Explore the vast range of titles available.

The redevelopment and transformation of industrial land has become an important part of urban renewal in China. This study adopts a spatial perspective to investigate the transformation of industrial land in Shenzhen based on a set of reliable data of all urban redevelopment projects of industrial land from 2010 to 2018. Research shows that the development of the real estate market, local government’s strategic demand for upgrading industrial structure, and the policy objective of improving land use intensity are important factors that affect the industrial land transformation. Industrial land has decreased significantly in urban renewal. About 881.79 ha (76.82%) of industrial land has been transformed into commercial, residential, and new industrial spaces. The planned industrial space is mainly located in the central and western regions, while the new commercial and residential spaces are mainly located outside the Special Economic Zone (SEZ). Redevelopment of industrial land has also transferred a certain scale of land to local governments for providing public facilities with an uneven spatial distribution between SEZ and non-SEZ. Therefore, industrial land transformation has brought significant effects on the urban spatial structure of this city. The study concludes with an evaluation of current industrial land redevelopment activities and provides suggestions for sustainable land development in the future.

This paper presents a distributed vibration control method using attachable absorbers for micro-vibration control of large space payload structures. The distributed vibration control system is modeled at three levels. The simplification of the attachable absorber model is discussed, and the single-channel ANC controller is extended to a multi-channel configuration. Based on the models, simulation analysis is conducted, revealing that the voltage–force output of the absorber in the low-frequency range can be simplified to a second-order system. During the distributed vibration control system simulation, a Simulink–GA hybrid optimization is applied to address the large number of converging parameters. The optimized parameters successfully control the vibration of all channels. Further analysis indicates that the coupling between control channels slightly reduces convergence speed but has no impact on the final control effect. Additionally, the control system can achieve the same results by independently tuning parameters for each channel. The experimental results, using absorber prototypes and a model with 12 sub-mirror structures, demonstrate that the method can control sub-mirror vibrations simultaneously, maintaining the flatness of the main mirror under disturbance, with a 90% reduction in vibration within 4 s. The coupling effect reduces the final convergence speed by approximately 10%, with a time difference of around 1 s.

We show that in gauge mediation models with tree-level R-symmetry breaking where supersymmetry and R-symmetries are broken by different fields, the gaugino mass either vanishes at one loop or finds a contribution from loop-level R-symmetry breaking. Thus tree-level R-symmetry breaking for phenomenology is either no-go or redundant in the simplest type of models. Including explicit messenger mass terms in the superpotential with a particular R-charge arrangement is helpful to bypass the no-go theorem, and the resulting gaugino mass is suppressed by the messenger mass scale.

The present study aimed to explore the effects of exogenous gibberellins (GAs) on seed germination and subsequent seedling growth of hemp (Cannabis sativa L.) under drought stress. Seeds of two industrial hemp cultivars i.e., ‘Yunma 1’, (YM) and ‘Bamahuoma’, (BM) were treated with different concentrations of GA3 solution (0, 200, 400, 600, 800 mg/L) at 20 °C for 8 h. The effect of pre-treatment was assessed on germination characteristics and physiological indexes on subsequent exposure to drought stress using 20% (m/v) polyethylene glycol (PEG) for 7 days. The results revealed that seed germination in hemp was sensitive to drought stress, as the germination indexes (germination rate and germination potential) decreased significantly, and seedling growth (hypocotyl length and radicle length) was impeded under 20% PEG-6000 condition. GA3 pre-treatment affected germination rate, germination potential, hypocotyl length and radicle length. With increasing GA3 concentration, these indexes first increased and then decreased. For seedling physiology characteristics in hemp, GA3-pretreatment remarkedly increased the osmotic regulating substances (soluble sugar and soluble protein contents) and the activities of antioxidant enzymes (SOD, superoxide dismutase and POD, peroxidase), while sharply decreased the lipid peroxidation (malondialdehyde, MDA) in seedlings grown under PEG-6000 induced drought stress. These results suggested that seeds pre-treated with GA3 could enhance the drought tolerance of hempseeds, and the optimal effect of GA3 for seed pre-treatment of YM and BM could be obtained when the concentration of GA3 solution reached 400 mg/L and 600 mg/L, respectively.

