This paper investigates the characteristics and mechanisms of femtosecond laser processing of natural single-crystal diamond cutting tool. Using finite element simulation methods, a two-temperature model of femtosecond laser processing of single-crystal diamond was constructed to simulate the ablation process under specific laser parameters. The findings suggest that, compared to nanosecond and picosecond lasers, femtosecond laser processing produces the smallest heat-affected zone. Additionally, the paper examines how parameters such as laser fluence, spot spacing, and material thickness affect the ablation depth, surface morphology, temperature, and residual stress of single-crystal diamond. The results indicate that as laser fluence increases and spot spacing decreases, the ablation depth, temperature, and residual stress increase. Additionally, the residual stress along the scanning direction is greater than that in the perpendicular direction. Temperature decreases as diamond thickness increases, but the residual stress value increases.

Acorus calamus var. angustatus Besser, a perennial herb of the Araceae family, was first reported in the Shen Nong's Herbal Classic and is widely distributed in southern China (Li 1979). It is important in traditional Chinese medicine for treating heart, stomach, and brain ailments (Lam et al. 2016). In March 2024, leaf spots were found on its leaves in a traditional Chinese medicine planting base in Yuexi County (30°91'56″ N, 116°19'24″ E), Anhui Province, with an incidence of about 35%. The symptoms began as small, light brown lesions that expanded, resulting in necrotic lesions ranging from 1 to 8 mm in diameter with brown halos. 3 × 3 mm sections, including both symptomatic and asymptomatic tissues, were cut from six infected plants. They were disinfected in 75% ethanol for 30 s, washed three times with sterile distilled water, transferred to Petri dishes containing potato dextrose agar (PDA) and incubated at 25 °C in the dark. Purified fungal isolates were obtained by the single-spore isolation method. The colonies on PDA initially appeared white, gradually became olive-green with 1 to 3 mm white margins and abundant aerial hyphae, while the reverse was greyish green to black. The conidia were light brown, ellipsoidal, obclavate, and 10.0 to 49.5 µm × 4.5 to 16.4 µm (mean 23.9 × 10.2 µm, n=50) in size, with 0 to 6 transverse septa and 0 to 6 longitudinal or oblique septa (n=50). Conidiophores were thick, dark brown, single-celled, with multiple conidial scars, measuring 12.8 to 146.8 × 2.9 to 6.1 (mean 50.6 × 4.2) µm (n=50). Based on above observations, the pathogen were identified as Alternaria spp. (Simmons 2007). Three representative isolates, SCP-1, SCP-2, and SCP-3 were selected for molecular identification. The Internal transcribed spacer (ITS), Alternaria major allergen (Alt a 1), and translation elongation factor 1-alpha (TEF1) genes were amplified with the primers ITS1/ITS4 (White et al. 1990), Alt-for/Alt-rev (Woudenberg et al. 2015) and EF1-728F/EF1-986R (Carbone and Kohn 1999), respectively. The sequences of the three isolates were consistent, and the sequences of isolate SCP-1 were submitted to NCBI GenBank (ITS, PP723104; Alt a1, PP708704; TEF1, PP708703). The ITS region of isolate SCP-1 was 100% similar to A. alternata TCS3002 (MN394880, Wang et al. 2023), the Alt a 1 gene was 100% similar to A. alternata CBS 620.83 (KP123868), and the TEF1 gene was 100% similar to A. alternata CBS 916.96 ex-type (KC584634). A phylogenetic tree based on sequences of ITS, Alt a 1 and TEF1 genes was constructed using the neighbor-joining method in MEGA 7 software, confirming the fungus as A. alternata. Three healthy plants of A. calamus var. angustatus were spayed with conidial suspension (1 × 107 conidia/ml) of isolate SCP-1. Three additional plants sprayed only with sterile distilled water were controls. All plants were covered with plastic bags to maintain a relative humidity of 90% for 48 h and incubated at 25 °C under a 12-h light photo-period. Twelve days post-inoculation, brown necrotic lesions developed on the inoculated leaves, enlarged, and the symptoms were similar to the original ones. The control plants remained healthy. The fungus was re-isolated from the infected plants and confirmed by morphological traits and molecular methods, fulfilling Koch's postulates. To our knowledge, there are no other reports of this fungus on A. calamus var. angustatus in Anhui, China. This report will help identify the disease based on field symptoms and provide a basis for disease management strategies of A. calamus var. angustatus.

