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131.
Distillers’ grains and corn fiber are the coproducts of the dry grind and wet corn milling industries, respectively. Availability of distillers’ grains and corn fiber at the ethanol plant and their high levels of lignocellulosic material make them attractive feedstock for conversion to ethanol. In this study, dilute sulfuric acid hydrolysis for the conversion of distillers’ grains and corn fiber to monomeric sugars and the formation of furfural were investigated. The extent of solubilization of biomass beyond monomeric sugars was also monitored. Biomass loadings in the range of 5–20 wt.% at 5% intervals, acid concentrations in the range of 0.5–1.5 vol.% at 0.5% intervals, and temperatures of 120 and 140 °C were studied. The highest yields of monomeric sugars were observed when the least amount of biomass loading was pretreated with the highest concentration of sulfuric acid and when the temperature was 140 °C. For the majority of the cases under consideration, the most effective period of hydrolysis appeared to be during the initial 20–30 min of the reaction. Formation of furfural during the course of hydrolysis was significantly lower at 120 °C and also lower for the distillers’ grains samples compared with the corn fiber samples. The total amount of the solubilized matter during the hydrolysis was significantly higher than the amount of the monomeric sugars. Analyses according to standard procedure were performed to quantify moisture, oil, carbohydrates, and ash in distillers’ grains and corn fiber samples. The total carbohydrate content of distillers’ grains and corn fiber were 57.7 ± 2.0 and 77.0 ± 1.0 wt.%, respectively. The presented results will provide a foundation for the suitability of the pretreated distillers’ grains and corn fiber for enzymatic hydrolysis step. 相似文献
132.
Seon-Yeong Kwak Jin-Mi Noh So-Hee Park Jang-Woong Byun Hye-Ryung Choi Kyoung-Chan Park Yoon-Sik Lee 《Bioorganic & medicinal chemistry letters》2010,20(2):738-741
Kojic acid–phenylalanine amide (KA–F–NH2), which showed an excellent tyrosinase inhibitory activity, did not inhibit melanogenesis in melanocyte due to its low cell permeability. To enhance its cell permeability by increasing lipophilicity, we prepared metal coordination compounds of KA–F–NH2 and characterized them by FT-IR and ICP analysis. The metal complex of KA–F–NH2 inhibited mushroom tyrosinase activity as much as KA–F–NH2 and reduced melanin contents in melanocyte efficiently. 相似文献
133.
134.
Azhar Muhammad Quoc Viet Nguyen Hoon Cheol Park Do Y.Hwang Doyoung Byun Nam Seo Goo 《仿生工程学报(英文版)》2010,7(2):134-141
<正> In an attempt to realize a flapping wing micro-air vehicle with morphing wings, we report on improvements to our previousfoldable artificial hind wing.Multiple hinges, which were implemented to mimic the bending zone of a beetle hind wing, weremade of small composite hinge plates and tiny aluminum rivets.The buck-tails of rivets were flared after the hinge plates wereassembled with the rivets so that the folding/unfolding motions could be completed in less time, and the straight shape of theartificial hind wing could be maintained after fabrication.Folding and unfolding actions were triggered by electrically-activatedShape Memory Alloy (SMA) wires.For wing folding, the actuation characteristics of the SMA wire actuator were modifiedthrough heat treatment.Through a series of flapping tests, we confirmed that the artificial wings did not fold back and arbitrarilyfluctuate during the flapping motion. 相似文献
135.
Thirumamagal BT Johnsamuel J Cosquer GY Byun Y Yan J Narayanasamy S Tjarks W Barth RF Al-Madhoun AS Eriksson S 《Nucleosides, nucleotides & nucleic acids》2006,25(8):861-866
Concise synthetic methods for synthesizing 3-carboranyl thymidine analogues (3CTAs) modified with cyclic and acyclic alcohols have been developed. The synthesis of these potential boron neutron capture therapy (BNCT) agents and their preliminary biological evaluation is described. 相似文献
136.