Optical imaging spacecraft needs adaptable vibration isolators to convey maneuvering forces stably and attenuate disturbances effectively, especially under multiple-level on-orbit working conditions. This paper proposes an active–passive integrated variable stiffness vibration isolator (API-VSVI), which employs a heterogeneous-signal fixed-step least mean square (HS-FSLMS) algorithm, to provide the necessary adaptability. Furthermore, the actuator’s capacity requirements can be further optimized based on the stiffness adjustment method. The API-VSVI prototype was firstly introduced, and the dynamic model was subsequently developed based on the derived equation of the stiffness. Then, the HS-FSLMS algorithm was proposed to simultaneously process the displacement and force signals for two different goals concerning different frequency bands. Through the comparative study of parameters, the appropriate range of the dynamic and control parameters was analyzed, following which one stiffness adjustment method was proposed according to the discussion on multilevel input modes. Finally, it was demonstrated by experiment results that the API-VSVI outperformed the VSVI in shaping the transmitted force. It appears that the maneuvering force amplification is actively regulated at less than 4%, and the disturbance suppression is improved to 92.7% by lowering the stiffness and then actively controlled to 98.5%.

Hemp is one of the most important green (i.e., environmentally sustainable) fibers. Planting density, nitrogen (N), phosphorus (P) and potassium (K) significantly affect the yield of hemp fiber. By optimizing the above main four cultivation factors is an important way to achieve sustainable development of high-fiber yield hemp crops. In this study, the effects of individual factors and factor × factor interactions on the yield of hemp fiber over two trial years were investigated by the central composite design with four factors, namely planting density, nitrogen application, phosphorus application, and potassium application rate. The influences of these four test factors on the yield of hemp fibers were in the order nitrogen fertilizer (X2) > planting density (X1) > potassium fertilizer (X4) > phosphate fertilizer (X3). To obtain yields of hemp with high-quality fiber greater than 2200 kg ha−1, the optimal range of cultivation conditions were planting density 329,950–371,500 plants/ha, nitrogen application rate 251–273 kg ha−1, phosphorus application rate 85–95 kg ha−1, and potassium application rate 212–238 kg ha−1. This study can provide important technical and theoretical support for the high-yield cultivation of hemp fiber into the future.

We propose generating functions, $\\textrm {RGF}_p(x)$ , for the quotients of numerical semigroups which are related to the Sylvester denumerant. Using MacMahon’s partition analysis, we can obtain $\\textrm {RGF}_p(x)$ by extracting the constant term of a rational function. We use $\\textrm {RGF}_p(x)$ to give a system of generators for the quotient of the numerical semigroup $\\langle a_1,a_2,a_3\\rangle $ by p for a small positive integer p, and we characterise the generators of ${\\langle A\\rangle }/{p}$ for a general numerical semigroup A and any positive integer p.

