The demand for particleboard is increasing along with economic and population growth.However,two major barriers to the manufacture of particleboard are a shortage of raw materials(woodchips)and the emission of formald...The demand for particleboard is increasing along with economic and population growth.However,two major barriers to the manufacture of particleboard are a shortage of raw materials(woodchips)and the emission of formaldehyde from conventional adhesives.Agricultural by-products such as corn stalks contain an abundance of renewable lignocellulosic fiber.This study evaluates the effect of citric acid as a natural adhesive and fire retardant addition on the physical,mechanical,and fire retardancy properties of particleboards fabricated from corn stalks.A cost-effective and inorganic salt,calcium carbonate,was tested to enhance the fire retardancy.Ammonium dihydrogen phosphate was also considered as a comparative control.Particleboards with the addition of calcium carbonate was pretreated with sodium chloride.The particleboards were pressed for 10 min at 200℃.Japanese Industrial Standard JIS A 5908:2022 was used as the benchmark for the physical and mechanical tests.Fire retardancy was dynamically tested by simulating a Bushfire Attack Level of 19 kW/m^(2).The particleboard with 25 wt%citric acid had superior mechanical properties and complied with the JIS A 5908 standard for Type 13 base particleboard.Particleboard with the addition of calcium carbonate(5%and 10%)showed significantly delayed pyrolysis time.展开更多
Maize stalk rot reduces grain yield and quality.Information about the genetics of resistance to maize stalk rot could help breeders design effective breeding strategies for the trait.Genomic prediction may be a more e...Maize stalk rot reduces grain yield and quality.Information about the genetics of resistance to maize stalk rot could help breeders design effective breeding strategies for the trait.Genomic prediction may be a more effective breeding strategy for stalk-rot resistance than marker-assisted selection.We performed a genome-wide association study(GWAS)and genomic prediction of resistance in testcross hybrids of 677 inbred lines from the Tuxpe?o and non-Tuxpe?o heterotic pools grown in three environments and genotyped with 200,681 single-nucleotide polymorphisms(SNPs).Eighteen SNPs associated with stalk rot shared genomic regions with gene families previously associated with plant biotic and abiotic responses.More favorable SNP haplotypes traced to tropical than to temperate progenitors of the inbred lines.Incorporating genotype-by-environment(G×E)interaction increased genomic prediction accuracy.展开更多
Chopped and spread maize stalks improve soil structure and fertility. However, because of the absence of research on airflow distribution in the chopping chamber, improvement of the spreading uniformity of chopped sta...Chopped and spread maize stalks improve soil structure and fertility. However, because of the absence of research on airflow distribution in the chopping chamber, improvement of the spreading uniformity of chopped stalks has been limited. Therefore, in this study, computational fluid dynamics (CFD) technology was applied to analyze the influence of structural and operational parameters of the chopping and spreading machine on the velocity, pressure, and turbulent kinetic energy distribution of airflow in the chopping chamber. The experimental factors considered were the relative position angle (RPA) between the collecting-chopping shaft and the sliding-supporting shaft, working velocity (WV) of the chopping chamber, and rotational velocity of the collecting-chopping blade (RVCCB). The results revealed that RPA and RVCCB had a significant influence on the maximum negative pressure in the inlet (MNPI), the proportion of negative pressure area at inlet (PNPAI), and the maximum pressure drop at inlet and outlet (MPDIO). Additionally, RVCCB had a strong influence on the maximum velocity, average velocity, and velocity variation coefficient of airflow at the outlet. Moreover, maximum turbulence (MT) and maximum turbulent kinetic energy dissipation rate (MTKEDR) showed a positive relationship with RVCCB. To determine the values of RPA, RVCCB, and WV, a multivariate parameters optimization regression model was constructed, which yielded the optimal values of 15°, 1800 r/min, and 0.50 m/s, respectively. Subsequently, a hyperbolic spiral-type guiding shell with an arc length of 90° was designed to enhance the uniform distribution of airflow in the chopping chamber. Finally, a validation experiment of airflow distribution was conducted. The results showed that the velocity difference between the simulation and the validation experiment was less than 15%, indicating the accuracy of CFD simulation, and the spreading uniformities of the chopped stalks were better than national standards. These findings can serve as technical and theoretical support for the design and optimization of chopping and spreading machines.展开更多
BACKGROUND Pituitary stalk interruption syndrome(PSIS)is a rare anatomical defect of the pituitary gland falling under the spectrum of holoprosencephaly phenotypes.It is characterized by a deficiency in anterior pitui...BACKGROUND Pituitary stalk interruption syndrome(PSIS)is a rare anatomical defect of the pituitary gland falling under the spectrum of holoprosencephaly phenotypes.It is characterized by a deficiency in anterior pituitary hormones,such as growth hormone,gonadotropins,and thyroid hormones.Due to the syndrome's rarity and nonspecific manifestations,there is a lack of standardized treatment strategies.Consequently,early diagnosis through imaging and on-time intervention are crucial for improving patients’outcomes.CASE SUMMARY A 30-year-old man presented with absent secondary sexual characteristics and azoospermia.Laboratory evaluation revealed a deficiency in gonadotropins,while thyroid function was mostly within normal ranges.Magnetic resonance imaging of the pituitary gland showed pituitary stalk agenesis,hypoplasia of the anterior pituitary,and ectopic posterior pituitary,leading to the diagnosis of PSIS.Initially,the patient underwent 6 mo of gonadotropin therapy without significant changes in hormone levels and secondary sexual characteristics.Pulsatile gonadotropin-releasing hormone therapy was then administered,resulting in the detection of sperm in the semen analysis within 3 mo.After 6 mo,routine semen tests showed normal semen quality.The couple faced challenges in conceiving due to abstinence and underwent three cycles of artificial insemination,which was unsuccessful.They also attempted in vitro fertilization,but unfortunately,the woman experienced a miscarriage 10 wk after the embryo transfer.CONCLUSION Early detection,accurate diagnosis,and timely treatment are crucial in improving the quality of life and fertility of PSIS patients.展开更多
BACKGROUND Pituitary stalk interruption syndrome(PSIS)is a rare disorder,often characterized by delayed growth and development,short stature,and hypogonadism as the main clinical manifestations.It is not clear whether...BACKGROUND Pituitary stalk interruption syndrome(PSIS)is a rare disorder,often characterized by delayed growth and development,short stature,and hypogonadism as the main clinical manifestations.It is not clear whether PSIS can lead to liver cirrhosis.CASE SUMMARY This paper reported a case of liver cirrhosis of unknown origin.The patient was admitted to Beijing Ditan Hospital Affiliated to Capital Medical University in November 2023.The diagnosis of PSIS complicated with liver cirrhosis was established after a series of blood tests and pituitary magnetic resonance imaging examination.CONCLUSION We also reviewed the literature from both domestic and international sources to deepen the clinical understanding of PSIS in conjunction with liver cirrhosis among medical practitioners.展开更多
