Effects of Different Nitrogen Fertilizer Treatments on Soil Enzymatic Activities in Mulberry Gardens

[ Objective] The present experiment was undertaken to investigate the effects of different nitrogen fertilizer application levels on soil enzymatic activities in mulberry gardens, thus providing reference for rational application of nitrogen fertilizer and production of high-quality mulberry leaves. [Method] Field experiments were conducted with three different nitrogen fertilizer application levels： N, （ 120.75 kg/hm2 ）, N2 （ 172.5 kg/hm2 ）, and N3 （207 kg/hm2 ）. Activities of catalase, urease, acid phosphatase and invertase in soil applied with different amount of nitrogen fertilizer were determined to analyze the correlation between soil enzymatic activities and mulberry leaf yield. [ Result] Activities of urease and invertase in soil were improved with the increasing application level of nitrogen fertil- izer; activities of catalase and acid phosphatase reached the highest in treatment N2. Activities of invertase and urease in soil exhibited significant positive correla- tions; activities of invertase and phosphatase exhibited significant positive correlations; extremely significant positive correlations were found between mulberry leaf yield and activities of urease, phosphatase and invertase in soil. [ Conclusion] Rationally applying nitrogen fertilizer can improve activities of invertase, phosphatase and urease in mulberry gardens ; activities of urease and invertase in soil can be used as indicators to evaluate soil properties in mulberry gardens.

Effects of Different Nitrogen Levels on Growth and Nitrogen Utilization of Sugarcane

[Objectives]To systematically study the effects of different nitrogen levels on the growth and nitrogen utilization of sugarcane in Guangxi.[Methods]Through field experiment and indoor analysis,different nitrogen application levels were set up to determine soil nitrogen content and sugarcane nitrogen content.The effects of different nitrogen levels on sugarcane yield,agronomic characters and nitrogen utilization were studied.[Results]The effect of nitrogen application rate on sugarcane yield showed a quadratic curve,and nitrogen application could significantly increase sugarcane yield,and the sugarcane yield reached the maximum when the nitrogen application rate reached 714 kg/ha.[Conclusions]With the increase of nitrogen application rate,sugarcane yield increased,but when it exceeded a certain range,the sugarcane yield decreased significantly.

Growth Performance and Adaptability of Sugarcane Combinations Under Different Ecological Environments

The experiments of sugarcane combination evaluation were conducted on 119 combinations during 2017-2018 crossing season in Nanning,Chongzuo and Laibin of Guangxi.The conjoint analysis of variance and estimation of genetic parameters were performed based on brix weight.Furthermore,combination stability was analyzed by regression analysis model and AMMI model.The results showed that differences in brix weight among combinations,environments and interaction between environments and combinations were all extremely significant(P<0.01),and the broad-sense heritability of brix weight belonged to medium level or slightly lower at the three sites.In both Chongzuo and Laibin,the variation coefficients of brix weight were large,but that in Nanning was small.Combinations 643,404,575,972,636,144,YC95,1470,755,409,701,832,YC37 and 579 performed high yield,high genetic stability and stronger adaptability.The results of comprehensive analysis in both brix weight and selection rate of combination showed that 449,YC127,796,YC44,533,570,YC123,391,546,403,YC90 and 252 performed high brix weight and high selection rate of combination in Nanning;combinations 643,212,YC61,432,903,YC95,YC44,368,YC83,YC127,YC112,701,411,YC90 and YC123 demonstrated high brix weight and high selection rate of combination in Chongzuo;and combinations 643,404,449,144,403 and YC48 had high brix weight and high selection rate of combination in Laibin.