Drought poses a major challenge to crop growth and yield, and exploring the drought tolerance of crops is an effective and economical approach to mitigating the effects of drought. To screen drought-tolerant germplasm resources and key functional genes related to drought tolerance in Brassica juncea L.(193 accessions), three treatments were applied at the germination and seedling stages:control(CK), moderate drought stress (M), and severe drought stress (S). Drought tolerance identification, GWAS, and RNA-Seq analysis of these materials under different treatments showed that drought stress significantly reduced the germination rate, aboveground and underground fresh weight at the seedling stage, harvest index at maturity, and expanded the root/shoot ratio. From the 193 materials, 24 drought-tolerant, 139 drought-tolerant medium, and 30 drought-sensitive materials were identified. The 77 SNPs identified by GWAS were associated with the relative germination rate at the germination stage, and the fresh weight of the aboveground and underground parts at the seedling stage, which could be integrated into 27 QTLs. WGCNA identified 15, 0, and 5 modules significantly related to drought tolerance in the aboveground and underground parts at the germination and seedling stages, respectively. By correlating the significant GWAS SNPs with the significant WGCNA modules, a total of 11 genes related to drought tolerance under moderate and severe drought stress were identified. These genes were involved in the regulation of auxin-responsive protein ( SAUR ), LEA protein, glucosidase, AP2/ERF , WRKY and GATA transcription factors, FLZ zinc finger domain, PRP , and b561 proteins. Among them, the BjuB035910 gene was detected in the underground parts of the seedling and germination stages under moderate drought stress. GWAS and selective sweep analysis jointly identified the 23.955-24.089 Mb region of chromosome B06, where four genes ( BjuB022264, BjuB022292, BjuB022282 , and BjuB022235 ) were located, as confirmed by WGCNA analysis. A total of 125 SNPs with high linkage disequilibrium were found in this region, and 12 haplotypes were detected, with Hap1 being present exclusively in drought-tolerant materials and Hap3-Hap12 distributed in drought-sensitive materials. These findings provide new insights into the drought tolerance mechanisms of B. juncea and will contribute to the breeding of drought-tolerant rapeseed varieties.

Hemp is a multipurpose crop that is cultivated worldwide for fiber, oil, and cannabinoids. Nitrogen (N) is a key factor for getting a higher production of hemp, but its application is often excessive and results in considerable losses in the soil–plant–water continuum. Therefore, a rational N supply is important for increasing N efficiency and crop productivity. The main objective of this paper was to determine the responses of four hemp cultivars to different levels of exogenous-N supply as nutrient solution during the vegetative growing period. The experiment was conducted at Yunnan University in Kunming, China. Yunma 1, Yunma 7, Bamahuoma, and Wanma 1 were used as the experimental materials, and five N supplying levels (1.5, 3.0, 6.0, 12.0, and 24.0 mmol/L NO3-N in the nutrient solution) were set by using pot culture and adding nutrient solution. The root, stem, and leaf of the plant were sampled for the determination of growth indexes, dry matter and N accumulation and distribution, and physiological indicators. The plant height, stem diameter, plant dry weight, and plant N accumulation of four hemp cultivars were significantly increased with the increase in exogenous-N supply. Root/shoot dry weight ratios, stem mass density, and N use efficiency decreased significantly with the increase in exogenous-N supply. Nitrogen accumulation, chlorophyll content, soluble protein content, and nitrate reductase activity in leaves were increased with the increase in exogenous-N supply. Among the four indexes, the increase in N accumulation was more than the increase in NR activity. The activities of superoxide dismutase and peroxidase in leaves were increased first and then decreased with the increase in exogenous-N supply, with the maximum value at N 6.0 mmol/L, while the content of malondialdehyde in leaves increased significantly when the level of exogenous-N supply exceeded 6.0 mmol/L. These results revealed that increasing the exogenous-N supply could improve the plant growth, dry matter accumulation, and N accumulation in hemp during the vegetative growth period, but N supply should not exceed 6.0 mmol/L. Among four hemp cultivars, Wanma 1 performed well at 6.0 mmol/L N application.

In the present study, we identified genes that are putatively involved in the production of fungal 10-hydroxycamptothecin via transcriptome sequencing and characterization of the Xylaria sp. M71 treated with salicylic acid (SA). A total of 60,664,200 raw reads were assembled into 26,044 unigenes. BLAST assigned 8,767 (33.7%) and 10,840 (41.6%) unigenes to 40 Gene Ontology (GO) annotations and 108 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, respectively. A total of 3,713 unigenes comprising 1,504 upregulated and 2,209 downregulated unigenes were found to be differentially expressed between SA-induced and control fungi. Based on the camptothecin biosynthesis pathway in plants, 13 functional genes of Xylaria sp. M71 were mapped to the mevalonate (MVA) pathway, suggesting that the fungal 10-hydroxycamptothecin is produced via the MVA pathway. In summary, analysis of the Xylaria sp. M71 transcriptome allowed the identification of unigenes that are putatively involved in 10-hydroxycamptothecin biosynthesis in fungi.