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1.
目的 柠檬酸磷酸酯(Phosphate citrate,PC)是存在于哺乳动物线粒体中的一种天然活性物质。研究发现柠檬酸磷酸酯可以抑制含钙晶体的形成,防止钙晶体在骨组织中的沉淀,能够作为一种潜在治疗骨关节炎和结石等疾病的药物。方法 鉴于现有柠檬酸磷酸酯合成路线复杂、成本高,不易大规模生产等问题,本文以柠檬酸为原料,三聚磷酸钠作为磷酰化试剂,利用植物马铃薯中天然存在的磷酸化酶为催化剂,催化合成了柠檬酸磷酸酯,采用单因素和响应面实验法探究了柠檬酸与三聚磷酸钠物料比、反应温度和反应时间对产物含量的影响,通过傅里叶红外光谱分析和电导率测定其结构。结果 柠檬酸与三聚磷酸钠物料比为1:3.8,反应温度为29℃,反应时间为19.5 h,产物含量可达50.57%。结论 本合成方法简单易行,成本低,产物含量高,为柠檬酸磷酸酯的合成提供了新的方法。  相似文献   
2.
吉林临江低品位硅藻土属高烧失三级硅藻土,脉石矿物主要为石英和钠长石。为提高该硅藻土纯度,对其进行了浮选分散剂选择试验,并对最佳浮选条件下所得浮选精矿进行了焙烧—酸浸试验。结果表明,在矿浆温度为40℃、p H为9、十二胺为捕收剂条件下浮选,三聚磷酸钠作为分散剂时浮选指标最佳。以三聚磷酸钠作为分散剂、十二胺为捕收剂,经1粗2精浮选获得了Si O2品位为79.38%、Al2O3品位为5.04%的硅藻土浮选精矿。该浮选精矿在600℃条件下焙烧1 h后,在室温条件下采用20%的硫酸浸出1.5 h,获得了Si O2品位为89.57%、Al2O3品位为4.77%、Fe2O3品位为0.71%的硅藻土精矿,达到了一级土的标准。  相似文献   
3.
The aim of this study was to prepare the new core‐shell nanocomplexes as vitamin E (VE) carriers through chitosan (CS) coating onto the liposomal membrane surface in combination with sodium tripolyphosphate (TPP) cross‐linking, and investigated their storage and thermal properties by dynamic light scattering, ζ potential and fluorescence. Results showed that no obvious aggregation of nanocomplexes particles appeared and the VE retention rate was over 80% during the 30‐day storage. Thermal experiments demonstrated that the modification of polymers enhanced the stability of liposomes against temperature, including suppressing particle aggregation, ζ potential inversion and membrane fluidity. Compared with the great leakage of VE from uncovered liposomes, the retention rate of VE loaded into nanocomplexes remained around 92% and 97% after heated at 65 °C for 30 min and 80 °C for 16 s, respectively. The findings proved that these nanocomplexes can be employed to protect VE for extending shelf‐life and enhancing thermostability, and provide feasibility for commercial usage.  相似文献   
4.
玉米醇溶蛋白不溶于水,限制了其作为营养物质在食品工业中的应用,因此,提高其溶解度十分必要。本实验中采用磷酸化修饰蛋白的方法,探究了三聚磷酸钠用量、反应时间、反应温度、反应pH四个因素对提高磷酸化玉米醇溶蛋白溶解度的影响,优化出玉米醇溶蛋白磷酸化的最佳工艺条件为:三聚磷酸钠用量25%,pH9.0,反应温度30℃,反应时间2.5h,此工艺条件下,磷酸化玉米醇溶蛋白的溶解度达15.4%。  相似文献   
5.