Kim J Kim H Lee Y Yang K Byun S Han K 《Journal of biochemistry and molecular biology》2006,39(3):329-334
RNAi (RNA interference) has become a popular means of knocking down a specific gene in vivo. The most common approach involves the use of chemically synthesized short interfering RNAs (siRNAs), which are relatively easy and fast to use, but which are costly and have only transient effects. These limitations can be overcome by using short hairpin RNA (shRNA) expression vectors. However, current methods of generating shRNA expression vectors require either the synthesis of long (50-70 nt) costly oligonucleotides or multi-step processes. To overcome this drawback, we have developed a one-step short-oligonucleotides- based method with preparation costs of only 15% of those of the conventional methods used to obtain essentially the same DNA fragment encoding shRNA. Sequences containing 19 bases homologous to target genes were synthesized as 17- and 31-nt DNA oligonucleotides and used to construct shRNA expression vectors. Using these plasmids, we were able to effectively silence target genes. Because our method relies on the one-step ligation of short oligonucleotides, it is simple, less error-prone, and economical. 相似文献
137.
So-Yon Park Kyu -Jin Noh Jeong -Hoon Yoo Jae -Woong Yu Byun -Woo Lee Jung -Gon Kim Hak Soo Seo Nam -Chon Paek 《Journal of Plant Biology》2006,49(6):455-462
The identification of molecular markers and marker-aided selection are essential to the efficient breeding of drought-tolerant
plants. However, because that characteristic is controlled by many quantitative trait loci, such markers that can screen and
trace desirable barley genotypes in a segregating population or germplasm have not yet been determined. Relative water content
has been used to estimate drought tolerance in plants because it is highly correlated with the drought index of yield. To
develop reliable gene-specific markers for identifying tolerant versus susceptible genotypes, we performed suppression subtractive
hybridization to identify candidate genes. We used two domestic barley cultivars, one having the highest RWC (drought-tolerant
‘Chalbori’) and the other having the lowest (drought-susceptible ‘Daebaekbori’). In response to dehydration at the early seedling
stage, rapid upregulation ofDehydrin3 (Dhn3) andDhn4 occurred in the drought-tolerant genotypes, but not in the susceptible ones. Similar results were obtained with mature plants
growing under frequent drought stress in the greenhouse. In addition,Dhn3 andDhn4 conferred higher drought tolerance when they were over-expressed in transgenicArabidopsis. Thus, in addition to using assessments of RWC, we propose thatDhn3 andDhn4 expressions can serve as drought-induced gene-specific markers to determine drought-tolerant barley genotypes at the seedling
stage. 相似文献
138.
139.
The authors published their article on the value of tear film breakup and Schirmer's tests in preoperative blepharoplasty evaluation in 1989. The purpose of this update is to expand the original article in light of refinements and experiences in subsequent years. It was concluded in the 1989 article that the abnormal tear film breakup and Schirmer's tests were not good predictors of possible postblepharoplasty dry eye complications. It was concluded in the review that the anatomy and the history including scleral show, lagophtholmus, negative vector, snap test, previous surgery, increased blinking, dryness, grittiness and pain were more important predictors of postoperative dry eye problems than the ocular tests. The authors' opinion remains so, and they do less preoperative tear film testing and place more emphasis on the history and the anatomy as predictors of potential problems. In this follow-up to the 1989 article, the authors include a survey from several surgeons as to how they evaluate their patients for elective aesthetic blepharoplasty, which in large measure confirms the authors' practice. 相似文献
140.
In eukaryotes, glutamate decarboxylase (GAD) expression was found in brain, kidney, and several kinds of tumor tissues. But its function has been emphasized only as a neurotransmitter-synthesizer, the role in controlling intracellular physiology is poorly understood. According to our studies, when GAD 67KD expression in colon cancer HT-29 cell was repressed by antisense DNA, the cell proliferation was significantly inhibited. GAD 67KD antisensed cells exhibited the low glutathione and high reactive oxygen species level. More importantly, these cells were extremely sensitive to butyrate or pH reduction, both of which naturally cause metabolic stress in the colon lumen, as well as H2O2 and ionizing radiation. These data indicate that GAD 67KD regulates the intracellular redox potential and is important for resistance to acidic or oxidative stress. So, based on these results, we suggest that inhibition of GAD 67KD expression has potentially important implications for overcoming the drug resistance of cancer cells. 相似文献