Vertical surface grinding (VSG) is an effective method that can adapt to multiple machining tasks, including stock removal machining to get high productivity and finish machining to obtain high-quality surfaces. Force prediction can reveal some mechanisms in the VSG process, conducing to the improved machining quality and efficiency. This paper aims to develop a novel analytical force model considering the actual wheel-workpiece contact geometry (WWCG). In the modeling process, the cup grinding wheel was divided into many microcutting layers along the wheel axis, and the expressions of geometrical-kinematic parameters were derived to characterize the material removal at different positions of the primary grinding zone (PGZ). A single-grain grinding force model was proposed based on chip formation and plastic pile-up mechanisms from an energy perspective. Based on the analysis of multiple-grain interactions at each micro-cutting layer, equations of the local and total grinding forces in the VSG process were then derived by synthesizing the single-grain forces. Findings show that the developed model could accurately predict the magnitudes of total grinding forces and provide the distributions of local grinding forces. The WWCG variation could significantly affect the grinding forces by altering the material removal rate of different micro-cutting layers. This work provides a new method for predicting grinding forces and theoretical guidance for optimizing machining parameters and tailoring the edge profiles of cup grinding wheels to adapt to specific machining tasks.

Bletilla striata is a perennial Orchidaceae which is widely distributed in Anhui, Hubei, Guizhou, Guangxi, Sichuan, Yunnan and other provinces in China (He et al. 2017). It has the effects of convergence, haemostasis, clearing away heat and detoxification, reducing swelling and generating muscle (He et al. 2017; Xu et al. 2019). With the reduction in wild resources of B. striata, cultivation can promote the effective conservation of B. striata germplasm resources. Fusarium root rot, leaf spot disease, and other diseases have been reported on this plant in China (Wang et al. 2022, Xu et al. 2022, Zhou et al. 2022). Coleosporium bletiae on B. striata has been reported in Guizhou, Sichuan, and Hubei provinces in China, with frequent occurrence and serious disease incidences in Guizhou province (Xu et al. 2022). In April to November 2021, rust was found in Anhui Bletilla planting base (30°09' to 30°46'N; 115°45' to 116°30'E). Approximately 17% of the B. striata plants showed disease symptoms (Figure S1). Uredinia are hypophyllous, scattered, round, powdery, and are associated with chlortic spots 1-4 mm wide on the upper side of the leaves. After mid-October, the temperature gradually decreased, and reddish-brown telia appeared around uredinia in circular shape. A total of 60 samples with typical symptoms were collected. Urediospore and teliospores were obtained by sterile needles, and their sizes were observed and measured under a microscope with sterile water. Urediospores were orange‒yellow, mainly oval in shape, 27.2-36.8 µm× 17.6-22.8 µm (n=60), and uniformly covered by verrucae on the surface (Figure S2 a-b). Teliospores were clavate, with a smooth surface and golden yellow contents, and gradually narrowed from top to base, ranging in size from 85.33-109.66 μm× 15.27-20.35 μm (n=60) (Figures S2 c-e). Three samples with typical symptoms were selected; approximately 200 μg of Urediospore of the rust pathogen were colleced per sampleand placed in 1.5 mL sterile centrifuge tubes for genomic DNA extraction by the CTAB method (Xu et al. 2022). The internal transcribed spacer (ITS) region of rDNA and large subunit (LSU) RNA genes were amplified using primer pairs ITS1/ITS4 (Leclerc et al., 2000) and NL1/NL4 (Zhang et al. 2012), respectively. The obtained sequences were deposited in GenBank (OP363678 for ITS and OP363683 for LSU), which were 100% identical with 100% coverage to the ITS sequence (MN108161, locality: Hubei) and the LSU sequence (KX386038) of Coleosporium bletiae. Based on morphological characteristics and DNA sequences, the isolates were identified as C. bletiae (Figures S2 and Figure S3). To confirm pathogenicity, 2-year-old healthy plants of B. striata were sprayed with 5 mL of urediospore suspension (2.6×105/mL). Plants sprayed with sterile distilled water were used as control. The test was conducted in an artificial climate incubator at 25 ± 1°C with a 12 h light/12 h dark photoperiod (relative humidity = 90%). The experiment was repeated three times. Two weeks after inoculation, typical yellowish chlorosis spots appeared on the leaf surface and a few yellow spore piles appeared on the leaves, which was consistent with the field symptoms (Figure S4). Control plants remained healthy. To our knowledge, this is the first report of C. bletiae causing rust on B. striata in Anhui province of China. Correct identification of this disease is of great importance to develop management strategies to control the disease. There may be seedling transport and spore transmission between Hubei and Anhui.