[Objective] To study the correlation between the biomechanical properties of rape stalks and rape stem lodging. [Method] Through axial compression tests to the stalks of 4 different rape varieties, the change rules of...[Objective] To study the correlation between the biomechanical properties of rape stalks and rape stem lodging. [Method] Through axial compression tests to the stalks of 4 different rape varieties, the change rules of maximum stem bearing ca- pacity, maximum compressive strength, elastic modulus and moment of inertia along plant height were analyzed, as well as the effect of different varieties and water contents on the biomechanical property indices of rape stalks. [Result] The maximum loads of rape stalks presented liner decrease trend along with the increase of stem height, and all reached the maximums below the height of 50 cm. The maximum stem compressive strength and elastic modulus of the 4 varieties were increased with ascending height, but in a slow rate with small change, thus the modulus of e- lasticity could be considered as unchanged. The maximum bearing capacity, maxi- mum compressive strength and elastic modulus of dry rape stalks were higher than wet stalks, indicating that the water contents of rape stalks had significant effect on their mechanical properties. According to the actual lodging situations in filed, stalks of variety No. 1 owned the worst biomechanical properties and lodging degree, while the biomechanical properties of No. 6 and F5 were better than No. 1 and No. 9, and they also had stronger lodging-resistance. [Conclusion] The study provides parameters and bases for the design of mechanized production and mechanical deep processing of crops, and can better reveal the physical natures of organisms. The methods used in this study can also be used to screen excellent crop stalks.展开更多
[Objective] The study aimed at reducing the economic cost in feeding Tenebrio molitor and improving the utilization ratio of corn stalks.[Method] The effects of different proportions of corn stalks on the weigh of Ten...[Objective] The study aimed at reducing the economic cost in feeding Tenebrio molitor and improving the utilization ratio of corn stalks.[Method] The effects of different proportions of corn stalks on the weigh of Tenebrio molitor and the contents of crude protein,crude fat,Ca,P,dry matter and crude ash in the half-dry matter of Tenebrio molitor had been studied in the laboratory.[Result] Compared with the recipes of all wheat bran and pure fine fodder,feeding Tenebrio molitor by applying 30%-60% of corn stalks could significantly improve the content of crude protein in the half-dry materials of Tenebrio molitor,but it was detrimental to the improvement in weight of Tenebrio molitor and the accumulation of crude fat.To be specific,the recipe V(50% of corn stalks + 50% of fine fodder) was beneficial to the accumulation of dry matter and crude ash.The recipe VII(70% of corn stalks + 30% of fine fodder) and the recipe VIII(70% of corn stalks treated with Guangda feed leaven + 30% of fine fodder) were beneficial to the accumulation of crude protein,Ca and P.There were differences among the influences of corn stalks in different treatments on the crude protein and other nutrition indicators of Tenebrio molitor.[Conclusion] Appropriately applying corn stalks can improve the accumulation of the crude protein,crude ash,dry matter,Ca and P of Tenebrio molitor but was detrimental to the growth and development of Tenebrio molitor and the accumulation of crude fat.展开更多
[Objective] This study aimed to study the adsorption performance of activated carbon prepared from corn stalks. [Methed] With granular activated carbon prepared from corn stalks as research object, adsorption performa...[Objective] This study aimed to study the adsorption performance of activated carbon prepared from corn stalks. [Methed] With granular activated carbon prepared from corn stalks as research object, adsorption performance simulation test equipment was set up to investigate the adsorption performance of the prepared activated carbon for methanol by static weight method. In addition, the effects of adsorption bed structure, activated carbon particle size in adsorption bed, addition amount of graphite powder in activated carbon and modified activated carbon on systematic adsorption performance were studied. [Result] Under conditions of same activated carbon and same adsorption temperature, the adsorption performance of new adsorption bed A (installed with finned diaphragm adsorbate tubes) was signifi- cantly better than that of unmodified adsorption bed B. Compared with adsorption bed B, adsorption bed A took 5 min shorter to reach the adsorption amount of 0.22 g/g. Under the same adsorption temperature, the adsorption performance of bed loaded with different-particle size activated carbon was significantly better than that loaded with same-particle size activated carbon. The bed loaded with different-particle size activated carbon took 16 min shorter to reach the adsorption capacity of 0.22 g/g compared with the bed loaded with same-particle size activated carbon. Adding proper amount of graphite powder in activated carbon could enhance the thermal conductivity and strengthen the adsorption properties. The optimum addition amount of graphite powder was 20% of the total amount of activated carbon. Com- pared with that of the control, the adsorption performance of activated carbon soaked by weak acidic solution was significantly improved. It took 3 min shorter to reach 87.1% of the equilibrium adsorption amount. [Conclusion] This study will provide reference for optimizing structural design of adsorption bed and adsorption refrigeration system.展开更多
Pretreatment of lespedeza stalks by steam explosion has been studied. The results indicate that steam-exploded pretreatment has strong effects on physical features, morphology, crystallinity, and composition of lesped...Pretreatment of lespedeza stalks by steam explosion has been studied. The results indicate that steam-exploded pretreatment has strong effects on physical features, morphology, crystallinity, and composition of lespedeza stalks as shown by scanning electron microscopy (SEM), infrared (IR), and X-ray diffraction spectrometry methods. After steam explosion, the cellulose and lignin contents of lespedeza stalks varied only slightly, but the hemicellulose content had decreased from 29.34% to 7.48%. The cellulose obtained by steam-exploded pretreatment had a higher degree of crystallinity than that of the raw material. At the explosion condition of 2.25 MPa and 4 min, lignocellulose is easier to hydrolyze by enzyme than the original lignocellulose. The concentration of reduced sugar in the hydrolyzate liquid increased from 71.77 to 162.84 g·L^-1.展开更多
Sweet potato (Ipomoea batatas Lam.) leaf stalks were cut into 20 cm length, and stored at 20, 6, and 2℃. The respiration rate, ethylene production, ascorbic acid, free amino acid, total chlorophyll content, freshne...Sweet potato (Ipomoea batatas Lam.) leaf stalks were cut into 20 cm length, and stored at 20, 6, and 2℃. The respiration rate, ethylene production, ascorbic acid, free amino acid, total chlorophyll content, freshness, and shelf life were determined during storage to investigate the effect of storage temperatures on the quality and physiological responses in sweet potato leaf stalks. Wound responses were observed as high respiration rate and ethylene production immediately after cutting. Sweet potato leaf stalks were found to be sensitive to chilling injury manifested as browning and water-soaking on the surface at 2℃. In contrast, sweet potato leaf stalks were susceptible to senescence, exhibited by etiolating and yellowing, at 20℃. Loss in weight and chlorophyll was minimized under low temperatures. High temperatures also caused the accumulation of amino acids with a significant loss of ascorbic acid and chlorophyll. Sweet potato leaf stalks had a storage life of 16 days at 6℃, 8 days at 2℃, and 6 days at 20℃, respectively.展开更多
