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1.
Shrimp head waste is a major byproduct of crustacean processing in North-eastern Brazil and represents an interesting source of bioactive molecules. Additionally, its use increases the sustainability of processing fishery products. The present study reports a process developed for recovering bioactive molecules from shrimp heads through autolysis. A protein hydrolysate (120 ± 0.4 g) formed by a 9% (w/v) solution was recovered and lyophilized from 1 kg of shrimp heads. Approximately 195 ± 0.5 mg of carotenoids was recovered as an ethanolic extract. The recovery of chitin and chitosan were 25 ± 2 g kg?1 and 17 ± 4 g kg?1 wet processing waste, respectively. Chitosans were characterized by 13C NMR, and FT-IR analysis and exhibited a variable degree of deacetylation (60–80%). Sulfated glycosaminoglycans that exhibited electrophoretic migration similar to mammalian standards were also recovered (79 ± 2 mg kg?1 wet processing waste), and their degradation products suggested the presence of C6-sulfated heparan sulfate. These data point to the feasibility of an integrated process for isolating highly bioactive molecules, such as sulfated- and amino-polysaccharides, with a broad spectrum of applications from shrimp processing waste.  相似文献   

2.
The cocoon of insect larvae is thought to help conserve water while affording mechanical protection. If the cocoon is a barrier to water loss, then it must also impose a barrier to inward oxygen diffusion. We tested this hypothesis in pupae of the silkworm, Bombyx mori. The rate of water loss and oxygen uptake (V?O2) at 25 °C was measured in control pupae in their naturally spun cocoon and in exposed pupae experimentally removed from their cocoon. Additional measurements included the oxygen diffusion coefficient, DO2, of the cocoon wall and dimensions and density of the cocoon fibers. Water loss (as % body mass loss) in both control and exposed pupae was ~ 1%.day? 1, and was not significantly different between populations. Similarly, V?O2 was statistically identical in both control and exposed pupae, at 0.22 ± 0.01 and 0.21 ± 0.02 mL g? 1 · h? 1, respectively. The silk fiber diameter was significantly different in the outer fibers, 26 ± 1 µm, compared with 16 ± 1 µm for the inner fibers lining the cocoon. Inner fibers were also spun significantly more densely (20.8 ± 1.2 mm? 1 transect) than outer fibers (8.3 ± 0.2). Mean DO2 at 25 °C was 0.298 ± 0.002 cm2 · s? 1, approximately the same as unstirred air. These data indicate that the cocoon, while creating a tough barrier offering mechanical protection to the pupa, imposes no barrier to the diffusion of oxygen or water vapor.  相似文献   

3.
Most feed is poor in iodine and iodine supplementation of cow's diets must guarantee milk iodine concentrations for humans that contribute to prevention of the deficiency and minimize the risk of exceeding an upper limit of iodine intake. Five Holstein cows were fed four iodine doses (via Ca(ΙO3)2·6H2O). In four sequential 14-d periods, doses of 0.2 (basal diet), 1.3, 5.1, and 10.1 mg iodine kg?1 diet dry matter (DM) were administered. Samples of milk were collected during each period; blood was also sampled from each cow for each iodine dosage. In an 18-d depletion period, a non-supplemented diet was provided. Iodine was determined by inductively coupled plasma-mass spectrometry. The iodine content of milk and serum reflected the iodine dosages in feed significantly. The levels for the four doses tested in milk were 101±32, 343±109, 1215±222, and 2762±852 μg iodine kg?1. The total amount of iodine in milk per day was 30–40% of ingested supplemental iodine. Omitting additional iodine resulted in a short-term reduction of serum and milk iodine following an exponential decay function. The iodine supplementation of 0.5–1.5 mg kg?1 diet DM represents the requirement of the cow, resulting in 100–300 μg iodine L?1 milk, which optimally contributes to human supply. The maximum dietary levels of former and present EU legislations (10 and 5 mg iodine kg?1 cow feed) increase the risk of iodine excess in humans.  相似文献   