Phytophthora sojae is a devastating pathogen of soybean [Glycine max (L.) Merr.] that causes Phytophthora root and stem rot (PRR) on soybean plants worldwide. The pathogen leads to evident differentiation of pathogenicity which brings some difficulties to the control of the disease. Soybean germplasm plays an important role in disease resistance to P. sojae. To understand the role of soybean in the pathogen differentiation of P. sojae, transcriptome sequencing and biological information technology were used to analyse the difference in transcriptional level of soybean response to P. sojae infection by two isolates BB8 and BZ9 with different pathogenicity. A total of 1596 differentially expressed genes (DEGs) were screened from the soybean plants treated with the strong pathogenic isolate BB8 and weak pathogenic isolate BZ9, of which 256 were upregulated and 1340 were downregulated in BZ9 treated samples. Gene Ontology analysis revealed that the highly enriched terms annotated in biological processes were metabolic process, cellular process and single-organism process. Kyoto Encyclopedia of Genes and Genomes pathways were distributed primarily in metabolism, environmental information processing and cellular processes. Photosynthesis-antenna proteins, photosynthesis, phenylpropanoid biosynthesis, carbon fixation in photosynthetic organisms, plant hormone signal transduction, flavonoid biosynthesis, carbon metabolism and nitrogen metabolism were the most substantial metabolic pathways. Ten candidate DEGs were selected and their expression levels were detected via fluorescence quantitative polymerase chain reaction. The expression trends were basically consistent with the results of RNA-seq detection, confirming the reliability of RNA-seq data. Taken together, this was the report on the transcriptome analysis of soybean in response to P. sojae using high-throughput sequencing. A number of DEGs and pathways were discovered, which provided valuable information for obtaining high-quality soybean resistance resources.

A new machining method that combines textured surface and water lubrication is proposed in this paper to improve the friction characteristics of ground silicon carbide (SiC). The effects of water film thickness and grinding speed on the nano-machining behavior of monocrystal cubic SiC are revealed using molecular dynamics simulation. Moreover, a Rayleigh chip thickness model is employed to predict surface roughness. According to the obtained results, friction characteristics and machinability of textured samples are strengthened compared with the non-textured sample. Behavior characteristics are further improved in water-lubricated conditions, which show that the temperature, grinding force, and friction coefficient decrease, while the hydrostatic stress and the von Mises stress increase. Therefore, tool wear and sub-surface damage are improved. Furthermore, an improved material removal performance is also achieved under high-speed grinding. Lastly, it is observed that surface roughness of ground SiC is improved in water lubrication and under high-speed grinding.

Ligustrum quihoui is a perennial shrub that has been cultivated in China as a landscape plant. In November 2020, leaf spots on L. quihoui were observed in several residential areas in the east of Anqing city. Symptoms first appeared as small dark brown dots on the leaf surface which then became larger, forming necrotic lesions and resulting in intense defoliation. To identify the pathogen, infected leaves were collected and cultured on potato dextrose agar (PDA). Three cultures were isolated from the diseased leaves, which grew to form olive green colonies after 5 days of incubation on PDA. Based on colony characteristics, morphology phylogenetic analysis of ribosome transcriptional spacers (rDNA-ITS), and pathogenicity tests, the causal agent of leaf spot on L. quihoui was identified as Corynespora cassiicola. This is the first report to show that C. cassiicola can cause leaf spot on L. quihoui.

