significant differences in the leaf area index at the heading stage, as well as no significant differences in canopy light transmittance during the grain-filling period between H24S1 and H14S3 in Hengyang, or between H28S2 and H14S4 in Liuyang. The differences in grain quality traits, including milling traits (brown, milled, and head rice rate), appearance traits (rice length, rice length-width ratio, chalky grain rate, and chalkiness degree), amylose and protein content, and pasting characteristics were also not significant between H24S1 and H14S3 in Hengyang, nor between H28S2 and H14S4 in Liuyang. This study indicates that the grain quality in hybrid rice is unaffected by decreasing the hill number per unit area integrated with increasing the seedling number per hill.

Based on the 0.25°×0.25° ERA5 reanalysis data and surface observation data of China Meteorological Administration， a study is conducted to investigate a large-scale sea fog event caused by an extratropical cyclone over the Yellow Sea in May 2020.Results are as follows： （1） The sea fog mainly occurred in the western and northern of the extratropical cyclone with properties of advection cooling fog and frontal fog.（2） The air sea temperature difference is between 0.5 ℃ and 2.5 ℃ during the occurrence of fog in the Yellow Sea and Bohai Sea.The dew point temperature of 2m is slightly higher than the sea surface temperature.（3） The phenomenon of rain turning into fog both in the western and northern of the extratropical cyclone.The temperature profile monitored by Qingdao L-band radar shows "double inversion" at 500 m and 1500 m altitude.（4） The convergence of moist air caused by extratropical cyclone is an important water vapor source for the occurrence and maintenance of this sea fog process.The humidification and evaporative cooling effects of precipitation also make the atmospheric saturation near the sea surface increase rapidly.（5） The sensible and latent heat fluxes in most of the Yellow Sea and Bohai Sea are negative.The turbulent heat flux is mainly represented by the transport from the atmosphere to the ocean.The vertical wind shear caused by extratropical cyclone enhances the atmospheric mechanical turbulence， which makes the atmosphere and the ocean carry out sufficient heat exchange， thus promoting the development of sea fog in the vertical direction.

Using the 6-hourly reanalysis data of European Center ERA-Interim with horizontal resolution of 0.25° × 0.25° and hourly typhoon operational data provided by the CMA (China Meteorological Administration), a new high-level environmental field factor is derived, and its application during the recurvature period of No. 14 Typhoon Yagi and No. 18 Typhoon Rumbia in 2018 is compared and analyzed. According to the comparison study, there is always a clear positive abnormal value area of high-level environmental field factor on the northeast of Rumbia during its northward movement, implying an obvious alteration of ∇•u→ and a big negative gradient of ∇u→ on the northeast of Rumbia. With the eastward movement of the westerly trough and the strengthening of the subtropical westerly jet, Rumbia is expected to veer northeast. However, the change of high-level environmental field factor on the northeast of Yagi is not noticeable, and Yagi is far away from the upper-level jet stream, which is not conducive to Yagi's northeast recurvature.

Understanding the yield attributes of the popular rice (Oryza sativa L.) hybrids can provide useful information for developing new hybrid rice varieties. Field experiments were conducted at two subtropical sites (Hengyang and Xingyi) in two years (2021 and 2022) to compare grain yield and yield attributes of three currently popular hybrid rice varieties (Jingliangyouhuazhan, Jingliangyou 534, and Longliangyouhuazhan) with three representative super hybrid rice varieties (Y-liangyou 1, Y-liangyou 2, and Y-liangyou 900). No significant differences in grain yield were observed between the group of popular hybrids and the group of super hybrids at Hengyang and Xingyi in 2021 or at Xingyi in 2022, but at Hengyang in 2022, the group of popular hybrids produced a 15% higher grain yield. The grain yield at Hengyang in 2022 was lower than that at Hengyang and Xingyi in 2021 and at Xingyi in 2022. At Hengyang in 2022, the group of popular hybrids had 9–15% higher panicles per m2, spikelet filling percentage, and harvest index but similar spikelets per panicle and total biomass production and 12% lower grain weight compared to the group of super hybrids. Correlation plot analysis showed that grain yield was significantly related to panicles per m2 but not other yield attributes across six varieties at Hengyang in 2022. These results indicated that the currently popular hybrid rice varieties had higher yield performance than the representative super hybrid rice varieties under the condition of relatively lower productivity, and the key factor for this higher yield performance in the popular hybrids was the higher panicles per m2. This finding highlights that more attention should focus on the yield performance under medium- and low-productivity conditions in hybrid rice breeding programs, and an effective breeding strategy is to select the varieties with high panicle numbers.