4.
Two tetracyanometalate building blocks, [Fe(5,5′-dmbipy)(CN)4]? (2) and [Fe(4,4′-dmbipy)(CN)4]? (3) (5,5′-dmbipy = 5,5′-dimethyl-2,2′-bipyridine; 4,4′-dmbipy = 4,4′-dimethyl-2,2′-bipyridine), and two cyano-bridged heterobimetallic complexes, [Cu2(bpca)2(H2O)2Fe2(5,5′-dmbipy)2(CN)8] · 2[Cu(bpca)Fe(5,5′-dmbipy)(CN)4] · 4H2O (4) and [Cu(bpca)Fe(4,4′-dmbipy)(CN)4]n (5) (bpca = bis(2-pyridylcarbonyl)amidate), have been synthesized and structurally characterized. Complex 4 contains two dinuclear and one tetranuclear heterobimetallic clusters in an asymmetric unit whereas the structure of complex 5 features a one-dimensional heterobimetallic zigzag chain. The Cu(II) ion is penta-coordinated in the form of a distorted square-based pyramid. Magnetic studies show ferromagnetic coupling between Cu(II) and Fe(III) ions with g = 2.28, J1 = 2.64 cm?1, J2 = 5.40 cm?1 and TIP = ?2.36 × 10?3 for complex 4, and g = 2.17, J = 4.82 cm?1 and zJ = 0.029 cm?1 for complex 5.  相似文献   

5.
Cr(VI) removal by Scenedesmus incrassatulus was characterized in a continuous culture system using a split-cylinder internal-loop airlift photobioreactor fed continuously with a synthetic effluent containing 1.0 mg Cr(VI) l?1 at dilution rate (D) of 0.3 d?1. At steady state, there was a small increase (6%) on the dry biomass (DB) concentration of Cr(VI)-treated cultures compared with the control culture. 1.0 mg Cr(VI) l?1 reduced the photosynthetic pigments content and altered the cellular morphology, the gain in dry weight was not affected. At steady state, Cr(VI) removal efficiency was 43.5 ± 1.0% and Cr(VI) uptake was 1.7 ± 0.1 mg Cr(VI) g?1 DB. The system reached a specific metal removal rate of 458 μg Cr(VI) g?1 DB d?1, and a volumetric removal rate of 132 μg Cr(VI) l?1 d?1.  相似文献   

6.
An intertidal oyster reef (~260 ha) was created by planting hatchery-reared seed oysters (Crassostrea rivularis) on an artificial concrete modular reef in the Deepwater Navigation Channel Regulation Project of the Yangtze River estuary. We examined the development of reef communities (oyster, barnacle and motile epibenthic macrofauna), characterized nekton use and assessed the habitat value of the constructed reef. The C. rivularis oyster population showed a rapid exponential increase with time and reached maximum density (3410 ± 241 ind./m2) and biomass (3175 ± 532 g/m2) after one year of restoration. The barnacle Balanus albicostatus was the most abundant sessile macrofauna and had a significantly greater density in the high intertidal zone than in the low intertidal zone (P < 0.05). The reef also supported diverse motile epibenthic macrofauna (11 mollusks, 11 crustaceans, 4 annelids and 2 fishes), and the reef-associated communities were numerically dominated by Neanthes japonica, Perinereis aibuhitensis, Nerita yoldi and Littorinopsis intermedia. A total of 50 nekton species (31 fishes, 9 shrimps and 10 crabs) utilized the constructed intertidal oyster reef, and grass shrimp Palaemon spp. dominated the nekton communities in term of abundance. Since the constructed intertidal oyster reef supports a variety of reef communities and abundant nektons, it should be recognized as an important and protective fish habitat in the Yangtze River estuary.  相似文献   

7.
The red-tailed phascogale is a small arboreal dasyurid marsupial that inhabits semi-arid to arid regions of Western Australia's wheat belt. Its body mass (34.7 g) is only ~15% of that predicted based on its phylogenetic position among other dasyuromorphs; we interpret this as an adaptation to its scansorial and semi-arid/arid lifestyle. The standard physiology of this species at a thermoneutral ambient temperature of 30 °C conforms to that of other dasyurid marsupials; body temperature (34.7 ± 0.37 °C), basal metabolic rate (0.83 ± 0.076 mL O2 g?1 h?1), evaporative water loss (1.68 ± 0.218 mg H2O g?1 h?1) and wet thermal conductance (3.8 ± 0.26 J g?1 h?1 °C?1) all fall within the 95% predication limits for the respective allometric relationships for other dasyurid species. Thermolability confers an energy savings at low Ta and water savings at high Ta. Torpor, observed at low Ta, was found to be more beneficial for energy savings than for water economy. The red-tailed phascogale therefore has a physiology suitable for the challenges of arid environments without any obvious requirement for adaptations to its scansorial lifestyle, other than its considerably lower-than-expected body mass.  相似文献   

