难使用的

The scheme is proven to be forward secure, which is based on the abstrusity of discrete logarithm and square rood modulo composite number problem.

新方案的特点是将当前密钥隐藏在签名中，仅使用与当前密钥有关的信息对消息进行签名，与后继密钥无关，签名的前向安全性基于离散对数和模合数平方根问题的难解性。

One of the hardest tasks facing those who fit these devices is working out the precise choreography of the voltages and timings that need to be applied to the 20 or so electrodes embedded in the auditory nerve, in order to make them work properly.

莱格兰德使用了该方式来优化耳蜗的移植，这有助于人们提高听力安装这种装置的人遇到的最难的一个任务是，解决电压与同步的精确安排，因为需要这些来应用于深埋于听觉神经里的20来个电极，以让装置工作得更好。

The results show that quartz cannot react with oleic irons at pH=8-10, because it is difficult to combine with metallic irons. On the contrary, clinochlore can adsorb with oleic ions because there are enough active metallic positive ions between the minerals layers which can combine with clinochlore. The clinochlore can be hydrophobic, and so the separation can be realized finally. At pH=9, the clinochlore removal rate is the maximum, the purity of SiO2 is 99.86%, and the recovery of SiO2 is 35%.

结果表明：在pH为8~10的碱性溶液中，粉石英难与金属阳离子缔合，所以，不与油酸根离子结合；而斜绿泥石解离后层间存在活性金属阳离子，可与油酸根离子发生化学吸附产生疏水作用，因而使用反浮选的方法能有效地实现二者的分离：当pH为9时，斜绿泥石的去除率最高，粉石英的纯度达99.86%，回收率为35%。

When I grow up, learning from simple to more difficult algebra calculus, from basic science to chemical and biological, and I used to use the know-how has been watered down.

当我长大后，学习内容也从简单的代数转到更难的微积分，从基础科学转到化学和生物，而我以前的诀窍使用起来也大不如前。

According to the discrete curvature on triangle meshes,more important features can be preserved in regions of high curvature after simplification.A method to get the new vertex after the collapse of a triangle based on discrete curvature and spherical surface estimation is also given.

通过三维扫描仪得到的数据构建的三角网格模型，由于其采样密度均匀，因此造成了数据量庞大，受到存储和传输带宽的限制，使得其很难在实际应用中直接使用。

Hydrophobically associating water-soluble polymer-based synthesis is difficult and not easily characterized, in part to hydrophobic chains connected to the water-soluble polymer, the general use of micellar copolymerization, or the use of the large surfactant monomer to copolymerization, polymer micelles need in the system by adding a large number of surface-active agent, which, after an increase of the complexity of the process.

疏水缔合型水溶性高分子很难合成，且不易表征，把疏水部分连接到水溶性聚合物链上，一般采用胶束共聚合或者使用具有表面活性的大单体进行共聚，胶束聚合需要在体系中加入大量的表面活性剂，这就增加了后处理过程的复杂性。

If arrive 25 years old later just use already late, right now skin quality already began to drop, daub elite element tenability the level at that time, very unpleasant farewell arrives before condition.

假如到25岁之后才使用就已经迟了，此时的皮肤素质已开始下降，涂抹精华素只可维持当时的水平，很难再回到以往的状态。

It is unclear that the objective of seven-year medical education is to culture high-grade utility talented man or scientific research man.

七年制医学教育的目的是培养高级实用型人才、还是科研型人才，存在很多不明了的地方，毕业后的使用也存在两者兼难。

"I go back and forth, and I'm hard-pressed to notice" whether there's regular or premium in the tank, says Jeff Jetter, principal chemist at Honda Research and Development Americas.

&我换来换去，很难觉察&油箱里的是普通还是高标号，姐夫杰特，本田美国研发主化学家说，他开的是阿库拉是基于使用高标号油设计的

Naturally occurring T-cell receptor and protein-MHC complexes have proven difficult to crystallize, so Kranz and his colleagues used novel protein engineering techniques to create smaller, stable versions.

过去证明自然发生的T细胞和蛋白-MHC复合物很难结晶，于是Kranz和同事使用利用全新的蛋白工程技术创建了更小的稳定模式。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。