We undertook a pyrolysis research on garlic stalks to solve its difficulty in use. We found that the inorganic salts in biomass played an important role in catalytic pyrolysis. Moreover, we studied the pyrolysis behav...We undertook a pyrolysis research on garlic stalks to solve its difficulty in use. We found that the inorganic salts in biomass played an important role in catalytic pyrolysis. Moreover, we studied the pyrolysis behavior under catalyst and catalyst-free conditions. The results showed that the weightlessness rate of garlic stalks was the highest at 550 ℃ under catalyst-free condition. The oil production rate increased with the increase of temperature and reached the peak at 550 ℃. Subsequently, as the temperature increased, the secondary cracking was intensified and oil production rate was decreased. The oil production rate increased significantly (almost 15%) under catalysis of KOH. However, the oil production rate was the highest at 500-600℃. What's more, we found that KOH played a major role in promoting decomposition of surface skin cells and subcutaneous fibrous layer of garlic stalks.展开更多
Lespedeza stalks were subjected to steam pretreatment at 210℃ for some steaming time before simultaneous saccharification and fermentation (SSF). Cellulose-derived glucose was extensively utilized by yeast during S...Lespedeza stalks were subjected to steam pretreatment at 210℃ for some steaming time before simultaneous saccharification and fermentation (SSF). Cellulose-derived glucose was extensively utilized by yeast during SSE The ethanol yields after steam pretreatment of the lespedeza stalks at 210℃ were 59.3%, 72.8% and 62.2% of the theoretically expected values when the steaming times were 2, 4 and 6 min, respectively. The highest yield from α-cellulose was 92.7% of the theoretical value. Steam explosion pretreatment of lespedeza stalks increased ethanol yields by a factor of 4.4, from 16.4% (untreated) to 72.8% (steam explosion pretreated).展开更多
In order to reduce the economic costs for breeding Tenebrio molitor L. and increase the utilization rate of corn stalk, with corn, wheat bran and corn stalk as the raw materials, 13 different compound feed were design...In order to reduce the economic costs for breeding Tenebrio molitor L. and increase the utilization rate of corn stalk, with corn, wheat bran and corn stalk as the raw materials, 13 different compound feed were designed by Minitab (R) 15.1.0.0. The design was then divided into two groups based on addition or without addition of vegetable leaves to study the effects of compound feed and vegetable leaves on growth and de- velopment of T. molitor. The results showed that body weight, duration, crude protein content and pupation rate of larvae and emergence rate of adults were significantly affected by compound feed and vegetable leaves ( P 〈 0.05). The larvae bred with feed 5 had the largest body weight, with the shortest duration; the larvae bred with feed 3 had the highest pupation rate; the larvae bred with feed 7 had the highest crude protein content; the adult bred with feed 9 had the largest emergence rate. Overall breeding effect of feed 7 + vegetable leaves was better than any other groups, with ideal indicators, higher utilization rate and lower breeding cost. Its formula was w (wheat bran) = 33.33%, w (corn) = 33.33%, w (corn stalks) = 33.33%. Therefore, the growth of T. molitorwas significantly affected by feed types, and feed 7 + vegetable leaves could be promoted in the production.展开更多
It is very difficult to directly spin the lignocellulose without pretreatment.Ionic liquids(ILs)are promising solvent to dissolve lignocellulose to prepare cellulose fiber.However,the degree of cellulose polymerizatio...It is very difficult to directly spin the lignocellulose without pretreatment.Ionic liquids(ILs)are promising solvent to dissolve lignocellulose to prepare cellulose fiber.However,the degree of cellulose polymerization(DP)is reduced when lignocellulose is dissolved in ILs,and the lignin removal rate is low.The elongation at break and tensile strength of the fibers obtained by spinning the lignocellulose dissolved in ILs are poor.In this paper,preparing cellulose fiber directly from lignocellulose based on dissolving corn stalk via[C4mim]Cl-L-arginine binary system is achieved.It shows that the removal rate of lignin can reach 92.35%and the purity of cellulose can reach 85.32%after corn stalk was dissolved at 150℃C for 11.5 h when the mass fraction of arginine is 2.5%.The elongation at break of fiber reached 10.12%and the tensile strength reached 420 MPa.It is mainly due to the fact that L-arginine not only inhibits the degradation of cellulose but also promotes the delignination.Without any pulping or pretreatment,preparing cellulose fibers via direct dissolution and extrusion may provide a simple and effective way to prepare many novel cellulose materials.展开更多
Millets are important natural grain source for wild and game birds and the domesticated varieties are good sources of grain for human and livestock nutrition as well as summer forage. Unlike sorghum, millet seed has l...Millets are important natural grain source for wild and game birds and the domesticated varieties are good sources of grain for human and livestock nutrition as well as summer forage. Unlike sorghum, millet seed has less anti-nutrient factors and is a better choice for animal feed formulations. Pearl millet is an example of such millets and has both forage- and grain-type varieties. However, opportunities exist for dual use of millet for grain and residue for forage. In this study two millets: Pennisetum glaucum (L.) R. Br. (Pearl millet var. TifGrain 102) and Panicum ramosum (L.) (Browntop millet) were evaluated for their response to potassium (K) and manganese (Mn) fertilizer. The experiment was a randomized complete block with treatments in a split-split arrangement. Potassium and Mn were supplied as K fertilizer (0-0-60) and manganese sulfate (MnSO4·2H2O), respectively. Potassium and Mn fertilizer rates and their interaction with each other and variety had no effect on determined parameters. TifGrain 102 grain yield averaged at 5900 kg·ha-1 was significantly greater than 4680 kg·ha-1 obtained for Browntop millet. While grain oil contents were similar, Browntop grain had greater contents of crude proteins. And except for K, Browntop seed had greater contents of all determined macro-and micronutrients. Residual stalks of Browntop had greater forage crude protein, total digestible nutrient (TDN) and lower acid detergent fiber (ADF). Browntop residual material had greater quantities of estimated net energy for growth (NEG), lactation (NEL), maintenance (NME). While TifGrain 102 residual stalks had greater contents of P and K, it had significantly lower contents of Ca, Mg and S compared to Browntop. Overall, while these two millets have shown good potential for dual use, Browntop may offer a better choice for high quality seed and residual stalks for forage.展开更多
Glucosinolates(GSLs) and their hydrolytic products contribute to the quality traits of rapeseed flowering stalk tissues, such as taste, flavor and anticarcinogenic properties(Glucoraphanin). However, little is known a...Glucosinolates(GSLs) and their hydrolytic products contribute to the quality traits of rapeseed flowering stalk tissues, such as taste, flavor and anticarcinogenic properties(Glucoraphanin). However, little is known about the genetic mechanisms of GSL accumulation in rapeseed flowering stalks. In this study, the variation and genetic architecture of GSL metabolites in flowering stalk tissues were investigated for the first time among a panel of 107 accessions. All GSL compounds exhibited continuous and wide variations in the present population. Progoitrin,glucobrassicanapin and gluconapin were the most abundant GSL compounds. Five quantitative trait loci(QTL) significantly associated with three GSL compounds were identified by genome-wide association study. GRA_C04 was under selected during modern breeding, in which the ratio of lower GSL haplotype(HAP2) in the accessions bred before 1990(52.56%) was significantly lower than that after 1990(78.95%). Four candidate genes, BnaA01. SOT16, BnaA06. SOT17, Bna A06. MYB51a, and Bna A06. MYB51b, were identified in the GTL_A01 and 4OH_A06 regions.These findings provide new insights into GSL biosynthesis in flowering stalk tissues and facilitate quality improvement in rapeseed flowering stalks.展开更多