The molecular dynamics (MD) model of nano-indentation process was established to study the crack evolution in single crystal during nano-indentation. Two workpieces with different cracks and one workpiece with no crack were selected for indentation simulation in this study. The parameters of atom displacement, coordination number (CN), temperature, potential energy and loading force in the indentation process are analyzed in detail. Cracks were found to close during nano-indentation. Two modes of crack closure are observed: cooperative displacement and indentation failure. The existence of cracks will affect the size of transformation zone and the coordination number of atoms after indentation. Besides, the existence of cracks will reduce the increase of temperature and potential energy, and the closing mode of cracks is found to affect the value of indentation load. In addition, the change of stress with indentation depth at crack tip is calculated by theoretical model. The calculated stress curves reveal the evolution trend of cracks during indentation. These results provide guidance for the production of silicon wafer with higher surface quality.

Dendrobium, the second largest genus of Orchidacea, are mainly distributed in Asia, Oceania and Europe (Ding et al., 2008). An emerging disease on D. huoshanense with symptoms resembling southern blight Sclerotium rolfsii Sacc. occurred during June to September from 2017 to 2020 in Huoshan, Lu'an, China. The yield and quality of D. huoshanense were seriously affected especially under greenhouse conditions in July, with a disease incidence of 42%. Early symptoms consisted of water-soaked lesions on the lower stem tissue. Then leaves turned pale green and withered, a dense white mycelial mat were formed on the lower stem along with 1- to 2-mm-diameter, white round sclerotia. Subsequently, infected stems collapsed with the whole stem yellow and withered, and with many dark brown sclerotia on withered stems. Sclerotia from 5 diseased plants were disinfected in 1% mercury bichloride for 10 s, rinsed in 75% ethanol for 30 s and then rinsed 4 times with sterile water, dried, and transferred to potato dextrose agar (PDA) with the cross section and incubated at 27 °C in darkness. Mycelia were selected from the edge of the colony and transferred to new PDA plates for purification of cultures after 3 days. Fungal colonies with white mycelia and abundant sclerotia developed after 7 days of incubation. Isolate morphological characteristics confirmed the identity as S. rolfsii (Mordue, 1974). To further confirm the identity of the causal fungus, the complete internal transcribed spacer (ITS) rDNA region, the elongation factor-1a gene (EF1a) and the large subunit (LSU) region of one representative isolate, MB-1, was amplified using the primers ITS1/ITS4 (White et al. 1990), EF1-983F/EF1-2218R (Rehner and Buckley 2005), and NL1/NL4 (O' Donnell et al. 1997), respectively. Sequences have been deposited in GenBank (Accession No. OM946593 for ITS, OL416131 for EF1a and OL373917 for LSU). There was 100% sequence identity to Athelia rolfsii (S. rolfsii) with the sequences MN610008.1 (ITS) and MW322687.1 (EF1a), and 99.84% sequence identity to MT225781.1 (LSU). Pathogenicity tests were performed by wound inoculation with culture discs of mycelia ( = 5 mm) on the stem base of 10-12 cm height plants (four stems per pot, one stem inoculated with one culture disc, four replicates). Four healthy stems of the plants served as a control. The test was conducted in an artificial climate incubator at 26±1 °C with a 16h light/8h dark photoperiod and plants were enclosed for 72 h in polyethylene bags (relative humidity = 90%). Two days post-inoculation, white mycelia developed in the wound and the leaves at the upper and lower parts of the wound began to turn yellow. Then the stem softened and turned yellow. White sclerotia were formed by the sixth day. By 12 days post-inoculation, stems were atrophied and collapsed, sclerotia were yellow brown, and most leaves showed yellow discolouration and fell off. S. rolfsii was re-isolated from infected plants. Control plants remained healthy. To our knowledge, this is the first report of S. rolfsii causing southern blight on D. huoshanense in Lu'an, China. Confirmation of the causal agent provides a basis for management of S. rolfsii in cultivated D. huoshanense.

The aim of the present study was to identify the pathogen responsible for anthracnose observed in Ligustrum japonicum Thunb 'Howardii' in the Anqing area of China. Three representative isolates of the pathogen were collected from the leaves of infected plants at different locations, using a tissue isolation method and then identified based on colony characteristics, morphology, multi-locus phylogenetic analysis and pathogenicity tests. All three representative isolates formed a phylogenetic clade with reference sequences of Colletotrichum siamense. This is the first study to report C. siamense as a causative agent of anthracnose on L. japonicum in Anqing, China.