Improving grain quality is critical to the development of hybrid rice. In recent years, multiple hybrid rice cultivars with superior grain quality have been developed in China through dedicated breeding efforts. However, limited information is available on yield performance and yield formation characteristics of these high-quality hybrid rice cultivars. In this study, field experiments were conducted to compare yield attributes between a recently developed indica hybrid rice with superior grain quality (Jingliangyou 1468, JLY1468) and a relatively older indica hybrid rice cultivar with high yield potential (Liangyoupeijiu, LYPJ). Results showed that grain yield was 13–17% higher in JLY1468 than in LYPJ. The higher grain yield of JLY1468 than of LYPJ was mainly attributable to a higher spikelet filling percentage, which was closely related to a higher harvest index resulting from a higher crop growth rate during the post-heading period. The results of this study suggest that late-stage vigor may be a vital trait for the development of indica hybrid rice cultivars with both high quality and high yield.

In this paper we introduce the convective vorticity vector and its application in the forecast and diagnosis of rainstorm. Convective vorticity vector is a parameter of vector field, different from scalar field, it contains more important information of physical quantities, so it could not be replaced. Considering the irresistible importance of vector field we will introduce the theory of vector field and its dynamic forecast method. With the convective vorticity vector and its vertical component's tendency equation, diagnostic analysis on the heavy-rainfall event caused by landfall typhoon “Morakot” in the year 2009 is conducted. The result shows that, the abnormal values of convective vorticity vector always changes with the development of the observed precipitation region, and their horizontal distribution is quite similar. Analysis reveals a certain correspondence between the convective vorticity vector and the observed 6-h accumulated surface rainfall, they are significantly related. The convective vorticity vector is capable of describing the typical vertical structure of dynamical and thermodynamic fields of precipitation system, so it is closely related to the occurrence and development of precipitation system and could have certain relation with the surface rainfall regions.

The demand for and consumption of soft-textured, high-quality rice with low amylose content have substantially increased in China with improved economic and living standards. Shifting sowing date is a common strategy to optimize temperature conditions and improve rice quality. In this study, a high-quality rice cultivar with low amylose content (Jingliangyou 1468) was grown under four sowing dates (May 15th and 25th, and June 4th and 14th) in 2019 and 2020 to determine the effects of sowing date on palatability-related traits and evaluate relationships between palatability-related traits and daily mean temperature during the grain-filling period. Results showed that delaying sowing date decreased daily mean temperature during the grain-filling period and consequently increased amylose content and setback viscosity of milled rice flour, which in turn increased hardness and chewiness of cooked rice. The finding of this study suggests that the strategy of delayed sowing does not improve the palatability of high-quality rice in the context of consumers’ preference for soft-textured rice.

Field experiments were conducted to compare two hybrid rice cultivars—a recently released high-quality cultivar (Jingliangyou 1468, JLY1468) and a relatively older cultivar (Liangyoupeijiu, LYPJ). Results showed that hardness, springiness, cohesiveness, resilience, and chewiness of cooked milled rice were all lower in JLY1468 than in LYPJ, due to its lower amylose content and altered paste properties of milled rice flour. Active digestion duration of cooked milled rice was 26% shorter and the glucose production rate from starch digestion was 33% faster in JLY1468 compared with LYPJ. Texture and starch digestion properties of cooked milled rice as a factor of temperature during the grain-filling period were different between LYPJ and JLY1468 due to differing amylose contents and gel consistencies of milled rice flour in response to temperature. This study highlights that attention should be paid to potential health risks associated with the development of high-quality hybrid rice cultivars with soft texture.