Stalk strength increases resistance to stalk lodging,which causes maize(Zea mays L.)production losses worldwide.The genetic mechanisms regulating stalk strength remain unclear.In this study,three stalk strength-relate...Stalk strength increases resistance to stalk lodging,which causes maize(Zea mays L.)production losses worldwide.The genetic mechanisms regulating stalk strength remain unclear.In this study,three stalk strength-related traits(rind penetrometer resistance,stalk crushing strength,and stalk bending strength)and four plant architecture traits(plant height,ear height,stem diameter,stem length)were measured in three field trials.Substantial phenotypic variation was detected for these traits.A genome-wide association study(GWAS)was conducted using general and mixed linear models and 372,331 single-nucleotide polymorphisms(SNPs).A total of 94 quantitative trait loci including 241 SNPs were detected.By combining the GWAS data with public gene expression data,56 candidate genes within 50 kb of the significant SNPs were identified,including genes encoding flavonol synthase(GRMZM2G069298,ZmFLS2),nitrate reductase(GRMZM5G878558,ZmNR2),glucose-1-phosphate adenylyltransferase(GRMZM2G027955),and laccase(GRMZM2G447271).Resequencing GRMZM2G069298 and GRMZM5G878558 in all tested lines revealed respectively 47 and 2 variants associated with RPR.Comparison of the RPR of the zmnr2EMS mutant and the wild-type plant under high-and low-nitrogen conditions verified the GRMZM5G878558 function.These findings may be useful for clarifying the genetic basis of stalk strength.The identified candidate genes and variants may be useful for the genetic improvement of maize lodging resistance.展开更多
Cellulose biomass is being investigated as a potential substrate for bioethanol production. Cassava stalks were successfully converted to ethanol by fermentation using Saccharomyces cerevisiae TISTR5048, S. cerevisiae...Cellulose biomass is being investigated as a potential substrate for bioethanol production. Cassava stalks were successfully converted to ethanol by fermentation using Saccharomyces cerevisiae TISTR5048, S. cerevisiae KM1195, S. cerevisiae KM7253 and co-culture of S. cerevisiae TISTR5048 and Candida tropicalis TISTR5045. The objective of this study was to assess the ethanol production from cassava stalks by dilute-acid pretreatment and enzymatic hydrolysis that were convertible into ethanol by mono-culture and co-culture of yeast strain. Cassava stalks 1.5% (w/v) in 0.1 M sulfuric acid was pretreated for 30 min at 135 ℃ under the pressure of 15 lb/inch2. The pretreated cassava stalk suspensions were neutralized to pH 5.5 for saccharification process. The enzyme solution (a-amylase, amyloglucosidase, cellulase, xylanase and pectinase solubilized in buffer pH 5.0) was used for hydrolysis ofpretreated cassava stalk at 50 ℃ for 24 h. The hydrolyaste was supplemented with additional nutrients. The culture was incubated at 30 ℃. The pretreatment of the stalk with dilute-acid resulted sugar yield of 0.57 g/g dry matter from enzymatic hydrolysis, which was higher than dilute-alkaline-pretreated and distilled water-pretreated stalk. The sugar hydrolysate was bioconverted to ethanol with separate hydrolysis and fermentation (SHF) and simultaneous saccharification and fermentation (SSF). The highest ethanol yields of 98.43% and 95.29% were obtained in SHF and SSF, respectively by S. cerevisiae KM1195. The fermentation time of SSF process was 24-32 h shorter than that of the SHF (= 56 h), but not significantly leading to difference in ethanol production (5.42 g/L-6.22 g/L for SSF; 5.9 g/L-6.23 g/L for SHF).展开更多
Corn stalk hydrothermal wastewater(CSHW)was used as a pretreatment for whole-slurry anaerobic co-digestion instead of conventional acid pretreatment.CSHW pretreatment was conducted at 20℃,35℃and 50℃for 3,6 and 9 h,...Corn stalk hydrothermal wastewater(CSHW)was used as a pretreatment for whole-slurry anaerobic co-digestion instead of conventional acid pretreatment.CSHW pretreatment was conducted at 20℃,35℃and 50℃for 3,6 and 9 h,after which all experimental groups were digested at 35℃for 24 days.This pretreatment method efficiently broke the lignocellulose structure of the corn stalk.Different from the volatile fatty acids(VFAs)content,the pH and RS contents were relatively higher than those of the control during the pretreatment process.Furthermore,the highest methane production[185.03 mL•g-1 VS(volatile solid)]was achieved at 55.46%under 35℃in 6 h,which was higher than that of the normal corn stalk anaerobic digestion.The VFAs contents and pH increased compared to CK upon the addition of NaOH to adjust pH,and the RS content also increased slightly due to the degradability of lignocellulose during the whole-slurry anaerobic co-digestion.This work provided a potential method to sustainably treat wastewater and improve fermentation performance.展开更多
This paper is concerned with the cooperative target stalking for a multi-unmanned surface vehicle(multi-USV)system.Based on the multi-agent deep deterministic policy gradient(MADDPG)algorithm,a multi-USV target stalki...This paper is concerned with the cooperative target stalking for a multi-unmanned surface vehicle(multi-USV)system.Based on the multi-agent deep deterministic policy gradient(MADDPG)algorithm,a multi-USV target stalking(MUTS)algorithm is proposed.Firstly,a V-type probabilistic data extraction method is proposed for the first time to overcome shortcomings of the MADDPG algorithm.The advantages of the proposed method are twofold:1)it can reduce the amount of data and shorten training time;2)it can filter out more important data in the experience buffer for training.Secondly,in order to avoid the collisions of USVs during the stalking process,an action constraint method called Safe DDPG is introduced.Finally,the MUTS algorithm and some existing algorithms are compared in cooperative target stalking scenarios.In order to demonstrate the effectiveness of the proposed MUTS algorithm in stalking tasks,mission operating scenarios and reward functions are well designed in this paper.The proposed MUTS algorithm can help the multi-USV system avoid internal collisions during the mission execution.Moreover,compared with some existing algorithms,the newly proposed one can provide a higher convergence speed and a narrower convergence domain.展开更多
文摘The demand for particleboard is increasing along with economic and population growth.However,two major barriers to the manufacture of particleboard are a shortage of raw materials(woodchips)and the emission of formaldehyde from conventional adhesives.Agricultural by-products such as corn stalks contain an abundance of renewable lignocellulosic fiber.This study evaluates the effect of citric acid as a natural adhesive and fire retardant addition on the physical,mechanical,and fire retardancy properties of particleboards fabricated from corn stalks.A cost-effective and inorganic salt,calcium carbonate,was tested to enhance the fire retardancy.Ammonium dihydrogen phosphate was also considered as a comparative control.Particleboards with the addition of calcium carbonate was pretreated with sodium chloride.The particleboards were pressed for 10 min at 200℃.Japanese Industrial Standard JIS A 5908:2022 was used as the benchmark for the physical and mechanical tests.Fire retardancy was dynamically tested by simulating a Bushfire Attack Level of 19 kW/m^(2).The particleboard with 25 wt%citric acid had superior mechanical properties and complied with the JIS A 5908 standard for Type 13 base particleboard.Particleboard with the addition of calcium carbonate(5%and 10%)showed significantly delayed pyrolysis time.