A label-free and selective sensor was established for uranyl ion (UO22+) detection based on a UO22+-dependent DNAzyme and liquid crystals (LCs). In the presence of UO22+, the substrate chains can be cleaved at the rA site by the DNAzyme strands. The cleaved products released from the DNAzyme strand will hybridize with the capture probes that are fixed on the LC sensing substrate to form double strands. The formation of double strands would disturb the original orientation and induce the rearrangement of liquid crystal molecules, resulting in the polarization images changing from uniform black to bright. Attributed to the specificity of the DNAzyme and the optical signal of the LC, a highly selective and label-free method was established with a detection limit of 25 nM. This approach showed satisfactory analytical performance and offered an inspiring platform for detecting other radioactive elements.

In this paper, molecular dynamics simulations were performed to simulate ion implantation and diamond grinding processes of SiC. Moreover, workpiece surface roughness was predicted based on Rayleigh probability distribution. Effects of ion implantation energy on the temperature, potential energy, cutting force, friction coefficient, and surface morphology of the workpiece during machining were analyzed. It has been revealed that the higher the ion implantation energy, the higher the proportion of internal damage, the lower the temperature rise rate in the workpiece, the lower the cutting force, the smaller the length and number of dislocations, the higher the removal efficiency of single abrasive particles, and the higher the final surface roughness. Among them, the changing trend of surface roughness is qualitative analysis under specific experimental conditions. In conclusion, ion implantation is favorable to SiC processing, and revealing its influence mechanisms has important guiding significance for practical applications.

Phytophthora sojae can cause soybean phytophthora blight, and greatly reduce soybean production. It is helpful to understand the pathogenic mechanism of P. sojae to prevent soybean phytophthora blight and ensures food security. Glycosyl hydrolases (GHs) disintegrate plant cell walls for nutrition and invasion, and they may act as an important virulence factor during P. sojae infection. To reveal the role of GHs in the main stages of P. sojae life cycle, we measured the expression level of genes, which encoded GHs, and constructed P. sojae transformants for biological function verification by the gene editing technology CRISPR-Cas9. In this study, four genes, encoded special GH proteins, with conserved glycine-rich were identified in the P. sojae genome, and their sequences were similar to those of the TOS1 family genes. One of them, the xp_009520987.1, was named PsGRGH, and was significantly upregulated during the germination of spores and in the early infection stages. The results revealed that PsGRGH was involved in the growth and mycelial morphology regulation in P. sojae, and was essential for its sporangium development and virulence. In addition, PsGRGH is localized on the cell membrane and plays an important role in tolerance toward Bacillus and abiotic stress.

OBJECTIVE To analyze the polymorphism of the HPA1-5,15 system of the donors in Zhangjiakou area. METHODS DNA was extracted from the blood samples of the donors, PCR- SSP method was used to divide HPA1-6, 15 genotype. The gene frequency and genotype frequency were calculated, compared with the difference and regiahal specificity of the populations in our country and foregiens was compared other populations. RESULTS The gene expression in the HPA-1, HPA-2 and HPA-4 systems were all homozygous aa, and the donors who expressed homozygous bb was not exessed. Among them, one heterozygous ab expression was found in both HPA-1 and HPA-4 systems (1%), and 14 cases of heterozygous ab expression were found in HPA-2 system (14%). The gene expression in the HPA-5 system was mainly homozygous aa (98%), and a very few expressed homozygous bb (2%) was found. The degree of heterozygosity of gene expression in the HPA-3 and HPA-15 systems was relatively high. The proprotion of the expression of aa, ab and bb in the HPA-3 system was respectively 46%, 40% and 14%, the proprotion of the expression of aa, ab and bb in the HPA-15 system was respectively 21%, 64% and 15%. CONCLUSION The gene frequency of platelet-specific antigen HPA1-5,15 system in zhangjiakou region shows local characteristics. The heterozygosity degree of gene expression in the HPA-3 and HPA-15 systems are both high, suggesting that they are more likely to result in alloimmunization and ineffective platelet transfusion, which should be pays attention to.