8.
A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was validated and applied to the in vitro determination of 4-[(hydroxyimino)methyl]-1-octylpyridinium cation (4-PAO), which can penetrate the blood–brain barrier and reactivate acetylcholinesterase (AChE) inhibited by alkylphosphonate in the brain, liver, lung, and kidney. The limit of detection (LOD) was 0.235 μg cation/g wet weight, and the quantification range and linearity of the calibration curve extended over a range of 0.470–941 μg cation/g wet weight. For the proof of applicability, when 4-PAO was administrated intravenously via the rat tail vein at 10% LD50, we were able to quantify the 4-PAO concentration in the tissues: brain 7.60 ± 1.32 μg cation/g wet weight (mean ± SD, n = 5), liver 26.8 ± 2.82 μg cation/g, lung 76.4 ± 24.9 μg cation/g, and kidney 638 ± 266 μg cation/g. In addition, the methods for 4-[(hydroxyimino)methyl]-1-decylpyridinium bromide (4-PAD) and 4-[(hydroxyimino)methyl]-1-(2-phenylethyl) pyridinium bromide (4-PAPE) were partly validated referring to the findings of the 4-PAO full validation. Thus, the LC-MS/MS method described in this study can be useful for quantification of pyridinium aldoxime methiodide (PAM)-type oximes in biological samples.  相似文献   

9.
Biological treatment of synthetic wastewater containing Cu(II) ions was realized in an activated sludge unit with pre-adsorption of Cu(II) onto powdered waste sludge (PWS). Box-Behnken experimental design method was used to investigate Cu(II), chemical oxygen demand (COD) and toxicity removal performance of the activated sludge unit under different operating conditions. The independent variables were the solids retention time (SRT, 5–30 d), hydraulic residence time (HRT, 5–25 h), feed Cu(II) concentration (0–50 mg L?1) and PWS loading rate (0–4 g h?1) while percent Cu(II), COD, toxicity (TOX) removals and the sludge volume index (SVI) were the objective functions. The data were correlated with a quadratic response function (R2 = 0.99). Cu(II), COD and toxicity removals increased with increasing PWS loading rate and SRT while decreasing with the increasing feed Cu(II) concentration and HRT. Optimum conditions resulting in maximum Cu(II), COD, toxicity removals and SVI values were found to be SRT of 30 d, HRT 15 h, PWS loading rate 3 g h?1 and feed Cu(II) concentration of less than 30 mg L?1.  相似文献   

10.
Herein we describe the discovery of compound 3g, a potent positive inotropic agent compared with the standard drug, milrinone. Compound 3g was developed from a series of 2-(4-substitutedbenzyl-1,4-diazepan-1-yl)-N-(3,4-dihydro-3-oxo-2H-benzo[b][1,4]oxazin-7-yl) acetamides found in an evaluation of inotropic activity by measuring left atrium stroke volume on isolated rabbit heart preparations. Several compounds showed favorable activities, but 3g was the most potent, with 7.68 ± 0.14% increased stroke volume (milrinone 2.38 ± 0.05%) at 1 × 10?5 M in our in vitro study. The chronotropic effects of compounds having significant inotropic effects were also evaluated.  相似文献   