Survey and Study of Soil Nutrients of Sugarcane Field in Southern Guangxi

To survey and analyze soil nutrients of sugarcane field in southern Guangxi and provide basic data for reasonable land use and scientific fertilization,combining GIS technology,a total of 498 samples of topsoil of typical soil types in southern Guangxi sugarcane planting areas were collected and soil nutrients were measured. Survey results indicate that the p H value of 95% soil in southern Guangxi is lower than 6. 5;acid soil is major soil type of sugarcane planting areas in southern Guangxi; the organic matter content is 6. 03- 44. 58 g / kg; alkali-hydrolyzable N is 14. 0- 175. 0 mg / kg; available P is 1. 7- 95. 0 mg / kg; available K is 11. 0- 358. 0 mg / kg; the content of most nutrients remains at medium level,and there is still a large gap with high-yield soil condition. In various trace elements,the average content of B is 0. 24 mg / kg,- 98% soil lacks B; the average content of available Mg is 62. 34 mg / kg and 69. 08% soil lacks Mg; the average content of active Ca is 592.68 mg / kg and the active Ca is relatively low in 54. 84% soil; the average content of available Zn is 0. 93 mg / kg,and 19. 08% soil lacks Zn;the average content of available Cu is 0. 65 mg / kg,and 7. 02% soil lacks Cu. It is concluded that the overall soil fertility of sugarcane planting areas in southern Guangxi is not high,the organic matter is relatively low,the content of rapidly available N,P and K is at medium or low level,the content of Fe and Mn is high,and the available Cu and available Zn of most soil remain at medium level.

Correlations between P2RX1 Expression and Gastrointestinal Cancers Prognosis and Immune Infiltration Based on Bioinformatics Analysis

This study was conducted to explore the correlations between the expression,methylation,and various clinicopathological factors of purinergic P2X1 receptor(P2RX1)and the prognosis of patients with gastrointestinal tumors.The Cancer Genome Atlas(TCGA)and the Genotype-Tissue Expression(GTEx)databases were used to analyze the expression of P2RX1 in different types of gastrointestinal cancers.Kaplan-Meier analysis and univariate Cox regression analysis were used to analyze the correlations between P2RX1 expression and the prognosis of various gastrointestinal tumors.Correlations between P2RX1 expression and N6 methyladenine(m6A)-related genes as well as immune checkpoint genes were analyzed by R packages(R version:4.0.3)based on TCGA database.The association between P2RX1 methylation level and the prognosis of patients with gastrointestinal cancers was analyzed using the MethSurv database.In order to explore the biological functions of P2RX1 in hepatocellular carcinoma,the Kyoto Encyclopedia of Genes and Genomes(KEGG)and Gene Ontology(GO)enrichment analysis were carried out using R software.In order to evaluate the correlations between P2RX1 and tumor immune infiltration,Spearman correlation test was performed.The correlations between P2RX1 expression and immune score as well as immune checkpoint genes were analyzed based on TCGA and Tumor Immune Estimation Resource(TIMER)databases.The expression of P2RX1 was found to be significantly downregulated in gastrointestinal tumors except in cholangiocarcinoma(P<0.05).High expression of P2RX1 tended to present better prognosis in hepatocellular carcinoma(P<0.05).It was noted that cg06475633 of P2RX1 presented a higher methylation level compared with other CpG sites in hepatocellular carcinoma.Overall,six CpGs of P2RX1 were associated with significant prognosis in patients with hepatocellular carcinoma(P<0.05).Among all the 20 m6A-related genes,Wilms'tumor 1-associating protein(WTAP)was the most strongly correlated with P2RX1 in hepatocellular carcinoma.Gene enrichment analysis showed that P2RX1 is widely involved in the proliferation,activation,organization,and differentiation of various immune cells.After investigating the TIMER database,P2RX1 was found to be tightly correlated with immune infiltrating cells in gastrointestinal tumors,especially with dendritic cells.Moreover,P2RX1 was found to be strongly positively associated with programmed cell death 1(PD1),programmed death-ligand 1(PD-L1),and cytotoxic T-lymphocyte-associated protein 4(CTLA4)in hepatocellular carcinoma(P<0.05).In conclusion,the dual role of P2RX1 in cancers and its involvement in the recruitment as well as regulation of tumor infiltrating cells in gastrointestinal cancers may be appreciated through this study.