基金funded by the CGIAR Research Program(CRP)on MAIZEthe USAID through the Accelerating Genetic Gains Supplemental Project(Amend.No.9 MTO 069033),and the One CGIAR Initiative on Accelerated Breeding+1 种基金funding from the governments of Australia,Belgium,Canada,China,France,India,Japan,the Republic of Korea,Mexico,the Netherlands,New Zealand,Norway,Sweden,Switzerland,the United Kingdom,the United States,and the World Banksupported by the China Scholarship Council。
文摘Maize stalk rot reduces grain yield and quality.Information about the genetics of resistance to maize stalk rot could help breeders design effective breeding strategies for the trait.Genomic prediction may be a more effective breeding strategy for stalk-rot resistance than marker-assisted selection.We performed a genome-wide association study(GWAS)and genomic prediction of resistance in testcross hybrids of 677 inbred lines from the Tuxpe?o and non-Tuxpe?o heterotic pools grown in three environments and genotyped with 200,681 single-nucleotide polymorphisms(SNPs).Eighteen SNPs associated with stalk rot shared genomic regions with gene families previously associated with plant biotic and abiotic responses.More favorable SNP haplotypes traced to tropical than to temperate progenitors of the inbred lines.Incorporating genotype-by-environment(G×E)interaction increased genomic prediction accuracy.
基金supported by Natural Science Foundation of Henan Province(Grant No.242300421560)Science and Technology Research Project of Henan(Grant No.232102110273)+2 种基金the Scientific Research Foundation for Advanced Talents of Henan University of Technology(Grant No.2022BS077)Training Plan of Young Backbone Teachers in Colleges and Universities in Henan Province(Grant No.2020GGJS088)the Cultivation Programme for Young Backbone Teachers in Henan University of Technology(Grant No.0503/21420191).
文摘Chopped and spread maize stalks improve soil structure and fertility. However, because of the absence of research on airflow distribution in the chopping chamber, improvement of the spreading uniformity of chopped stalks has been limited. Therefore, in this study, computational fluid dynamics (CFD) technology was applied to analyze the influence of structural and operational parameters of the chopping and spreading machine on the velocity, pressure, and turbulent kinetic energy distribution of airflow in the chopping chamber. The experimental factors considered were the relative position angle (RPA) between the collecting-chopping shaft and the sliding-supporting shaft, working velocity (WV) of the chopping chamber, and rotational velocity of the collecting-chopping blade (RVCCB). The results revealed that RPA and RVCCB had a significant influence on the maximum negative pressure in the inlet (MNPI), the proportion of negative pressure area at inlet (PNPAI), and the maximum pressure drop at inlet and outlet (MPDIO). Additionally, RVCCB had a strong influence on the maximum velocity, average velocity, and velocity variation coefficient of airflow at the outlet. Moreover, maximum turbulence (MT) and maximum turbulent kinetic energy dissipation rate (MTKEDR) showed a positive relationship with RVCCB. To determine the values of RPA, RVCCB, and WV, a multivariate parameters optimization regression model was constructed, which yielded the optimal values of 15°, 1800 r/min, and 0.50 m/s, respectively. Subsequently, a hyperbolic spiral-type guiding shell with an arc length of 90° was designed to enhance the uniform distribution of airflow in the chopping chamber. Finally, a validation experiment of airflow distribution was conducted. The results showed that the velocity difference between the simulation and the validation experiment was less than 15%, indicating the accuracy of CFD simulation, and the spreading uniformities of the chopped stalks were better than national standards. These findings can serve as technical and theoretical support for the design and optimization of chopping and spreading machines.
基金Weifang Fundamental Research Projects,No.WFWSJK-2023-052.
文摘BACKGROUND Pituitary stalk interruption syndrome(PSIS)is a rare anatomical defect of the pituitary gland falling under the spectrum of holoprosencephaly phenotypes.It is characterized by a deficiency in anterior pituitary hormones,such as growth hormone,gonadotropins,and thyroid hormones.Due to the syndrome's rarity and nonspecific manifestations,there is a lack of standardized treatment strategies.Consequently,early diagnosis through imaging and on-time intervention are crucial for improving patients’outcomes.CASE SUMMARY A 30-year-old man presented with absent secondary sexual characteristics and azoospermia.Laboratory evaluation revealed a deficiency in gonadotropins,while thyroid function was mostly within normal ranges.Magnetic resonance imaging of the pituitary gland showed pituitary stalk agenesis,hypoplasia of the anterior pituitary,and ectopic posterior pituitary,leading to the diagnosis of PSIS.Initially,the patient underwent 6 mo of gonadotropin therapy without significant changes in hormone levels and secondary sexual characteristics.Pulsatile gonadotropin-releasing hormone therapy was then administered,resulting in the detection of sperm in the semen analysis within 3 mo.After 6 mo,routine semen tests showed normal semen quality.The couple faced challenges in conceiving due to abstinence and underwent three cycles of artificial insemination,which was unsuccessful.They also attempted in vitro fertilization,but unfortunately,the woman experienced a miscarriage 10 wk after the embryo transfer.CONCLUSION Early detection,accurate diagnosis,and timely treatment are crucial in improving the quality of life and fertility of PSIS patients.