11.
Recently, a bubbleless membrane bioreactor (BMBR) has been successfully developed for biosurfactant production by Bacillus subtilis [1]. In this study, for the first time, continuous culture were carried out for the production of surfactin in a BMBR, both with or without a coupled microfiltration membrane. Results from continuous culture showed that a significant part of biomass was immobilized onto the air/liquid membrane contactor. Immobilized biomass activity onto the air/liquid membrane contactor was monitored using a respirometric analysis. Kinetics of growth, surfactin and primary metabolites production were investigated. Planktonic biomass, immobilized biomass and surfactin production and productivity obtained in batch culture (3 L) of 1.5 days of culture were 4.5 g DW, 1.3 g DW, 1.8 g and 17.4 mg L?1 h?1, respectively. In continuous culture without total cell recycling (TCR), the planktonic biomass was leached, but immobilized biomass reached a steady state at an estimated 6.6 g DW. 11.5 g of surfactin was produced after 3 days of culture, this gave an average surfactin productivity of 54.7 mg L?1 h?1 for the continuous culture, which presented a surfactin productivity of 30 mg L?1 h?1 at the steady state. TCR was then investigated for the continuous production, extraction and purification of surfactin using a coupled ultrafiltration step. In continuous culture with TCR at a dilution rate of 0.1 h?1, planktonic biomass, immobilized biomass, surfactin production and productivity reached 7.5 g DW, 5.5 g DW, 7.1 g and 41.6 mg L?1 h?1 respectively, after 2 days of culture. After this time, biomass and surfactin productions stopped. Increasing dilution rate to 0.2 h?1 led to the resumption of biomass and surfactin production and these values reached 11.1 g DW, 10.5 g DW, 7.9 g and 110.1 mg L?1 h?1, respectively, after 3 days of culture. This study has therefore shown that with this new integrated bioprocess, it was possible to continuously extract and purify several grams of biosurfactant, with purity up to 95%.  相似文献   

12.
Four series of [1,2,4]triazolo[3,4-a]phthalazine and tetrazolo[5,1-a]phthalazine derivatives bearing substituted piperazine moieties were synthesized and evaluated for their positive inotropic activity by measuring the left atrium stroke volume in isolated rabbit-heart preparations. Several compounds were developed and showed favorable activities compared to the standard drug milrinone, with (4-([1,2,4]triazolo[3,4-a]phthalazin-6-yl)piperazin-1-yl)(p-tolyl)methanone (5g) being identified as the most potent with an increased stroke volume of 19.15 ± 0.22% (milrinone: 2.46 ± 0.07%) at a concentration of 3 × 10–5 M. A preliminary study of mechanism of action revealed that 5g displayed its positive inotropic effect may be related to the PDE-cAMP-PKA signaling pathway. Compounds exhibiting inotropic effects were also evaluated in terms of the chronotropic effects.  相似文献   

13.
Teleost fish often live in an environment in which osmoregulatory mechanisms are critical for survival and largely unknown in larval fish. The effects of a single important marine ion (K+) on survival and ion regulation of larval Gulf killifish, an estuarine, euryhaline teleost, were determined. A four-week study was completed in four separate recirculating systems with newly hatched larvae. Salinity in all four systems was maintained between 9.5 and 10‰. Two systems were maintained using crystal salt (99.6% NaCl) with K+ supplementation (1.31 ± 0.04 mmol/L and 2.06 ± 0.04 mmol/L K+; mean ± SEM), one was maintained with crystal salt and no K+ supplementation (0.33 ± 0.05 mmol/L K+), the fourth system was maintained using a standard marine mix salt (2.96 ± 0.04 mmol/L K+), the salt mix also included standard ranges of other ions such as calcium and magnesium. Larvae were sampled throughout the experiment for dry mass, Na+/K+-ATPase (NKA) activity, whole body ion composition, relative gene expression (NKA, Na+/K+/2Cl? cotransporter (NKCC) and cystic fibrosis transmembrane conductance regulator (CFTR)), and immunocytochemistry staining for NKA, NKCC, and CFTR. Larvae stocked into water with no K+ supplementation resulted in 100% mortality within 24 h. Mortality and dry mass were significantly influenced by K+ concentration (P  0.05). No differences were observed among treatment groups for NKA activity. At 1 dph NKA mRNA expression was higher in the 0.3 mmol [K+] group than in other treatment groups and at 7 dph differences in intestinal NKA and CFTR staining were observed. These data indicate that the rearing of larval Gulf killifish may be possible in ion deficient water utilizing specific ion supplementation.  相似文献   