Head milled rice is the main form of rice for sale and consumption. However, previous studies on the yield change due to the development of new cultivars in rice generally focus on grain yield but few on head milled rice yield. In this study, field experiments were conducted in two years (2019 and 2020) to compare head milled rice yield and associated traits (grain yield, milled recovery traits, and shape and chalkiness traits of rice grains) between two middle-season hybrid rice cultivars released 18 years apart, i.e., Jingliangyou 1468 (JLY1468), a recently-released cultivar with high eating quality, and Liangyoupeijiu (LYPJ), an old cultivar with high grain yield. JLY1468 had higher head milled rice yield than LYPJ by 30% in 2019 and by 33% in 2020. The higher head milled rice yield in JLY1468 than in LYPJ was attributable to improvements in both grain yield, and head milled rice rate (HMRR). The improvement in HMRR in JLY1468 compared to LYPJ was mainly attributable to a reduction in chalkiness degree, which was associated with a decrease in rice grain size. The results of this study provide evidence for the improvement in head milled rice yield in middle-season hybrid rice with the development of new cultivars in recent years.

Inbred rice has been grown more and more widely, while the planting area of hybrid rice has decreased by approximately 25% in China since 1995. This study aimed to assess the changes in grain yield and yield attributes due to cultivar development in indica (Oryza sativa ssp. indica) inbred rice in China. Field experiments were conducted in 2019 and 2020 to determine the performance of grain yield and yield attributes of an indica super inbred rice cultivar Jinnongsimiao (JNSM) released in 2010 by comparing it with an indica high-yielding inbred rice cultivar Guichao 2 (GC2) released in 1978 and an indica super hybrid rice cultivar Y-liangyou 900 (YLY900) released in 2016. Results showed that JNSM produced 18% higher grain yield than GC2 but 6% lower grain yield than YLY900. Compared with GC2, JNSM had higher spikelets per panicle, spikelet-filling percentage, and harvest index by 67%, 4%, and 11%, respectively. Compared with YLY900, JNSM had 14% lower grain weight and 19% lower biomass production during the pre-heading period. The difference in biomass production during the pre-heading period between JNSM and YLY900 was explained more by crop growth rate than growth duration. This study suggests that (1) the recently released indica super inbred rice cultivar JNSM outyields the old indica high-yielding inbred rice cultivar GC2 as a result of increasing panicle size, spikelet-filling percentage, and harvest index, and (2) further improvement in grain yield in indica inbred rice can be achieved by improving biomass production through promoting pre-heading crop growth.

Ensuring rice (Oryza sativa) self-sufficiency in China relies significantly on achieving high grain yields in hybrid rice production. This study conducted field experiments across two site-years, comparing grain yield per unit of land area, grain yield generated per seedling, and associated yield traits for a hybrid rice variety under two combinations of hill spacing and the number of seedlings per hill. The combinations included a hill spacing of 30 cm × 14 cm with one seedling per hill (H14S1) and a hill spacing of 30 cm × 24 cm with three seedlings per hill (H24S3). The results revealed that H14S1 consistently outperformed H24S3, demonstrating a 7%–16% increase in grain yield per unit of land area and an impressive 88%–104% higher grain yield generated per seedling. H14S1 exhibited 56%–77% more panicles formed per seedling and 10%–15% more spikelets per panicle compared to H24S3. H14S1 produced 78%–115% higher biomass at heading and maturity per seedling and 8%–25% higher biomass at heading and maturity per tiller than H24S3. This study underscores the importance of promoting the individual growth and development of seedlings as a crucial strategy for achieving higher grain yield in hybrid rice production. [ABSTRACT FROM AUTHOR]