文摘BACKGROUND Pituitary stalk interruption syndrome(PSIS)is a rare disorder,often characterized by delayed growth and development,short stature,and hypogonadism as the main clinical manifestations.It is not clear whether PSIS can lead to liver cirrhosis.CASE SUMMARY This paper reported a case of liver cirrhosis of unknown origin.The patient was admitted to Beijing Ditan Hospital Affiliated to Capital Medical University in November 2023.The diagnosis of PSIS complicated with liver cirrhosis was established after a series of blood tests and pituitary magnetic resonance imaging examination.CONCLUSION We also reviewed the literature from both domestic and international sources to deepen the clinical understanding of PSIS in conjunction with liver cirrhosis among medical practitioners.
基金Supported by the Special Fund for Crop Breeding of Sichuan Provincial Department of Education,China (2006LD006)the Rapeseed Breeding Research Program of Science & Technology Department of Sichuan Province,China (2006YZGG-5-5)~~
文摘[Objective] To study the correlation between the biomechanical properties of rape stalks and rape stem lodging. [Method] Through axial compression tests to the stalks of 4 different rape varieties, the change rules of maximum stem bearing ca- pacity, maximum compressive strength, elastic modulus and moment of inertia along plant height were analyzed, as well as the effect of different varieties and water contents on the biomechanical property indices of rape stalks. [Result] The maximum loads of rape stalks presented liner decrease trend along with the increase of stem height, and all reached the maximums below the height of 50 cm. The maximum stem compressive strength and elastic modulus of the 4 varieties were increased with ascending height, but in a slow rate with small change, thus the modulus of e- lasticity could be considered as unchanged. The maximum bearing capacity, maxi- mum compressive strength and elastic modulus of dry rape stalks were higher than wet stalks, indicating that the water contents of rape stalks had significant effect on their mechanical properties. According to the actual lodging situations in filed, stalks of variety No. 1 owned the worst biomechanical properties and lodging degree, while the biomechanical properties of No. 6 and F5 were better than No. 1 and No. 9, and they also had stronger lodging-resistance. [Conclusion] The study provides parameters and bases for the design of mechanized production and mechanical deep processing of crops, and can better reveal the physical natures of organisms. The methods used in this study can also be used to screen excellent crop stalks.
基金Supported by National Special Fund for Scientific Research in Public Welfare Trade(Agriculture)(200803033-B0602-01)Project of Hebei Province Scientific and Technological Department(10221019)+1 种基金Project of Qinghuangdao City Science and Technology Burea of Hebei Province(201001A152)Foundation of Education Committee of Hebei Province(2003308)~~
文摘[Objective] The study aimed at reducing the economic cost in feeding Tenebrio molitor and improving the utilization ratio of corn stalks.[Method] The effects of different proportions of corn stalks on the weigh of Tenebrio molitor and the contents of crude protein,crude fat,Ca,P,dry matter and crude ash in the half-dry matter of Tenebrio molitor had been studied in the laboratory.[Result] Compared with the recipes of all wheat bran and pure fine fodder,feeding Tenebrio molitor by applying 30%-60% of corn stalks could significantly improve the content of crude protein in the half-dry materials of Tenebrio molitor,but it was detrimental to the improvement in weight of Tenebrio molitor and the accumulation of crude fat.To be specific,the recipe V(50% of corn stalks + 50% of fine fodder) was beneficial to the accumulation of dry matter and crude ash.The recipe VII(70% of corn stalks + 30% of fine fodder) and the recipe VIII(70% of corn stalks treated with Guangda feed leaven + 30% of fine fodder) were beneficial to the accumulation of crude protein,Ca and P.There were differences among the influences of corn stalks in different treatments on the crude protein and other nutrition indicators of Tenebrio molitor.[Conclusion] Appropriately applying corn stalks can improve the accumulation of the crude protein,crude ash,dry matter,Ca and P of Tenebrio molitor but was detrimental to the growth and development of Tenebrio molitor and the accumulation of crude fat.
基金Supported by Science and Technology Innovation Plan for Outstanding Scholars in Henan Province(2014KJCXJCRC015)~~
文摘[Objective] This study aimed to study the adsorption performance of activated carbon prepared from corn stalks. [Methed] With granular activated carbon prepared from corn stalks as research object, adsorption performance simulation test equipment was set up to investigate the adsorption performance of the prepared activated carbon for methanol by static weight method. In addition, the effects of adsorption bed structure, activated carbon particle size in adsorption bed, addition amount of graphite powder in activated carbon and modified activated carbon on systematic adsorption performance were studied. [Result] Under conditions of same activated carbon and same adsorption temperature, the adsorption performance of new adsorption bed A (installed with finned diaphragm adsorbate tubes) was signifi- cantly better than that of unmodified adsorption bed B. Compared with adsorption bed B, adsorption bed A took 5 min shorter to reach the adsorption amount of 0.22 g/g. Under the same adsorption temperature, the adsorption performance of bed loaded with different-particle size activated carbon was significantly better than that loaded with same-particle size activated carbon. The bed loaded with different-particle size activated carbon took 16 min shorter to reach the adsorption capacity of 0.22 g/g compared with the bed loaded with same-particle size activated carbon. Adding proper amount of graphite powder in activated carbon could enhance the thermal conductivity and strengthen the adsorption properties. The optimum addition amount of graphite powder was 20% of the total amount of activated carbon. Com- pared with that of the control, the adsorption performance of activated carbon soaked by weak acidic solution was significantly improved. It took 3 min shorter to reach 87.1% of the equilibrium adsorption amount. [Conclusion] This study will provide reference for optimizing structural design of adsorption bed and adsorption refrigeration system.
文摘Pretreatment of lespedeza stalks by steam explosion has been studied. The results indicate that steam-exploded pretreatment has strong effects on physical features, morphology, crystallinity, and composition of lespedeza stalks as shown by scanning electron microscopy (SEM), infrared (IR), and X-ray diffraction spectrometry methods. After steam explosion, the cellulose and lignin contents of lespedeza stalks varied only slightly, but the hemicellulose content had decreased from 29.34% to 7.48%. The cellulose obtained by steam-exploded pretreatment had a higher degree of crystallinity than that of the raw material. At the explosion condition of 2.25 MPa and 4 min, lignocellulose is easier to hydrolyze by enzyme than the original lignocellulose. The concentration of reduced sugar in the hydrolyzate liquid increased from 71.77 to 162.84 g·L^-1.
基金supported bythe National Natural Science Foundation of China.
文摘Sweet potato (Ipomoea batatas Lam.) leaf stalks were cut into 20 cm length, and stored at 20, 6, and 2℃. The respiration rate, ethylene production, ascorbic acid, free amino acid, total chlorophyll content, freshness, and shelf life were determined during storage to investigate the effect of storage temperatures on the quality and physiological responses in sweet potato leaf stalks. Wound responses were observed as high respiration rate and ethylene production immediately after cutting. Sweet potato leaf stalks were found to be sensitive to chilling injury manifested as browning and water-soaking on the surface at 2℃. In contrast, sweet potato leaf stalks were susceptible to senescence, exhibited by etiolating and yellowing, at 20℃. Loss in weight and chlorophyll was minimized under low temperatures. High temperatures also caused the accumulation of amino acids with a significant loss of ascorbic acid and chlorophyll. Sweet potato leaf stalks had a storage life of 16 days at 6℃, 8 days at 2℃, and 6 days at 20℃, respectively.