14.
Polyhydroxyalkanoates (PHAs) have been recognized as good substitutes for the non-biodegradable petrochemically produced polymers. However, their high (real or estimated) current production cost limits their industrial applications. This work exploits two strategies to enhance PHAs substitution potential: the increase in PHA volumetric productivity in high density cultures and the use of waste glycerol (GRP), a by-product from the biodiesel industry, as primary carbon source for cell growth and polymer synthesis. Cupriavidus necator DSM 545 was used to accumulate poly(3-hydroxybutyrate) (P(3HB)) from GRP and from commercial glycerol (PG) as control substrate. On PG, productivities between 0.6 gPHB L?1 h?1 and 1.5 gPHB L?1 h?1 were attained. The maximum cell DW was 82.5 gDW L?1, the P(3HB) content being 62%. When GRP was used, 68.8 gDW L?1 with a P(3HB) accumulation of 38% resulting in a final productivity of 0.84 gPHB L?1 h?1 was obtained. By decreasing the biomass concentration at which accumulation was triggered, a productivity of 1.1 gPHB L?1 h?1 (50% P(3HB), w/w) was attained using GRP. P(3HB) molecular weights (Mw) ranged from 7.9 × 105 to 9.6 × 105 Da.  相似文献   

15.
Sugar gliders, Petaurus breviceps (average body mass: 120 g) like other small wild mammals must cope with seasonal changes in food availability and weather and therefore thermoregulatory and energetic challenges. To determine whether free-ranging sugar gliders, an arboreal marsupial, seasonally adjust their energy expenditure and water use, we quantified field metabolic rates (FMR) and water flux at a seasonal cool-temperate site in eastern Australia. Thirty six male and female sugar gliders were labelled with doubly labelled water for this purpose in spring, summer and autumn. The mean FMR was 159 ± 6 kJ d? 1 (spring), 155 ± 8 kJ d? 1 (summer), and 152 ± 20 kJ d? 1 (autumn) and the mean FMR for the three seasons combined was 158 ± 5 kJ d? 1 (equivalent to 1.33 kJ g? 1 d? 1 or 780 kJ kg? 0.75 d? 1). The mean total body water was 83 ± 2 g, equal to 68.5% of body weight. Mean water flux was 29 ± 1 mL day? 1. Season, ambient temperature or sex did not affect any of the measured and estimated physiological variables, but body mass and total body water differed significantly between sexes and among seasons. Our study is the first to provide evidence for a constant FMR in a small mammal in three different seasons and despite different thermal conditions. This suggests that seasonal changes in climate are compensated for by behavioural and physiological adjustments such as huddling and torpor known to be employed extensively by sugar gliders in the wild.  相似文献   

16.
Maximal activity of the immobilized d-psicose 3-epimerase from Agrobacterium tumefaciens on Duolite A568 beads was achieved at pH 9.0 and 55 °C with borate, and at pH 8.5 and 50 °C without borate. The half-lives of the immobilized enzyme at 50 °C with and without borate were increased 4.2- and 128-fold compared to that of the free enzyme without borate, respectively. The immobilized enzyme with borate produced 441 g l?1 psicose from 700 g l?1 fructose at pH 9.0 and 55 °C, whereas 193 g l?1 psicose was produced without borate at pH 8.5 and 50 °C after 120 min in a batch reaction. The immobilized enzyme in a packed-bed bioreactor without borate was produced continuously 325 g l?1 psicose from 500 g l?1 fructose at a dilution rate of 1.62 h?1 over a 236 h period with productivity of 527 g l?1 h?1 while that without borate produced 146 g l?1 psicose at 4.15 h?1 over a 384-h period with productivity of 606 g l?1 h?1. The operational half-lives of the enzyme with and without borate in the bioreactor were 601 and 645 h, respectively. In the present study, psicose was produced stably with high productivity using the immobilized d-psicose 3-epimerase in the presence of borate.  相似文献   