生成式对抗网络的不稳定性分析及其处理技术

生成式对抗网络(generative adversarial networks,GANs)训练的不稳定性问题一直是GANs研究领域最具挑战性的问题之一.目前,仍未从理论上找到影响GANs训练稳定性的根本原因及有效的解决办法.本文通过理论分析发现,GANs训练的不稳定性主要是由于训练最优判别器与最小化生成器之间相互矛盾所致.经逐步分析得出,控制判别器的Lipschitz常数是解决GANs不稳定性问题的关键,进而提出一种有针对性的梯度惩罚技术来解决此问题.最后,本文从损失函数的振荡幅度(收敛性)、梯度总体变化趋势,以及网络整体性能3个方面进行了全面对比实验.结果显示,本文所提出的惩罚技术对处理GANs训练的不稳定性问题具有显著的效果.

Construction of Highly Emissive Pt(Ⅱ) Metallacycles upon Irradiation

Photoswitchable or photoactivatable fluorescent species have been found wide applications within supramolecular chemistry and materials science.In this study,we successfully constructed two highly emissive Pt(Ⅱ)metallacycles from the diarylethene ligands via coordination-driven self-assembly.Different from the most known fluorescent metallacycles,the obtained metallacycles have displayed"turn-on"fluorescence switching.They are non-fluorescent in solution,but they emit highly yellow or orange fluorescence under ultraviolet irradiation.The metallacycles were well characterized by 1H NMR,31P NMR and ESI-TOF-MS.The photochromic properties of the resultant metallacycles were investigated by 1H NMR,31P NMR,UV/Vis spectrum and fluorescence spectrum.Notably,NMR studies revealed that these two metallacycles featured excellent cyclization efficiency(90% conversion efficiency).Moreover,the closed-ring isomers of the metallacycles displayed relatively high quantum yield(ФF=0.5).DFT simulations demonstrated that the antiparallel configuration of the diarylethene ligand had an angle closed to 120°,which was more stable in energy compared to the parallel configuration,thus allowing for the facile construction of highly emissive metallacycles.We believe that such highly emissive metallacycles which are in-situ prepared upon irradiation can be used as new fluorescence materials for sensing and bioimaging in the future.

Self-assembly of Pyrene-modified Rhomboidal Metalloden- drimers via Directional Metal-ligand Bonding Approach

设计并且经由方向性的 metal-ligand 的修改分核的长斜方形的 metallodendrimers R1R6 自己组装结合的途径被描述。由采用包含分核 120 敺搠獩牴扩瑵潩 ? 景 ? 偄华 ? 敷敲搠瑥牥業敮 ? 祢搠湹浡捩氠杩?

Dithienylethene metallodendrimers with high photochromic efficiency

It has been challenging to achieve multi-photochromic systems without affecting the individual photoswitching properties of the constituent units. Herein, we present the design and synthesis of a new family of platinum-acetylide dendrimers containing up to twenty-one photochromic dithienylethene(DTE)units that exhibit both high photochromic efficiency and individual switching properties. Upon irradiation with ultraviolet(UV) and visible(vis) light, the resultant metallodendrimers display high conversion yield and good fatigue resistance. More interestingly, cyclization-cycloreversion kinetics revealed that the photochromic property of each DTE unit in these metallodendrimers is unaffected by its neighbor and the full ring-closure of up to twenty-one DTE units in one single dendrimer has been achieved.

Facile construction of Zn(Ⅱ)-porphyrin-cored [5]rotaxane and its controllable aggregation behaviours

Rotaxanes have attracted more and more attentions because of their diverse applications as sensors,catalysts, and functional materials. The construction of highly ordered and discrete multirotaxanes with the well-defined structure remains a challenge. Herein, a symmetric [5]rotaxane with zinc porphyrin as core and the neutral platinum-acetylide as the linkage was synthesized with high yield. The [5]rotaxane was well characterized with NMR spectroscopy and MALDI-TOF mass spectrometry. Interestingly, it was found that the [5]rotaxane showed the controllable aggregation behaviours in different solution compositions. For example, in non-polar solution, the [5]rotaxane could self-assemble into the largescaled solid nanospheres while the nanofibers were formed in polar solvent. Further investigation revealed that the [5]rotaxane displayed J-type aggregation in solution driven by p-p interaction. Notably,the similar structure without DPP[5]A formed the irregular morphology at the same condition,suggesting that the existence of rotaxanes endowed the complex with a relative rigid structure to facilitate the formation of the ordered aggregates.