基金Supported by National Major Water Project of Eleventh Five-Year Plan(2008ZX07105002)~~
文摘We undertook a pyrolysis research on garlic stalks to solve its difficulty in use. We found that the inorganic salts in biomass played an important role in catalytic pyrolysis. Moreover, we studied the pyrolysis behavior under catalyst and catalyst-free conditions. The results showed that the weightlessness rate of garlic stalks was the highest at 550 ℃ under catalyst-free condition. The oil production rate increased with the increase of temperature and reached the peak at 550 ℃. Subsequently, as the temperature increased, the secondary cracking was intensified and oil production rate was decreased. The oil production rate increased significantly (almost 15%) under catalysis of KOH. However, the oil production rate was the highest at 500-600℃. What's more, we found that KOH played a major role in promoting decomposition of surface skin cells and subcutaneous fibrous layer of garlic stalks.
文摘Lespedeza stalks were subjected to steam pretreatment at 210℃ for some steaming time before simultaneous saccharification and fermentation (SSF). Cellulose-derived glucose was extensively utilized by yeast during SSE The ethanol yields after steam pretreatment of the lespedeza stalks at 210℃ were 59.3%, 72.8% and 62.2% of the theoretically expected values when the steaming times were 2, 4 and 6 min, respectively. The highest yield from α-cellulose was 92.7% of the theoretical value. Steam explosion pretreatment of lespedeza stalks increased ethanol yields by a factor of 4.4, from 16.4% (untreated) to 72.8% (steam explosion pretreated).
基金Supported by Agricultural Research Project of Shaanxi Provincial Science and Technology Department(2012.k02-10)Innovation and Entrepreneurship Training Project of University Students in Shaanxi Province(1252)Special Funds of Ecology for Construction of High-level University in Shaanxi Province(2012SXTS03)
文摘In order to reduce the economic costs for breeding Tenebrio molitor L. and increase the utilization rate of corn stalk, with corn, wheat bran and corn stalk as the raw materials, 13 different compound feed were designed by Minitab (R) 15.1.0.0. The design was then divided into two groups based on addition or without addition of vegetable leaves to study the effects of compound feed and vegetable leaves on growth and de- velopment of T. molitor. The results showed that body weight, duration, crude protein content and pupation rate of larvae and emergence rate of adults were significantly affected by compound feed and vegetable leaves ( P 〈 0.05). The larvae bred with feed 5 had the largest body weight, with the shortest duration; the larvae bred with feed 3 had the highest pupation rate; the larvae bred with feed 7 had the highest crude protein content; the adult bred with feed 9 had the largest emergence rate. Overall breeding effect of feed 7 + vegetable leaves was better than any other groups, with ideal indicators, higher utilization rate and lower breeding cost. Its formula was w (wheat bran) = 33.33%, w (corn) = 33.33%, w (corn stalks) = 33.33%. Therefore, the growth of T. molitorwas significantly affected by feed types, and feed 7 + vegetable leaves could be promoted in the production.
基金This research was financially supported by the National Natural Science Foundation of China(No.21878292,No.21606240,No.21878314)K.C.Wong Education Foundation(No.GJTD-2018-04)the Strategic Priority Research Program of Chinese Academy of Science(No.XDA21060300).
文摘It is very difficult to directly spin the lignocellulose without pretreatment.Ionic liquids(ILs)are promising solvent to dissolve lignocellulose to prepare cellulose fiber.However,the degree of cellulose polymerization(DP)is reduced when lignocellulose is dissolved in ILs,and the lignin removal rate is low.The elongation at break and tensile strength of the fibers obtained by spinning the lignocellulose dissolved in ILs are poor.In this paper,preparing cellulose fiber directly from lignocellulose based on dissolving corn stalk via[C4mim]Cl-L-arginine binary system is achieved.It shows that the removal rate of lignin can reach 92.35%and the purity of cellulose can reach 85.32%after corn stalk was dissolved at 150℃C for 11.5 h when the mass fraction of arginine is 2.5%.The elongation at break of fiber reached 10.12%and the tensile strength reached 420 MPa.It is mainly due to the fact that L-arginine not only inhibits the degradation of cellulose but also promotes the delignination.Without any pulping or pretreatment,preparing cellulose fibers via direct dissolution and extrusion may provide a simple and effective way to prepare many novel cellulose materials.
文摘Millets are important natural grain source for wild and game birds and the domesticated varieties are good sources of grain for human and livestock nutrition as well as summer forage. Unlike sorghum, millet seed has less anti-nutrient factors and is a better choice for animal feed formulations. Pearl millet is an example of such millets and has both forage- and grain-type varieties. However, opportunities exist for dual use of millet for grain and residue for forage. In this study two millets: Pennisetum glaucum (L.) R. Br. (Pearl millet var. TifGrain 102) and Panicum ramosum (L.) (Browntop millet) were evaluated for their response to potassium (K) and manganese (Mn) fertilizer. The experiment was a randomized complete block with treatments in a split-split arrangement. Potassium and Mn were supplied as K fertilizer (0-0-60) and manganese sulfate (MnSO4·2H2O), respectively. Potassium and Mn fertilizer rates and their interaction with each other and variety had no effect on determined parameters. TifGrain 102 grain yield averaged at 5900 kg·ha-1 was significantly greater than 4680 kg·ha-1 obtained for Browntop millet. While grain oil contents were similar, Browntop grain had greater contents of crude proteins. And except for K, Browntop seed had greater contents of all determined macro-and micronutrients. Residual stalks of Browntop had greater forage crude protein, total digestible nutrient (TDN) and lower acid detergent fiber (ADF). Browntop residual material had greater quantities of estimated net energy for growth (NEG), lactation (NEL), maintenance (NME). While TifGrain 102 residual stalks had greater contents of P and K, it had significantly lower contents of Ca, Mg and S compared to Browntop. Overall, while these two millets have shown good potential for dual use, Browntop may offer a better choice for high quality seed and residual stalks for forage.