17.
The aim of this study was to determine the efficacy of dietary administration of Lactobacillus pentosus PL11 on growth performance and the immune and antioxidant systems in Japanese eel Anguilla japonica challenged with Edwardsiella tarda. A total of 75 Japanese eels (24.63 ± 0.83 g) were grouped into 5 treatment diets which were a control diet (C) without E. tarda and 4 treatment diets with E. tarda challenge, including C for E. tarda challenge (NC), C plus L. pentosus PL11 supplemented diet (108 cfu g?1) (T-PL11), C plus L. pentosus KCCM 40997 supplemented diet (108 cfu g?1) (T-Lp) and C plus Weissella hellenica DS-12 supplemented diet (108 cfu g?1) (T-Wh) for 5 weeks (4 week before and 1 week after challenge). The results showed enhanced growth performance in fish fed the diet containing L. pentosus PL11 compared to others. The growth performance parameters including specific growth rate (SGR) and weight gain (WG), feed intake (FI), feed conversion ratio (FCR) and survival were significantly (P < 0.05) higher in fish maintained on L. pentosus PL11 supplemented diet compared to C and NC. T-PL11 group also shows a significant increase in the levels of plasma immunoglobulin M, CAT and SOD activities compared to NC. Hematological parameters and mieloperoxidase were significantly better in fish fed the L. pentosus PL11 supplemented diet than in the control. L. pentosus PL11 supplementation recover the reduced expression of SOD, CAT and heat shock protein 70 genes in liver and intestine in pathogen challenged fishes. In conclusion the result of the current study demonstrated L. pentosus PL11 potential as an alternative to antibiotic supplementation to improve the growth and health performance of Japanese eel (A. japonica).  相似文献   

18.
In this study, a membrane biofilm reactor performance for toluene as a model pollutant is presented. A composite membrane consisting of a porous polyacrylonitrile (PAN) support layer coated with a very thin (0.3 μm) dense polydimethylsiloxane (PDMS) top layer was used. Batch experiments were performed to select an appropriate inocula (slaughterhouse wastewater treatment sludge with a specific toluene consumption rate of 118 ± 23 μg g?1 VSS L?1) among the three available sources of inoculums. The maximum elimination capacity gas-side reactor volume based (EC)v and membrane based (EC)m, max obtained were 609 g m?3 h?1 and 1.2 g m?2 h?1 respectively, which is much higher than other membrane bioreactors. Further experiments involved the study of the membrane biofilm reactor flexibility when operational parameters as temperature, loading rate etc. were modified. In all cases, the membrane biofilm reactor showed a rapid adaptation and new steady-states were obtained within hours. Overall, the results illustrate that membrane bioreactors can potentially be a good option for treatment of air pollutants such as toluene.  相似文献   

19.
Numerous studies have demonstrated that endotoxin plays an important role in the development and progression of hepatic cirrhosis. However, there is no effective remedy for the prevention and treatment of intestinal endotoxemia. Taurine has been reported to have beneficial effects on endotoxemia. Oats have been shown to absorb intestinal toxins and increase excretion of intestinal toxins. The present study was to investigate whether a combination of taurine and oat has an additive inhibitory effect on endotoxin release in a rat liver ischemia/reperfusion model. Our results showed that the combination of taurine (300 mg kg?1 d?1) and oat fiber (15 g kg?1 d?1) significantly reduced endotoxin levels in the portal vein by 36.3% when compared to the control group (0.168 ± 0.035 Eu/ml in the treatment group vs 0.264 ± 0.058 Eu/ml in the control group, P < 0.01). The treatment of taurine (300 mg kg?1 d?1) and oat fiber (15 g kg?1 d?1) induced 21.5% and 18.4% reduction in endotoxin levels, respectively, when compared to the control group (P < 0.05). We conclude that the combination of taurine and oat fiber achieved an additive inhibitory effect on intestinal endotoxin release, which might be an effective approach for the treatment of intestinal endotoxemia.  相似文献   

20.
Propolis is a gummy material made by honeybees for protecting their hives from bacteria and fungi. The main objective of this study is to determine the chemical compositions and concentrations of organic compounds in the extractable organic matter (EOM) of propolis samples collected from four different regions in Yemen. The propolis samples were extracted with a mixture of dichloromethane and methanol and analyzed by gas chromatography–mass spectrometry (GC–MS). The results showed that the total extract yields ranged from 34% to 67% (mean = 55.5 ± 12.4%). The major compounds were triterpenoids (254 ± 188 mg g−1, mainly α-, β-amyryl and dammaradienyl acetates), n-alkenes (145 ± 89 mg g−1), n-alkanes (65 ± 29 mg g−1), n-alkanoic acids (40 ± 26 mg g−1), long chain wax esters (38 ± 25 mg g−1), n-alkanols (8 ± 3 mg g−1) and methyl n-alkanoates (6 ± 4 mg g−1). The variation in the propolis chemical compositions is apparently related to the different plant sources. The compounds of these propolis samples indicate that they are potential sources of natural bio-active compounds for biological and pharmacological applications.  相似文献   

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