Selective isolation of Kunitz trypsin inhibitor (KTI) and lectin from soybean whey solutions by different types of chitosan beads was investigated. The chitosan beads were co-crosslinked with tripolyphosphate/genipin in solutions at pH 5, 7 or 9 (CB5, CB7, CB9). The maximum adsorption ratios of chitosan beads to KTI and lectin were observed at pH 4.4 and 5.4, respectively; highly selective separation was also demonstrated at these pHs. The adsorption ratios increased with temperature, rising between 5 and 25 °C. CB9 produced the best adsorption ratio, followed by CB7 then CB5. The critical interaction governing absorption of chitosan beads to KTI and lectin could be hydrogen bonding. At pH 9, KTI and lectin desorbed efficiently from CB7 with desorption ratios of 80.9% and 81.4%, respectively. The desorption was most likely caused predominantly by electrostatic repulsion. KTI and lectin can effectively be selectively isolated from soybean whey using this novel separation technique.  相似文献   
6.
在真空干燥器中,加入一定量待测气体的水溶液,保持真空干燥器中待测气体浓度恒定。利用此装置研究了氨气浓度、三聚磷酸二氢铝吸附大气和水蒸气后,对三聚磷酸二氢铝吸附氨气动力学的影响。结果表明,三聚磷酸二氢铝吸附氨气,可用一级动力学方程和Elovich动力学方程模型描述;氨水浓度对吸附量和平衡吸附时间有显著影响;三聚磷酸二氢铝吸附空气后,对吸附量和平衡吸附时间无影响;三聚磷酸二氢铝吸附水蒸气后,对吸附量和平衡吸附时间均有影响。  相似文献   
7.
李原  熊德元  莫炳荣  胡容平 《应用化工》2011,40(8):1343-1345
基于重量法,以助溶剂TP溶解缩合磷酸铝,氯化-二氯双(乙二胺)合钴为沉淀剂,考察了样品加入量,溶解时间及沉淀反应时间对测定结果的影响。结果表明,取样1 g,溶解时间2 h,沉淀反应时间15 m in,测定结果的相对标准偏差RSD=0.39%,与热失重仪器分析法(含量测定)测定结果的相对误差为0.23%,该测定方法简捷,具有实用性。  相似文献   
8.
The adsorption amount, ζ-potential of cement particles and fluidity of cement paste were tested to research the competitive adsorption between naphthalene superplasticizer(FDN) and STPP. The experimental results showed that the presence of STPP could significantly improve the fluidity of cement paste and reduce the fluidity loss with FDN. There existed a competitive adsorption between STPP and FDN. STPP and calcium ions formed complexes; they preferentially adsorbed onto surface of cement particles and preempt adsorption points of FDN; and it reduced adsorption amount of FDN. In the absence of STPP, saturation adsorption amount of FDN was 5.93 mg/g; but when the dosage of STPP was 0.1%, it reduced to 4.3 mg/g(about 72.5%). The adsorption amount of FDN was reduced by STPP, but ζ-potential of cement particles enhanced and fluidity of cement paste increased because of strong negative charge effect of the complexes. Adsorption of the complexes would delay Ca2+ into liquid and inhibit formation of active adsorption points. Then, content of FDN in liquid increased with the addition of STPP and ζ-potential of cement particles became stable. In this way, fluidity loss of cement paste reduced.  相似文献   
9.
The inhibition and its mechanism of sodium tripolyphosphate (STP) composited with super plasticizers (SPs) on hydration of α-calcium sulfate hemihydrate were studied by setting time, strength, hydration heat, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), electronic probe micro analysis (EPMA), scanning electron microscopy (SEM) and differential scanning calorimeter (DSC) measurements. The experimental results show that compared with STP addition, compositing STP with polycarboxylate (PC) plasticizer, the final setting time is prolonged from 0.5h to 2hs. While formulating STP with naphthalene-based plasticizer (NAP) or sulfonate melamine formaldehyde plasticizer (SMF), the final setting time is reduced to quarter of an hour. Similar changes can also be found in the rate of exothermic hydration and hydration degree. Formulating STP with suitable addition of PC can enhance the strength, while compositing STP and NAP or SMF weakens the strength. Besides, adding STP or STP and SMF, obvious movement (more than 1ev) of binding energy of Ca2p1/2 and Ca2p3/2 is detected. Compared with STP addition, content of the characteristic element (P) of STP is cut down form 1.1% to 0.49% by compositing STP with SMF. Furthermore, as hydration age increases, hydration inhibition in the presence of admixtures weakens and even disappears within 56 h.  相似文献   
10.
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