基金supported by the Key Research and Development project of Hubei Province (Grant Nos. 2020BBB083, 2021BBA097 and 2021BBA102)the National Key Research and Development Program of China (Grant No. 2016YFD0100202)。
文摘Glucosinolates(GSLs) and their hydrolytic products contribute to the quality traits of rapeseed flowering stalk tissues, such as taste, flavor and anticarcinogenic properties(Glucoraphanin). However, little is known about the genetic mechanisms of GSL accumulation in rapeseed flowering stalks. In this study, the variation and genetic architecture of GSL metabolites in flowering stalk tissues were investigated for the first time among a panel of 107 accessions. All GSL compounds exhibited continuous and wide variations in the present population. Progoitrin,glucobrassicanapin and gluconapin were the most abundant GSL compounds. Five quantitative trait loci(QTL) significantly associated with three GSL compounds were identified by genome-wide association study. GRA_C04 was under selected during modern breeding, in which the ratio of lower GSL haplotype(HAP2) in the accessions bred before 1990(52.56%) was significantly lower than that after 1990(78.95%). Four candidate genes, BnaA01. SOT16, BnaA06. SOT17, Bna A06. MYB51a, and Bna A06. MYB51b, were identified in the GTL_A01 and 4OH_A06 regions.These findings provide new insights into GSL biosynthesis in flowering stalk tissues and facilitate quality improvement in rapeseed flowering stalks.
基金supported by the National Natural Science Foundation of China(31972487,31902101,32172009 and 32061143030)the Innovative Research Team of Universities in Jiangsu Province,the Science and Technology Development Plan Project of Henan Province(212102110152)+1 种基金the High-end Talent Project of Yangzhou Universitythe Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)。
文摘Stalk strength increases resistance to stalk lodging,which causes maize(Zea mays L.)production losses worldwide.The genetic mechanisms regulating stalk strength remain unclear.In this study,three stalk strength-related traits(rind penetrometer resistance,stalk crushing strength,and stalk bending strength)and four plant architecture traits(plant height,ear height,stem diameter,stem length)were measured in three field trials.Substantial phenotypic variation was detected for these traits.A genome-wide association study(GWAS)was conducted using general and mixed linear models and 372,331 single-nucleotide polymorphisms(SNPs).A total of 94 quantitative trait loci including 241 SNPs were detected.By combining the GWAS data with public gene expression data,56 candidate genes within 50 kb of the significant SNPs were identified,including genes encoding flavonol synthase(GRMZM2G069298,ZmFLS2),nitrate reductase(GRMZM5G878558,ZmNR2),glucose-1-phosphate adenylyltransferase(GRMZM2G027955),and laccase(GRMZM2G447271).Resequencing GRMZM2G069298 and GRMZM5G878558 in all tested lines revealed respectively 47 and 2 variants associated with RPR.Comparison of the RPR of the zmnr2EMS mutant and the wild-type plant under high-and low-nitrogen conditions verified the GRMZM5G878558 function.These findings may be useful for clarifying the genetic basis of stalk strength.The identified candidate genes and variants may be useful for the genetic improvement of maize lodging resistance.
文摘Cellulose biomass is being investigated as a potential substrate for bioethanol production. Cassava stalks were successfully converted to ethanol by fermentation using Saccharomyces cerevisiae TISTR5048, S. cerevisiae KM1195, S. cerevisiae KM7253 and co-culture of S. cerevisiae TISTR5048 and Candida tropicalis TISTR5045. The objective of this study was to assess the ethanol production from cassava stalks by dilute-acid pretreatment and enzymatic hydrolysis that were convertible into ethanol by mono-culture and co-culture of yeast strain. Cassava stalks 1.5% (w/v) in 0.1 M sulfuric acid was pretreated for 30 min at 135 ℃ under the pressure of 15 lb/inch2. The pretreated cassava stalk suspensions were neutralized to pH 5.5 for saccharification process. The enzyme solution (a-amylase, amyloglucosidase, cellulase, xylanase and pectinase solubilized in buffer pH 5.0) was used for hydrolysis ofpretreated cassava stalk at 50 ℃ for 24 h. The hydrolyaste was supplemented with additional nutrients. The culture was incubated at 30 ℃. The pretreatment of the stalk with dilute-acid resulted sugar yield of 0.57 g/g dry matter from enzymatic hydrolysis, which was higher than dilute-alkaline-pretreated and distilled water-pretreated stalk. The sugar hydrolysate was bioconverted to ethanol with separate hydrolysis and fermentation (SHF) and simultaneous saccharification and fermentation (SSF). The highest ethanol yields of 98.43% and 95.29% were obtained in SHF and SSF, respectively by S. cerevisiae KM1195. The fermentation time of SSF process was 24-32 h shorter than that of the SHF (= 56 h), but not significantly leading to difference in ethanol production (5.42 g/L-6.22 g/L for SSF; 5.9 g/L-6.23 g/L for SHF).
基金Supported by the Technological Project of Heilongjiang Province"the Open Competition Mechanism to Select the Best Candidates"(2022ZXJ05C01-03)。
文摘Corn stalk hydrothermal wastewater(CSHW)was used as a pretreatment for whole-slurry anaerobic co-digestion instead of conventional acid pretreatment.CSHW pretreatment was conducted at 20℃,35℃and 50℃for 3,6 and 9 h,after which all experimental groups were digested at 35℃for 24 days.This pretreatment method efficiently broke the lignocellulose structure of the corn stalk.Different from the volatile fatty acids(VFAs)content,the pH and RS contents were relatively higher than those of the control during the pretreatment process.Furthermore,the highest methane production[185.03 mL•g-1 VS(volatile solid)]was achieved at 55.46%under 35℃in 6 h,which was higher than that of the normal corn stalk anaerobic digestion.The VFAs contents and pH increased compared to CK upon the addition of NaOH to adjust pH,and the RS content also increased slightly due to the degradability of lignocellulose during the whole-slurry anaerobic co-digestion.This work provided a potential method to sustainably treat wastewater and improve fermentation performance.
基金supported in part by the National Natural Science Foundation of China(61873335,61833011,62173164)the Project of Science and Technology Commission of Shanghai Municipality,China(20ZR1420200,21SQBS01600,22JC1401400,19510750300,21190780300)the Natural Science Foundation of Jiangsu Province of China(BK20201451)。
文摘This paper is concerned with the cooperative target stalking for a multi-unmanned surface vehicle(multi-USV)system.Based on the multi-agent deep deterministic policy gradient(MADDPG)algorithm,a multi-USV target stalking(MUTS)algorithm is proposed.Firstly,a V-type probabilistic data extraction method is proposed for the first time to overcome shortcomings of the MADDPG algorithm.The advantages of the proposed method are twofold:1)it can reduce the amount of data and shorten training time;2)it can filter out more important data in the experience buffer for training.Secondly,in order to avoid the collisions of USVs during the stalking process,an action constraint method called Safe DDPG is introduced.Finally,the MUTS algorithm and some existing algorithms are compared in cooperative target stalking scenarios.In order to demonstrate the effectiveness of the proposed MUTS algorithm in stalking tasks,mission operating scenarios and reward functions are well designed in this paper.The proposed MUTS algorithm can help the multi-USV system avoid internal collisions during the mission execution.Moreover,compared with some existing algorithms,the newly proposed one can provide a higher convergence speed and a narrower convergence domain.