Structural colors of high performance and economically feasible fabrication are desired in various applications. Herein, we demonstrate that reflective full-color filters based on the interference effect can be realized in periodic Fabry-Perot (F-P) nanocavity arrays of the same thickness. Enabled by simply adjusting the nanocavity size and array period, the resonant wavelengths can be successively tuned in the whole visible light range, which is mainly attributed to the varied effective refractive index introduced by the different filling density of the F-P nanocavity. Compared to the plasmonic colors utilizing the similar nanostructures, the proposed interference colors offer unique advantages of higher color contrast, wider gamut, and lower fabrication requirements. Besides, these color filters do not involve modulating the vertical dimensions of the F-P nanocavities, which is conducive to the monolithic integration of multicolor optical cavities and their large-area applications in consumable products combined with replica patterning techniques, such as nanoimprinting and soft lithography.

本文从被侵染的大豆根茎及土壤中分离了5株病原真菌,在V8培养基上能较好的生长菌落呈现白色绒毛状松散.5株病原菌均能产生卵孢子和孢子囊,孢子囊低温诱导释放游动孢子,它们趋向性侵染大豆根部.利用特异性引物ITS6和ITS8扩增其保守序列区域,经测序比对与NCBI发布的大豆疫霉菌株序列同源性为100％;根据形态学和分子生物学结果鉴定为大豆疫霉.5株大豆疫霉的生长速率和致病力存在差异,其致病力与生长速率以及致病基因的表达成正相关关系.

The population structure of Phytophthora capsici among asexual and sexual progenies was analyzed using ISSR. Thirty asexual progenies of one parent and three sexual populations were assayed for genetic diversity using 5 ISSR primers and DNA from 120 offspring of P. capsici was amplified. In total, 71 reproducible ISSR fragments were obtained, of which 100% were polymorphic, revealing high polymorphism among the isolates. Among them, the percentages of polymorphism of sexual and asexual progeny isolates were 100.00 and 77.46%, respectively. Genetic similarity coefficients among all the isolates ranged from 0.54 to 0.73. The sexual offspring population showed much more variability than the asexual offspring population with 76.26% variability attributed to diversity within populations as compared with 23.74% among populations. This research reveals that the sexual progeny population of P. capsici contributes more genetic diversity than that of asexual progeny population.

In order to clarify the mechanism of polishing of double diamond abrasive particles, in this study, the mechanism of material removal and the evolution of single crystal Si workpiece surface under the three-body polishing condition were investigated. The effect of the depth of polishing and the transverse/longitudinal spacing of the double abrasive grains on the three-body polishing were examined. The purpose is to reveal the phase transition, surface morphology, surface damage, material removal rate, temperature, potential energy, and friction force for polishing Si wafer. The analysis of coordination number clarified that the number of phase transition atoms by polishing and abrasion increased with increasing polishing depth and transverse distance of the nanoparticles on the Si work surface, but not especially obvious with increasing longitudinal spacing. Temperature analysis shows that when the polishing depth is 1 nm, the polishing temperature is 456 K, while when the polishing depth is 3 nm, the polishing temperature is 733 K. The temperature difference between the longitudinal group and the transverse group is only 30–40 K. The larger the transverse abrasive grain spacing or the smaller the polishing depth, the smaller the surface roughness; however, the longitudinal abrasive grain spacing has no obvious correlation with the surface roughness.

Ultra-high-speed grinding is an effective technology used in high-performance precision grinding of engineering ceramic, glass, carbide, titanium alloy, stainless steel and other difficult materials. In ultra-high-speed grinding, grinding wheel speed reaches 150?300 m/s or higher, comparable to muzzle velocity of a bullet. When the working grinding wheel is broken during high-speed rotation, the flying speed of the debris is even higher than the muzzle velocity of a bullet. This condition poses a threat to the operator?s safety and damages the machine tool, resulting in large economic losses. This study assessed the accidental explosion of an ultra-high-speed bronze bond CBN grinding wheel in actual working process. Based on fractography analysis of explosion grinding wheel and numerical analysis of the grinding wheel safety caused by centrifugal force, grinding forces, and adhesive failure between the grinding wheel matrix and abrasive layer, this study investigated the causes of the explosion of an ultra-high-speed grinding wheel. The following reasons for the accident were found: (1) defects appear at thread holes in the abrasive layer of the grinding wheel, (2) powder metallurgy defects in the transition layer of the grinding wheel, (3) fatigue cracks appear along the interface between the bond and grain under the centrifugal and grinding forces, and (4) adhesive failure at the interface between the grinding wheel matrix and abrasive layer.